Journal articles on the topic 'Lake Sunrise'
To see the other types of publications on this topic, follow the link: Lake Sunrise.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 32 journal articles for your research on the topic 'Lake Sunrise.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Korovessis, Panagiotis. "Sunrise at Pamvotida Lake (Ioannina, Greece)." Spine 40, no. 1 (January 2015): i. http://dx.doi.org/10.1097/01.brs.0000459538.40114.fa.
Full text
2
Li, Zhijun, Qingkai Wang, Mingguang Tang, Peng Lu, Guoyu Li, Matti Leppäranta, Jussi Huotari, Lauri Arvola, and Lijuan Shi. "Diurnal Cycle Model of Lake Ice Surface Albedo: A Case Study of Wuliangsuhai Lake." Remote Sensing 13, no. 16 (August 23, 2021): 3334. http://dx.doi.org/10.3390/rs13163334.
Full textAbstract:
Ice surface albedo is an important factor in various optical remote sensing technologies used to determine the distribution of snow or melt water on the ice, and to judge the formation or melting of lake ice in winter, especially in cold and arid areas. In this study, field measurements were conducted at Wuliangsuhai Lake, a typical lake in the semi-arid cold area of China, to investigate the diurnal variation of the ice surface albedo. Observations showed that the diurnal variations of the ice surface albedo exhibit bimodal characteristics with peaks occurring after sunrise and before sunset. The curve of ice surface albedo with time is affected by weather conditions. The first peak occurs later on cloudy days compared with sunny days, whereas the second peak appears earlier on cloudy days. Four probability density distribution functions—Laplace, Gauss, Gumbel, and Cauchy—were combined linearly to model the daily variation of the lake ice albedo on a sunny day. The simulations of diurnal variation in the albedo during the period from sunrise to sunset with a solar altitude angle higher than 5° indicate that the Laplace combination is the optimal statistical model. The Laplace combination can not only describe the bimodal characteristic of the diurnal albedo cycle when the solar altitude angle is higher than 5°, but also reflect the U-shaped distribution of the diurnal albedo as the solar altitude angle exceeds 15°. The scale of the model is about half the length of the day, and the position of the two peaks is closely related to the moment of sunrise, which reflects the asymmetry of the two peaks of the ice surface albedo. This study provides a basis for the development of parameterization schemes of diurnal variation of lake ice albedo in semi-arid cold regions.
3
Guo, Yinglian, Jisong Sun, Guirong Xu, Zhiming Zhou, and Jizhu Wang. "Influence of Underlying Surface on Distribution of Hourly Heavy Rainfall over the Middle Yangtze River Valley." Advances in Meteorology 2022 (December 21, 2022): 1–14. http://dx.doi.org/10.1155/2022/9696174.
Full textAbstract:
The variation of boundary layer circulation caused by the influence of complex underlying surface is one of the reasons why it is difficult to forecast hourly heavy rainfall (HHR) in the middle Yangtze River Valley (YRV). Based on the statistics of high-resolution observation data, it is found that the low resolution data underestimate the frequency of HHR in the mountain that are between the twain-lake basins in the middle YRV (TLB-YRV). The HHR frequency of mountainous area in the TLB-YRV is much higher than that of Dongting Lake on its left and is equivalent to the HHR frequency of Poyang Lake on its right. The hourly reanalysis data of ERA5 were used to study the variation of boundary layer circulation when HHR occurred. It can be found that the boundary layer circulation corresponding to different underlying surfaces changed under the influence of the weather system. Firstly, the strengthening of the weather system in the early morning resulted in the strengthening of the southwest low-level air flow, which intensified the uplift of the windward slope air flow on the west and south slopes of the mountainous areas in the TLB-YRV. As a result, the sunrise HHR gradually increases from the foot of the mountain. The high-frequency HHR period of sunrise occurs when the supergeostrophic effect is weakened, the low-level vorticity and frontal forcing are strengthened, and the water vapor flux convergence begins to weaken. Secondly, the high-frequency HHR period of the sunset is caused by stronger local uplift and more unstable atmospheric stratification, but the enhanced local uplift is caused by the coupling of the terrain forcing of the underlying surface and the enhanced northern subgeostrophic flow, which causes the HHR to start closer to the mountain top at sunset than at sunrise.
4
Amyot, Marc, David RS Lean, Laurier Poissant, and Marie-Renée Doyon. "Distribution and transformation of elemental mercury in the St. Lawrence River and Lake Ontario." Canadian Journal of Fisheries and Aquatic Sciences 57, S1 (March 14, 2000): 155–63. http://dx.doi.org/10.1139/f99-248.
Full textAbstract:
Elemental Hg (Hg0) is a volatile species that is responsible for water-to-air transfer of Hg in Lake Ontario and the St. Lawrence River. We conducted two cruises in 1998 to identify spatial and temporal patterns in Hg0 levels in these systems and performed field and laboratory experiments on redox transformations of Hg. Elemental Hg concentrations were higher in Lake Ontario than in the St. Lawrence River. At stations in Lake Ontario, Hg0 levels were higher at the bottom of the water column than at the surface, whereas they were homogeneous throughout the water column of the river. Elemental Hg concentrations were generally higher in July than in September and, in contrast with experiments on inland lakes, were relatively constant during the day except for a narrow peak at sunrise. Field and laboratory experiments showed that photoreduction of Hg(II) in St. Lawrence River water was substrate limited and was influenced by visible and ultraviolet radiation. Pseudo first-order kinetics best described photoreduction, with k values between 1 and 2·h-1.
5
Levy, I., P. A. Makar, D. Sills, J. Zhang, K. L. Hayden, C. Mihele, J. Narayan, M. D. Moran, S. Sjostedt, and J. Brook. "Unraveling the complex local-scale flows influencing ozone patterns in the southern Great Lakes of North America." Atmospheric Chemistry and Physics Discussions 10, no. 8 (August 23, 2010): 19763–810. http://dx.doi.org/10.5194/acpd-10-19763-2010.
Full textAbstract:
Abstract. This study examines the complexity of various processes influencing summertime ozone levels in the southern Great Lakes region of North America. Results from the Border Air Quality and Meteorology (BAQS-Met) field campaign in the summer of 2007 are examined with respect to land-lake differences and local meteorology using a large array of ground-based measurements, aircraft data and simulation results from a high resolution (2.5 km) regional air-quality model, AURAMS. Analyses of average ozone mixing ratio from the entire BAQS-Met intensive campaign period support previous findings that ozone levels are higher over the southern Great Lakes than over the adjacent land. However, there is great heterogeneity in the spatial distribution of surface ozone over the lakes, particularly over Lake Erie during the day, with higher levels located over the southwestern end of the lake. Results suggest that some of these increased ozone levels are due to local emission sources in large nearby urban centers. The land-lake differences in ozone mixing ratios are most pronounced during the night in a shallow inversion layer of about 200 m above the surface. After sunrise, these differences have a limited effect on the total mass of ozone over the lakes during the day time, though they may cause elevated ozone levels in the lake breeze air. A large reservoir layer of ozone is predicted by the AURAMS model over Lake Erie at night, centered between 600–1000 m above ground and extending into the land over Cleveland. The model also predicts a vertical circulation during the day with an updraft over Detroit-Windsor and downdraft over Lake St. Clair, which transports ozone up to 1500 m above ground and results in high ozone over the lake. Oscillations in ground level ozone mixing ratios were observed on several nights and several ground monitoring sites, with amplitudes of up to 40 ppbv and time periods of 15–40 min.
6
Levy, I., P. A. Makar, D. Sills, J. Zhang, K. L. Hayden, C. Mihele, J. Narayan, M. D. Moran, S. Sjostedt, and J. Brook. "Unraveling the complex local-scale flows influencing ozone patterns in the southern Great Lakes of North America." Atmospheric Chemistry and Physics 10, no. 22 (November 22, 2010): 10895–915. http://dx.doi.org/10.5194/acp-10-10895-2010.
Full textAbstract:
Abstract. This study examines the complexity of various processes influencing summertime ozone levels in the southern Great Lakes region of North America. Results from the Border Air Quality and Meteorology (BAQS-Met) field campaign in the summer of 2007 are examined with respect to land-lake differences and local meteorology using a large array of ground-based measurements, aircraft data, and simulation results from a high resolution (2.5 km) regional air-quality model, AURAMS. Analyses of average ozone mixing ratio from the entire BAQS-Met intensive campaign period support previous findings that ozone levels are higher over the southern Great Lakes than over the adjacent land. However, there is great heterogeneity in the spatial distribution of surface ozone over the lakes, particularly over Lake Erie during the day, with higher levels located over the southwestern end of the lake. Model results suggest that some of these increased ozone levels are due to local emission sources in large nearby urban centers. While an ozone reservoir layer is predicted by the AURAMS model over Lake Erie at night, the land-lake differences in ozone mixing ratios are most pronounced during the night in a shallow inversion layer of about 200 m above the surface. After sunrise, these differences have a limited effect on the total mass of ozone over the lakes and land during the day, though they do cause elevated ozone levels in the lake-breeze air in some locations. The model also predicts a mean vertical circulation during the day with an updraft over Detroit-Windsor and downdraft over Lake St. Clair, which transports ozone up to 1500 m above ground and results in high ozone over the lake. Oscillations in ground-level ozone mixing ratios were observed on several nights and at several ground monitoring sites, with amplitudes of up to 40 ppbv and time periods of 15–40 min. Several possible mechanisms for these oscillations are discussed, but a complete understanding of their causes is not possible given current data and knowledge.
7
Ghan, David, J. D. McPhail, and K. D. Hyatt. "The temporal-spatial pattern of vertical migration by the freshwater copepod Skistodiaptomus oregonensis relative to predation risk." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 6 (June 1, 1998): 1350–63. http://dx.doi.org/10.1139/f98-027.
Full textAbstract:
Skistodiaptomus oregonensis vertical migration in Kennedy Lake and Paxton Lake may be an adaptation to avoid predation by threespine stickleback (Gasterosteus aculeatus). In Kennedy Lake, juvenile sockeye salmon (Oncorhynchus nerka) and the mysid Neomysis mercedis are also predators that potentially drive the vertical migration. A corollary of the hypothesis that predation selects for vertical migration is that the extent and timing of the vertical migration decreases predation risk. This corollary is tested for each of the potential predators. Laboratory experiments indicate that stickleback feeding rate decreases below 1.6 µE ·s-1 ·m-2. In Kennedy and Paxton lakes, S. oregonensis occupied depths below this light intensity during the day. Furthermore, as S. oregonensis ascended at dusk and descended at dawn, they remained within light intensities that reduced stickleback predation rate. In Kennedy Lake, hydroacoustic data coupled with information in the literature on feeding behaviour of juvenile sockeye indicate that this species move to surface waters to feed before sunrise and after sunset. Vertically migrating S. oregonensis are near the surface during the twilight feeding periods of juvenile sockeye. The timing of S. oregonensis vertical migration also does not reduce the time it is in contact with the predator N. mercedis.
8
Gussoni, Carlos Otávio A., and André C. Guaraldo. "Comportamento de forrageamento do pernilongo-de-costas-brancas, Himantopus melanurus (Vieillot, 1817) (Aves: Recurvirostridae) em Santa Gertrudes, SP, Brasil." Lundiana: International Journal of Biodiversity 7, no. 2 (June 28, 2007): 149–50. http://dx.doi.org/10.35699/2675-5327.2006.23155.
Full textAbstract:
The foraging behavior of two White-backed stilts (Himantopus melanurus) was studied in a lake at the municipality of Santa Gertrudes, state of São Paulo, Brazil. The foraging strategies observed were classified in two categories: pluging (65.8% of total maneuvers) and pecking (34.3%). Only in 26.8% of the foraging maneuvers the individuals captured preys (72.9% by plunging and 27.1% by pecking). When comparing both strategies, plunging was successful 29.7% of the times, but pecking only 21.2%. At the study site, individuals foraged only up to 20 m away from the lake margin. The foraging area exploited by the White-backed stilts was estimated in about 720 m2. Foraging activities lasted since before sunrise until after sunset.
Keywords: White-backed stilt, foraging behavior, plunging, pecking.
9
Silsbe, Greg M., Ralph E. H. Smith, and Michael R. Twiss. "Quantum efficiency of phytoplankton photochemistry measured continuously across gradients of nutrients and biomass in Lake Erie (Canada and USA) is strongly regulated by light but not by nutrient deficiency." Canadian Journal of Fisheries and Aquatic Sciences 72, no. 5 (May 2015): 651–60. http://dx.doi.org/10.1139/cjfas-2014-0365.
Full textAbstract:
Unattended sensor networks are a cost-effective strategy to enhance the resolution of environmental datasets and are required to understand how large aquatic ecosystems respond to complex stressors (e.g., climate change). We made unattended and continuous measurements of the quantum yield of photosystem II ([Formula: see text]) photochemistry in the surface mixed layer of Lake Erie during three lake-wide cruises to observe how phytoplankton physiology varied across nutrient and taxonomic gradients. Three prominent diel [Formula: see text] patterns were noted. The diel maximum consistently occurred at sunrise or sunset, nocturnal measurements were consistently lower than diel maxima, and daytime values were strongly diminished by nonphotochemical quenching. The diurnal pattern was modeled as a function of irradiance to a mean accuracy of 0.03 to 0.04. Contrary to previously published reports in Lake Erie, [Formula: see text] was largely insensitive to indices of nutrient deficiency through space and time. This finding was consistent with much recent literature about [Formula: see text] and suggests that Lake Erie phytoplankton, like many others, can tune their photosynthetic machinery to maintain relatively high efficiency of photochemistry in photosystem II even when deficient in phosphorus or nitrogen.
10
Chrust, Morgan F., C. David Whiteman, and Sebastian W. Hoch. "Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah." Journal of Applied Meteorology and Climatology 52, no. 5 (May 2013): 1187–200. http://dx.doi.org/10.1175/jamc-d-12-0221.1.
Full textAbstract:
AbstractThermally driven valley-exit jets were investigated at Utah’s Weber Canyon, a main tributary of the Great Salt Lake basin. An intensive measurement campaign during July–September 2010 supplemented longer-term measurements to characterize the wind and temperature structure in the vicinity of the canyon exit. Exit jets at Weber Canyon are most frequent in late summer or early fall. Strong low-level-wind jets formed at the canyon exit on 75 of 90 nights (83%) during the measurement campaign, with the best-developed winds forming during synoptically undisturbed, clear-sky periods. Winds inside the canyon consisted of a weak down-valley flow layer that occupied most of the 1000-m depth of the canyon. The flow was observed to descend, thin, and accelerate at the valley exit, producing winds that were typically 2.5 times as strong but much more shallow than those inside the canyon. Maximum nighttime jet-axis wind speeds of 15–20 m s−1 are typically found about 80–120 m above the ground at the canyon exit on clear undisturbed nights in the late summer and fall. The jets form 1–3 h after sunset, approach a near-steady state during the late night, and continue until 5–6 h after sunrise, although slowly losing speed after sunrise. The jet is a local modification at the canyon exit of the thermally driven down-valley flow. Its continuation after sunrise is thought to be caused by the nighttime buildup and persistence of a cold-air pool in the Morgan Basin at the east end of the canyon. The potential for utilizing the exit jet for wind power generation is discussed.
11
Biegalski, S. R., S. Landsberger, and R. Hoff. "High bromine aerosol concentrations near Lake Huron from long-range transport from the Arctic during polar sunrise." Journal of Geophysical Research: Atmospheres 102, no. D19 (October 1, 1997): 23337–43. http://dx.doi.org/10.1029/97jd01648.
Full text
12
Nalewajko, C., B. Paul, K. Lee, and H. Shear. "Light History, Phosphorus Status, and the Occurrence of Light Stimulation or Inhibition of Phosphate Uptake in Lake Superior Phytoplankton and Bacteria." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 2 (February 1, 1986): 329–35. http://dx.doi.org/10.1139/f86-042.
Full textAbstract:
Phosphate uptake in Lake Superior was stimulated by light on 17 out of 34 occasions, inhibited on 10, and unaffected on 7. In a stepwise multiple regression model the variables explaining most of the variance in the light effect on phosphate uptake were, in decreasing order of importance, the light history as estimated by hours of sunshine in previous 3 d, phosphate turnover time, phytoplankton biovolume, and time of day. Stimulation was most common in spring at inshore stations, while inhibition occurred mainly in spring at offshore stations. We suggest that light-limited but phosphorus-sufficient phytoplankton show the former, but extremely low light adapted populations, the latter response. We discovered an apparent diurnal pattern in the response, with maximal stimulation by light during daylight hours and inhibition predominating at sunrise and sunset.
13
Glova, GJ, and PM Sagar. "Feeding in a Nocturnally active fish, Galaxias brevipinnis, in a New Zealand stream." Marine and Freshwater Research 40, no. 3 (1989): 231. http://dx.doi.org/10.1071/mf9890231.
Full textAbstract:
To determine the diel feeding periodicity and diet of a lake-inlet population of Galaxias brevipinnis in New Zealand, samples of benthos, drift and fish were collected over a 24-h period in summer. Both numerically and gravimetrically, fish stomach contents revealed that feeding started some time after sunset, peaked towards midnight, and virtually ceased after sunrise. Benthic invertebrates were consumed almost exclusively, with ephemeropterans, trichopterans, and dipterans constituting 95% of the total foods eaten, a major proportion being chironomid larvae. Size of prey eaten compared with size of invertebrates in the benthos differed significantly during the night; this indicated that some size-selective feeding occurred. The benthic feeding habit of Galaxias brevipinnis appears to allow it to forage on relatively small prey during the night, a phenomenon that has been reported for other bottom-dwelling native fish species in New Zealand.
14
Simpson, Joanne, G. Roff, B. R. Morton, K. Labas, G. Dietachmayer, M. McCumber, and R. Penc. "A Great Salt Lake Waterspout." Monthly Weather Review 119, no. 12 (December 1, 1991): 2741–70. http://dx.doi.org/10.1175/1520-0493-119-12-2740.1.
Full textAbstract:
Abstract A waterspout funnel and spray ring were observed under a cumulus line over the Great Salt Lake for about 5 min shortly after sunrise on 26 June 1985. Videotaped features strongly suggested that the funnel rotation was anticyclonic, These observations have been used as the basis for a study of the initiation and evolution of waterspouts through a series of numerical experiments at two scales, that of a cloud and a waterspout. The cloud scale has been simulated using an improved Goddard-Schlesinger model with nearby Salt Lake City soundings. The main model improvements have been 1) a parameterized, three-class ice phase and 2) a line initialization in addition to the more common axisymmetric buoyant bubble. Cloud-scale vortex pairs developed for each mode of initiation, but a much stronger, more upright, low-level anticyclonic vortex grew from the line initiation than from the bubble. However, cumulus-scale vortices are common while waterspouts are rare, and the real test of a model is whether a waterspout can develop in the limited cumulus lifetime. The 600-m horizontal grid of the cloud model cannot resolve waterspouts, and a modified Monash high-resolution axisymmetric vortex model with vertical domain and small section has been “embedded” at selected positions and initiated at selected times in the computed flow field of the cloud. Many experiments have been carried out with the vortex model. In the most important series, the boundary conditions were changed with the fields of the model cumulus as it evolved, and the time at which the vortex was started was varied through the lifetime of the parent cloud. Results showed that for each mode of cloud initiation, the vortex that started at the anticyclonic center grew faster than those started at other centers. This result fits with the observed anticyclonic rotation of the waterspout, strongly suggesting that the cloud vorticity was important in its initiation. The greatest azimuthal speed for the bubble-initiated cloud was 11 ms−1 when the vortex model was started at 28 min cloud time with time-varying boundary conditions, whereas it was 21 m s−1 when started at 12 min in the line-initiated cloud. Speeds were comparable when the inner domain moved with the anticyclonic cloud center. These speeds are close to the spray-ring threshold azimuthal velocity of roughly 22 m s−1 estimated by Golden from photographs. Together, these model results support the hypothesis that, at least in some circumstances, cloud processes alone can produce waterspouts in the absence of external vorticity sources such as surface convergence lines or other shear features.
15
Shadrin, Nickolai, Elena Anufriieva, Alexander Latushkin, Alexander Prazukin, and Vladimir Yakovenko. "Daily Rhythms and Oxygen Balance in the Hypersaline Lake Moynaki (Crimea)." Water 14, no. 22 (November 18, 2022): 3753. http://dx.doi.org/10.3390/w14223753.
Full textAbstract:
Field observations of the diurnal behavior of several parameters (oxygen concentration, chlorophyll fluorescence, photosynthetically active radiation (PAR), wind speed, temperature, suspended matter concentration, and zooplankton abundance) were conducted at three sites in the marine hypersaline lake Moynaki (Crimea). The diurnal course of PAR followed a bell-shaped form, with the maximum at 14:00 on the 15th and 16th of September 2021. The oxygen concentration varied over a wide range from 3.2 to 9.3 mg L−1, demonstrating a clear diurnal rhythm. From sunrise until about 17:30, it increased. Both the maximum and minimum values were marked on the site where there were Ruppia thickets. The daily rhythm of Chlorophyll a concentration was clearly expressed during the observation period, varying from 2.49 to 18.65 µg L−1. A gradual increase in the concentration of chlorophyll a began after 10:00 and lasted until about 2:30–3:00 of the next day. The daily production of oxygen during photosynthesis averaged 27.3 mgO L−1 day−1, and the highest values were noted at the windward site of 37.9 mgO L−1 day−1, and the lowest at the leeward site of 19 mgO L−1 day−1. The total respiration of the community per day was, on average, 15.9 mgO L−1 day−1. It averaged 63% of the primary production created. The contribution of animals to the total oxygen consumption of the community was small, averaging 5%.
16
Sand-Jensen, Kaj, Mikkel René Andersen, Kenneth Thorø Martinsen, Jens Borum, Emil Kristensen, and Theis Kragh. "Shallow plant-dominated lakes – extreme environmental variability, carbon cycling and ecological species challenges." Annals of Botany 124, no. 3 (June 12, 2019): 355–66. http://dx.doi.org/10.1093/aob/mcz084.
Full textAbstract:
Abstract Background Submerged plants composed of charophytes (green algae) and angiosperms develop dense vegetation in small, shallow lakes and in littoral zones of large lakes. Many small, oligotrophic plant species have declined due to drainage and fertilization of lakes, while some tall, eutrophic species have increased. Although plant distribution has been thoroughly studied, the physiochemical dynamics and biological challenges in plant-dominated lakes have been grossly understudied, even though they may offer the key to species persistence. Scope Small plant-dominated lakes function as natural field laboratories with eco-physiological processes in dense vegetation dictating extreme environmental variability, intensive photosynthesis and carbon cycling. Those processes can be quantified on a whole lake basis at high temporal resolution by continuously operating sensors for light, temperature, oxygen, etc. We explore this hitherto hidden world. Conclusions Dense plant canopies attenuate light and wind-driven turbulence and generate separation between warm surface water and colder bottom waters. Daytime vertical stratification becomes particularly strong in dense charophyte vegetation, but stratification is a common feature in small, shallow lakes also without plants. Surface cooling at night induces mixing of the water column. Daytime stratification in plant stands may induce hypoxia or anoxia in dark bottom waters by respiration, while surface waters develop oxygen supersaturation by photosynthesis. Intensive photosynthesis and calcification in shallow charophyte lakes depletes dissolved inorganic carbon (DIC) in surface waters, whereas DIC is replenished by respiration and carbonate dissolution in bottom waters and returned to surface waters before sunrise. Extreme diel changes in temperature, DIC and oxygen in dense vegetation can induce extensive rhythmicity of photosynthesis and respiration and become a severe challenge to the survival of organisms. Large phosphorus pools are bound in plant tissue and carbonate precipitates. Future studies should test the importance of this phosphorus sink for ecosystem processes and competition between phytoplankton and plants.
17
Naud, Marc, and Pierre Magnan. "Diel onshore–offshore migrations in northern redbelly dace, Phoxinus eos (Cope), in relation to prey distribution in a small oligotrophic lake." Canadian Journal of Zoology 66, no. 6 (June 1, 1988): 1249–53. http://dx.doi.org/10.1139/z88-182.
Full textAbstract:
Northern redbelly dace, Phoxinus eos (Cope), exhibit diel onshore–offshore migrations in a small oligotrophic Quebec lake. The fish swim in shoals in the littoral zone during the day, migrate to the pelagic zone at sunset, where the shoals break up into single fish, and then go back to the littoral zone at sunrise. Dace eat mainly two cladocerans, Daphnia and Holopedium. Zooplankton sampling indicated that Daphnia were significantly more abundant in the pelagic zone than in the littoral zone, and Holopedium were rarely found in the littoral zone. Dace showed a significant preference for a dense cover habitat over a sparse cover habitat in the littoral zone during the day. Our results support the hypothesis that dace migrate to the pelagic zone at sunset to increase their feeding efficiency on zooplankton. The foraging benefits of remaining in the offshore zone may be offset by increased risk of predation by brook charr, Salvelinus fontinalis (Mitchill), during the daylight hours, thus resulting in diel onshore–offshore migrations.
18
Henderson-Pekarik, Keelin, Richard Hedley, Justin Johnson, Jeremiah Kennedy, and Erin Bayne. "Passive Acoustic Monitoring of Gunshot Activity in Cooking Lake-Blackfoot Provincial Recreation Area." Alberta Academic Review 2, no. 2 (September 10, 2019): 35–36. http://dx.doi.org/10.29173/aar44.
Full textAbstract:
In the past, monitoring hunting behavior has been limited to self-reported numbers. However, the ability of autonomous recording units to monitor soundscapes may make them suitable for assessing spatio-temporal shooting patterns. Our goal for this project was to find out if it is possible to use acoustic monitoring to track human activity, and if there were differences in seasonal or daily shooting intensities. We hypothesized that shooting intensity would decrease from September to November and from the afternoon till morning due to people being less likely to go shooting in cooler temperatures. A grid of 91 ARU’s were deployed between September 2nd and November 30th, 2018 in Cooking Lake-Blackfoot Provincial Recreation Area. They were set to record continuously between sunrise and sunset with some recording during the night as well. We selected a random subset of 30 minute recordings, visualized them using spectrograms; visual representations of sound with time on the x-axis and frequency on the y-axis, and counted the gunshots in each. We compared differences in gunshot detections between months and different times of day using analysis of variance (ANOVA). There were no statistical differences found in seasonal or daily shooting intensities. One reason for this may be that sample sizes were low, due to the time needed to manually process recordings. We demonstrated that ARU’s can be used to provide us with an accurate way of assessing shooting patterns and therefore, be useful for monitoring other human behaviors such as detecting poachers, or assessing compliance with hunting laws.
19
Wu, Shanshan, Haibo Zou, and Junjie Wu. "The Diurnal Variations of GPS PWV near Poyang Lake in China during Midsummer." Advances in Meteorology 2020 (July 21, 2020): 1–11. http://dx.doi.org/10.1155/2020/6241507.
Full textAbstract:
With the 1 h-averaged data of atmospheric precipitable water vapor (PWV) for 2015–2018 retrieved from 18 ground-based Global Positioning System (GPS) observation stations near Poyang Lake (PL), China, the diurnal variations of the PWV during midsummer (July-August) are studied by the harmonic method. Results show that significant diurnal variations of PWV are found at the 18 GPS stations. The harmonics with 24 h cycle (diurnal cycle) over PL (i.e., Duchang and Poyang) and Nanchang city only have about 50% (or even smaller than 50%) of variance contribution with the amplitude of about 0.2 mm, while above 70% (or even 80%) of variance contribution occurs elsewhere around PL, with the amplitude of about 0.9 mm. The harmonics with diurnal cycles in most stations peak from afternoon to evening (i.e., 1200-2000 LST), but one exception is Duchang site, where the diurnal cycle peaks in the morning (i.e., 1000 LST). Moreover, the harmonics with 12 h cycle (semidiurnal cycle) have the relatively uniform amplitude of about 0.2 mm, but their variance contributions show uneven distribution, with the contributions of about or above 50% in PL and Nanchang city (the semidiurnal cycles peak about 0000 LST or 1200 LST) and below 30% (or even 10%) in other areas. The preliminary diagnosis analysis shows that the diurnal variation of the low-level (below 850 hPa) air temperature (increasing after the sunrise, decreasing after the sunset, and peaking around 1400-1800 LST) may be responsible for the diurnal cycle. Moreover, in PL (Duchang and Poyang) and Nanchang city, the effects (heating or cooling) of lake and urban, the diurnal variation of the 10 m wind over PL, and the acceleration of PL on overlying air also contributed to the diurnal variation of PWV.
20
Bonter, David N., Therese M. Donovan, and Elizabeth W. Brooks. "Daily Mass Changes in Landbirds During Migration Stopover on the South Shore of Lake Ontario." Auk 124, no. 1 (January 1, 2007): 122–33. http://dx.doi.org/10.1093/auk/124.1.122.
Full textAbstract:
Abstract Assigning conservation priorities to areas used by birds during migration requires information on the relative quality of areas and habitats. The rate at which migratory birds replenish energy reserves during stopover may be used as an indicator of stopover-site quality. We estimated the rate of mass gain of 34 landbird species during stopover at a near-shore terrestrial site on the south shore of Lake Ontario in New York during 12 migration seasons from 1999 to 2004. The average rate of mass gain was estimated by relating a measure of condition to time of capture (hour after sunrise) with linear regression. Data from 25,385 captures were analyzed. Significantly positive rates of mass change were detected for 20 of 30 species during spring migration and 19 of 21 species during autumn migration. No significantly negative trends were detected in either season. Daily rates of mass gain across all species averaged 9.84% of average lean body weight during spring migration and 9.77% during autumn migration. Our regression estimates were significantly greater than estimates from traditional analyses that examine mass changes in recaptured birds. Analyses of mass changes in recaptured birds revealed a mean daily change of −0.68% of average lean mass in spring and 0.13% in autumn. Because of sampling biases inherent in recapture analyses, the regression approach is likely more accurate when the assumptions of the method are met. Similar studies in various habitats, landscapes, and regions are required to prioritize conservation efforts targeting migratory stages of the annual cycle. Cambios de Peso Diarios de Aves Terrestres durante las Paradas Migratorias en la Costa sur del Lago Ontario
21
Zhong, Shiyuan, Hee-Jin In, Xindi Bian, Joseph Charney, Warren Heilman, and Brian Potter. "Evaluation of Real-Time High-Resolution MM5 Predictions over the Great Lakes Region." Weather and Forecasting 20, no. 1 (February 1, 2005): 63–81. http://dx.doi.org/10.1175/waf-834.1.
Full textAbstract:
Abstract Real-time high-resolution mesoscale predictions using the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) over the Great Lakes region are evaluated for the 2002/03 winter and 2003 summer seasons using surface and upper-air observations, with a focus on near-surface and boundary layer properties that are important for applications such as air quality and fire weather predictions. The summer season predictions produce a cold bias in maximum daily temperature and a warm bias in minimum temperature that together lead to a good prediction of daily mean temperature but a smaller-than-observed diurnal temperature cycle. In winter, the predicted near-surface temperatures are lower both day and night, yielding good agreement with the observed amplitude of the diurnal temperature cycle but relatively large cold bias in daily mean temperature. The predicted temperatures in the boundary layer are also systematically lower than the observed temperatures in the two seasons. The cold bias is consistent with the wetter-than-observed lower atmosphere in the model prediction, which in turn can be attributed to an inadequate specification of soil moisture. In both seasons, the model produced substantially more precipitation in all categories, especially in the heavy precipitation category, and the overprediction is primarily associated with more widespread area coverage in the model prediction. The chances of producing a false precipitation forecast are substantially higher than missing an observed precipitation event. Small systematic errors are found in the predictions of low-level winds, but above the boundary layer, the predicted winds are predominantly from the west, while the observed winds are from the west-northwest. The model is able to capture the general development and evolution of the lake–land breezes in areas surrounding Lake Michigan during summer, although errors exist in the strengths of the breezes and the timing of their transition. Predicted early morning inversions are slightly stronger than observed in winter and weaker than observed in summer. The weak summer morning inversion results in a rapid inversion breakup followed by an earlier growth of a mixed layer after sunrise. Despite the head start, the predicted mixed-layer heights in late afternoon are lower than those observed, suggesting that either the predicted surface sensible heat flux may be too low or the boundary layer flux divergence may be too high. Decreasing horizontal grid spacing from 12 to 4 km results in little improvement in the predictions of near-surface and boundary layer properties except for precipitation, for which the model bias is significantly reduced by the increase in horizontal resolution. The cold and wet biases and errors in inversion strengths and mixed-layer development call for extra caution when using products from mesoscale forecasts in applications such as air pollution and fire weather prediction.
22
Boudala, Faisal S., Di Wu, George A. Isaac, and Ismail Gultepe. "Seasonal and Microphysical Characteristics of Fog at a Northern Airport in Alberta, Canada." Remote Sensing 14, no. 19 (September 29, 2022): 4865. http://dx.doi.org/10.3390/rs14194865.
Full textAbstract:
Reduction in visibility (Vis) due to fog is one of the deadliest severe weather hazards affecting aviation and public transportation. Nowcasting/forecasting of Vis reduction due to fog using current models is still problematic, with most using some type of empirical parameterization. To improve the models, further observational studies to better understand fog microphysics and seasonal variability are required. To help achieve these goals, the seasonal and microphysical characteristics of different fog types at Cold Lake airport (CYOD), Alberta, Canada were analyzed using hourly and sub-hourly METAR data. Microphysical and meteorological measurements obtained using the DMT Fog Monitor FM-120 and the Vaisala PWD22 were examined. The results showed that radiation fog (RF) dominates at CYOD in summer while precipitation, advection and cloud-base-lowering fogs mostly occur in fall and winter. All fog types usually form at night or early morning and dissipate after sunrise. The observed dense fog events (Vis < 400 m) were mainly caused by RF. The observed mean fog particle spectra () for different fog types and temperatures showed bimodal n(D) (with two modes near 4 μm and 17–25 μm; the maximum total number concentration () was 100 cm−3 and 20 cm−3, respectively, corresponding to each mode). Parameterizations of Vis as a function of liquid water content () and were developed using both the observed Vis and calculated Vis based on . It was found that the observed Vis was higher than the calculated Vis for warm fog with > 0.1 gm−3 and most of the mass was contributed by the large drops. Based on the observed Vis, the relative error of the visibility parameterization as a function of both and (32%) was slightly lower than that (34%) using alone for warm fogs.
23
Short, J., and J. Hone. "Calibrating Aerial Surveys of Kangaroos by Comparison With Drive Counts." Wildlife Research 15, no. 3 (1988): 277. http://dx.doi.org/10.1071/wr9880277.
Full textAbstract:
Densities of red and western grey kangaroos and euros were assessed by aerial survey and compared with densities obtained in the same area by drive counts. The survey area (12.1 km2) was long, narrow and sparsely vegetated. Lakes and a kangaroo-proof fence bounded the area on three sides facilitating the drive count. Densities from aerial surveys ranged between 38 and 54% of the corresponding drive counts for red kangaroos, between 15 and 23% for western grey kangaroos, and between 9 and 10% for euros. The time of morning at which the surveys were conducted altered these percentages. About twice as many red and western grey kangaroos were counted on aerial surveys at sunrise compared to surveys 3.5 h later.
24
Ringelberg, J. "Changes in Light Intensity and Diel Vertical Migration: a Comparison of Marine and Freshwater Environments." Journal of the Marine Biological Association of the United Kingdom 75, no. 1 (February 1995): 15–25. http://dx.doi.org/10.1017/s0025315400015162.
Full textAbstract:
Proximate aspects of diel vertical migration in the freshwater and marine environment are compared using data from the literature. Examples of migrations in both environments are presented, from which it is concluded that relative changes in light intensity before sunrise and after sunset are primary causes of migrations. Experiments have shown that photoreactive behaviour is enhanced in the presence of predators but inhibited by shortage of food. These factors are called secondary causal factors. A hierarchy of causal factors is proposed. In lakes fish exudates suffice but in marine biotopes like bays, it is possible that fish have to be actually present for enhancement to take effect. To what extent the presented stimulus-response mechanism holds for mesopelagic animals in oceans is discussed on the basis of vertical distributions of euphausiids.
25
Nishijima, Kate A., Marisa M. Wall, Maureen M. Fitch, Lionel S. Sugiyama, Ronald C. Keith, and Wayne T. Nishijima. "Evaluating Hawaii-grown Papaya for Resistance to Internal Yellowing Disease Caused by Enterobacter cloacae." HortScience 45, no. 9 (September 2010): 1357–64. http://dx.doi.org/10.21273/hortsci.45.9.1357.
Full textAbstract:
Papaya (Carica papaya L.) cultivars and breeding lines were evaluated for resistance to Enterobacter cloacae (Jordan) Hormaeche & Edwards, the bacterial causal agent of internal yellowing disease (IY), using a range of concentrations of the bacterium. Linear regression analysis was performed and IY incidence was positively correlated with increasing inoculum concentrations for susceptible cultivars Kapoho Solo and Laie Gold but not for resistant cultivars or lines. It was determined that the inoculum concentration of 9 to 10 Log10 colony-forming units per milliliter (cfu/mL) was able to reliably differentiate resistant and susceptible papaya germplasm. Red-fleshed cultivars SunUp and Sunrise were the most resistant papaya groups evaluated at this dose concentration. Yellow-fleshed cultivars, Kapoho Solo and Laie Gold, were susceptible to E. cloacae. ‘Rainbow’, an F1 hybrid between ‘SunUp’ and ‘Kapoho Solo’ that is yellow-fleshed, was moderately resistant to E. cloacae, exhibiting limited symptoms of the disease. Yellow-fleshed I-Rb F5/F6, an advanced inbred line derived from ‘Rainbow’, is resistant and offers the potential of improving resistance of yellow-fleshed commercial cultivars. A colorimeter was used to objectively measure internal flesh color and distinguish between infected and non-infected tissue in red- and yellow-fleshed papayas using L*C*H* color space analysis. Symptomatic tissue (72.4 and 79.0°) had higher hue angle means than non-symptomatic tissue (62.8 and 75.0°) for all cultivars or lines in red- and yellow-fleshed papayas, respectively. Yellow (“Y”) hue color also distinguished infected tissue from non-infected tissue. Symptomatic tissue that had Y hue color resulted in 79 to 81° hue angle means among red- or yellow-fleshed papayas. Our results demonstrated the usefulness of colorimetry to help detect infected papaya tissue. In surveys of naturally infected papaya, high populations (8.57 × 107 cfu/g) of E. cloacae were recovered in infected fruit of ‘Kapoho Solo’ and represent a food safety concern for fresh and processed papaya. In isolations from inoculated fruits, we observed decreases of ≈1 to 2 Log10 cfu/g in final bacterial populations when high-dose range inoculum concentrations (9 to 12 Log10 cfu/mL) were used. This dose range may represent a saturation range for E. cloacae inoculation.
26
Dole, John M., Zenaida Viloria, Frankie L. Fanelli, and William Fonteno. "Postharvest Evaluation of Cut Dahlia, Linaria, Lupine, Poppy, Rudbeckia, Trachelium, and Zinnia." HortTechnology 19, no. 3 (January 2009): 593–600. http://dx.doi.org/10.21273/hortsci.19.3.593.
Full textAbstract:
Vase life of ‘Karma Thalia’ dahlia (Dahlia ×hybrida), ‘Lace Violet’ linaria (Linaria maroccana), ‘Sunrise’ lupine (Lupinus hartwegii ssp. cruickshankii), ‘Temptress’ poppy (Papaver nudicaule), ‘Indian Summer’ rudbeckia (Rudbeckia ×hybrida), ‘Jemmy Royal Purple’ trachelium (Trachelium caeruleum), and ‘Benary's Giant Scarlet’ and ‘Sun Gold’ zinnias (Zinnia elegans) was determined after being subjected to postharvest handling procedures. Cut dahlia, lupine, poppy, rudbeckia, trachelium, and ‘Sun Gold’ and ‘Benary's Giant Scarlet’ zinnia flowers could be held in unamended tap or deionized (DI) water with no effect on vase life. Vase life of linaria was longest when placed in DI water with 8-hydroxyquinoline citrate and a solution pH of 3.5. A vase solution of 2% sucrose without foam extended consumer vase lives for linaria, trachelium, and ‘Benary's Giant Scarlet’ zinnia. Floral foam or 2% or 4% sucrose had no effect on the consumer vase life of dahlia, lupine, rudbeckia, and poppy. Trachelium and rudbeckia did not tolerate a 20% sucrose treatment for 24 h, whereas linaria and ‘Benary's Giant Scarlet’ zinnia had a longer vase life with a 10% sucrose pulse than a water-only pulse. For trachelium, the longest (17.5 days) consumer vase life occurred when the Chrysal Professional 2 Processing solution (CP2) was used after pretreatment with DI water. Either of two commercial holding solutions, CP2 or Floralife Professional (FLP), similarly extended the vase life of linaria. The use of FLP or CP2 improved consumer vase life of dahlia, lupine, and poppy compared with DI water. Dahlia, trachelium, and zinnia flowers could not be cold stored at 2 °C. Lupine and poppy could be stored at 2 °C wet or dry for 2 weeks. Linaria and rudbeckia could be cold stored for 3 weeks. Lupine and trachelium were susceptible to 1 μL·L−1 exogenous ethylene, which induced floret abscission in lupine and stopped floret opening in trachelium. 1-Methylcyclopropene and silver thiosulfate similarly suppressed the ethylene effect. Cut linaria, zinnia, dahlia, rudbeckia, and poppy flowers were unaffected by exogenous ethylene.
27
"Sunrise Over Lake Tahoe." Spine 29, no. 15 (August 2004): i. http://dx.doi.org/10.1097/00007632-200408010-00001.
Full text
28
"“Sunrise over Lake Morey”." SPINE 45, no. 2 (January 2020): i. http://dx.doi.org/10.1097/01.brs.0000651452.00193.8b.
Full text
29
Austin-Fafard, Shelby Brandon, Michelle DeWolfe, Camille Partin, and Bernadette Knox. "Detailed mapping and lithogeochemistry of Neoarchean volcanic rocks: Beaulieu volcanic belt, Slave Craton, NWT." USURJ: University of Saskatchewan Undergraduate Research Journal 6, no. 1 (March 4, 2020). http://dx.doi.org/10.32396/usurj.v6i1.509.
Full textAbstract:
Neoarchean volcanic rocks of the Beaulieu River volcanic belt structurally overlie basement rocks of the Sleepy Dragon Complex (ca. 2.85 Ga), approximately 100 km east northeast of Yellowknife. The volcanic belt is comprised of complex lithofacies, including basalt, andesite, rhyolite, and associated volcaniclastic rocks, and hosts the Sunrise volcanogenic massive sulfide deposit. The absolute age of the volcanic strata is not known, nor is the stratigraphy well-defined; therefore, the Beaulieu River volcanic belt cannot be easily correlated to other greenstone belts within the Slave craton. The main objective of this study is to document the litho- and chemo-stratigraphy of the volcanic rocks, and particularly the rhyolite dome, located at the south end of Sunset Lake to reconstruct their volcanic and petrogenetic evolution, and determine their relationship to the volcanic strata that hosts the Sunrise VMS deposit, located ~6km to the north of the study area. Detailed mapping (1:2000) was completed over two field seasons (2018 and 2019) and shows that the volcanic rocks in the south Sunset Lake area comprise a complex stratigraphy consisting of basaltic, andesitic and rhyolitic lithofacies. This includes massive to pillow basalt and andesite, with lesser amounts of massive to in-situ brecciated, weakly quartz-plagioclase porphyritic rhyolite, heterolithic tuff to lapilli- tuff and felsic tuff to tuff breccia. The felsic clasts within the felsic volcaniclastic rocks are similar in composition to the coherent rhyolite. Units have a trace element geochemical signatures that vary from tholeiitic to calc-alkaline, arc-like rocks. Volumetrically, the volcanic strata in the south Sunset Lake area has a significant amount of volcaniclastic rocks, ranging from tuff to tuff breccia units. The volcaniclastic rocks are interpreted to have been deposited by a series of debris flows and eruption-fed density currents. The stratigraphy of the volcanic rocks in south Sunset Lake is very similar to that of the stratigraphy that hosts the Sunrise VMS deposit. Evidence of a vent proximal environment (e.g. rhyolite dome, peperite, syn-volcanic intrusions) and porous, volcanic debris accumulating on the seafloor highlight conditions favourable for volcanogenic massive sulfide-type mineralization in the south Sunset Lake area.
30
Yamini and SR Singara Subramanian. "A Study on the Peripheral Atmosphere Supporting Lotus Flower of India’s Backwater- Kerala." AYUSHDHARA, July 8, 2022, 9–13. http://dx.doi.org/10.47070/ayushdhara.v9i3.956.
Full textAbstract:
Lotus flowers from Kerala’s Vembanad Lake have been extracted from specific core water locations along with water samples and has been analysed in order to develop dried Lotus Tea as in Bags with name as “Indian Pankaj” that will help in health-related issues as being a natural treatment for disorders like insomnia, high cholesterol, diabetes, anxiety, stress etc., being a part of daily routine. It is found that the water supporting these lotus petals from Vembanad lake is having traces of calcium, magnesium, chloride, sulphate, silicate, sodium, bicarbonate and potassium in good content, rich in antioxidants along with essential nutrients to support white blood cells, the fluid mechanism, the immune transporter which ensures that the atmosphere of lake is full of essential minerals in order to support this lotus tea from Kerala, Backwaters. Too, because of the Vitamin D enrichment making these water lilies exceptional as they used to bloom in the first half of morning and used to shut down slowly when approaching to evening i.e., it functions according to the sunrise with sunlight. Observed the same when brought to room temperature for testing and trials. Pictures are enclosed in the paper. As we know that sunlight in its own is a therapy for so many diseases. Drinking Vitamin D enriched water is eligible to remove deficiencies of bones and blood via purification. Therefore, in this study, it is suggested to drink this beverage containing lotus extracts that will be able to develop a strong metabolism against certain infections and disorders in order to maintain a healthy medicine free living. Lastly, but not at least, would like to add up via saying- Let food be your first medicine and kitchen be your pharmacy. That’s the power of Lotus Petals.
31
Pamula, Hanna, Agnieszka Pocha, and Maciej Klaczynski. "Towards the Acoustic Monitoring of Birds Migrating at Night." Biodiversity Information Science and Standards 3 (June 18, 2019). http://dx.doi.org/10.3897/biss.3.36589.
Full textAbstract:
Every year billions of birds migrate between their breeding and wintering areas. As birds are an important indicator in nature conservation, migratory bird studies have been conducted for many decades, mostly by bird-ringing programmes and direct observation. However, most birds migrate at night, and therefore much information about their migration is lost. Novel methods have been developed to overcome this difficulty; including thermal imaging, radar, geolocation techniques, and acoustic recognition of bird calls. Many bird species are detected by their characteristic sounds. This method of identification occurs more often than by direct observation, and therefore recordings are widely used in avian research. The commonly used approach is to record the birds automatically, and to manually study the bird sounds in the recordings afterwards (Furnas and Callas 2015, Frommolt 2017). However, the tagging of recordings is a tedious and time-consuming process that requires expert knowledge, and, as a result, automatic detection of flight calls is in high demand. The first experiments towards this used energy thresholds or template matching (Bardeli et al. 2010, Towsey et al. 2012), and later on the machine and deep learning methods were applied (Stowell et al. 2018). Nevertheless, not many studies have focused specifically on night flight calls (Salamon et al. 2016, Lostanlen et al. 2018). Such acoustic monitoring could complement daytime avian research, especially when the field recording station is close to the bird-ringing station, as it is in our project. In this study, we present the initial results of a long-term bird audio monitoring project using automatic methods for bird detection. Passive acoustic recorders were deployed at a narrow spit between a lake and the Baltic sea in Dąbkowice, West Pomeranian Voivodeship, Poland . We recorded bird calls nightly from sunset till sunrise during the passerine autumn migration for 3 seasons. As a result, we collected over 3000 hours of recordings each season. We annotated a subset of over 50 hours, from different nights with various weather conditions. As avian flight calls are sporadic and short, we created a balanced set for training - recordings were divided into partially overlapping 500-ms clips, and we retained all clips containing calls and created about the same number of clips without bird sounds. Different signal representations were then examined (e.g. mel-spectrograms and multitaper). Afterwards, various convolutional neural networks were checked and their performance was compared using the area under the receiver operating characteristic curve (AUC) measure. Moreover, an initial attempt was made to take advantage of the transfer learning from image classification models. The results obtained by the deep learning methods are promising (AUC exceeding 80%), but higher bird detection accuracy is still needed. For a chosen bird species – Song thrush (Turdus philomelos) – we observed a correlation between calls recorded at night and birds caught in the nets during the day. This fact, as well as the promising results from the detection of calls from long-term recordings, indicate that acoustic monitoring of nocturnal birds has great potential and could be used to supplement the research of the phenomenon of seasonal bird migration.
32
Hayes, Michael C., Mary L. Moser, Brian J. Burke, Aaron D. Jackson, and Nicholas S. Johnson. "Behavior of Female Adult Pacific Lamprey Exposed to Natural and Synthesized Odors." Journal of Fish and Wildlife Management, January 28, 2022. http://dx.doi.org/10.3996/jfwm-21-014.
Full textAbstract:
Abstract Conservation and management of Pacific Lamprey Entosphenus tridentatus and other imperiled lamprey species could include the use of chemosensory cues to attract or repel migrating adults. For restoration programs, using cues to help guide lamprey through fishway entrances might improve passage of adult lamprey at dams. In contrast, odors might repel unwanted invasive Sea Lamprey Petromyzon marinus in the Laurentian Great Lakes from spawning habitats or improve trapping efficiency. We conducted bioassays with Pacific Lamprey in a two-choice maze to evaluate the behavioral response of preovulatory adult females to introduced chemical cues and changes in flow. During overnight tests, for each female we measured the number of entries into each arm of the maze and the amount of time spent in each arm after application of natural odors from prespawning conspecifics (males and females) in one of the arms. Using the same methods, we also tested whether adult females were attracted to natural odor from spermiating males, to a synthesized (artificially produced) component of a Sea Lamprey sex pheromone (3-keto petromyzonol sulfate), or to an attraction flow (12 L/min as reference). In all tests, the lamprey showed consistent nocturnal activity, typically moving from sunset until sunrise and remaining inactive during daylight hours. For natural odors, the number of entries and the amount of time females spent in the treatment arm were not significantly different between control and treatment periods. However, females spent significantly less time in the treatment arm with the synthesized 3-keto petromyzonol sulfate than when we delivered no odor. Females showed strong, positive responses to the attraction flow and with our assay, we could identify significant behavioral responses when the differences between the control and experimental means were greater than 15–20%. The response of lampreys to sex pheromones may be species-specific, with Pacific Lamprey less likely to respond to conspecific odors than Sea Lamprey.