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Phillips, Susan Elizabeth Penny. "Tertiary marine prosobranchs: larval dispersal and geographic range". Thesis, Virginia Tech, 1993. http://hdl.handle.net/10919/44171.
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Rasmuson, Leif. "The Influence of Behavior and Hydrodynamics on the Dispersal of Dungeness Crab, Cancer magister, Larvae". Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/19671.
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The Dungeness crab fishery is the most economically important on the West Coast; however, it has experienced dramatic fluctuations in annual catch. Previous research has shown the annual catch of megalopae is correlated with the commercial catch. The catch of megalopae is correlated with the phase of the Pacific Decadal Oscillation (PDO), the day of the year of the spring transition and the amount of upwelling following the spring transition. Further, the daily catch of megalopae is correlated with the internal tide.
We developed individual based models of Dungeness crab dispersal, which we validated with results from a light trap. We demonstrated that the retention of larvae in the California Current is enhanced during negative phase PDOs. Further, we suggest that larvae migrate to or almost to the bottom each day. Specifically, megalopae exhibit a twilight vertical migration off of the continental shelf and remain in the neuston on the continental shelf. This concentrates megalopae at the continental shelf break.
We also observed megalopae in situ and demonstrated that they swim in the neuston with the surface current at speeds of ~ 10 cm s-1. Using these results and data from a mooring, we demonstrated that this behavior would increase the distance internal waves would transport larvae. We analyzed mooring data and suggest that catch of megalopae is greater when the thermocline is deep and weak and there is less horizontal shear. We hypothesize this allows internal waves to remain coherent longer on the continental shelf. We show that the spring transition coincides with a shallowing of the thermocline, which would ultimately lead to the development of internal waves of depression rather than elevation. We hypothesize that the change in surface flow, based on whether the wave is one of elevation or depression, explains why most megalopae are caught following the spring transition.
In general, these findings help us better understand the dispersal of Dungeness crabs. We suggest the dispersal patterns support Michael Sinclair’s member vagrant hypothesis. Further, we suggest these findings apply to many of the continental shelf species in the California Current.
This dissertation includes both published and unpublished co-authored materials.
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Taggart, Christopher Thomas. "Mortality of larval capelin (Mallotus villosus Muller) : environmental and density correlates during post-emergent dispersal". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72771.
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Brink, Laura Ann. "Cross-shelf transport of planktonic larvae of inner shelf benthic invertebrates". Thesis, Thesis (M.S.)--University of Oregon, 1996, 1997. http://hdl.handle.net/1794/10073.
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Hoover, Trent. "Hydrodynamic controls on the movement of invertebrate larvae and organic matter in small streams". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1394.
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The movement of organisms and resources within ecosystems are essential elements in the productivity, stability, and distribution of communities. This thesis examines how water velocity, a defining factor of lotic systems, influences the dispersion of benthic organisms and particulate organic matter in small stream ecosystems. Variation in movement-related behaviours in two rheophilous (‘flow-loving’) mayflies (Epeorus and Baetis) and two rheophobic (‘flow-avoiding’) mayflies (Ameletus and Paraleptophlebia) were compared to determine how benthic organisms disperse between and within habitat patches in hydrodynamically complex landscapes. The degree to which water velocity and particle shape influence the retention of organic matter (including deciduous leaves, conifer needles, red-cedar fronds, and branch fragments) was examined to determine how physical factors determine detrital resource availability in streams.
Although water velocity did not influence the crawling rates of Baetis and Ameletus in daylight conditions, both mayflies dispersed rapidly upstream in low-velocity flows in dark conditions. Drift rates of both mayflies were lower in daylight than dark conditions, and were generally inversely related to their habitat preferences. Escape responses in grazing Epeorus, Baetis, and Ameletus larvae in a range of flow conditions showed that retreat distance was more sensitive than flight initiation distance to variation in water velocity, suggesting that hydrodynamics mediate the risks of predation and the costs of flight in stream systems. Comparisons of the transport distances of live larvae, dead larvae, and passive tracer particles in low and high water velocities showed that drift distance varied substantially among taxa, and that behavioural control over drift distance generally declined as water velocity increased.
While organic matter particles generally travelled further in high-velocity reaches, leaves were retained in riffles when they impacted on protruding clasts, while ‘stiff’ particles were retained when they settled into streambed interstices. Leaves placed in high-velocity microhabitats were broken down more slowly than leaves in low-flow areas, likely due to the exclusion of large-bodied detritivores.
In conclusion, this thesis supports the view that hydrodynamic forces control trophic interactions and local population dynamics in stream ecosystems by directly altering the physical – and sometimes behavioural – processes of particle entrainment, transport, and deposition.
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Miller, Raeanne Gwen. "Larval dispersal and population connectivity : implications for offshore renewable energy structures". Thesis, University of the Highlands and Islands, 2013. https://pure.uhi.ac.uk/portal/en/studentthesis/larval-dispersal-and-population-connectivity-implications-for-offshore-renewable-energy-structures(ee382e5b-0923-48f4-bc44-0e7ede647b3d).html.
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The installation of marine renewable energy devices (MREDs) is progressing rapidly along many coastlines. It has been suggested that MRED arrays could provide stepping-stones for larval dispersal, mediating species range expansions or invasions. As common members of hard-substrate fouling communities and likely colonisers of MREDs, the larval dispersal processes of barnacles (Cirripedia: Thoracia) in the Firth of Lorn (Scotland) are assessed at scales ranging from mm to 10s – 100s km. At the scale of the organism itself, significant differences in larval mass densities and sinking velocities were observed between species of cirripedes, suggesting that larval physiology and morphology play an important role in water column vertical positioning. The importance of vertical positioning to horizontal transport and dispersal of larvae was identified in field surveys of the horizontal and vertical distributions of cirripede larvae, which revealed the interplay of wind-driven and tidally-oscillating currents in determining transport distances. Numerical simulations of larval dispersal based on a threedimensional hydrodynamic model then demonstrated that larvae with shallower abundance distributions often experienced greater horizontal transport, but that net dispersal distances were often greater for larvae deeper in the water column. Overall, simulated transport and dispersal distances were greatest for particles released at habitats further from the coast, such as MREDs, suggesting that the connectivity of these adult populations may be enhanced. Together, larval morphology, vertical positioning, and the coastal proximity of adult habitat could serve as useful indicators of larvae capable of reaching nearby newly installed offshore structures. For locations designated for MRED development in the Firth of Lorn, it is suggested that species with dispersal abilities similar to the cirripedes in this study could feasibly use these structures as stepping-stones for dispersal and range expansion, which could have important consequences when fouling communities are comprised of commercially important or invasive species.
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Ostrow, D. Gigi, i n/a. "Larval dispersal and population genetic structure of brachiopods in the New Zealand fiords". University of Otago. Department of Marine Science, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070308.144342.
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New Zealand�s fourteen deep-water fiords have complex physical and hydrographic features as well as strong environmental gradients, all of which may influence the population structure of organisms that inhabit the fiords. I examined the population structure of the brachiopod Terebratella sanguinea over ecological and evolutionary time scales in relation to physical and hydrographic features of the fiords. To further explore the role of larval dispersal in this system, comparisons between population genetic structure of T. sanguinea and a brachiopod with a contrasting larval dispersal strategy (Liothyrella neozelanica) were made.
Aspects of the life history of the articulate brachiopod Terebratella sanguinea were measured. I measured density and size throughout Doubtful Sound and growth at outer (5 km from outer coast) and inner fiord sites (13.5 km from outer coast). Additionally, reproductive periodicity was measured at a single site within Doubtful Sound. Terebratella sanguinea occurred at significantly lower densities and was significantly smaller at the outer fiord site (p < 0.05), however growth rates between an inner and outer fiord site did not differ significantly. Terebratella sanguinea was found to have separate sexes and synchronous maturation of oocytes with spawning occurring in the austral winter. These results indicated that, on an ecological time scale, the environmental gradient of the fiords influences aspects of T. sanguinea population structure.
In order to determine the influence of the fiord environment on genetic population structure, patterns among T. sanguinea from across Fiordland were assessed using two genetic markers, and these data were compared to hydrodynamic variables. Ten sites (322 individuals) were included in a preliminary allozyme analysis, and 20 sites (358 individuals) were used for the amplified fragment length polymorphism (AFLP) analysis. Patchy genetic differentiation was revealed with both markers, and a break between Long Sound and the other Fiordland sites was detected with AFLP markers. My results suggest hydrodynamic features of this region may isolate organisms that can disperse only during a planktonic larval phase, however this isolation is visible in genetic patterns only at the most extreme values of the hydrodynamic variables.
To better understand how the fiord environment influences population structure of organisms that disperse via planktonic larvae, I compared population genetic structure of two sympatric brachiopod species that differ in planktonic larval duration. Genetic analysis using the AFLP technique revealed population structuring corresponding to the contrasting modes of larval dispersal. AMOVA analysis indicated Liothyrella neozelanica, a brachiopod that broods its larvae, had more limited exchange among sites within a fiord than did T. sanguinea, a brachiopod that does not brood its larvae. In general, the fiord hydrographic conditions may be creating opportunities for local genetic differentiation (for example Long Sound) in organisms capable of longer distance dispersal, but organisms with lower potential for dispersal are more strongly influenced by ontogeny than by hydrography.
Understanding the population structure of some of the marine fauna of Fiordland is an important cornerstone for the developing management plan for the area. Conservation of the underwater resources of this World Heritage Area can be successful if the structure of the system and the mechanisms driving this structure are taken into account.
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Wood, Sally. "Modelling present and future dispersal of coral larvae : implications for the response of corals to climate change". Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.682361.
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Corals, sessile as adults, disperse by releasing a pelagic larval stage into the water, which drifts with the ocean currents over potentially thousands of kilometres between reef habitats. Determining patterns of dispersal is an important but difficult task for reef conservation science; coral larvae are impossible to track directly in the marine environment. Biophysical models provide an essential tool to explore the patterns and drivers of dispersal. However, they have previously been utilised at regional scales, excluding the potential for long-distance transport events of particular importance to coral biogeography. In light of recent computational advances, I develop the first high-resolution global model of coral larval dispersal. The model provides critical evidence regarding the influence of dispersal on coral biogeography, highlighting vulnerable isolated areas as well as important sources and stepping stones for dispersal. For example, eastern Pacific reefs emerge as some of the most isolated globally. Contrary to hypotheses of increased dispersal into this region during El Nino events, I find only westward dispersal out of the eastern Pacific over a 10 year period, including the extreme 1997-98 El Nino. The Galapagos Islands act as the sole source for dispersal across the 6000 km separating eastern from central Pacific reefs. The model is the first to incorporate the effects of environmental factors (temperature and ocean pH) on larval physiology, predicted to result in alterations to patterns of dispersal with climate change. I find that dispersal patterns are especially sensitive to the effect of temperature on larval mortality, although the response varies geographically. Increases in temperatures predicted for 2060 reduce long-distance dispersal and increase local retention in the model, potentially reducing the scale over which /management efforts will be effective. Future work will aim to incorporate various other factors likely to influence future dispersal, informing management of reefs under climate change.
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Lundkvist, Elisabeth. "Diversity, dispersal, and interactions among diving beetles and mosquitoes in Swedish wetlands /". Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek796s.pdf.
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Ockhuis, Samantha Angelique Natasha. "The “suitcase hypothesis” – can eddies provide a pathway for gene flow between Madagascar and KwaZulu-Natal?" Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2475.
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Thesis (MTech (Oceanography))--Cape Peninsula University of Technology, 2016.Similarities in marine fauna found off the coasts of southern Madagascar and KwaZulu-Natal (KZN, South Africa) led to the development of the “Suitcase Project”, with the aim of establishing whether eddies that form off southern Madagascar may package and transport biological material, as if in a suitcase, across the Mozambique Channel. In pursuit of this question, sampling was conducted on the southern Madagascan shelf and along a transect across a cyclonic eddy which originated off the southern tip of Madagascar, between the 15th and 23rd of July 2013. Bongo nets (300 and 500 μm-mesh) and a neuston net (900 μm-mesh) were used to collect zooplankton within the upper 200 m and at the surface, respectively. Samples were sorted for meroplankton (larval stages of fish and benthic invertebrates) under a stereo microscope, particularly seeking species known to be common to both the east coasts of Madagascar and South Africa and, thus potential indicators of connectivity between these regions. Larvae of crabs, rock lobster, and fish were used for DNA barcoding. Zooplankton biovolume and abundance were compared between the eddy core, eddy periphery and outer regions of the eddy, as well as stations from the Madagascan shelf. Mean neuston biovolume on the Madagascan (0.08 mL m-3) was not significantly higher than that in the eddy (0.06 mL m-3). Mean bongo biovolume in the upper 200 m was much higher on the Madagascan shelf (0.62 mL m-3) than in the eddy (0.16 mL m-3) although only 2 stations were sampled on the shelf. Highest biovolume in the eddy was recorded in the west eddy zone (0.25 mL m-3) and west outer zone (0.23 mL m-3), which was not statistically significantly higher than the eddy core (0.12 mL m-3) and east eddy zone (0.17 mL m-3). Meroplankton was comprised of coastal origin taxa and was most abundant on the shelf and in the eddy perimeters. Larval goat-fish, Parupeneus fraserorum was identified, a newly described mullid, and has been recorded on both the coasts of Madagascar and KZN, SA. Larvae of coastal invertebrate species identified, include the squat lobster Allogalathea elegans and camel shrimp Rhynchocinetes durbanensis. Other larval fish identified, but not found in high abundance include the families of reef associated fishes, for example: Apogonidae, Labridae, Pomacentridae, Priacanthidae, Serranidae and Sparidae. Higher zooplankton biovolumes, larval abundances and reef-associated larval assemblages found on the Madagascan shelf and in the periphery of the cyclonic eddy compared to the core in this study provide support for the suitcase hypothesis that planktonic organisms are entrained within eddies as they propagate south-westwards of the Madagascan shelf. However, further studies are required to determine whether planktonic larvae are able to cross the Mozambique Channel and reach the KZN coast in time to settle.
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McCulloch, Anita. "Nearshore topographic fronts : their effect on larval settlement and dispersal at Sunset Bay, Oregon". Thesis, Thesis (M.S.)--University of Oregon, 2001, 2001. http://hdl.handle.net/1794/10077.
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Pattrick, Paula. "Larval fish dynamics in the shallow nearshore of Eastern Algoa Bay with particular emphasis on the effects of currents and swimming abilities on dispersal". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005139.
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The larval fish assemblage in the shallow, nearshore region of a proposed marine protected area (MPA) in eastern Algoa Bay, temperate South Africa was investigated. Current velocities and direction and the swimming abilities of late-stage larvae were further assessed to determine potential larval movement to and from the MPA. In total, 6045 larval fishes were collected along two depth contours (~5m and ~15m) in the shallow nearshore of eastern Algoa Bay using stepped-oblique bongo net tows, twice per season for two years (March 2005 – January 2007). These larvae represented 32 families and 78 species. The Gobiidae, Cynoglossidae, Clupeidae, Engraulidae and Sparidae were the dominant fish families. Catches varied significantly between seasons peaking in spring with a mean of 64 larvae/100m3. Preflexion stage larvae dominated catches (75%). All developmental stages of Diplodus capensis, Engraulis capensis, Heteromycteris capensis, Sardinops sagax and Pomadasys species were found in the study area. It appears that these species use the shallow nearshore as a nursery area. Analysis of 12 months (May 2006 – May 2007) data from a bottom-moored Acoustic Doppler Current Profiler within the study area showed that offshore south eastward (39%) and onshore north westward currents (33%) dominated. The south westward current (15%) and north eastward current (12%) occurred less frequently. Current velocity decreased with depth in the nearshore, with a mean velocity of ~29 cms⁻¹ recorded at a depth of 4 m and a mean velocity of ~11 cms⁻¹ recorded at a depth of 14 m. Understanding the dispersal and movement of marine fish larvae in coastal habitats requires knowledge of active swimming abilities. The critical speed and endurance swimming of late stage larvae of two common inshore species occurring in the study area, Diplodus capensis and Sarpa salpa (Family Sparidae), were measured in a laboratory swimming chamber. The mean U-crit value for D. capensis (18.6 cms⁻¹) was similar to that of S. salpa (18.0 cms⁻¹), whereas mean endurance (km swum) was greater in S. salpa (8.4 km) than D. capensis (5.9 km). These swimming abilities exceed the average current velocities observed in the shallow nearshore providing larvae with the ability to greatly alter their passive dispersal trajectories and ultimately influence their distribution in the nearshore.
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Fuchs, Heidi L. "Biophysical coupling between turbulence, veliger behavior, and larval supply". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/39193.
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Thesis (Ph. D.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references.
The goals of this thesis were to quantify the behavior of gastropod larvae (mud snails Ilyanassa obsoleta) in turbulence, and to investigate how that behavior affects larval supply in a turbulent coastal inlet. Gastropod larvae retract their velums and sink rapidly in strong turbulence. Turbulence-induced sinking would be an adaptive behavior if it resulted in increased larval supply and enhanced settlement in suitable coastal habitats. In laboratory experiments, mud snail larvae were found to have three behavioral modes: swimming, hovering, and sinking. The proportion of sinking larvae increased exponentially with the turbulence dissipation rate over a range comparable to turbulence in a tidal inlet, and the mean larval vertical velocity shifted from upward to downward in turbulence resembling energetic nearshore areas. The larval response to turbulence was incorporated in a vertical advection-diffusion model to characterize the effects of this behavior on larval supply and settlement in a tidal channel. Compared to passive larvae, larvae that sink in turbulence have higher near-bed concentrations throughout flood and ebb tides.
(cont.) This high larval supply enables behaving larvae to settle more successfully than passive larvae in strong currents characteristic of turbulent tidal inlets. A study was conducted at Barnstable Harbor, MA to estimate the responses of larvae to turbulence in the field. Gastropod larvae from different coastal environments had genus-specific responses to turbulence, suggesting that larvae use turbulence for large-scale habitat selection. On ebb tides, mud snail larvae had a similar response to turbulence as in the laboratory, with greater sinking velocities in strong turbulence. Behavior estimates differed for flood and ebb tides, indicating that additional physical cues influence behavior. Turbulence-induced sinking behavior would enhance retention and promote settlement of mud snail larvae in habitats like Barnstable Harbor.
by Heidi L. Fuchs.
Ph.D.
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Tapia, Fabián. "Adult demography and larval processes in coastal benthic populations : intertidal barnacles in Southern California and Baja California". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/39192.
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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2005.Includes bibliographical references.
The geographic distribution and dynamics of coastal benthic populations are shaped by physical - biological interactions affecting larval dispersal and the demography of juvenile and adult individuals. This thesis focused on nearshore patterns of larval distribution and regional patterns in demography of intertidal barnacles in Southern and Baja California. Horizontal and vertical distributions, and the mortality rates of larvae, were assessed from short term (i.e. days) small- scale observations (0.1-1 km) in nearshore waters. Observations on spatial variability of adult barnacle demography were gathered over 1.5 years at scales of hundreds of kilometers. Stage-specific horizontal distributions and nearshore current measurements suggested that larvae of Balanus g-landula and Chthamalus spp. may experience limited dispersal. High mortality rates could further limit travel distances and the exchange of individuals among disjunct populations. Data on vertical distributions indicated that nauplii and cyprids of Balanus nubilus and Pollicipes polymerus occur at different depths. Nauplii remained near the surface at all times, whereas cyprids occurred in the bottom half of the water column.
(cont.) Such distributions, combined with vertical variability in horizontal flows, might cause the observed horizontal segregation of nauplii and cyprids. Differences in survival, growth rate, size structure, and per capita fertility of adult Balanus glandula were observed between Dana Point (Southern California) and Punta Baja (Baja California), a site located near the species' southern limit of distribution. Effects of spatial differences in demography on population persistence were assessed with a stage-structured matrix model. Model analyses indicated that the Punta Baja population is more susceptible to environmental stochasticity and more prone to local extinction than populations located further north. This thesis emphasizes the importance of characterizing factors that affect the dynamics of benthic populations at multiple spatial-temporal scales, and the usefulness of small scale high- frequency observations of nearshore phenomena, especially in relation with the dispersal of larvae.
by Fabián J. Tapia.
Ph.D.
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Silver, Gregory Shell. "Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream". PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2358.
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Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range.
We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat.
Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances.
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Underwood, Jim. "Routine and rare genetic connections in corals off northwest Australia and the implications for conservation". University of Western Australia. School of Animal Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0158.
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[Truncated abstract] The extent to which marine populations are connected by larval dispersal is crucial to their distribution, maintenance and diversity. Thus, for the effective conservation of threatened systems such as coral reefs, understanding patterns of connectivity is essential. However, the biophysical mechanisms that retain or disperse larvae within and among populations are poorly understood. Though the open ocean environment provides the opportunity for long-distance dispersal, if this potential is only rarely realised, recruits produced from afar are unlikely to contribute to the local-scale demography of populations over ecological time frames, but will limit broad-scale genetic diversification over evolutionary time. This thesis explores the extent of genetic and demographic connectivity of two species of reef-building corals over a range of spatial scales among the discontinuous reef systems of northwest Australia. ... Putative source and sink dynamics were not random, but were associated with levels of disturbance and recovery from a recent and catastrophic coral bleaching. When S. hystrix samples from another two offshore systems were included in the analysis, large differences among systems showed that gene flow over hundreds of kilometres is rare over microevolutionary time scales that account for connections over multiple generations. Levels of subdivision over the same spatial scales were markedly lower in the acroporid coral, Acropora tenuis, than in S. hystrix. These results are congruent with expectations based on reproductive mode; in contrast to S. hystrix, which releases brooded larvae that are competent to settle immediately, A. tenuis broadcasts its gametes, and after external fertilisation, the larvae need to develop for several days before they are competent to settle. Despite the differences in levels of broad-scale subdivision, in both species significant differentiation was detected between reefs within systems (>10 km), and between sites within some reefs (< 10 km). These results indicate not only that dispersal between reefs and even some reef patches is restricted, but also that hydrodynamics influence retention of brooded and spawned larvae in similar ways. Further analysis of A. tenuis populations from two coastal systems detected significant differences in genetic diversity among the four major systems of northwest Australia. Additionally, genetic divergence between the coastal and offshore zones was greater than expected by the geographic separation of systems, indicating that connectivity between these zones via transport of A. tenuis larvae on oceanic currents occurs rarely even over microevolutionary time scales. This study has two primary implications for conservation. First, since coastal and offshore reefs of northwest Australia appear to be discrete genetic entities, they have independent evolutionary potential to adapt to local conditions and environmental change. Second, systems, reefs and some reef patches of northwest Australia are demographically independent units. Therefore, designs of coral reserve networks should consider routine dispersal distances of kilometres to a few tens of kilometres.
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Lam, Adriane R. "Paleobiogeographic Analyses of Late Ordovician Faunal Migrations: Assessing Regional and Continental Pathways and Mechanisms". Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1428515661.
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Kim, Stacy L. "Larval dispersal between hydrothermal vent habitats". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40566.
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Holzhausen, Hurian Gallinari. "Movimentação larval de lepidópteros-praga em soja e milho". Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152498.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
RESUMO - Chrysodeixis includens (Walker) e Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) são consideradas pragas de grande importância na cultura da soja, enquanto Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) é considerada importante na cultura do milho no Brasil Central. Para o controle bem-sucedido dessas pragas usando plantas Bt, bem como o desenvolvimento de estratégias do manejo de resistência, é essencial conhecer a movimentação do estágio larval desses insetos. O estudo foi conduzido dentro de gaiolas teladas (3,00 x 3,00 x 1,80 m), a fim de evitar infestações naturais. As lagartas foram liberadas em uma planta localizada no centro das gaiolas. As lagartas e as injurias foram observadas a fim de registrar a posição na planta e a localização na gaiola. Lagartas de C. includens e H. armigera apresentaram movimentação entre as plantas de soja, enquanto lagartas de D. saccharalis praticamente se mantiveram nas plantas onde houve a liberação. Com isso, a adoção de mistura de sementes não Bt e Bt para o estabelecimento de refúgio em cultivos Bt pode ser adequado apenas para D. saccharalis.
ABSTRACT - Chrysodeixis includens (Walker) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) are considered pests of great importance in soybean crop, while Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) is considered important in maize crop in the Brazilian Central region. For the successful control of these pests using Bt plants as well as development of resistance management strategies, it is essential to know the larval stage movement of these insects. The study was carried out inside saran cages (3.00 x 3.00 x 1.80 m), in order to avoid natural infestation. Larvae were released in a plant located in the center of the cages. Larvae and injuries were observed in order to register the position in the plant and the location in the cage. Larvae of C. includens e H. armigera moved between soybean plants, whereas D. saccharalis practically remained in the plants where they were released. Thus, the adoption of non-Bt and genetically modified seed mixture for refuge establishment in Bt crops may be suitable only for D. saccharalis.
134533/2015-1
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Puls, Amy L. "Transport of zooplankton in South Slough, Oregon". Thesis, Thesis (M.S.)--University of Oregon, 2002, 2002. http://hdl.handle.net/1794/10057.
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Irisson, Jean-Olivier. "Approche comportementale de la dispersion larvaire en milieu marin = Behavioural approach to larval dispersal in marine systems". Phd thesis, Ecole pratique des hautes études - EPHE PARIS, 2008. http://tel.archives-ouvertes.fr/tel-00344625.
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La plupart des organismes marins démersaux présentent une phase larvaire pélagique avant le recrutement dans la population adulte. Cet épisode pélagique est souvent la seule opportunité de dispersion au cours du cycle de vie. De ce fait, il structure les connections entre populations, qui régissent la dynamique et la composition génétique des métapopulations benthiques. Cependant, ces "larves" ne sont pas de simples ébauches des adultes, dispersées au gré des courants en attendant leur métamorphose. Ce sont des organismes souvent très spécifiquement adaptés à leur milieu. Dans cette thèse nous nous sommes efforcés d'évaluer l'impact du comportement des larves lors de la phase pélagique. Nous nous sommes focalisés sur les larves de poissons (coralliens plus spécifiquement) dont les capacités sensorielles et motrices sont particulièrement élevées. Des approches expérimentales ont été développées afin de quantifier leur orientation et leur nage in situ. Grâce à une observation synchrone des caractéristiques physiques du milieu et de la distribution des larves lors d'une campagne océanographique, nous avons tenté de caractériser leur distribution en trois dimensions dans le milieu pélagique, afin de comprendre les interactions physico-biologiques déterminant le recrutement. Enfin, une approche de modélisation novatrice, faisant appel à des concepts de minimisation des coûts et de maximisation des bénéfices habituellement utilisés en économie ou en théorie de l'approvisionnement optimal, a permis d'intégrer le comportement des larves aux modèles Lagrangiens de dispersion
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Conceição, Larissa da Silva. "Movimentação Larval de Spodoptera frugiperda (J. E. Smith) (Lepidoptera : Noctuidae) em Milho Cultivado no Sistema Santa Fé /". Jaboticabal, 2019. http://hdl.handle.net/11449/183419.
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Orientador: Odair Aparecido FernandesResumo: O cultivo de milho pode ser realizado em consórcio com outras gramíneas como Urochloa ruziziensis (Germain & Evrard). Assim, a lagarta-do- cartucho pode se desenvolver nesta última e se movimentar posteriormente para o milho. Entretanto, larvas em estádios de desenvolvimento mais avançados podem não ser afetadas pela concentração expressa de proteína inseticida nos híbridos de milho. Diante disso, o objetivo desse trabalho foi avaliar a movimentação de larvas de Spodoptera frugiperda (J.E. Smith) em cultivo de milho cultivado em consórcio com U. ruziziensis. O estudo foi conduzido em campo e em gaiolas teladas. Os tratamentos consistiram em milho híbrido Bt e milho não Bt cultivados em consórcio ou não, além do cultivo solteiro de U. ruziziensis. Os resultados indicaram que larvas neonatas de S. frugiperda se movimentam do milho para o capim e vice- versa. Isto favoreceu a sobrevivência dos insetos, principalmente nas situações de consórcio quando dois recursos alimentares estavam disponíveis. Por outro lado, não se verificou a presença de larvas de 4o a 6o ínstares em plantas de milho Bt em consórcio com U. ruziziensis. Isto sugere que a expressão de proteína Vip 3 é suficientemente elevada para causar mortalidade mesmo em larvas mais desenvolvidas. Estes resultados são importantes para aprimoramento do atual programa de manejo de resistência de insetos às táticas de controle para garantir a maior durabilidade da tecnologia e constatar se o capim pode ser usado como refúgio ... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
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Phillips, Susan Elizabeth Penney. "Tertiary marine prosobranchs : larval dispersal and geographic range /". This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08042009-040456/.
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Jarvis, Marley. "Physical Oceanography, Larval Dispersal, and Settlement Across Nearshore Fronts". Thesis, University of Oregon, 2015. http://hdl.handle.net/1794/18711.
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The larvae of coastal species interact with nearshore currents that are complex and can alter dispersal. I investigated two sites in southern Oregon with different nearshore hydrodynamics: the first site, Sunset Bay, is a small cove with a topographic front that extends across the mouth during upwelling-favorable winds. Using holey sock drogues at 1.5 m and 5.5 m depths and surface drifters at 10 cm depth, I found that, when the front was present, water at 1.5 m was retained within the bay whereas water was exchanged across the front at a depth of 5.5 m. Surface drifters indicated a surface convergence. Surface plankton tows on either side and within the frontal convergence (a shore-parallel foam line) found significantly higher concentrations of barnacle cyprids, crab megalopae and zoea, polychaete larvae, platyhelminthes juveniles, isopods, amphipods, harpacticoid copepods, and fish eggs. Crustacean nauplii (barnacle, euphausiid, and copepod) and calanoid copepods were not concentrated in the convergence, and when the front and foam line were absent, no taxa were concentrated. Plankton tows taken within the foam line as it dissipated shoreward during a wind-reversal event found that concentrations of cyprids, megalopae, and gastropod veligers remained high as the foam line moved, suggesting that it acts as a moving convergence propagating competent larvae shoreward.
I measured settlement of two taxa at Sunset Bay and Shore Acres, an open-coast site <2 km away. Barnacle settlement measured every other day from June-September 2013 was significantly cross-correlated with the maximum daily tidal height at lags of -2 days at Sunset Bay and +2 and +4 days at Shore Acres. Settlement was also significantly negatively cross-correlated with wave height at a lag of -4 days at Sunset Bay. Coralline algae settlement measured during eight 48-hr periods in July-August 2013 was significantly negatively correlated with wave height (n = 8, R2 = 0.76, P = 0.0049) at Shore Acres but not at Sunset Bay. Despite the close proximity of the Sunset Bay and Shore Acres sites, settlement patterns differed between taxa, suggesting that differences in nearshore hydrodynamics might affect the supply of water and larvae to shore.
This dissertation includes unpublished co-authored material.
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Domingues, Carla Sofia Portela. "Population genetics of C. Maenas : oceanography and larval dispersal". Doctoral thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/973.
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Doutoramento em BiologiaDecifrar a complexa interacção entre os ciclos de vida de espécies marinhas e a oceanografia revela-se fundamental para a compreensão do fluxo genético e da conectividade no meio marinho. Nas espécies marinhas com desenvolvimento indirecto o fluxo de genes entre populações depende da distância que separa as populações, bem como da interacção entre a duração do desenvolvimento larvar, do comportamento das larvas e dos padrões de circulação oceânica. A conectividade larvar influencia uma variedade de processos como a dinâmica de stocks e de populações, a distribuição e limites geográficos das espécies, a estrutura genética das populações e a dispersão de espécies invasivas e reveste-se consequentemente de uma importância fundamental na identificação das unidades populacionais evolucionariamente relevantes e para a gestão e conservação marinhas. Os marcadores genéticos e os Modelos Individuais Acoplados a Modelos Físico-Biológicos (“ICPBMs”) são actualmente ferramentas fundamentais para o estudo dos padrões de dispersão larvar e para avaliar o nível de conectividade populacional. A presente tese respeita à avaliação das escalas espaciais de conectividade de populações de uma espécie costeira, o caranguejo Carcinus maenas, e utiliza conjuntamente informação de marcadores genéticos, análise de séries temporais de fornecimento de larvas e um modelo numérico de circulação oceânica. O primeiro capítulo introduz a temática da conectividade em espécies marinhas e inclui algumas referências aos métodos moleculares, analíticos e de modelação seguidos ao longo da tese. Através da utilização de múltiplas ferramentas – avaliação da estrutura genética geográfica de C. maenas na sua distribuição nativa com recurso a marcadores de DNA (microssatélites) (Capítulo 2), avaliação da estrutura genética temporal das larvas que formam os eventos de fornecimento larvar à Ria de Aveiro, NW Portugal (Capítulo 3), descrição da variabilidade inter-anual do fornecimento larvar à Ria de Aveiro, NW Portugal (Capítulo 4) e validação de um modelo ICPBM que descreve os padrões observados de fornecimento (Capítulo 5) – esta tese espera poder contribuir para uma melhor compreensão dos mecanismos que regulam o fluxo de genes e a conectividade entre populações de organismos marinhos. No Capítulo 6 são apresentadas as principais conclusões da investigação. A análise genética com recurso a microssatélites indicou que as populações de C. maenas são geneticamente homogéneas ao longo de várias centenas de km, dentro da distribuição nativa da espécie. Paralelamente, não foram encontrados indícios da existência de reprodução por “sweepstakes” em C. maenas de populações da costa oeste da Península Ibérica, visto que não se obtiveram diferenças genéticas significativas entre os eventos larvares. Também não se encontrou qualquer estrutura familiar entre as larvas que formam cada episódio de fornecimento, e não houve nenhuma redução significativa da variabilidade genética das larvas quando comparada com a de caranguejos adultos. A análise de séries temporais de suprimento de larvas na Ria de Aveiro em cinco anos estudados indica que este é um fenómeno episódico e variável, sendo os maiores episódios de fornecimento coincidentes com as marés vivas e acentuados por fortes ventos de sul. O modelo ICPBM foi validado com sucesso e parece fornecer uma estimativa realística das escalas espaciais e temporais de dispersão larvar, de acordo com as observações da estrutura genética e da ausência de reprodução por “sweepstake” em C. maenas da costa oeste da Península Ibérica
Unravelling the interactions between life-history strategies and oceanographic processes is central to the understanding of gene flow and connectivity in the marine environment. In particular, for marine species with indirect development gene flow between populations depends on the distance separating the populations and on the interaction between duration of the larval phase, larval behaviour and current patterns. Larval connectivity affects many processes, including stock and population dynamics, species ranges, population genetic structure, and the spread of invasive species and is therefore an important consideration to identify evolutionary relevant population unit and for marine management and conservation efforts. Genetic markers and Individual-based Coupled Physical-Biological Models (ICPBMs) are two of the tools currently available for tracking dispersal pathways of larvae and to assess the degree of population connectivity. The present thesis concerns the spatial and temporal scale assessment of population connectivity of a coastal marine species, the shore crab Carcinus maenas, making use of genetic markers, time series larval supply analysis and an oceanographic numerical model. Chapter 1 introduces the thematic of marine species connectivity, including a brief reference to the molecular, analytical and modelling methods followed during the study. Making use of an interdisciplinary approach – assessment of genetic geographical structure with microsatellite markers within C. maenas native range (Chapter 2), assessment of temporal genetic structure of larvae forming each supply event to the Ria de Aveiro, NW Portugal (Chapter 3), description of interannual variability of larval supply to the Ria de Aveiro, NW Portugal (Chapter 4) and validation of an ICPBM to describe the observed time series of supply (Chapter 5) – the aims of this thesis is to contribute to our understanding of the mechanisms regulating gene flow and connectivity among marine populations. Finally, in Chapter 6 the main results and conclusions achieved are presented. Microsatellites analysis indicated that C. maenas populations were genetically similar across hundreds of km, within the species native range. Additionally, there was no evidence of sweepstakes reproduction in C. maenas from western Iberian coast populations since there were no significant differences amongst larval events. Among larvae in each episode, no genetic relatedness was found, and larvae did not present reduced genetic variability when compared to adult crabs. On a long time scale, larval supply to the Ria de Aveiro was episodic and variable throughout five different studied years, with highest supply numbers generally occurring around spring tides and enhanced by strong southerly winds. The ICPBM was successfully validated and appears to provide a realistic estimate of the observed spatial and temporal scales of the larval dispersal, consistent with the observations on genetic structure and lack of sweepstake reproduction in C. maenas from western Iberian coast.
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Snauffer, Evgeniya Lyubomirova. "Modeling herring and hake larval dispersal in the Salish Sea". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/43967.
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The Salish Sea includes Juan De Fuca Strait, Puget Sound, and the Strait of Georgia
(SoG), which separates Vancouver Island from mainland British Columbia. Hake and herring are
commercially important fish and both species use SoG as larval rearing grounds. Drift tracks of
larvae for these species were simulated using a regional circulation model and a particle-tracking
model, for up to six weeks after they hatch. Larvae with different behaviors (such as surface
drifters or performing diel vertical migration) are traced in the springs of each of the years 2007,
2008, and 2009. Since herring larvae stay in the top 12m, their distribution is heavily influenced
by the wind storms. Strong winds to the north during the hatching period wash herring larvae out
of SoG and lead to poor recruitment later. Alternatively, wind storms blowing to the south help
retain herring larvae in the Salish Sea. Northern and southern parts of SoG are weakly connected
for herring larvae. Hake larvae reside deeper in the water column (50-200m) and the distribution
of the hake larvae released in the central SoG is shaped by a deep gyre with cross-strait currents.
Behavior changes distribution for both types of larvae but there is no single pattern. Behavior
may enhance retention in SoG for the northern herring larvae. This study helps to identify
important herring larvae habitat in the Strait of Georgia.
Supplementary video materials available at: http://hdl.handle.net/2429/43966
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Jones, Benjamin Thomas. "Trait-based modeling of larval dispersal in the Gulf of Maine". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112889.
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Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 151-163).
Population connectivity is a fundamental process that governs the spatial and temporal dynamics of marine ecosystems. For many marine species, population connectivity is driven by dispersal during a planktonic larval phase. The ability to obtain accurate, affordable, and meaningful estimates of larval dispersal patterns is therefore a key aspect of understanding marine ecosystems. Although field observations provide insight into dispersal processes, they do not provide a comprehensive assessment. Individual-based models (IBMs) that couple ocean circulation and particle-tracking models provide a unique ability to examine larval dispersal patterns with high spatial and temporal resolution. Obtaining accurate results with IBMs requires simulating a sufficient number of particles, and the sequential Bayesian procedure presented in chapter 2 identifies when the number of particles is adequate to address predefined research objectives. In addition, this method optimizes the particle release locations to minimize the requisite number of particles. Even after applying this method, the computational expense of IBM studies is still large. The model in chapter 3 seeks to increase the affordability of IBM studies by transferring some of the calculations to graphics processing units. Chapter 4 describes three algorithms that assist in interpreting IBM output by identifying coherent geographic clusters from population connectivity data. The first two algorithms have existed for nearly a decade and recently been applied separately to marine ecology, and we provide a direct comparison of the results from each. Additionally, we develop and present a new algorithm that simultaneously considers multiple species. Finally, in chapter 5, we apply these tools and a trait-based modeling framework to assess which species traits are most likely to impact dispersal success and patterns in the Gulf of Maine. We conclude that the traits influencing spawning distributions and habitat requirements for settlement are most likely to influence dispersal.
by Benjamin Thomas Jones.
Ph. D.
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Phelps, Jack. "Modelling hydrodynamic transport and larval dispersal in North-East Atlantic Shelf seas". Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2026939/.
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This thesis presents a series of numerical modelling studies into hydrodynamic transport and larval dispersal. The initial investigation seeks to evaluate retention timescales in Liverpool Bay. The flushing time and residence time are equal to 136 days and 103 days respectively, however small concentrations of seawater are retained over several years due to vigorous tidal mixing. The age distribution is shown to be highly variable and dependent upon tracer input duration, however salinity can be used to estimate the mean age, which is not directly observable in practice. Chapters 3, 4 and 5 all focus upon the dispersal of meroplanktonic larvae and aim to determine how larval behaviour affects their transport. Vertical migration is a significant influence upon larval dispersal within each case study, although the effect of this behaviour is conditional upon local hydrodynamic conditions. For example diel vertical migration promotes dispersal in the western Irish Sea, however the identical swimming pattern facilitates local retention in the eastern Irish Sea. The ecological implications of these findings are discussed. This thesis concludes with an investigation into the impact of large CO2 leakages on the marine carbonate system at potential carbon sequestration sites in the North Sea. Perturbations to seawater pH are found to vary according to the rate, duration and location of CO2 input. The northern North Sea is particularly vulnerable to large perturbations ( > 1 pH units) during the summer months, as the strong seasonal thermocline suppresses CO2 outgasing.
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Johnson, Collin Hauer. "Self-fertilization, Larval Dispersal, and Population Structure in the Marine Bryozoan Bugula stolonifera". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10180.
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Although the process by which fertilization occurs in bryozoans is well described, the ability to self-fertilize and the subsequent ecological consequences are poorly understood. Culturing experiments were conducted examining the effects of selfing on offspring survival and reproduction in the simultaneous hermaphrodite Bugula stolonifera collected from Eel Pond, Woods Hole, MA. Results from these experiments document significant decreases in survival and fecundity of selfed offspring, compared to outcrossed controls, suggesting that these animals are not routinely self-fertilizing in Eel Pond. How these arborescent colonies minimize selfing remains unclear, but it is hypothesized that conspecific aggregations could serve to minimize the chances that a colony utilizes its own sperm for fertilization. The genetic composition of these aggregations was investigated using a newly developed microsatellite library. As larvae routinely metamorphose on conspecific colonies, the possibility that larvae select or avoid their maternal colony was also investigated. Analyses of genetic structure document homogeneity throughout these aggregations on extremely small spatial scales, suggesting high amounts of larval dispersal within aggregations. When combined with results from parentage-exclusion and kinship analyses, these results indicate that a colony's nearest neighbors are not composed of siblings, potentially minimizing inbreeding. Molecular analyses were then used to determine if the high larval dispersal within aggregations resulted in high mixing between aggregations. Sites within Eel Pond separated by 100-300 m were routinely sampled from 2009 to 2011, and analyses were conducted to investigate potential inter- and intra-annual genotypic differentiation within and between aggregations. Results document that although low levels of mixing could result in increased homogeneity between some aggregations, barriers to genetic exchange prevent mixing between most sites. Further, inter-annual comparisons within sites document that significant differentiation can occur between reproductive seasons. Hence, any potential homogeneity achieved between sites during one reproductive season will likely be lost by the beginning of the next reproductive season. Additionally, while sampling in Eel Pond in 2010, I document the first occurrence from the western Atlantic Ocean of another aggregating arborescent bryozoan, Tricellaria inopinata. The growth and reproductive biology of these animals was monitored throughout 2011; results suggest that this introduction is likely to persist.
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Damerau, Malte [Verfasser]. "Comparative population genetics, larval dispersal and evolutionary aspects of Antarctic fishes (Notothenioidei) / Malte Damerau". Kiel : Universitätsbibliothek Kiel, 2014. http://d-nb.info/1047578867/34.
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Edwards, Karen Pehrson Werner Francisco E. "Towards defining larval dispersal and population connectivity on the south east U.S. continental shelf". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,391.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Marine Sciences." Discipline: Marine Sciences; Department/School: Marine Sciences.
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Lockwood, Dale Richard. "The effects of larval dispersal and spatial heterogeneity on the design of marine reserves /". For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Monteiro, Ana Rita Andril. "Genetic structure of mussel population in NE Atlantic and Mediterranean: connectivity between deep-sea habitats". Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17460.
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Mestrado em Ecologia AplicadaSpecies persist over time, due to exchange of individuals between subpopulations. In the marine environment, most benthic organisms have complex life cycles including pelagic larvae that are transported by ocean currents promoting species dispersal. Larval dispersal connects geographically distant populations and determines population structure. The knowledge about this biologic process provides relevant information for conservation of marine populations. This study investigates the genetic structure and connectivity of deep-sea mussel populations between fragmented habitats in the NE Atlantic and Mediterranean. The mitochondrial Cytochrome Oxidase I (mtCOI) gene was used to analyze site-specific genetic diversity and the population structure of two mussel species, Idas modiolaeformis and “Idas” simpsoni. Populations of each species are not geographically isolated. The presence of one dominant haplotype for each species suggests shared ancestral polymorphisms between Mediterranean and NE Atlantic populations. The overall high genetic differentiation observed in I. modiolaeformis indicates that the metapopulation is structured. Distant populations, located in Atlantic and E Mediterranean, revealed low genetic distances, suggesting gene flow between the two regions. Genetic and geographical distances support an island model of I. modiolaeformis population structure. A major drawback of this study is concerned with the discrepant number of individuals among populations. Further research will be needed, using more specimens and other gene markers, to investigate connectivity patterns at different spatial scales.
As espécies persistem ao longo do tempo devido à troca de indivíduos entre subpopulações. No ambiente marinho, a maioria dos organismos bentónicos têm ciclos de vida complexos, envolvendo larvas pelágicas que são transportadas por correntes oceânicas contribuindo para dispersão das espécies. A dispersão larvar estabelece conectividade entre populações geograficamente separadas e afeta a estrutura da população. O conhecimento deste processo biológico promove informações importantes para a conservação de populações marinhas. Este estudo investiga a estrutura genética e conectividade de populações de mexilhão de profundidade entre habitats fragmentados no NE Atlântico e Mediterrânico. O gene mitocondrial, Citocromo Oxidase I (mtCOI), foi utilizado para analisar diversidade genética por local e a estrutura populacional de duas espécies de mexilhão, Idas modiolaeformis e "Idas" simpsoni. As populações de cada uma das espécies não se encontram geograficamente isoladas. A presença de um haplótipo dominante para cada espécie sugere a partilha de polimorfismos ancestrais entre populações do Mediterrâneo e do NE Atlântico. As populações de I. modiolaeformis demonstraram uma elevada diferenciação genética, indicando estruturação da metapopulação. Populações distantes umas das outras, localizadas no Atlântico e E Mediterrâneo, revelaram baixas distâncias genéticas, sugerindo fluxo genético entre as duas regiões. Distâncias genéticas e geográficas suportam o modelo de ilha como o modelo para a estrutura populacional de I. modiolaeformis. Uma grande desvantagem deste estudo está relacionada com o número discrepante de indivíduos entre populações. Para investigar os padrões de conectividade em diferentes escalas espaciais serão necessários mais estudos, utilizando mais espécimes e outros marcadores genéticos.
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Garcia, Berdeal Irene. "Hydrography and flow in the axial valley of the Endeavour segment : implications for larval dispersal /". Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11034.
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Reis, Jesus Leonel da Costa dos. "Modelação da dispersão e conectividade larvar a NW da Península Ibérica". Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16395.
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Mestrado em Meteorologia e Oceanografia FísicaA cultura de mexilhão na costa NW da Península Ibérica, explorada desde o início do século XX, tem vindo a crescer na economia desta região. Desta forma, torna-se necessário conhecer os detalhes do ciclo de vida das larvas de mexilhão, durante a sua fase planctónica. Com o objetivo de estudar a dispersão, a conectividade larvar, e o recrutamento de larvas de mexilhão nas diferentes regiões da costa NW da Península Ibérica, foi implementado um modelo lagrangiano, ROFF. Este permite simular as trajetórias, o crescimento nas diferentes fases larvares, a taxa de mortalidade abiótica e por advecção para o ano particular, 2009. Os resultados obtidos com este modelo foram validados através da comparação com um conjunto de observações em estações amostradas nas Rias Baixas Galegas. Através da análise das matrizes de conectividade e do balanço de líquido, observou-se que a Ria de Arousa é a maior fornecedora de larvas. Para além disto, a Ria de Muros é a que apresenta um balanço emissãoreceção mais favorável. E ainda uma tendência na conectividade larvar em direção a N ao logo do ano, observando um fornecimento liquido de larvas nas regiões a N das principais Rias.
The mussel culture in the NW coast of the Iberian Peninsula, is exploited since the beginning of the XX Century, has been growing in the economy of this region. Thus, it is important to understand the details of the life cycle of mussel larvae, during its planktonic stage. In order to study a dispersion, the larvar connectivity, and the recruitment of mussel larvae in different regions of the NW coast of the Iberian Peninsula, it was implemented a Lagrangian model, ROFF. This allows the simulation of trajectories, growth in different larvar stages, the abiotic mortality rate and the advection for the year 2009. The results obtained with this model were validated through comparison with a set of observations at stations sampled in the four main Rias. Through the analysis of connectivity matrices and the net supply, it was observed that the Arousa’s Ria is the largest supplier of larvae. Furthermore, the Ria de Muros is the one presenting a more favorable emission - reception balance. And yet a trend in larvar connectivity towards the N throughout the year, noting a liquid supply of larvae in the regions N of the main Rias.
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Gomes, Guilherme [UNESP]. "Processos auto-organizados: efeitos de substâncias químicas que agem no sistema nervoso sobre o desenvolvimento e padrão de dispersão larval pós-alimentar de dípteros (Calliphoridae e Muscidae)". Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/99538.
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A ordem Diptera desperta grande interesse nos estudos científicos devido à importância agrícola, sanitária, veterinária e forense, dependendo da espécie em estudo. A espécie Chrysomya megacephala (Fabricius) foi introduzida há cerca de 30 anos no Brasil e é de considerável importância médico-sanitária, além de poder ser utilizada em estudos forenses, na estimativa de intervalo pós-morte (IPM) em humanos. A espécie Musca domestica (Linnaeus) tem distribuição cosmopolita e é bastante comum no ambiente urbano e pode também transportar formas infectantes de muitas doenças. Nessas moscas, após o desenvolvimento dos imaturos em substratos discretos e efêmeros, as larvas abandonam o substrato alimentar em busca de um sítio para pupação, processo chamado de dispersão larval pós-alimentar. No entanto, em ambiente natural, tanto a fonte alimentar como o substrato de pupação podem estar contaminados com substâncias químicas, sendo que algumas destas podem ser de interesse forense ou ser aplicadas no controle de pragas. Assim, o principal objetivo do presente trabalho é procurar dar contribuição a um melhor conhecimento dos efeitos do ansiolítico Diazepam [Diazepam NQ® 10mg] sobre o desenvolvimento larval e comportamento de dispersão larval e do inseticida Fipronil [Regent 800 WG®] sobre a dispersão pós-alimentar das larvas de duas espécies de moscas (C. megacephala e M. domestica). Na análise do desenvolvimento larval, pôde-se observar que a presença de Diazepam no substrato alimentar aumenta o tempo de desenvolvimento larval, retardando o ganho de massa por tempo nas duas espécies estudadas, quando se compara ao grupo controle. Já o comportamento de dispersão larval foi alterado na presença de Fipronil ou de Diazepam, em relação ao controle, sendo que a profundidade de enterramento e a distância das pupas do centro de irradiação...
Some species of Diptera have a great medical and veterinary importance, acting as vectors of many diseases, addiction of having a considerable agricultural, commercial and ecological importance and other ones having forensic importance. Flies utilize discrete and ephemeral breeding sites for larval nutrition. After the exhaustion of food, larvae begin dispersing in search of sites to pupate or to additional food sources, a process referred as post feeding larval dispersal. However, in natural environments these breeding or feeding sites can be contaminated with chemical substances. Some of these substances can be of forensic interest or be applied in pest control. In the present study, the main objective was to investigate the effect of Diazepam® [Diazepam NQ® 10mg] and Fipronil® [Regent 800 WG®] on immature stages of Chrysomya megacephala (Diptera: Calliphoridae) and Musca domestica (Diptera: Muscidae). The larvae were reared on artificial diet and rabbit liver on which different dosages of Diazepam were administrated in order to study the effects of this drug on the development and post feeding larval dispersal of the two species. Different dosages of the insecticide Fipronil were disposed in circular arena used as pupation substrate to investigate the effects on post feeding larval dispersal. The results showed that time required for larval development were significantly longer in colonies fed in contact with Diazepam than in the control ones, delaying the increase of mass per unit time in the two studied species. The larval dispersal behavior was modified in the presence of Fipronil and Diazepam, in comparison to arenas without the drugs. It was also observed that the burial depth and distance of the irradiation center were shorter than in the control groups for the two species... (Complete abstract click electronic address below)
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Galindo, Heather Michelle. "Traveling into the unknown : using genes to track marine larval dispersal across ecological and evolutionary timescales /". May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Cuif, Marion. "Combinaison de la modélisation biophysique et de marquages isotopiques pour estimer la connectivité démographique des populations marines : application à Dascyllus aruanus dans le lagon sud-ouest de Nouvelle-Calédonie". Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066526/document.
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Comprendre la dynamique des populations marines est essentiel à une gestion efficaceet requiert des connaissances sur la dispersion et la connectivité entre populationsqui sont encore très lacunaires. Beaucoup d’organismes marins ont un cycle de viebipartite avec une phase larvaire pélagique qui représente souvent la seule possibilitéde dispersion. De nouvelles techniques de mesure de la dispersion larvaire, parmarquage ou modélisation, ont été développées durant ces quinze dernières années.Cependant, les résultats de ces deux types d’approches ont rarement été comparésau sein d’un même système marin, limitant l’utilisation des modèles de dispersiondans les modèles de métapopulation. Dans cette thèse, nous utilisons ces deux typesd’approches pour étudier la connectivité larvaire d’un poisson de récif corallien,Dascyllus aruanus, dans le lagon sud-ouest de Nouvelle-Calédonie. Notre modèle dedispersion montre que la rétention larvaire présente une variabilité temporelle élevéeà l’échelle lagonaire et à l’échelle d’un patch de récif, et atteint périodiquement desvaleurs élevées malgré des temps moyens de résidence courts. Le marquage artificieltransgénérationnel des otolithes montre des taux d’auto-recrutement relativementbas à l’échelle de la saison reproductive, suggérant une ouverture importante despopulations, et une variabilité temporelle considérable de l’auto-recrutement. Enfin,les grandes différences entre les résultats du modèle et ceux des marquages appuientle besoin de mieux comprendre les processus qui facilitent la rétention larvaire commeles comportements de homing et la circulation des courants à très petite échelleUnderstanding marine populations dynamics is critical to their effective management,and requires information on patterns of dispersal and connectivity that are still poorlyknown. Many marine organisms have a bipartite life history with a pelagic larvalstage that often represents the only opportunity for dispersal. In the last decade,new empirical and simulation approaches to measuring larval dispersal have beendeveloped, but results from these two different approaches have rarely been comparedin the context of a single marine system, impeding the use of larval dispersal modelsin metapopulation models supporting decision making. In this doctoral research, weused both approaches to investigate larval connectivity for a coral reef fish, Dascyllusaruanus, in the South-West Lagoon of New Caledonia. Our biophysical dispersalmodel shows that larval retention exhibits considerable temporal variability at bothlagoon and patch reef scales and periodically reaches large values despite low averagewater residence time. Artificial transgenerational marking of embryonic otoliths inthe wild also showed relatively low self-recruitment rates indicating high populationopenness at the reproductive season scale, with considerable monthly variability ofself-recruitment. Large quantitative discrepancies between simulations and empiricalresults emphasize the need to better understand processes that facilitate local retention,such as homing behavior and very small scale circulation patterns
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Lohmeyer, Adam M. "Larval Asian carp in the upper and middle Mississippi River : an index of establishment and dispersal potential /". Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1559854851&sid=20&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Kernehan, Colleen D. "Determination of the fine scale, temporal pattern of larval release by female blue crabs and application of this information to mathematical models of larval dispersal and recruitment". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 1.71 Mb., 74 p, 2006. http://wwwlib.umi.com/dissertations/fullcit/1435933.
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Drexler, Michael. "Evaluating the use of larval connectivity information in fisheries models and management in the Gulf of Mexico". Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7499.
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Connectivity is a major contributor to the overall dynamics of marine populations. However, it still remains challenging to describe connectivity on ecologically meaningful scales of time and space. This is a major impediment to evaluating the impacts of marine protected area with respect to fisheries management objectives.
This dissertation brings together a wide array of spatial and connectivity information in the Gulf of Mexico (GOM) with the goal of 1) understanding the spatial distribution of fish populations and source-sink dynamics and 2) evaluating whether this information can be integrated, through a modeling framework, to identify closed areas that could be beneficial to fisheries management in the Gulf of Mexico.
First, a generalized additive modelling (GAM) approach is used to describe the distribution of a large number of species groups (i.e. functional groups) across the Gulf of Mexico (GOM) using a large fisheries independent data set (SEAMAP) and climate scale (decades) oceanographic conditions. Next a numerical Lagrangian particle transport model was developed that incorporates two major connectivity processes; site specific larval production and oceanographic transport for an entire large marine ecosystem and over multiple years. The two components are then combined to develop larval dispersal patterns for the entire GOM and identify areas operating as larval sources and sinks. Last, this information is integrated into an end-to-end ecosystem model to evaluate effectiveness of closing source and sink areas for the management of reef fish fisheries.
Closed area managemeny simlautions for reef fish indicated closing reef fish source areas, as opposed to sinks, in the GOM is most efficient method of increasing total biomass and yield. However, the impacts across individual functional groups were site specific. Ultimately, these simulations demonstrate the inclusion of connectivity information could improve fishery management objectives in an ecosystem context.
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Queiroga, Henrique. "Processos de dispersão e recrutamento das larvas do caranguejo Carcinus Maenas (L.) na Ria de Aveiro". Doctoral thesis, Universidade de Aveiro, 1995. http://hdl.handle.net/10773/978.
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Ross, Rebecca E. "Investigating the role of larval dispersal models in the development of an 'ecologically coherent' network of deep sea marine protected areas". Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/6560.
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There is currently worldwide pressure to establish Marine Protected Area (MPA) networks which are self-sustaining and will persistently protect habitats and species. In order for MPA networks to be effective, the species targeted for conservation must be able to disperse between protected areas and maintain a gene-flow necessary for population sustainability and persistence. This warrants new research on how to quantify and map faunal dispersal to ensure that protection will be effective and sustainable. Population genetic methods have merit, with the ability to track parentage and gene flow between areas directly. However the costs, quantity of samples, and time required to genetically quantify dispersal for multiple species make these approaches prohibitive as the only method of assessment, especially in relatively inaccessible offshore waters. Dispersal modelling is now becoming more accessible and may fulfil immediate needs in this field (although ground truthing will be necessary in the future). There have been very few dispersal modelling studies focussed on deep sea or offshore areas, predominantly due to the lack of high resolution hydrodynamic models with sufficient geographic extent away from shore. Current conclusions have been drawn based on shallow water coastal studies, informing offshore MPA network size and spacing. However the differences between these two environments may mean that dispersal abilities are not comparable. Deep water receives less influence from wind and weather, and the scales are vastly different in terms of a) the depth ranges covered, b) the planktonic larval durations (PLDs) of animals, and c) the geographic areas concerned as a consequence. Global hydrodynamic models with reasonable resolution are now becoming more accessible. With the outputs from these models, and freely available particle simulators, it is becoming more practical to undertake offshore deep water dispersal studies. This thesis aims to undertake an analysis of these accessible modelling tools within a deep sea context. The guidelines which are currently available to dispersal modellers are yet to encompass the needs of deep water modellers which may require some additional considerations given the extended depth range covered and the different hydrodynamic drivers away from the air/sea interface. Chapter 1 reviews the larval dispersal process, the factors which may affect dispersal success, and those which should be incorporated into future predictions of dispersal. The current methods for assessing larval dispersal are explored covering genetics, elemental tagging and modelling approaches with an extended look at modelling considerations. Existing marine conservation policy is also touched on in the context of connectivity and larval dispersal. Chapter 2 is designed to inform future deep sea modellers on how to parameterise and understand a dispersal model. As models appear as a ‘black box’ to the majority of users, sensitivity tests can offer a way of scaling model inputs and tempering expectations from model outputs. A commonly used model pairing (the HYCOM hydrodynamic model and the Connectivity Modeling System) is assessed, using parameters which link to the temporal and spatial scales of mixing in the modelled system: timestep of particle tracer, horizontal and vertical positioning of release points, release frequency of larvae, and temporal range of simulation. All parameters were shown to have a decreased sensitivity with depth, with patterns reflecting local watermass structure. Future studies observing similar hydrodynamic conditions seeking to optimise their model set up would be advised to stratify their model release locations with depth. A means to incorporate all sensitivity test results into optimal input parameters for future studies is demonstrated. Chapter 3 investigates whether dispersal models provide any advantage over a “sphere of influence” estimate based on average current speeds and PLDs: there is no use pursuing dispersal modelling if the outputs are too erroneous to provide any advantage over a back-of-the-envelope calculation. This chapter examines the outputs of two dispersal models driven by two different hydrodynamic models in order to observe the variability in prediction between models. This model comparison revealed a greater disparity between hydrodynamic model predictions than has been previously understood by ecologists. The two models compared (POLCOMS and HYCOM) may equally be considered as suitable to promote realism in the study region, but slight differences in resolution and numerical error handling resulted in dispersal predictions from which opposing conclusions can be drawn. This chapter therefore emphasises the necessity for model ground truthing before predictions can be trusted. Chapter 4 assimilates the findings of the previous chapters and applies their advice to a study of MPA network dispersal connectivity. Using the hydrodynamic model which performed best in chapter 3 (HYCOM), a simulation was undertaken for cold water coral (Lophelia pertusa (Linnaeus 1758)) larval dispersal between already established MPAs in the NE Atlantic. As larval characters have only been observed ex situ, dispersal was simulated using two null models (passive and active vertical migration) and averaged to provide an intermediate prediction. A method for assessing dispersal within MPAs and MPA networks is offered based on the intermediate prediction, as well as a network wide assessment of the difference in dispersal patterns for passive and active larvae. It was found that the existing network performs well at supplying larvae to non-networked sites, but performs poorly at supplying other MPAs. The ‘best’ MPAs were central to the network and facilitated the traverse of regional gaps in suitable habitat. The ‘worst’ MPAs were peripheral to the network and small in size. Network-wide passive and active dispersal matrices had no significant difference between them. However site specific variability in the effect of vertical migration was detected subject to variability in local topographic barriers to dispersal, only some of which could be surmounted with vertical migration. All chapters aim to inform future deep sea dispersal modellers, and encourage exploration of this tool in other contexts, as well as marine conservation. The thesis cautions against the transplantation of shallow water assumptions to deep water environments, and advocates region specific studies and mandatory ground truthing of predictions. An upcoming study will ground truth the findings of this thesis with both genetic and oceanographic data, allowing the accuracy of study results to be quantified.
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Callwood, Karlisa A. "Use of Larval Connectivity Modeling to Determine Settlement Habitats of Panulirus argus in The Bahamas as a Pre-cursor to Marine Protected Area Network Planning". Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/59.
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Caribbean spiny lobster (Panulirus argus) is a popular and heavily exploited seafood throughout its range. This species supports the primary fishery in many Caribbean countries, especially in the Bahamas, which reports the highest catches and where spiny lobster serves as the number one food export. P. argus possesses one of the longest pelagic larval durations of any marine species, ranging from 6-12 months. This allows for the possibility of long-range dispersal, which would make it difficult to determine if local adult populations originate from areas close-by or within the same countries/jurisdictions, thus presenting implications for conservation and management of the species. This project seeks to explore the policy implications of lobster larval dispersal in the Bahamas by examining the larval connectivity of locally spawned P. argus in order to determine the mean dispersal kernel and to identify hotspots of settlement within the area. A coupled biophysical model was used to simulate larval transport from scaled egg production of 47 release locations within the Bahamas. The model was initialized bi-weekly from April through May, the highest months of larvae production in the Bahamas, with each model run occurring for a maximum of 180 days. The dispersal kernel for the Bahamas was calculated to be an average of 100-300 km, indicating that the larvae released within its boundaries typically settled there as well. Due to the long pelagic larval duration, larval particles were able to travel extensive distances, averaging trajectories covering distances of 4000 km and greater from the source locations. Yet, those same larval particles still settled in locations within the Bahamas, suggesting local retention, which varies from the common perception that lobster in the Bahamas originate elsewhere. This knowledge can be used to assess and perhaps reevaluate conservation and management strategies related to the Bahamian P. argus fishery, including the implementation of MPAs and/or MPA networks, input and output management controls, and other management tools.
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STOCCO, L. B. "Conectividade entre populações de peixes recifais ao longo da Cadeia Vitória-Trindade: o papel da dispersão larval". Universidade Federal do Espírito Santo, 2015. http://repositorio.ufes.br/handle/10/3857.
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Previous issue date: 2015-02-27Peixes recifais adultos são relativamente sedentários e a fase larval pode permitir a dispersão para locais distantes. Porém, ainda há incertezas sobre o quanto da produção ictioplanctônica é retida no local de origem e o quanto é dispersa e como as diferentes populações e espécies variam neste aspecto. O transporte larval, ditado por respostas biológicas e pelas condições físicas do ambiente, permite a conectividade entre populações. A Cadeia Vitória-Trindade (CVT) é constituída por seis montes submarinos pelas ilhas Trindade e Martin Vaz dispostos linear e perpendicularmente à costa do Espírito Santo e parece atuar como alpondras para peixes recifais. O trabalho objetivou analisar o fluxo de larvas ao longo da CVT. Foram feitas duas coletas na região e as larvas de peixes capturadas foram classificadas em recifal, epipelágica ou mesopelágica, de acordo com o habitat ocupado pelo adulto. Larvas de peixes mesopelágicos foram as mais abundantes e diversas em todos os locais, exceto sobre o monte submarino mais próximo à costa. Foi observado que a densidade e a riqueza de larvas de peixes recifais estão associadas a fatores como presença de locais rasos, distância de fontes externas de propágulos e dinâmica de correntes, tornando difícil o reconhecimento de algum padrão espacial. Foi realizada a simulação do transporte larval de peixes recifais no programa Ichthyop 3.2 utilizando um modelo hidrodinâmico ROMS referente à região entre a costa brasileira e o monte submarino mais distante da costa (i.e. não inclui as ilhas). A modelização do transporte foi realizada para dois tipos biológicos, com características de ampla (pelagic larval duration PLD- de 40 a 45 dias) e de baixa (PLD de 30 a 35 dias e presença de migração vertical) capacidade dispersiva. A simulação mostrou que há fluxo de larvas ao longo da CVT e regiões adjacentes com a necessidade de etapas intermediárias para o transporte entre os extremos da cadeia, caracterizando o modelo de alpondras modificado. Os fluxos larvais dos dois tipos biológicos se mostraram semelhantes. Dessa forma, a dispersão larval tem importante papel na conectividade de populações de peixes recifais ao longo dos montes submarinos da CVT e entre eles e a costa.
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Nixon, John Bruce. "Dispersion modelling using finite-difference methods with application to larval western king prawn (Pencieus latisulcatus) in Spencer Gulf, South Australia /". Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phn736.pdf.
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Wan, Pak-ho, i 溫柏豪. "The role of Masked Palm Civet (Paguma larvata) and Small IndianCivet (Viverricula indica) in seed dispersal in Hong Kong, China". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42664664.
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Gomes, Leonardo [UNESP]. "Processos auto-organizados em agregados de larvas de moscas-varejeiras em dispersão pós-alimentar: experimentação, modelagem e validação". Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/106580.
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Um dos principais propósitos da investigação de fenômenos em qualquer área de atuação é encontrar uma forma adequada de representação dos processos envolvidos que seja o mais simples possível. O estudo da auto-organização em agregados de organismos biológicos não pode fugir a este propósito, e foi realizado aqui em três etapas: experimentação, modelagem e validação. A experimentação vai permitir definir claramente os padrões de comportamento a serem analisados e interpretados. A modelagem irá recorrer a estratégias espaço-temporais para a síntese de explanações matemáticas, para as interações e modos de agir dos organismos. Finalmente, a validação estará baseada em simulações computacionais, comparações com os resultados experimentais e interpretação paramétrica dos modelos resultantes. Foi predominante junto ao processo de modelagem o uso apenas das informações provenientes das observações realizadas e dados experimentais coletados, caracterizando uma abordagem de modelagem bottom-up, em detrimento da incorporação de hipóteses intuitivas a respeito dos mecanismos envolvidos, procedimento típico das abordagens top-down. Além disso, a acurácia do modelo em reproduzir resultados experimentais não foi o único e principal fator de avaliação da qualidade dos modelos resultantes, pois o aspecto mais importante a ser considerado junto aos modelos é a capacidade de ampliar o conhecimento acerca do fenômeno envolvido. Embora existam muitas manifestações de auto-organização na natureza e que poderiam ser tomadas como casos de estudo, este projeto se propôs a investigar o processo de dispersão larval pós-alimentar em moscas-varejeiras do gênero Chrysomya. Essas moscas foram introduzidas no Brasil em meados dos anos 70, e são de considerável importância médico-sanitária...
In any area of investigation, one of the main goals is to identify the simplest and most adequate representation of the phenomenon being studied. The study of selforganization in aggregates of organisms is no exception to this rule. In the work described here, we used a combination of laboratory experiments, modeling and validation to clearly identify patterns of behavior. For modeling, spatiotemporal strategies were used to develop mathematical explanations of the interactions and ways organisms act. The final validation was based on computer simulations, comparisons with experimental results and parametric interpretation of the resulting models. The modeling was based on observations and data collected during the experiments, an approach known as bottom-up modeling, and which contrasts with top-down modeling that depends on the incorporation of intuitive hypotheses about the mechanisms involved. Apart from the accuracy of the model in reproducing the experimental results, the most important aspect to be considered is the ability of the resulting model(s) to increase our knowledge about a given phenomenon. In this investigation, we used postfeeding larval dispersal in blowflies of the genus Chrysomya as a model to study self-organization. Chrysomya blowflies were introduced into Brazil in the mid-1970s, and are of considerable medicosanitary importance since they are vectors of enteropathogens that cause facultative myiasis in animals and man; these flies are also used in forensic studies to estimate the postmortem interval (PMI) in humans. The larval stage in these flies is the principal period in which there is competition for discrete, ephemeral food resources in the wild. After exhaustion of the food resources, the larvae leave the food... (Complete abstract, click electronic address below)
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Gomes, Leonardo. "Processos auto-organizados em agregados de larvas de moscas-varejeiras em dispersão pós-alimentar : experimentação, modelagem e validação /". Rio Claro : [s.n.], 2005. http://hdl.handle.net/11449/106580.
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Orientador: Claudio José Von ZubenBanca: Arício Xavier Linhares
Banca: Wesley Augusto Conde Godoy
Banca: Janyra Oliveira Costa
Banca: Margareth M.M. Queiroz
Resumo: Um dos principais propósitos da investigação de fenômenos em qualquer área de atuação é encontrar uma forma adequada de representação dos processos envolvidos que seja o mais simples possível. O estudo da auto-organização em agregados de organismos biológicos não pode fugir a este propósito, e foi realizado aqui em três etapas: experimentação, modelagem e validação. A experimentação vai permitir definir claramente os padrões de comportamento a serem analisados e interpretados. A modelagem irá recorrer a estratégias espaço-temporais para a síntese de explanações matemáticas, para as interações e modos de agir dos organismos. Finalmente, a validação estará baseada em simulações computacionais, comparações com os resultados experimentais e interpretação paramétrica dos modelos resultantes. Foi predominante junto ao processo de modelagem o uso apenas das informações provenientes das observações realizadas e dados experimentais coletados, caracterizando uma abordagem de modelagem bottom-up, em detrimento da incorporação de hipóteses intuitivas a respeito dos mecanismos envolvidos, procedimento típico das abordagens top-down. Além disso, a acurácia do modelo em reproduzir resultados experimentais não foi o único e principal fator de avaliação da qualidade dos modelos resultantes, pois o aspecto mais importante a ser considerado junto aos modelos é a capacidade de ampliar o conhecimento acerca do fenômeno envolvido. Embora existam muitas manifestações de auto-organização na natureza e que poderiam ser tomadas como casos de estudo, este projeto se propôs a investigar o processo de dispersão larval pós-alimentar em moscas-varejeiras do gênero Chrysomya. Essas moscas foram introduzidas no Brasil em meados dos anos 70, e são de considerável importância médico-sanitária... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In any area of investigation, one of the main goals is to identify the simplest and most adequate representation of the phenomenon being studied. The study of selforganization in aggregates of organisms is no exception to this rule. In the work described here, we used a combination of laboratory experiments, modeling and validation to clearly identify patterns of behavior. For modeling, spatiotemporal strategies were used to develop mathematical explanations of the interactions and ways organisms act. The final validation was based on computer simulations, comparisons with experimental results and parametric interpretation of the resulting models. The modeling was based on observations and data collected during the experiments, an approach known as bottom-up modeling, and which contrasts with top-down modeling that depends on the incorporation of intuitive hypotheses about the mechanisms involved. Apart from the accuracy of the model in reproducing the experimental results, the most important aspect to be considered is the ability of the resulting model(s) to increase our knowledge about a given phenomenon. In this investigation, we used postfeeding larval dispersal in blowflies of the genus Chrysomya as a model to study self-organization. Chrysomya blowflies were introduced into Brazil in the mid-1970s, and are of considerable medicosanitary importance since they are vectors of enteropathogens that cause facultative myiasis in animals and man; these flies are also used in forensic studies to estimate the postmortem interval (PMI) in humans. The larval stage in these flies is the principal period in which there is competition for discrete, ephemeral food resources in the wild. After exhaustion of the food resources, the larvae leave the food... (Complete abstract, click electronic address below)
Doutor
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Wotton, Debra Mary. "Consequences of dispersal failure: kereru and large seeds in New Zealand". Thesis, University of Canterbury. Biological Sciences, 2007. http://hdl.handle.net/10092/2509.
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The decline of kereru (Hemiphaga novaeseelandiae) may limit dispersal of large-seeded plants in New Zealand, but the consequences of this are unknown. I determined kereru disperser effectiveness by modelling seed dispersal distances (using seed retention times and movement patterns). Mean seed retention time was significantly longer for larger-seeded species, ranging from 37-181 minutes. Wild radiotracked kereru were sedentary, remaining at one location for up to 5.25 hours. The mean flight distance was 77 m and the maximum was 1, 457 m. Estimated mean seed dispersal distances for tawa (Beilschmiedia tawa), puriri (Vitex lucens), and fivefinger (Pseudopanax arboreus) were 95, 98, and 61 m respectively. Kereru dispersed 66-87% of ingested seeds away from the parent tree, with 79-88% of seeds dispersed <100 m and < 1% dispersed over 1,000 m. In a field seed-fate experiment, "pre-human" conditions (cleaned seeds, low density, away from parent, and protected from mammals) increased survival compared to "post-human" conditions (whole fruits, high density, under parent, not protected) for both taraire (Beilschmiedia tarairi; 15% vs. 2% survival to one year respectively) and karaka (Corynocarpus laevigatus; 60% vs. 11% to two years, respectively). Fruit diameter varied considerably within karaka, taraire, and tawa, although theoretically not enough for them to be swallowed by other birds. Nevertheless, other birds are reported to occasionally take fruits of nearly all large-seeded species. Small tawa seeds produced smaller seedlings in the glasshouse; therefore selection of only smaller seeds by alternative dispersers may negatively affect tawa recruitment. Kereru are generally not gape-limited, and fruit size preferences were independent of mean fruit size. Kereru provide effective dispersal by moving most seeds away from the parent, and enhancing seed and seedling survival. Therefore, both dispersal failure and introduced mammals negatively affect the regeneration of large-seeded trees in New Zealand.