Journal articles: 'Estuarine and freshwater ecology'

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Tittley, Ian. "Ecology of Freshwater and Estuarine Wetlands." Botanical Journal of the Linnean Society 155, no. 3 (November 2007): 447. http://dx.doi.org/10.1111/j.1095-8339.2007.00701.x.

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Huxham, Mark. "Ecology of Freshwater and Estuarine Wetlands." Freshwater Biology 53, no. 3 (March 2008): 635. http://dx.doi.org/10.1111/j.1365-2427.2007.01910.x.

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Moore-Maley, Benjamin L., Debby Ianson, and Susan E. Allen. "The sensitivity of estuarine aragonite saturation state and pH to the carbonate chemistry of a freshet-dominated river." Biogeosciences 15, no. 12 (June 20, 2018): 3743–60. http://dx.doi.org/10.5194/bg-15-3743-2018.

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Abstract. Ocean acidification threatens to reduce pH and aragonite saturation state (ΩA) in estuaries, potentially damaging their ecosystems. However, the impact of highly variable river total alkalinity (TA) and dissolved inorganic carbon (DIC) on pH and ΩA in these estuaries is unknown. We assess the sensitivity of estuarine surface pH and ΩA to river TA and DIC using a coupled biogeochemical model of the Strait of Georgia on the Canadian Pacific coast and place the results in the context of global rivers. The productive Strait of Georgia estuary has a large, seasonally variable freshwater input from the glacially fed, undammed Fraser River. Analyzing TA observations from this river plume and pH from the river mouth, we find that the Fraser is moderately alkaline (TA 500–1000 µmol kg−1) but relatively DIC-rich. Model results show that estuarine pH and ΩA are sensitive to freshwater DIC and TA, but do not vary in synchrony except at high DIC : TA. The asynchrony occurs because increased freshwater TA is associated with increased DIC, which contributes to an increased estuarine DIC : TA and reduces pH, while the resulting higher carbonate ion concentration causes an increase in estuarine ΩA. When freshwater DIC : TA increases (beyond ∼ 1.1), the shifting chemistry causes a paucity of the carbonate ion that overwhelms the simple dilution/enhancement effect. At this high DIC : TA ratio, estuarine sensitivity to river chemistry increases overall. Furthermore, this increased sensitivity extends to reduced flow regimes that are expected in future. Modulating these negative impacts is the seasonal productivity in the estuary which draws down DIC and reduces the sensitivity of estuarine pH to increasing DIC during the summer season.

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Matich, Philip, Robert J. Nowicki, Jonathan Davis, John A. Mohan, Jeffrey D. Plumlee, Bradley A. Strickland, Thomas C. TinHan, R. J. David Wells, and Mark Fisher. "Does proximity to freshwater refuge affect the size structure of an estuarine predator (Carcharhinus leucas) in the north-western Gulf of Mexico?" Marine and Freshwater Research 71, no. 11 (2020): 1501. http://dx.doi.org/10.1071/mf19346.

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The life histories of estuarine species are often adapted to the environmental variability they experience. However, estuaries are increasingly vulnerable to natural and anthropogenic changes, necessitating an understanding of how shifting conditions affect the survival, behaviour and population structure of estuarine-dependent animals. In this study we used data from fisheries-independent surveys collected across six estuaries with variable salinity regimes in Texas, USA, from 1975 to 2016 to investigate the role sources of freshwater inflow play in shaping juvenile bull shark Carcharhinus leucas size structure. High frequencies of co-occurrence with similarly sized conspecifics (59% of capture events) suggest bull sharks segregated within Texan estuaries based on body size. Bull shark sizes increased with distance to the nearest source of freshwater inflow, although effect sizes were small and access to freshwater habitats may be more important in shaping size-dependent distribution patterns. River mouths were disproportionately used by smaller juveniles (<90-cm total length, TL) and avoided by larger juveniles (>135cm TL). However, the use of river mouths decreased in estuaries characterised by limited freshwater inflow and greater variability in salinities at river mouths, highlighting geographic differences in the functions these habitats provide as potential environmental and predator refugia. Young-of-the-year (i.e. age-0) sharks also increased their use of river mouths throughout the 40-year study period, revealing the growing importance of river mouths as potential nursery habitats.

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Mai, Ana Cecilia Giacometti, and João Paes Vieira. "Review and consideration on habitat use, distribution and life history of Lycengraulis grossidens (Agassiz, 1829) (Actinopterygii, Clupeiformes, Engraulididae)." Biota Neotropica 13, no. 3 (September 2013): 121–30. http://dx.doi.org/10.1590/s1676-06032013000300015.

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In this paper, we present a summary of the current knowledge of Lycengraulis grossidens, a widely distributed coastal fish that occurs from Belize to Argentina. This species is abundant in estuaries along the Southwest Atlantic Coast and is important for recreational fishing, and as bycatch of shrimp fisheries. We compiled data available on taxonomy, phylogeny, ecology, fisheries and organized conceptually the life cycle of the species according to modern estuarine-use classification. Our review showed that along its geographic distribution and inside some particular environments (i.e., estuaries and costal lagoons) the species have been classified in a variety of ways in order to describe the remarkable complexity of habitat use that varies from freshwater resident, anadromous, marine migrant, estuarine resident, marine stragglers, catadromous to semi-catadromous. We conclude that L. grossidens is able to reproduce either in freshwater or estuarine water and postulate that it has a high plasticity in habitat use and life history, with migratory and resident contingents in the same local population. There seems to be a latitudinal change in migratory behavior of this species along the South America Coast, prevailing anadromous or semi-anadromous pattern at higher latitudes and marine migrants at the tropical northeast coast of Brazil.

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Sheaves, Marcus, Ross Johnston, and Kátya Abrantes. "Fish fauna of dry tropical and subtropical estuarine floodplain wetlands." Marine and Freshwater Research 58, no. 10 (2007): 931. http://dx.doi.org/10.1071/mf06246.

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Estuarine floodplain wetland pools occur adjacent to marine coasts and estuaries throughout the world. In Australia’s dry tropics and sub-tropics, low and irregular rainfall means estuarine wetland pools are isolated for much of the time, resulting in varied within-pool conditions, with chemistry ranging from fresh to hypersaline, depending on the balance between freshwater and marine inputs and the time between connections. Varied physical conditions and irregular connectivity provide the potential for substantial faunal difference among pools. The present study compares the compositions and structures of the fish fauna of a broad cross section of estuarine wetland pools adjacent to the estuary of the Fitzroy River, one of the largest rivers in Australia’s dry tropical/subtropical zone. Ten pools were sampled between February 2004 and May 2005. The total species richness was low, with the 6123 fish recorded over the study, comprising only 44 species. This low species richness was reflected at the individual pool level, with a maximum total richness of 25 species in a single pool. Different pools had faunas that differed as a function of the proportion of the community comprised of marine spawned, compared with freshwater spawned, species. This was a reflection of the extent of connectivity to freshwater and marine systems, which determined both the physical nature of pools and the sources of faunal supply. Despite faunal differences among pools, at a functional level pool fish faunas were dominated by detritivores, regardless of pool type, size, season or connectedness.

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Pusey, Bradley J., Timothy D. Jardine, Stuart E. Bunn, and Michael M. Douglas. "Sea catfishes (Ariidae) feeding on freshwater floodplains of northern Australia." Marine and Freshwater Research 71, no. 12 (2020): 1628. http://dx.doi.org/10.1071/mf20012.

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Flooding of the terminal floodplains of northern Australian rivers provides a greatly expanded, productive habitat accessed by both freshwater and estuarine fishes. This study aimed to determine the extent to which sea catfishes (Ariidae) make use of floodplains and the reasons for doing so (i.e. spawning, feeding). Nine species were collected from floodplains and adjacent distributaries of the Mitchell and Flinders rivers; floodplain use was largely restricted to freshwater species. Evidence of prior wet season spawning was recorded for some species, and mesenteric lipid deposits indicated that fish were in good condition. However, little evidence of spawning on floodplains was found. Stomach content analysis and stable isotope analysis indicated dietary partitioning, particularly between freshwater and estuarine species, but also within freshwater species, and indicated that some species were responsive to variations in food availability. Isotope analyses suggest extensive movement between freshwater, estuarine and marine habitats at different life history stages for the catfish assemblage studied. Terminal floodplains of northern Australian rivers provide important temporary habitat for adult sea catfishes to feed upon, but do not appear to be used as spawning grounds.

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Robins, Julie B., Ian A. Halliday, Jonathan Staunton-Smith, David G. Mayer, and Michelle J. Sellin. "Freshwater-flow requirements of estuarine fisheries in tropical Australia: a review of the state of knowledge and application of a suggested approach." Marine and Freshwater Research 56, no. 3 (2005): 343. http://dx.doi.org/10.1071/mf04087.

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The freshwater-flow requirements of estuarine fisheries in tropical areas are reviewed, with reference to species important to fisheries in northern Australia. Fisheries production, in terms of catch, is often elevated during, or as a consequence of, years with higher river flow, but the causality of these relationships often remains unproven. Scientific information on the freshwater-flow requirements important to fisheries production is increasingly being sought during the planning, allocation and management of water resources within Australia and in other countries around the world. Frequently, such advice is based on the analysis of catch and freshwater flow (or rainfall), or on life-history information. Clarifying fisheries-specific goals of water management would assist in prioritising research into the freshwater-flow requirements of estuarine fisheries. A framework that integrates life-history information and correlative analyses is suggested to assist in understanding the freshwater-flow requirements of estuarine fisheries. The framework is also useful in identifying knowledge gaps and pertinent research questions. The approach is illustrated through its application to identifying key freshwater-flow events likely to be important for fisheries production in a dry tropical estuary in Queensland, Australia.

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Mai, Ana C. G., Lizandra J. Robe, Luis F. Marins, and João P. Vieira. "Genetic relationships between landlocked and coastal populations of Lycengraulis grossidens (Engraulidae) in south-eastern South America: evidence for a continental colonisation route with secondary transitions to the coastal region." Marine and Freshwater Research 68, no. 2 (2017): 342. http://dx.doi.org/10.1071/mf15355.

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The anchovies of the genus Lycengraulis are the product of an evolutionary transition from a marine to freshwater environment that occurred in South America during the Miocene epoch. Lycengraulis grossidens originated from freshwater lineages and is currently distributed in estuaries and coastal zones. Nevertheless, based on otolith chemistry, there are landlocked individuals in the Uruguay River. The aim of the present study was to investigate the spatiotemporal scenario by which these landlocked individuals reached their current distribution: whether through a north-to-south continental route based on the connection between basins or from the marine environment. To this end, a fragment of the mitochondrial (mt)DNA control region was analysed from individuals collected along freshwater, estuarine and marine environments. We found a significant genetic differentiation between freshwater and coastal (estuarine and marine) populations. Larger haplotype diversities and female effective population size values were found in the coastal population. Nevertheless, the outgroup rooting positioned some Uruguay River haplotypes as hypothetical ancestors in the directed network and as early offshoots in the phylogeny, suggesting the landlocked population as an ancestral lineage. Therefore, the phylogenetic history and biogeography are consistent with a north-to-south continental colonisation route putatively associated with ancient connections between the Amazon and Parana basins followed by new evolutionary transitions to the coastal region associated with Quaternary sea level oscillations.

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Adams, Aaron J., and R. Kirby Wolfe. "Occurrence and persistence of non-native Cichlasoma urophthalmus (family Cichlidae) in estuarine habitats of south-west Florida (USA): environmental controls and movement patterns." Marine and Freshwater Research 58, no. 10 (2007): 921. http://dx.doi.org/10.1071/mf07086.

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The geographic scope of species introductions has increased dramatically in the last 200 years. One of the greatest challenges to understanding the ecological consequences of non-native species is that it has been difficult to identify the attributes that allow them to become established outside their native range. This challenge is compounded by anthropogenic habitat alteration that often enhances the establishment and expansion of non-native species. Fishes in the family Cichlidae are notoriously adaptive, and contribute more non-native species to North America than any other fish family. This is especially true in Florida (USA), where 18 cichlid species have become established. The Mayan cichlid (Cichlasoma urophthalmus) was first documented in south Florida in 1983, and is present in many freshwater and estuarine habitats. This study reports a northward range expansion by C. urophthalmus, demonstrates the connectivity between altered freshwater habitats and tidal estuarine habitats, and suggests that the estuarine populations are ephemeral and dependent upon colonisation from populations in altered freshwater habitats.

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Mariano-Jelicich, Rocío, Germán García, and Marco Favero. "Fish composition and prey utilization of the black skimmer (Rynchops niger) in mar Chiquita coastal lagoon, Argentina." Brazilian Journal of Oceanography 62, no. 1 (March 2014): 1–10. http://dx.doi.org/10.1590/s1679-87592014034806201.

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Lagoons along the western coast of the South Atlantic Ocean shelter high densities of juvenile fish and are key areas for several seabirds that rely on the resources offered by this kind of ecosystem. The objective of this study was to analyze fish composition and abundance in shallow-water areas of the estuarine region of Mar Chiquita Coastal Lagoon (Argentina) and the diet composition of the Black skimmer (Rynchops niger) during its non-breeding season as well as evaluating its inter-annual variations. Fish were sampled with a beach-seine net and the skimmers' diet was analyzed from their pellets. The estuarine-dependent marine fishes were the best represented bio-ecological category followed by freshwater fishes. Significant differences were observed in fish abundance and composition between and within years. Species richness was higher during the summer season and during the first year sampled. The occurrence of freshwater fishes as an important and diverse group of the Mar Chiquita estuarine area contrasted with previous reports. The diet of the Black skimmer included freshwater, estuarine and marine fish species. Skimmers forage in the shallow waters of the estuarine area of the Mar Chiquita Coastal lagoon though little similarity was observed between its diet and local fish abundance. These results emphasize the importance of performing these evaluations in order to improve the quality of studies and the interpretations of top predators foraging ecology.

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Glover, David C., Dennis R. DeVries, and Russell A. Wright. "Growth of largemouth bass in a dynamic estuarine environment: an evaluation of the relative effects of salinity, diet, and temperature." Canadian Journal of Fisheries and Aquatic Sciences 70, no. 3 (March 2013): 485–501. http://dx.doi.org/10.1139/cjfas-2012-0295.

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Some freshwater fishes occur regularly in estuarine areas that experience spatial and seasonal variation in marine influence. These dynamic abiotic and biotic conditions potentially influence food consumption and growth. We found that effects of an estuarine environment on the growth of largemouth bass (Micropterus salmoides) in Alabama's Mobile–Tensaw River Delta depended on body size, distance from the marine source, and amount of freshwater inflow. Incremental growth analyses demonstrated that young largemouth bass (<age-3) grew more rapidly downstream in the estuarine environment declining with distance upstream; this relationship was reversed for older fish with faster growth in fresher, upstream areas. The magnitude of freshwater inflow influenced the relationship between age-specific growth and proximity to Mobile Bay. Bioenergetics simulations suggest that interactions among size-specific metabolic cost of salinity, maximum water temperature, and spatial differences in both salinity and prey energetic content can explain these growth patterns. The cost–benefit of the estuarine environment to largemouth bass is not only dynamic seasonally, but also changes ontogenetically because of shifts in salinity tolerance and prey use.

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Burford, M. A., A. T. Revill, D. W. Palmer, L. Clementson, B. J. Robson, and I. T. Webster. "River regulation alters drivers of primary productivity along a tropical river-estuary system." Marine and Freshwater Research 62, no. 2 (2011): 141. http://dx.doi.org/10.1071/mf10224.

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Worldwide, rivers continue to be dammed to supply water for humans. The resulting regulation of downstream flow impacts on biogeochemical and physical processes, potentially affecting river and estuarine productivity. Our study tested the hypothesis that primary production in the downstream freshwater reaches of a dammed river was less limited by light and nutrients relative to downstream estuarine primary production. In a tropical dryland Australian river estuary, we found that water-column primary productivity was highest at freshwater sites that had lowest light attenuation. Nitrogen may also have limited primary productivity. Below the freshwater zone was a region of macrotidal mixing with high concentrations of suspended soil particles, nutrients and chlorophyll a, and lower but variable primary productivity rates. Light controlled productivity, but the algal cells may also have been osmotically stressed due to increasing salinity. Further downstream in the estuary, primary productivity was lower than the freshwater reaches and light and nutrient availability appear to be a factor. Therefore the reduced magnitude of peak-flow events due to flow regulation, and the resulting decrease in nutrient export, is likely to be negatively impacting estuarine primary production. This has implications for future development of dams where rivers have highly seasonal flow.

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Mills, Courtenay E., Wade L. Hadwen, and Jane M. Hughes. "Looking through glassfish: marine genetic structure in an estuarine species." Marine and Freshwater Research 59, no. 7 (2008): 627. http://dx.doi.org/10.1071/mf07215.

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Through the use of mitochondrial DNA (ATP8 gene), the prediction of intermediate genetic structuring was investigated in two species of estuarine glassfish (Ambassis marianus and Ambassis jacksoniensis) (Perciformes : Ambassidae) to determine the possibility of a generalised ‘estuarine’ genetic structure. Individuals were collected from estuaries in eastern Australia between Tin Can Bay (Queensland) in the north and Kempsey (New South Wales) in the south. Analysis of the haplotype frequencies found in this region suggested panmictic populations with star-like phylogenies with extremely high levels of genetic diversity, but with no correlation between geographic distance and genetic distance. Non-significant FST and ΦST suggested extensive dispersal among estuaries. However, Tajima’s D and Fu’s FS values suggest ‘mutation–genetic drift equilibrium’ has not been reached, and that population expansions occurring 262 000 (A. marianus) and 300 000 (A. jacksoniensis) years ago may obscure any phylogeographic structuring or isolation by distance. The finding of panmixia was contrary to the prediction of genetic structuring intermediate between that of marine fish (shallowly structured) and freshwater fish (highly structured), suggesting high dispersal capabilities in these species.

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Russell, D. J., and A. J. McDougall. "Movement and juvenile recruitment of mangrove jack, Lutjanus argentimaculatus (Forsskål), in northern Australia." Marine and Freshwater Research 56, no. 4 (2005): 465. http://dx.doi.org/10.1071/mf04222.

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Lutjanus argentimaculatus, tagged and released in coastal rivers and estuaries, were found to have made inter- and intra-riverine, coastal and offshore movements. A small proportion of the recaptures made offshore movements to reef habitats of up to 315 km and these recaptures were fish that were at liberty, on average, more than twice as long as those fish that had made intra-riverine movements. Most juvenile fish <400-mm length to caudal fork (LCF) resident in rivers were recaptured less than a kilometre from where they were released. The proportion of fish making sizeable movements increased with increasing recapture size, with about of 20% of larger fish (400–500-mm LCF) making offshore, inter-riverine or coastal movements. Larger fish were primarily caught offshore, whereas smaller fish <~338-mm LCF were exclusively caught in estuarine and freshwater habitats. Recruitment of juveniles into estuarine and lower freshwater riverine habitats occurred from about February. There was temporal variability of recruitment of mangrove jack into some river systems and their relative abundance within the river system was inversely proportional to the distance from the sea. Overfishing of juveniles when they are concentrated in inshore areas could have adverse implications for mangrove jack stocks.

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STEVENSON, J. COURT. "Comparative ecology of submersed grass beds in freshwater, estuarine, and marine environments." Limnology and Oceanography 33, no. 4_part_2 (1988): 867–93. http://dx.doi.org/10.4319/lo.1988.33.4_part_2.0867.

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Stevenson, J. Court. "Comparative ecology of submersed grass beds in freshwater, estuarine, and marine environments1." Limnology and Oceanography 33, no. 4part2 (July 1988): 867–93. http://dx.doi.org/10.4319/lo.1988.33.4part2.0867.

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Johnston, C. E., and J. C. Cheverie. "Comparative Analysis of lonoregulation in Rainbow Trout (Salmo gairdneri) of Different Sizes Following Rapid and Slow Salinity Adaptation." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 12 (December 1, 1985): 1994–2003. http://dx.doi.org/10.1139/f85-247.

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Plasma ionic values and gill (Na+,K+)-ATPase activity were compared for rainbow trout (Salmo gairdneri) of three different fork lengths (< 11, 11–15, and > 15 cm) following transference (1) from freshwater directly into seawater of 28–29‰ (DTT), (2) from freshwater directly into an estuarine environment at Fortune Bay where salinity fluctuated primarily between 17 and 29‰ (DTF), (3) from freshwater into a salinity that slowly increased to 28‰ in 22 d (SAT), and (4) from freshwater into freshwater (FC). Trout of all sizes displayed better growth, lower mortality, and better ionoregulatory capacity as judged by plasma Na+, K+, and Cl− concentrations and (Na+,K+)-ATPase activity in sea cages in Fortune Bay (DTF). The poorest ionoregulatory capacity and growth was in the direct transfer from freshwater to salinity of 28–29‰ (DTT). Failure of small trout to adapt to constantly high salinity of 28–29‰ was due to a slower development of (Na+,K+)-ATPase activity, excessively high plasma Na+ and Cl− concentrations, hemoconcentration, and tissue dehydration. Except for trout severely stressed by high salinity, growth in seawater was more favorable than in freshwater. Prince Edward Island estuaries are very favorable as adaptation and rearing areas for small and large rainbow trout.

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Marinês, Garcia, and Talgatti Dávia Marciana. "The DiatomAnorthoneis dulcisHein from Southern Brazil: Morphology and Ecology." Research Letters in Ecology 2008 (2008): 1–5. http://dx.doi.org/10.1155/2008/140245.

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A new geographic locality forAnorthoneis dulcisis reported. The paper describes the distribution and relative abundance ofA. dulcisin Lagoa dos Patos lagoon (a lagoon in Rio Grande do Sul state, Brazil) from samples collected between 2004 and 2005, and shows that this rare species is present all year round. This study extends the species distribution to South America indicating that the species can thrive on sand grains in lentic estuarine, and freshwater areas. It widens the range of tolerance to environmental parameters. The valve fine structure, morphology, and dimensions are in agreement with the original diagnosis.

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martin, r. aidan. "conservation of freshwater and euryhaline elasmobranchs: a review." Journal of the Marine Biological Association of the United Kingdom 85, no. 5 (October 2005): 1049–73. http://dx.doi.org/10.1017/s0025315405012105.

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published data on the diversity, life history, ecology, and status of freshwater and euryhaline elasmobranchs was reviewed in the context of anthropogenic threats and principles of conservation biology. at least 171 species of elasmobranch, representing 68 genera and 34 families, are recorded from fresh or estuarine waters. of these, over half are marginal in estuaries, less than one-tenth are euryhaline, and one-fifth are obligate in fresh water. obligate freshwater elasmobranchs are dominated by myliobatoid stingrays, of which two-thirds are potamotrygonids endemic to atlantic drainages of south america. freshwater and euryhaline elasmobranchs adhere to strongly k-selected life histories and feed at high trophic levels, similar to those of their marine relatives. however, freshwater and euryhaline elasmobranchs are also subject to habitat constraints, notably more limited volume and physicochemical variability than the ocean, that may render them more vulnerable than marine elasmobranchs to the effects of human activities. the greatest diversity and abundance of freshwater and euryhaline elasmobranchs occur in tropical countries with enormous and rapidly increasing human populations, notably south america, west africa, and south-east asia. knowledge of the biology, distribution, ecology, and status of freshwater and euryhaline elasmobranchs is frustrated by unresolved taxonomic problems, which are briefly summarized. to clarify selected issues in the conservation of freshwater and euryhaline elasmobranchs, special attention is given to sharks of the genus glyphis, pristids, and potamotrygonids. to foster live release when possible as well as prevent discard of specimens and loss of data, an illustrated key to differentiate carcharhinus from glyphis sharks is provided. obligate freshwater elasmobranchs with limited geographic ranges are deemed most vulnerable to extinction, but euryhaline elasmobranchs that require access to the sea to breed are also at significant risk. based on the foregoing data and principles of conservation biology, suggested action plans for the conservation of freshwater and euryhaline elasmobranchs and the conservation of freshwater habitats are provided.

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McCulloch, Malcolm, Mike Cappo, James Aumend, and Wolfgang Müller. "Tracing the life history of individual barramundi using laser ablation MC-ICP-MS Sr-isotopic and Sr/Ba ratios in otoliths." Marine and Freshwater Research 56, no. 5 (2005): 637. http://dx.doi.org/10.1071/mf04184.

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Otoliths preserve a continuous geochemical record of its life history, from the earliest natal stage through to adulthood. Using in situ laser ablation (UV) multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) measurements of Sr isotopic compositions together with elemental abundances (Ca, Sr, Ba and Mg), we show how it is possible to characterise the various types of habitats encountered throughout the lifecycle history of individual barramundi. Unlike trace element concentrations, which can be modulated by physiological processes, Sr isotopic compositions of otoliths provide a direct fingerprint of the water mass in which the fish lived. Elemental abundances, in particular Sr/Ba ratios are, however, shown to be especially sensitive to transitional environments, such as estuaries. The flexibility of the barramundi’s life history is confirmed by the present study, with the existence of both marine and freshwater nurseries, with some individuals spending their entire life cycle in fresh water, some entirely in marine and others moving between freshwater estuarine and marine habitats.

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Zapata, Martha J., and S. Mažeika P. Sullivan. "Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary." Marine and Freshwater Research 70, no. 4 (2019): 541. http://dx.doi.org/10.1071/mf18130.

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Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

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Zapata, Martha J., and S. Mažeika P. Sullivan. "Corrigendum to: Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary." Marine and Freshwater Research 70, no. 4 (2019): 609. http://dx.doi.org/10.1071/mf18130_co.

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Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

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Wuertz, S., C. E. Miller, R. M. Pfister, and J. J. Cooney. "Tributyltin-resistant bacteria from estuarine and freshwater sediments." Applied and Environmental Microbiology 57, no. 10 (1991): 2783–89. http://dx.doi.org/10.1128/aem.57.10.2783-2789.1991.

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Levings, C. D., N. A. Hvidsten, and B. Ø. Johnsen. "Feeding of Atlantic salmon (Salmo salar L.) postsmolts in a fjord in central Norway." Canadian Journal of Zoology 72, no. 5 (May 1, 1994): 834–39. http://dx.doi.org/10.1139/z94-113.

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The feeding habits of postsmolt Atlantic salmon (Salmo salar) caught by two-boat trawling were studied in Trondheimsfjord in central Norway. Fish caught in the inner fjord near the estuaries of the Orkla and Gaula rivers had recently fed on food produced in freshwater and estuarine habitats, namely stonefly and mayfly nymphs and gammarid amphipods. Stomach contents of postsmolts caught farther seaward were dominated by adult insects, with smaller proportions of the food volume originating from marine pelagic (larval fish, hyperiid amphipods, calanoid copepods) and nearshore (gammarid amphipods) habitats.

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Starratt, Scott W. "Diatoms in Estuaries and Tidal Marshes." Paleontological Society Papers 13 (October 2007): 85–109. http://dx.doi.org/10.1017/s1089332600001479.

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Diatoms from estuarine and marsh sediments can be used to evaluate a number of geological processes. Information on salinity, elevation, and substrate derived from modern assemblages have been used to determine local and regional Holocene sea level history, identify seismic and tsunami events, and aid in the recognition of regional variations in precipitation. In order to apply diatoms to these questions, it is necessary to have a detailed knowledge of the ecology of marine, brackish, and freshwater taxa, as well as an understanding of the taphonomic processes that determine the final diatom assemblage. The potential for studies of pre-Holocene estuarine depositional systems is largely limited by the availability of study sites.

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27

Shapiro, Karen, John Largier, Jonna A. K. Mazet, William Bernt, John R. Ell, Ann C. Melli, and Patricia A. Conrad. "Surface Properties of Toxoplasma gondii Oocysts and Surrogate Microspheres." Applied and Environmental Microbiology 75, no. 4 (December 5, 2008): 1185–91. http://dx.doi.org/10.1128/aem.02109-08.

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ABSTRACT The physical properties that govern the waterborne transmission of Toxoplasma gondii oocysts from land to sea were evaluated and compared to the properties of carboxylated microspheres, which could serve as surrogates for T. gondii oocysts in transport and water treatment studies. The electrophoretic mobilities of T. gondii oocysts, lightly carboxylated Dragon Green microspheres, and heavily carboxylated Glacial Blue microspheres were determined in ultrapure water, artificial freshwater with and without dissolved organic carbon, artificial estuarine water, and artificial seawater. The surface wettabilities of oocysts and microspheres were determined using a water contact angle approach. Toxoplasma gondii oocysts and microspheres were negatively charged in freshwater solutions, but their charges were neutralized in estuarine water and seawater. Oocysts, Glacial Blue microspheres, and unwashed Dragon Green microspheres had low contact angles, indicating that they were hydrophilic; however, once washed, Dragon Green microspheres became markedly hydrophobic. The hydrophilic nature and negative charge of T. gondii oocysts in freshwater could facilitate widespread contamination of waterways. The loss of charge observed in saline waters may lead to flocculation and subsequent accumulation of T. gondii oocysts in locations where freshwater and marine water mix, indicating a high risk of exposure for humans and wildlife in estuarine habitats with this zoonotic pathogen. While microspheres did not have surface properties identical to those of T. gondii, similar properties shared between each microsphere type and oocysts suggest that their joint application in transport and fate studies could provide a range of transport potentials in which oocysts are likely to behave.

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28

Hu, Yuhai, Tao Jiang, Hongbo Liu, Xiubao Chen, and Jian Yang. "Otolith Microchemistry Reveals Life History and Habitat Use of Coilia nasus from the Dayang River of China." Fishes 7, no. 6 (October 26, 2022): 306. http://dx.doi.org/10.3390/fishes7060306.

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The estuarine tapertail anchovy Coilia nasus is distributed throughout the Dayang River. However, the life history and habitat use of this fish remain unknown. Here, the microchemistry patterns of Sr and Ca in 23 otoliths collected from the lower reaches of the Dayang River were analyzed using an X-ray electron probe microanalyzer. The anchovies were divided into two patterns: (1) with low Sr/Ca ratios (<3.0) and a single bluish Sr concentration map, indicating that it only experienced a freshwater habitat during its whole life, and (2) with Sr/Ca ratios fluctuating between low and high (>3.0) phases and Sr concentration maps showing various colors, including blue, green, yellow, and red, from the core to the edge of otoliths, whose larvae hatched in freshwater and spent their first winter in brackish or sea waters. The juveniles then stayed in estuarine water areas for further growth and feeding until sexual maturity, when the mature adults returned to the spawning grounds in the river. The co-existence of freshwater residents and anadromous C. nasus in the Dayang River has been studied for the first time, and its possible spawning ground was discovered. These findings provide essential information to effectively protect this species and guide its rational, sustainable utilization.

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LAGARE, NICKEL JEAN S., EMMARIE F. MAPI-OT, ZILJIH S. MOLINA, JEMATEO B. NERI, OLGA M. NUÑEZA, and JOSE CHRISTOPHER E. MENDOZA. "On a collection of freshwater and estuarine crabs (Crustacea: Brachyura) from Mindanao Island, the Philippines." Zootaxa 4868, no. 3 (October 28, 2020): 301–30. http://dx.doi.org/10.11646/zootaxa.4868.3.1.

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The brachyuran fauna of the large southern Philippine island of Mindanao is poorly known, with only a few freshwater and estuarine crab species described or recorded in the last 30 years. Renewed interest in crab biodiversity has led to recent, small-scale surveys (2016–2019) of freshwater and estuarine habitats in various localities in Mindanao, which have yielded a good diversity of brachyuran crabs. As a result, a total of 26 species of brachyuran crab, representing 6 families (Hymenosomatidae, Oziidae, Gecarcinidae, Sesarmidae, Varunidae, and Ocypodidae), are reported here. Of these, 15 species are new records for the main island of Mindanao, 6 of which are also new records for the Philippines. Remarks on the taxonomy, distribution, and natural history of these species are also provided.

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30

Archetti, Renata, and Maurizio Luca Mancini. "Freshwater discharge by estuarine transition flow near cesenatico (Italy)." Journal of Coastal Research 65 (January 2, 2013): 13–18. http://dx.doi.org/10.2112/si65-003.1.

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31

Anderson, Laura. "Darold P. Batzer and Rebecca R. Sharitz (eds): Ecology of freshwater and Estuarine Wetlands." Biological Invasions 9, no. 8 (February 2, 2007): 1009–10. http://dx.doi.org/10.1007/s10530-007-9093-1.

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32

Buzzelli, Christopher, Brian Boutin, Mayra Ashton, Barbara Welch, Patricia Gorman, Yongshan Wan, and Peter Doering. "Fine-Scale Detection of Estuarine Water Quality with Managed Freshwater Releases." Estuaries and Coasts 37, no. 5 (December 13, 2013): 1134–44. http://dx.doi.org/10.1007/s12237-013-9751-8.

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33

Neilson, John D., Glen H. Geen, and Daniel Bottom. "Estuarine Growth of Juvenile Chinook Salmon (Oncorhynchus tshawytscha) as Inferred from Otolith Microstructure." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 5 (May 1, 1985): 899–908. http://dx.doi.org/10.1139/f85-114.

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The growth of juvenile chinook salmon (Oncorhynchus tshawytscha) in the Sixes River Estuary, Oregon, was inferred from otolith microstructure. Otolith increments appeared to be formed daily, on average, and a transition between those produced during freshwater residence and estuary residence was apparent. Otolith microstructure was also examined with respect to time series of water temperature, population density, and benthic standing crop data. While the results supported the hypothesis of food-limited growth, elevated water temperatures in midsummer may have decreased food conversion efficiencies, thus also contributing to an observed growth rate decline. It was also found that from counts of otolith increments formed during freshwater life, fish that hatched relatively late tended to spend less time in freshwater before moving downstream to the estuary.

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34

Crump, Byron C., Charles S. Hopkinson, Mitchell L. Sogin, and John E. Hobbie. "Microbial Biogeography along an Estuarine Salinity Gradient: Combined Influences of Bacterial Growth and Residence Time." Applied and Environmental Microbiology 70, no. 3 (March 2004): 1494–505. http://dx.doi.org/10.1128/aem.70.3.1494-1505.2004.

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ABSTRACT Shifts in bacterioplankton community composition along the salinity gradient of the Parker River estuary and Plum Island Sound, in northeastern Massachusetts, were related to residence time and bacterial community doubling time in spring, summer, and fall seasons. Bacterial community composition was characterized with denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA. Average community doubling time was calculated from bacterial production ([14C]leucine incorporation) and bacterial abundance (direct counts). Freshwater and marine populations advected into the estuary represented a large fraction of the bacterioplankton community in all seasons. However, a unique estuarine community formed at intermediate salinities in summer and fall, when average doubling time was much shorter than water residence time, but not in spring, when doubling time was similar to residence time. Sequencing of DNA in DGGE bands demonstrated that most bands represented single phylotypes and that matching bands from different samples represented identical phylotypes. Most river and coastal ocean bacterioplankton were members of common freshwater and marine phylogenetic clusters within the phyla Proteobacteria, Bacteroidetes, and Actinobacteria. Estuarine bacterioplankton also belonged to these phyla but were related to clones and isolates from several different environments, including marine water columns, freshwater sediments, and soil.

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35

Taplin, L. E., G. C. Grigg, L. A. Beard, and T. Pulsford. "Osmoregulatory mechanisms of the Australian freshwater crocodile, Crocodylus johnstoni , in freshwater and estuarine habitats." Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology 169, no. 3 (April 22, 1999): 215–23. http://dx.doi.org/10.1007/s003600050214.

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36

Elsdon, Travis S., and Bronwyn M. Gillanders. "Alternative life-history patterns of estuarine fish: barium in otoliths elucidates freshwater residency." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 5 (May 1, 2005): 1143–52. http://dx.doi.org/10.1139/f05-029.

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Elemental concentrations in fish otoliths (earstones) can reconstruct environmental histories of fish if predictable relationships between the environment and elemental incorporation are established. We assessed whether fresh water occupancy of black bream (Acanthopagrus butcheri) can be inferred from otolith barium concentrations (Ba was standardized to calcium (Ca) and expressed as a ratio, Ba:Ca). Otolith Ba:Ca of fish was correlated with ambient Ba:Ca. Using the natural relationships of increasing ambient and otolith Ba:Ca with decreasing salinity, fish from fresh- and salt-water environments were distinguishable. Fish caught in fresh water had approximately double the otolith Ba:Ca of those from salt-water estuaries, for both summer and winter collections. Fish with otolith Ba:Ca ≤5 µmol·mol1 were classified as resident in salt water, and those with ≥6 µmol·mol1 as resident in fresh water. Transects of Ba:Ca across fish otoliths classified fish to fresh- or salt-water environments. Fish were identified as having migratory patterns typical of residents, migrants with irregular patterns of diadromy, or migrants with cyclic patterns of anadromomy. Multiple migratory behaviours occurred in fish from the same estuary, indicating far more complex migratory behaviours than were previously known. The application of otolith Ba:Ca to infer freshwater occupancy of fish has rarely been studied, yet may provide more accurate classifications of estuarine environments than strontium (Sr) isotopes and otolith Sr:Ca.

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37

Gell, Peter A. "Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin." Pacific Conservation Biology 26, no. 2 (2020): 130. http://dx.doi.org/10.1071/pc18085.

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The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site’s listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.

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38

Gell, Peter A. "Corrigendum to: Watching the tide roll away – contested interpretations of the nature of the Lower Lakes of the Murray Darling Basin." Pacific Conservation Biology 26, no. 2 (2020): 211. http://dx.doi.org/10.1071/pc18085_co.

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The Murray Darling Basin Plan (Murray Darling Basin Authority 2012) represents the largest investment by government in an Australian environmental management challenge and remains highly conflicted owing to the contested allocation of diminishing water resources. Central to the decision to reallocate consumptive water to environmental purposes in this Plan was the case made to maintain the freshwater character of two lakes at the terminus of the Murray Darling Basin, in South Australia. This freshwater state was identified as the natural condition on the basis of selected anecdotal evidence and was enshrined in the site's listing under the Ramsar Convention. The commitment to the freshwater state was challenged under drought when sea water was seen as a means of averting acidification when low river flows risked the exposure of sulfidic sediments. Independent evidence from water quality indicators (diatoms) preserved in lake sediment records, however, attested to an estuarine, albeit variable, condition before the commissioning of near-mouth barrages in 1940. This interpretation for a naturally estuarine history, published after peer review, was overlooked in a report to the South Australian government, which argued, without the provision of new evidence from the lakes, that they were fresh for their entire history. This revised interpretation is widely cited in the scientific literature, government reports and online discussion and underpins a watering strategy aimed at a freshwater future for the Lower Lakes. The allocation of large volumes of fresh water to achieve this condition presents significant difficulties owing to the highly contested nature of water use across the Basin.

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39

Cox, T. J. S., T. Maris, K. Soetaert, D. J. Conley, S. Van Damme, P. Meire, J. J. Middelburg, M. Vos, and E. Struyf. "From heterotrophy to autotrophy: a freshwater estuarine ecosystem recovering from hypereutrophication." Biogeosciences Discussions 6, no. 3 (June 3, 2009): 5431–59. http://dx.doi.org/10.5194/bgd-6-5431-2009.

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Abstract. Increased organic matter and nutrient loads have induced major changes in aquatic systems, including hypoxia and algal blooms. In enclosed ecosystems these changes were often not gradual due to non-linear mechanisms. Here we report a 40 year record of eutrophication and hypoxia on an estuarine ecosystem and its recovery from hypereutrophication. We observe a paradoxical increase in chlorophyll a concentrations with decreasing nutrient inputs, and we hypothesise that algal growth was inhibited due to hypereutrophication, either by elevated ammonium concentrations, severe hypoxia or the production of harmful substances in such a reduced environment. We study the dynamics of a simple but realistic mathematical model, incorporating the assumption of algal growth inhibition. It shows an autotrophic equilibrium with low ammonia inputs, and a heterotrophic equilibrium with high ammonia inputs. At intermediate ammonia inputs it displays two alternative stable states. We conclude that the recovery of hypereutrophic riverine/estuarine systems can exhibit threshold-like behaviour.

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40

Wildish, D. J. "Ecology and natural history of aquatic Talitroidea." Canadian Journal of Zoology 66, no. 11 (November 1, 1988): 2340–59. http://dx.doi.org/10.1139/z88-349.

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A review of the ecology of amphipods belonging to the superfamily Talitroidea (Crustacea, Amphipoda) is presented. Species of Talitroidea are characteristically able to hop by rapid flicks of the urosome. They include land hoppers, which are true land-inhabiting forms excluded from detailed consideration in this review, as well as aquatic Talitroidea. Aquatic Talitroidea are found throughout much of the world in freshwater, estuarine, and marine conditions in littoral and infralittoral habitats, and an ecological habitat classification is presented. Subjects discussed include taxonomy, life history, dispersal, and the ecological factors affecting the survival of shore hoppers. The synecological role of shore hoppers in the aquatic ecosystem, e.g., in mineralizing primary production, is relatively minor although it may be locally important. The evolutionary ecology of land hopper origins from ancestors resembling shore hoppers is discussed, in the absence of direct evidence, based on likely colonization routes suggested by the distribution of contemporary talitroids.

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41

Wang, Gongpei, Qindong Tang, Zhi Chen, Dingli Guo, Lei Zhou, Han Lai, and Guifeng Li. "Otolith Microchemistry and Demographic History Provide New Insight into the Migratory Behavior and Heterogeneous Genetic Divergence of Coilia grayii in the Pearl River." Fishes 7, no. 1 (January 17, 2022): 23. http://dx.doi.org/10.3390/fishes7010023.

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Coilia grayii is the anadromous form of anchovy that is distributed in the East and South China Seas. It is a common fish species in the estuarine area of the Pearl River. Nevertheless, freshwater populations appear upstream in the Pearl River, but the migratory pathway has been mostly impeded by dam construction. Behavioral differences and constrained habitat within tributaries are suspected of promoting genetic divergence in these populations. In this study, we investigated the migratory behavior and genetic divergence of six populations of C. grayii fragmented by dams based on the otolith strontium/calcium (Sr/Ca) ratio, mitochondrial DNA, and microsatellite genotyping. All populations were in freshwater with low Sr/Ca ratios, except the estuarine population (Humen population) hatched in brackish water. Reduced nucleotide diversity corresponding to distance was observed. Populations from distant hydrological regions exhibited a decline in genetic diversity and a significant difference with the remaining populations after fitting the isolation by distance model. Pairwise fixation indices confirmed these results and moderate and significant differentiation was found between Hengxian site and downstream sites. Furthermore, STRUCTURE analyses revealed that all separated populations exhibited an admixed phylogenetic pattern except for individuals from the Hengxian locality. The upstream sites showed significantly increased resistance to gene flow from the estuarine population because of isolation by the dam. The results of the neutrality test and Bayesian skyline plots demonstrated complex demography—individuals’ experienced historical expansion and partial upper-dam populations had recently undergone a colonization, forming a new genetic structure. Accordingly, this study demonstrates differences in the migration pattern and genetic differentiation of C. grayii as a consequence of demographic history and current processes (habitat fragmentation and colonization).

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42

Joesoef, Andrew, David L. Kirchman, Christopher K. Sommerfield, and Wei-Jun Cai. "Seasonal variability of the inorganic carbon system in a large coastal plain estuary." Biogeosciences 14, no. 21 (November 8, 2017): 4949–63. http://dx.doi.org/10.5194/bg-14-4949-2017.

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Abstract. Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3− concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11) during high discharge and low (0.94) during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2), most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3−) inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2 × 109 mol C yr−1 and 16.5 ± 10.6 × 109 mol C yr−1, respectively, while net DIC production within the estuary including inputs from intertidal marshes is estimated to be 5.1 × 109 mol C yr−1. The small difference between riverine input and export flux suggests that, in the case of the Delaware Estuary and perhaps other large coastal systems with long freshwater residence times, the majority of the DIC produced in the estuary by biological processes is exchanged with the atmosphere rather than exported to the sea.

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43

Wellsbury, Peter, Rodney A. Herbert, and R. John Parkes. "Bacterial activity and production in near-surface estuarine and freshwater sediments." FEMS Microbiology Ecology 19, no. 3 (March 1996): 203–14. http://dx.doi.org/10.1111/j.1574-6941.1996.tb00213.x.

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44

Martinez-Macchiavello, J. C., A. Tatur, S. Servant-Vildary, and R. Del Valle. "Holocene environmental change in a marine-estuarine-lacustrine sediment sequence, King George Island, South Shetland Islands." Antarctic Science 8, no. 4 (December 1996): 313–22. http://dx.doi.org/10.1017/s095410209600048x.

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Sedimentological features and cluster analysis of diatom assemblages were used to investigate a local Holocene prograding sequence of marine-estuarine-lacustrine sediments. It consists of upward finning and thinning sediment cycles formed at the mouth of a meltwater stream during regional isostatic uplift, which followed early Holocene deglaciation and marine inundation events. The sequence begins in the lower Holocene sublittoral sand (marine diatoms and abundant molluscs) overlying, with a transgressive base, the deltic (?) clastic sediment marking probably one of the pre-Holocene interglacial periods (index diatom Actinocyclus ingens suggests an age >0.62 Ma). The lower Holocene marine sand was truncated by middle Holocene gravity flows, bearing volcanic ash. They were deposited in a high energy estuarine environment (brackish diatoms). The beach subsequently formed separated the estuary from the sea and changed it into a freshwater lake. Accumulation of moss and gyttja, containing a freshwater diatom assemblage, marks the final late Holocene stage of this coastal sedimentary sequence, which can be considered as typical for deglaciation periods in the maritime Antarctic.

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45

Coutant, Charles C., and C. H. Chen. "Strontium Microstructure in Scales of Freshwater and Estuarine Striped Bass (Morone saxatilis) Detected by Laser Ablation Mass Spectrometry." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 6 (June 1, 1993): 1318–23. http://dx.doi.org/10.1139/f93-149.

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A laser ablation microprobe with mass spectrometry was used to examine the variability of Sr concentration among and within scales of striped bass (Morone saxatilis). These exploratory studies demonstrated that the technique is capable of showing differences that we relate to environmental conditions. There were marked differences in scale Sr concentrations at high spatial resolution between striped bass from freshwater reservoirs in Tennessee (low Sr) and the Roanoke River – Albemarle Sound estuary system in North Carolina (high Sr). A peak in Sr concentration was found near the scale focus of striped bass collected in the freshwater Roanoke River (but not in scales from reservoir fish) that may identify saltwater parentage or estuarine rearing. In fish from the Roanoke River and Albemarle Sound, we observed spatial variations across annuli that might reflect movements between fresh and saline water. There was a typical Sr profile with depth through the estuarine scales that exhibited a peak of unresolved significance near the inside surface. Laser ablation mass spectrometry of Sr in fish scales appears to be a valuable technique for life history analyses.

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46

Mazumder, S. K., M. De, A. G. Mazlan, C. C. Zaidi, S. M. Rahim, and K. D. Simon. "Impact of global climate change on fish growth, digestion and physiological status: developing a hypothesis for cause and effect relationships." Journal of Water and Climate Change 6, no. 2 (October 8, 2014): 200–226. http://dx.doi.org/10.2166/wcc.2014.146.

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Global climate change is impacting and will continue to impact on marine and estuarine fish and fisheries. Data trends show climate change effects ranging from fish growth, digestion physiology and performance in marine and freshwater ecosystems. The present study was designed to develop a concept for a cause and effect understanding with respect to climate-induced temperature and salinity changes and to explain ecological findings based on physiological processes. The concept is based on a wide comparison of fish species. The preliminary conclusion can be drawn that warming will cause a shift of distribution limits for fish species with a change in growth performance, gastric evacuation performance and physiology, or even extinction of the species in the world. In association with the elevated seawater temperature growth performance will also be changed with water quality parameters, for example, salinity. Our interpretations of evidence include many uncertainties about the future of affected fish species. Therefore, it is essential to conduct research on the physiology and ecology of marine, estuarine and freshwater fishes, particularly in the tropics where comparatively little research has been conducted and where temperature fluctuation is comparatively lower. As a broader and deeper information base accumulates, researchers will be able to make more accurate predictions and forge relevant solutions.

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47

Vanalderweireldt, Lucie, Gesche Winkler, Marc Mingelbier, and Pascal Sirois. "Early growth, mortality, and partial migration of striped bass (Morone saxatilis) larvae and juveniles in the St. Lawrence estuary, Canada." ICES Journal of Marine Science 76, no. 7 (July 4, 2019): 2235–46. http://dx.doi.org/10.1093/icesjms/fsz116.

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Abstract After being extirpated from the St. Lawrence Estuary (SLE), striped bass (Morone saxatilis) were reintroduced in 2002, and by 2008 they were naturally reproducing. The increase of this reintroduced population prompted the need to document its nursery habitats utilization, which contribute to species recruitment. We analysed mortality-dispersion rates and the growth of larvae and juveniles in relation to their occurrence and migration patterns. From June to September 2014, we collected striped bass distributed in four estuarine habitats: the upstream freshwater section (UP), the oligohaline (O-ETM) and the mesohaline (M-ETM) estuarine turbidity maximum zone, and the downstream polyhaline section (DOWN). Based on otolith microstructure and microchemistry, 305 back-calculated growth and 36 migration trajectories have been reconstructed. The UP and the O-ETM provided optimal conditions wherein which larvae and juveniles exhibited fastest growth. In the SLE, we emphasized the co-existence of a freshwater resident contingent and two migrant contingents to the M-ETM and DOWN. We propose that migrants adopt an adaptive migration behaviour to avoid suboptimal conditions and strong intraspecific competition from resident in the upstream habitats. The potential advantage of a downstream migration later in the season might be an adaptative strategy to promote their survival during the early life stages.

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48

Meynecke, J. O. "Coastal habitat connectivity ? implications for declared fish habitat networks in Queensland, Australia." Pacific Conservation Biology 15, no. 2 (2009): 96. http://dx.doi.org/10.1071/pc090096.

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Estuaries are widely recognized as key habitats supporting nearshore secondary production and catch of commercial fisheries. In Queensland, some of these coastal marine habitats are protected by the declared fish habitat programme run by the Department of Primary Industries and Fisheries. Expected environmental changes for Australian estuarine systems include reduced freshwater flow, increased sedimentation and with them, a loss of connectivity. At present, the relationship between the protected declared fish habitat and habitat connectivity remains unknown. By comparing long term coastal fish catch data with geomorphic characteristics of coastal habitats structural connectivity was previously identified as a potential driver of commercial fish catch in Queensland. An ecology landscape approach was used for this study to identify potential fish habitat hotspots along the coastline of Queensland thus allowing better defined networks of declared fish habitats. A comparison between this approach and the current declared fish habitats demonstrated potential deficits and provided important insights for fisheries management. Declared fish habitats should be placed in coastal habitats with high structural connectivity to ensure sustainability of fisheries in light of environmental changes.

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Ryan, T. H., P. G. Rodhouse, C. M. Roden, and M. P. Hensey. "Zooplankton Fauna of Killary Harbour: the Seasonal Cycle of Abundance." Journal of the Marine Biological Association of the United Kingdom 66, no. 3 (August 1986): 731–48. http://dx.doi.org/10.1017/s0025315400042326.

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Killary Harbour is a fjord-like inlet on the west coast of Ireland and is an important site for suspended culture of mussels. As part of a study of the production ecology of the inlet, the zooplankton fauna was sampled quantitatively at two week intervals, between February 1981 and January 1982 using nets with mesh apertures of 90 and 335 μm. The dominant holozooplankton species of Killary Harbour are typical of inshore or neritic waters but there are also representatives of estuarine and oceanic faunas. Inflow of water into the bay below the surface layer of low salinity apparently maintains conditions suitable for neritic species and accounts for similarities between the zooplankton faunas inside and outside the bay. Large populations of estuarine species presumably do not develop because of the variability of freshwater discharge. During September 1981 there was evidence of an intrusion of oceanic water into the bay.

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Andres, Michael J., Jeremy M. Higgs, Paul O. Grammer, and Mark S. Peterson. "Argulus from the Pascagoula River, MS, USA, with an Emphasis on Those of the Threatened Gulf Sturgeon, Acipenser oxyrinchus desotoi." Diversity 11, no. 12 (December 5, 2019): 232. http://dx.doi.org/10.3390/d11120232.

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Abstract:

Species of Argulus (Branchiura Thorell, 1864) are common ectoparasites of freshwater, estuarine, and marine fishes. Argulid identification and taxonomy is often confusing because many species are reported to parasitize multiple host species, have similar morphological characters, and come from various salinity regimes. Gulf sturgeon is an anadromous fish natal to drainages in the north-central Gulf of Mexico, and as with many endangered species, has a poorly documented parasite community. During Gulf sturgeon tagging and monitoring studies (2016–2019) in the Pascagoula River, MS, USA, species of Argulus were collected from Gulf sturgeon as well as other incidentally captured fishes. Argulus flavescens Wilson, 1916 was found on Gulf sturgeon and flathead catfish, Argulus americanus Wilson, 1902 on bowfin, and Argulus bicolor Bere, 1936 on Atlantic stingray. We provide morphological details and measurements for these species as well as the first confirmed 28S rDNA molecular data. Argulus flavescens was more abundant and prevalent on larger Gulf sturgeon and on sturgeon captured in freshwater rather than estuarine habitats. Our results indicate that A. flacescens may not tolerate estuarine salinities and that the anadromous life-history pattern of Gulf sturgeon could help rid them of A. flavescens when they emigrate from their riverine habitats.

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Journal articles on the topic 'Estuarine and freshwater ecology'

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