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1
Binder, Thomas R., Stephen C. Riley, Christopher M. Holbrook, et al. "Spawning site fidelity of wild and hatchery lake trout (Salvelinus namaycush) in northern Lake Huron." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 1 (2016): 18–34. http://dx.doi.org/10.1139/cjfas-2015-0175.
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Fidelity to high-quality spawning sites helps ensure that adults repeatedly spawn at sites that maximize reproductive success. Fidelity is also an important behavioural characteristic to consider when hatchery-reared individuals are stocked for species restoration, because artificial rearing environments may interfere with cues that guide appropriate spawning site selection. Acoustic telemetry was used in conjunction with Cormack–Jolly–Seber capture–recapture models to compare degree of spawning site fidelity of wild and hatchery-reared lake trout (Salvelinus namaycush) in northern Lake Huron. Annual survival was estimated to be between 77% and 81% and did not differ among wild and hatchery males and females. Site fidelity estimates were high in both wild and hatchery-reared lake trout (ranging from 0.78 to 0.94, depending on group and time filter), but were slightly lower in hatchery-reared fish than in wild fish. The ecological implication of the small difference in site fidelity between wild and hatchery-reared lake trout is unclear, but similarities in estimates suggest that many hatchery-reared fish use similar spawning sites to wild fish and that most return to those sites annually for spawning.
2
Willis, Theodore V., and John J. Magnuson. "Patterns in fish species composition across the interface between streams and lakes." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 5 (2000): 1042–52. http://dx.doi.org/10.1139/f00-028.
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We compared fish species compositions among four site types (lake, lake mouth, stream mouth, stream) along the gradient from stream to lake for 12 tributary mouths. Comparison of species richness, rarefaction species diversity, and species density all supported the same pattern: stream-mouth sites contained the highest number of species, followed by stream sites, lake-mouth sites, and lake sites, even though lake and lake-mouth sites yielded more individuals and were larger in area and volume. Principal components analysis formed three clusters of mixed sites based on similarities in dominant fish species rather than designations of lake, lake mouth, etc. Rank order assemblage tests revealed that species composition of tributary-mouth sites was similar in only one quarter of the systems sampled; other systems showed a transition from "lake" to "stream" species compositions at or near the tributary mouth. Species assemblage comparisons within site types between systems revealed low consistency in the composition of stream-mouth sites and high consistency for the other site types. We concluded that the tributary mouth fits the definition of an ecotone and speculate that the difference in hydrologic and geomorphic properties of streams and lakes played a role in the patterns that we saw on either side of the tributary mouth.
3
Girard, Caroline, Julie C. Brodeur, and Alice Hontela. "Responsiveness of the interrenal tissue of yellow perch (Perca flavescens) from contaminated sites to an ACTH challenge test in vivo." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 2 (1998): 438–50. http://dx.doi.org/10.1139/f97-224.
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The effects of chronic toxic stress on the hypothalamo-pituitary-interrenal (HPI) axis were investigated in yellow perch (Perca flavescens) captured at a reference site (Lake Memphremagog) and two sites contaminated with heavy metals and organic contaminants (Ile Perrot and Iles de la Paix, Lake St. Louis) in spring, summer, and fall. Cortisol secretion of the fish was stimulated in situ by an acute capture stress or by an i.p. injection of 4 IU/100 g body mass of porcine corticotropin (ACTH1-39). The response to both these challenges was lower in perch from the highly contaminated site than in perch from the reference site in the spring but not in summer. In fall, fish from the highly contaminated site had, as in spring, a lower response to ACTH than fish from the reference site. The reduced ability of perch to respond to capture stress or to ACTH indicates that the interrenal tissue in fish from contaminated sites is functionally impaired. Cortisol-impaired fish also had abnormal carbohydrate metabolism. The reduced ability of wild fish from contaminated sites to respond to a standardized ACTH challenge may be used as an early indicator of contamination-induced chronic stress.
4
Ching, Hilda Lei. "Occurrence of the eyefluke, Diplostomum (Diplostomum) baeri bucculentum Dubois et Rausch, 1948, in salmonid fishes of northern British Columbia." Canadian Journal of Zoology 63, no. 2 (1985): 396–99. http://dx.doi.org/10.1139/z85-060.
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As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.
5
Watson, Breanna M., Carlo A. Biagi, Sara L. Northrup, et al. "Distinct diel and seasonal behaviours in rainbow trout detected by fine-scale acoustic telemetry in a lake environment." Canadian Journal of Fisheries and Aquatic Sciences 76, no. 8 (2019): 1432–45. http://dx.doi.org/10.1139/cjfas-2018-0293.
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The fine-scale behavioural activities of rainbow trout (Oncorhynchus mykiss) in nature are not well understood, but are of importance for identifying interactions with the ecosystem and of interest to conservationists and recreational anglers. We have undertaken a high-resolution acoustic telemetry study to identify the distinct movement patterns of 30 rainbow trout in a freshwater lake, specifically examining swim speed, area of movement, and site preference in both summer and winter. Activity levels were reduced in winter compared with summer across all fish, but ranking of individuals was consistent. In summer, 16/30 fish displayed diel movement, in which they travelled to a different area of the lake at dawn and returned at dusk, while other fish maintained their site preference regardless of the time of day or swam more randomly throughout the lake. These patterns were minimized in winter, where there was a reduction in cross-lake movement under ice and only 4/30 fish displayed diel movement. Winter conditions may limit the capability (physiological limitations) and (or) motivation (prey availability) for diel behaviours observed in summer.
6
Blanchfield, Paul J., Lori S. Tate, and Cheryl L. Podemski. "Survival and behaviour of rainbow trout (Oncorhynchus mykiss) released from an experimental aquaculture operationThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”." Canadian Journal of Fisheries and Aquatic Sciences 66, no. 11 (2009): 1976–88. http://dx.doi.org/10.1139/f09-127.
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The potential for farmed fish that have escaped from open-cage aquaculture operations to affect native populations will depend on their survival and behaviour in the wild. We used standard commercial practices to rear 10 tonnes of rainbow trout ( Oncorhynchus mykiss ) in a 23 ha lake at the Experimental Lakes Area (Ontario, Canada). Each fall (2003–2005), we released farmed rainbow trout (escapees) into the study lake and monitored their movements using automated positioning telemetry. Rainbow trout experienced high annual mortality (~50%), with none surviving beyond 3 years. Farmed fish had narrowly defined pelagic distributions that comprised the upper few metres of the water column, even when at the cage site. Although released rainbow trout dispersed throughout the study lake, most spent significant portions of time at the cage site, especially during normal operation when commercial feed was available. Core use areas (50% Kernel) included the farm for half of the released fish. Surviving rainbow trout showed continued reliance upon the cage site in their second year. However, wide dispersal, high growth rate, and lack of reliance on the cage site by some escaped fish warrant further research to assess potential effects of open-cage aquaculture in the water bodies where the industry occurs.
7
Trewin, Nigel H. "Palaeoecology and sedimentology of the Achanarras fish bed of the Middle Old Red Sandstone, Scotland." Transactions of the Royal Society of Edinburgh: Earth Sciences 77, no. 1 (1986): 21–46. http://dx.doi.org/10.1017/s0263593300010737.
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ABSTRACTThe Achanarras fish bed of Middle Devonian age in the Orcadian Basin was deposited in a large freshwater lake of variable productivity in which thermal stratification was normally developed. The fish bed consists of lacustrine laminites of organic, carbonate (dolomite and calcite) and clastic types. Carbonate laminae were precipitated as a result of photosynthetic activity and organic laminae were deposited following algal decay, clastic material was introduced by processes including overflow and interflow currents and wind transport.The fish bed represents a major lacustrine transgression during a wetter climatic period which provided connections to other lakes and by overflow to the sea. Calcitic laminites represent the deepest water (>60 m) phase with greatest faunal variety due to availability of migration routes and stability of environments caused by lake overflow.Initial lake transgression was characterised byDipteras-dominated faunas which reappear as the last surviving fish during lake regression. Further regression resulted in the introduction of turbidites to the laminites.Many fish were preserved following mass mortalities induced by algal blooms, mixing of waters by storms and lake overturn. Most of the fish inhabited shallow areas of the lake and drifted as rotting carcases to their final site of deposition. The fauna comprises a variety of benthonic and nektonic fish including predators, scavengers and omnivorous forms. Fish such asCoccosteusrepresented almost exclusively by adults may have bred outside the area of the lake.
8
Pietrock, Michael, and Olesya Hursky. "Fish and ecosystem health as determined by parasite communities of lake whitefish (Coregonus clupeaformis) from Saskatchewan boreal lakes." Water Quality Research Journal 46, no. 3 (2011): 219–29. http://dx.doi.org/10.2166/wqrjc.2011.004.
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In northern Canada, there is increasing concern about the potential negative impacts of industrial activities on wildlife and ecosystems. Therefore, a study was conducted on lake whitefish (Coregonus clupeaformis) from Montreal and Reindeer lakes, Saskatchewan, to assess fish health and condition, and ecosystem integrity of these northern lakes. In Montreal Lake, all fish were infected by ≥2 parasite species. The most prevalent parasite at this site was the larval trematode Ichthyocotylurus erraticus, which was detected in all fish examined. All Reindeer Lake whitefish were shown to harbour ≥1 parasite species. The most prevalent parasite (found in 87.9% of fish) at this locality was the larval trematode Diplostomum sp. Macroscopically visible pathogenic changes were not noted. Gross energy values of whitefish were 4.40 ± 0.88 MJ/kg and 5.14 ± 1.14 MJ/kg for Montreal Lake and Reindeer Lake, respectively, indicating that fish have sufficient energy stores to withstand stressful conditions. The parasite communities were species-rich and diverse, with Shannon diversity indices of 2.12 (Montreal Lake) and 2.02 (Reindeer Lake). The ratios of allogenic/autogenic as well as planktonic/benthic parasite species did not indicate atypical environmental conditions. Together the findings suggest that in both lakes there is currently no significant anthropogenic impact on the whitefish populations and ecosystem health.
9
Long, Kelsie, David Heslop, and Eelco J. Rohling. "Quantitative assessment of the oxygen isotope composition of fish otoliths from Lake Mungo, Australia." Quaternary Research 102 (February 1, 2021): 234–46. http://dx.doi.org/10.1017/qua.2020.121.
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AbstractThe Willandra Lakes region is a series of once interconnected and now-dry lake basins in the arid zone of southeastern Australia. It is a UNESCO World Heritage Site of cultural, archaeological, and geological significance, preserving records of Aboriginal occupation and environmental change stretching back to at least 50 ka. Linking the archaeology with the commensurate palaeoenvironmental information is complicated by the millennial time spans represented by the past hydrological record preserved in the sediment vs. the subdecadal evidence of each archaeological site. Oxygen isotope records across annual growth rings of fish otoliths (ear stones) can elucidate flooding and drying regimes on subannual scales. Otoliths from hearth sites (fireplaces) link lake hydrology with people eating fish on the lakeshore. Oxygen isotopic trends in hearth otoliths from the last glacial maximum (LGM) were previously interpreted in terms of high evaporation under dry conditions. However, this ignored hydrology-driven changes in water δ18O. Here, a mass balance model is constructed to test the effect lake desiccation has on water δ18O and how this compares with the LGM otolith records. Based on this modelling, we suggest that Lake Mungo otolith signatures are better explained by evaporation acting on full lakes rather than by lake drying.
10
Mercer, Margaret, Peter C. Searle, Roberto Cifuentes, Evelyn Habit, and Mark C. Belk. "Morphometric Response of Galaxias maculatus (Jenyns) to Lake Colonization in Chile." Diversity 12, no. 6 (2020): 219. http://dx.doi.org/10.3390/d12060219.
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Body and head shape in fish responds to environmental factors such as water flow rate, food sources, and niche availability. However, the way in which fish respond to these environmental factors varies. In Central Chile, multiple river and lake systems along the coast provide an ideal study site to investigate these types of shape changes. We use geometric morphometrics to characterize shape differences in Galaxias maculatus (Jenyns) between river and lake populations. Lake fish converge on a shape with a more fusiform body, narrower head, and larger eyes, while river fish have a more robust body, rounder head, and smaller eyes. These shape changes are consistent with a shift to zooplanktivorous foraging in lakes, as evidenced in other systems. Unlike some fish species that develop polymorphisms in body shape after colonization (e.g., benthic and limnetic forms), G. maculatus in lakes exhibit a monomorphic limnetic form.
11
Fry, Brian, Patricia L. Mumford, Franklin Tam, et al. "Trophic position and individual feeding histories of fish from Lake Okeechobee, Florida." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 4 (1999): 590–600. http://dx.doi.org/10.1139/f98-204.
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We used C and N stable isotope measurements to identify trophic position and feeding histories of fish from Lake Okeechobee, one of the largest lakes in North America. When δ15N values were used to estimate trophic levels, analyses of about 500 individual fish collected in two seasons at five sites showed that trophic level varied from 2 (herbivore) to 4.3 (second-level carnivore) among the 29 fish species examined. Lower trophic levels predominated among small fish caught at a littoral marsh site, and highest trophic levels were found among larger offshore fish. Marsh fish showed about three times the C isotope variation than did offshore fish, consistent with the wider array of foods in the marsh versus offshore food web. In addition to these community-level results, there were often unexpected large isotopic differences between individuals in almost all fish species examined, suggesting large differences in individual feeding behavior. Isotopic analyses indicate long-term differences in feeding among individuals, in addition to the short-term differences often observed in stomach content studies. Long-term individual variation in fish foraging may be important in understanding variation in other biochemical parameters measured in fish, such as Hg or PCB contents.
12
Kuczyński, Tomasz, and Piotr Pieckiel. "Ichthyofauna species composition comparison in two estuarine lakes: Ptasi Raj and Mikoszewskie located in the Natura 2000 site "Ostoja w Ujściu Wisły"." Biuletyn Instytutu Morskiego 33, no. 1 (2018): 121–29. http://dx.doi.org/10.5604/01.3001.0012.8015.
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The purpose of the following studies was to get knowledge about the composition of the ichthyofauna of two estuarine lakes: Mikoszewskie and Ptasi Raj in the Natura 2000 area “Ostoja w Ujściu Wisły” (PLH220044), located within the delta estuary created by two channels of the Vistula river: Wisła Śmiała and Przekop Wisły, reaching the Gulf of Gdańsk. Despite the research conducted on the existing flora and fauna in both nature reserves, the ichthyofauna of the lakes has not been studied so far. In order to determine as completely as possible the taxonomic composition and the quantitative structure of ichthyofauna, the different fishing gear was used: fyke nets, NORDIC multimash survey gillnets, minnow traps. In Mikoszewskie lake, there were caught a total of 774 fish representing 17 species. Higher fish number in catches, with a comparable effort applied, were recorded on the Ptasi Raj lake, where a total of 2032 fish representing 16 species were captured. Out of all 26 species found, only 9 of them were found in both water reservoirs. As it transpires from the above data, both lakes, despite seemingly similar location, due to different hydrological conditions, clearly differ in terms of the structure of inhabiting ichthyofauna. Based on the analysis of the results of conducted fish catches, it can be concluded that the ichthyofauna of the Mikoszewskie Lake is characteristic for freshwater habitats, whereas in the waters of the Ptasi Raj lake, fish populations depend on a permanent connection with the estuary waters of the Wisła Śmiała channel.
13
Shields, Barbara A., Kevin S. Guise, and James C. Underhill. "Chromosomal and Mitochondrial DNA Characterization of a Population of Dwarf Cisco (Coregonus artedii) in Minnesota." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 8 (1990): 1562–69. http://dx.doi.org/10.1139/f90-177.
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This study compared the chromosome complement and mitochondrial DNA profile of a population of dwarf cisco in Ten Mile Lake, Cass County, Minnesota, to two populations of normal-sized Coregonus artedii in order to determine if the dwarf fish were conspecific with C. artedii. Chromosomal analysis revealed a diploid chromosome number (2n = 80) the same as reported for C. artedii. Mitochondrial DNA (mtDNA) analysis revealed unexpected levels of intrapopulational diversity in each study population, with the dwarf fish displaying the highest level of mtDNA diversity. Heteroplasmy, restriction site polymorphisms, and three size variants were documented. Each population was characterized by a unique profile of mtDNA clonal types, yet interpopulational comparisons revealed more similarities between the dwarf fish in Ten Mile Lake and the two normal populations than between the populations of normal-sized fish. Based on these data, the dwarf fish of Ten Mile Lake should be considered conspecific with Coregonus artedii.
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Herbst, Seth J., Bryan S. Stevens, Daniel B. Hayes, and Patrick A. Hanchin. "Estimating walleye (Sander vitreus) movement and fishing mortality using state-space models: implications for management of spatially structured populations." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 3 (2016): 330–48. http://dx.doi.org/10.1139/cjfas-2015-0021.
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Fish often exhibit complex movement patterns, and quantification of these patterns is critical for understanding many facets of fisheries ecology and management. In this study, we estimated movement and fishing mortality rates for exploited walleye (Sander vitreus) populations in a lake-chain system in northern Michigan. We developed a state-space model to estimate lake-specific movement and fishery parameters and fit models to observed angler tag return data using Bayesian estimation and inference procedures. Informative prior distributions for lake-specific spawning-site fidelity, fishing mortality, and system-wide tag reporting rates were developed using auxiliary data to aid model-fitting. Our results indicated that postspawn movement among lakes was asymmetrical and ranged from approximately 1% to 42% per year, with the largest outmigration occurring from the Black River, which was primarily used by adult fish during the spawning season. Instantaneous fishing mortality rates differed among lakes and ranged from 0.16 to 0.27, with the highest rate coming from one of the smaller and uppermost lakes in the system. The approach developed provides a flexible framework that incorporates seasonal behavioral ecology (i.e., spawning-site fidelity) in estimation of movement for a mobile fish species that will ultimately provide information to aid research and management for spatially structured fish populations.
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Ridgway, Mark S., James A. MacLean, and J. Cameron MacLeod. "Nest-site fidelity in a centrarchid fish, the smallmouth bass (Micropterus dolomieui)." Canadian Journal of Zoology 69, no. 12 (1991): 3103–5. http://dx.doi.org/10.1139/z91-436.
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Individual nesting male smallmouth bass (Micropterus dolomieui) in Lake Opeongo, Ontario, were followed for 11 years to determine the degree of nest-site fidelity from one year to the next. Only data from males nesting for the first and second time in consecutive years were included. The data indicate that 21.4% of all first-time nesting males returned to nest the following year. Nesting males rarely skipped a year after their 1st year of nesting. There was a strong tendency for males to return close (<20 m) to their previous year's nest site. Approximately 81 % renested within 200 m of their previous nest site, while the remainder nested between 200 and 1200 m from their previous nest site. This is the first report of nest-site fidelity for individual fish and is similar to published accounts of nest fidelity in birds.
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Munkittrick, K. R., C. B. Portt, G. J. Van Der Kraak, I. R. Smith, and D. A. Rokosh. "Impact of Bleached Kraft Mill Effluent on Population Characteristics, Liver MFO Activity, and Serum Steroid Levels of a Lake Superior White Sucker (Catostomus commersoni) Population." Canadian Journal of Fisheries and Aquatic Sciences 48, no. 8 (1991): 1371–80. http://dx.doi.org/10.1139/f91-164.
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White sucker (Catostomus commersoni) collected from a site receiving primary-treated bleached kraft mill effluent (BKME) were older and had a higher condition factor than fish at a reference site and grew more slowly than fish from three other areas of Lake Superior. The BKME-exposed fish also exhibited an increased age to maturity, smaller gonads, lower fecundity with age, an absence of secondary sex characteristics in males, and females failed to show an increase in egg size with age. Lower serum estradiol and testosterone concentrations and greater hepatic mixed-function oxidase (MFO) activity, as measured by conversion of diphenyloxazole and benzo[ajpyrene were also observed in the BKME-exposed fish. The level of MFO activity varied with season; differences could not be detected between sites during the spring spawning period, but were markedly elevated (up to ninefold) at the BKME site during the summer. The poorer performance of fish at the BKME site appears to be related to decreased levels of serum steroids and consequent abnormalities in reproductive development and carbohydrate metabolism, although the relationship of the changes in steroid levels with the increased hepatic enzyme activity remains to be established.
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Moncayo-Estrada, Rodrigo, Carlos Escalera-Gallardo, and Owen T. Lind. "Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae) during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis." Neotropical Ichthyology 9, no. 4 (2011): 815–24. http://dx.doi.org/10.1590/s1679-62252011000400012.
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This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy) and interannual (low and high volume conditions). The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapala, Mexico, revealed the significant influence of contrasting conditions (P=0.0002). Seasonally, segregation was more related to species dominance in the dry season and exclusively related to environmental characteristics in the rainy season. Interanually, biotic influence occurred in the shallowest and the deepest episodes of the lake. Environmental characteristics influenced species distribution when the lake reached 25% of its volume. Site, depth, temperature, and salinity were the leading factors influencing fish distribution. These results emphasize the necessity to implement different management strategies according to lake volume, particularly when a critical threshold is reached.
18
Brazner, John C., Danny K. Tanner, Naomi E. Detenbeck, et al. "Regional, watershed, and site-specific environmental influences on fish assemblage structure and function in western Lake Superior tributaries." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 6 (2005): 1254–70. http://dx.doi.org/10.1139/f05-031.
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The relative importance of regional, watershed, and in-stream environmental factors on fish assemblage structure and function was investigated in western Lake Superior tributaries. We selected 48 second- and third-order watersheds from two hydrogeomorphic regions to examine fish assemblage response to differences in forest fragmentation, watershed storage, and a number of other watershed, riparian, and in-stream habitat conditions. Although a variety of regional, fragmentation, and storage-related factors had significant influences on the fish assemblages, water temperature appeared to be the single most important environmental factor. We found lower water temperatures and troutsculpin assemblages at lower fragmentation sites and higher temperatures and minnowsuckerdarter assemblages as storage increased. Factors related to riparian shading and flow separated brook trout streams from brown trout (Salmo trutta) rainbow trout (Oncorhynchus mykiss) streams. Functionally, fish assemblages at lower fragmentation sites were dominated by cold-water fishes that had low silt tolerance and preferred moderate current speeds, while fishes with higher silt tolerances, warmer temperature preferences, and weaker sustained swimming capabilities were most common at higher storage sites. Our results suggest that site-specific environmental conditions are highly dependent on regional- and watershed-scale characters and that a combination of these factors operates in concert to influence the structure and function of stream fish assemblages.
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Dutta, S. P. S., D. Slathia, D. Slathia, and Chandbala K. "Incidences of winter fish kill in subtropical Surinsar Lake (Ramsar Site) in Shivalik hills of Jammu (J&K)." Environment Conservation Journal 15, no. 3 (2014): 35–40. http://dx.doi.org/10.36953/ecj.2014.15305.
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Mass mortality of fish was observed in the morning on 02-02-2011 in winter monomictic Surinsar lake, Jammu and has been reported. Maximum count of dead fish was shared by Puntius spp. (P. ticto, P. conchonius and P. sophore). Other dead fishes of family Cyprinidae include Rasbora rasbora, Esomus danrica and Cyprinus carpio communis. A few dead specimens of air breathing Heteropneustes fossilis and Channa punctatus were also seen. In the present paper, possible causes of fish kill have been described.
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Pratt, Thomas C., and Karen E. Smokorowski. "Fish habitat management implications of the summer habitat use by littoral fishes in a north temperate, mesotrophic lake." Canadian Journal of Fisheries and Aquatic Sciences 60, no. 3 (2003): 286–300. http://dx.doi.org/10.1139/f03-022.
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Compensation measures in response to Fisheries and Oceans Canada (DFO) Policy for the Management of Fish Habitat includes provisions for habitat creation and enhancement. Thus, an assessment of nearshore habitat utilization patterns by fishes is needed to put DFO compensation measures in the context of the "no net loss of the productive capacity of fish habitat" directive. Measures of abundance, richness, and diversity of fishes were compared across nine habitat types in a lake using rapid visual underwater assessment. Multivariate analyses separated habitats into three groups and identified two distinct species assemblages. Most species were associated with macrophytes, but a few were primarily associated with rocky substrate. Shallow mud (open) habitats contained significantly fewer species and had lower mean scores and diversity than all other habitat types. Rocky habitats had lower mean scores and diversity than some vegetated habitat types containing similar fish assemblages. Surprisingly, within-site fish assemblage heterogeneity was similar to among-site heterogeneity, and among-habitat heterogeneity was lower than within-habitat heterogeneity, further supporting our inability to distinguish among vegetated habitat types. Our results suggest that habitat heterogeneity is critical in maintaining diverse communities and that compensation measures should account for differences in fishhabitat associations among varied habitats.
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Benson, Barbara J., and John J. Magnuson. "Spatial Heterogeneity of Littoral Fish Assemblages in Lakes: Relation to Species Diversity and Habitat Structure." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 7 (1992): 1493–500. http://dx.doi.org/10.1139/f92-165.
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We quantified the spatial heterogeneity in nearshore fish community composition within six Wisconsin lakes and examined its relation to habitat heterogeneity and species diversity. Fish abundance was estimated annually (1981–84) using seines at six sites in each lake. Substrate type, macrophyte growth form, and depth gradient were noted at each site. Species richness was estimated as the expected number of species when the number of individuals was held constant over lakes (rarefaction). Fish community spatial heterogeneity (the average percent dissimilarity in fish species composition over all possible pairs of seine sites within a lake) differed among lakes; it was positively correlated with within-lake variation in the depth gradient and with species diversity as estimated by rarefaction. We tested whether differences in community spatial heterogeneity among lakes resulted simply from differences in species diversity using a randomization test based on random permutations of the rows (seine hauls) in the species composition data matrix. Lakes differed in the extent to which the observed community heterogeneity exceeded the randomization results. Spatial heterogeneity of the fish community, as opposed to sampling phenomena resulting from differences in richness, was a strong factor in some lakes.
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Sweke, Emmanuel Andrew, Julius Michael Assam, Abdillahi Ismail Chande, Athanasio Stephano Mbonde, Magnus Mosha, and Abel Mtui. "Comparing the Performance of Protected and Unprotected Areas in Conserving Freshwater Fish Abundance and Biodiversity in Lake Tanganyika, Tanzania." International Journal of Ecology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/7139689.
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Marine protected areas have been shown to conserve aquatic resources including fish, but few studies have been conducted of protected areas in freshwater environments. This is particularly true of Lake Tanganyika, Tanzania. To better conserve the lake’s biodiversity, an understanding of the role played by protected areas in conserving fish abundance and diversity is needed. Sampling of fish and environmental parameters was performed within the Mahale Mountains National Park (MMNP) and nearby unprotected areas at depths between 5 m and 10 m. Twelve replicates of fish sampling were performed at each site using gillnets set perpendicularly to the shore. Mann-Whitney tests were performed, and the total amount of species turnover was calculated. A total of 518 individual fish from 57 species were recorded in the survey. The fish weight abundance was fivefold greater in the MMNP than in the unprotected areas. Fish abundance and diversity were higher in the MMNP than in the unprotected areas and decreased with distance from it. Our findings confirmed the importance of the protected area in conserving fish resources in Lake Tanganyika. The study provides baseline information for management of the resources and guiding future studies in the lake and other related ecosystems. Management approaches that foster awareness and engage with communities surrounding the MMNP are recommended for successful conservation of the resources in the region.
23
Lamsal, Pramod, Krishna Prasad Pant, Lalit Kumar, and Kishor Atreya. "Diversity, Uses, and Threats in the Ghodaghodi Lake Complex, a Ramsar Site in Western Lowland Nepal." ISRN Biodiversity 2014 (April 27, 2014): 1–12. http://dx.doi.org/10.1155/2014/680102.
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This study documents aquatic and terrestrial/riparian biodiversity in an anthropogenically disturbed Ramsar site, the Ghodaghodi Lake complex, in the Western Nepal surveyed during the summer season (March-April) of 2007. The study site comprises three major interconnected lakes: Ghodaghodi (138 ha), Nakharodi (70 ha), and Bainshwa (10 ha). Five transect lines for aquatic macrophytes and three transect lines and 37 sampling plots were laid to sample terrestrial/riparian plants, birds, and animals. Five sample plots were established for fish and aquatic bird. A total of 45 species of aquatic macrophytes, 54 species of terrestrial/riparian vegetation, 19 fish species, 41 bird species, 17 mammals (endangered and vulnerable), and 5 reptiles (critically endangered, vulnerable, and near threatened) were recorded at the lake complex. Local people have used most of the aquatic and terrestrial plants for different purposes while many of the potential medicinal plant species were still untapped. Persistent anthropogenic threats, like excessive harvesting and poaching, habitat destruction—population pressure, forest fragmentation, siltation, fertilizer and pesticide seepage, water pollution, overgrazing, and unmanaged irrigation system found over the lake complex, endangered the existing biodiversity. The suggested remedial measures are further exploration of medicinal potential, prioritization of in situ biodiversity conservation strategies, and implementation of awareness program at local level against anthropogenic threats.
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El Ghizi, Sara, Nezha El Aadel, Mohamed Sadik, Mohammed El Bouch, and Mustapha Hasnaoui. "The physicochemical characteristics and the pollution level of Dayet Er-Roumi Lake in Morocco." E3S Web of Conferences 234 (2021): 00036. http://dx.doi.org/10.1051/e3sconf/202123400036.
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The management of natural surface water resources requires an understanding and knowledge of water quality. The Lake Dayet Er-Roumi (classified as a Site of Biological and Ecological Interest (SIBE)) is the only permanent continental lake of low altitude in Morocco, this international attraction site is subject to various sources of anthropogenic pollution, in addition to the effects of climate change (thermal variability, lack of precipitation, etc.). The objective of this work is to quantify and assess the quality of the waters lake, and its tributaries through Spatio-temporal monitoring of several physicochemical parameters during two seasons (winter and summer) of the year 2019. All the physicochemical analysis (such as temperature, hydrogen potential, electrical conductivity, dissolved oxygen, nitrates, orthophosphates, and chlorides) were carried out at 7 study stations (5 stations at lake level and 2 stations representing the tributaries). Statistical calculation of the data set revealed high concentrations of chlorides in both seasons and orthophosphates during the summer season, with average nitrate concentrations during the winter season. The results obtained show that the pH of the water is basic with a very high electrical conductivity showing a load of water in different minerals. These results greatly exceed the standards of fish water quality and surface water quality. They show that the lake Dayet Er-Roumi is polluted. Strategies to limit the pollution of the lake must be implemented by decision-makers at all levels, in order to avoid several ecological problems (fish mortality for example).
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Fladmark, Knut R., Jonathan C. Driver, and Diana Alexander. "The Paleoindian Component at Charlie Lake Cave (HbRf 39), British Columbia." American Antiquity 53, no. 2 (1988): 371–84. http://dx.doi.org/10.2307/281025.
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Charlie Lake Cave (HbRf 39) is a stratified site in northeastern British Columbia, Canada, containing a fluted-point component at the base of the excavated deposits. The small artifact assemblage includes a fluted point, stone bead, core tool, and retouched flake. A diverse associated fauna includes fish, birds, and mammals, indicating a more open environment than exists today. Radiocarbon dates suggest that the artifact assemblage was deposited about 10,500 years ago.
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Liang, Shu Xuan, Yun Xiao Wang, and Zhe Qin. "Spatial-Temporal Distribution of Manganese in Lake Baiyangdian, China." Advanced Materials Research 726-731 (August 2013): 194–98. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.194.
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The concentrations of Mn in water and sediments of different functional areas in Lake Baiyangdian were monitored in representative months from 2009 to 2010. The results showed that the concentration of Mn had spatial-temporal distribution characteristics. Mn in the overlying water ranged from 0.05 to 2.39 mgL-1, and was higher in May and October than that in August and March. Sites in the fish-rearing zone had the highest Mn concentration, while natural site had the lowest Mn concentration. The concentration of Mn in the surface of sediments ranged from 144.95 to 1317.04 mgkg-1. The concentration of Mn was higher in March than in other months. Sites in the duck-rearing zone had the highest Mn concentration, while garbage dumping site had the lowest Mn concentration. Human activity such as aquaculture had an obvious effect on the concentration of Mn in Lake Baiyangdian.
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Neuenhoff, Rachel D., Jonah L. Withers, Lori A. Davis, et al. "Discovery of an Undocumented Lake Sturgeon Spawning Site in the Headwaters of the Niagara River." Journal of Fish and Wildlife Management 9, no. 1 (2018): 266–73. http://dx.doi.org/10.3996/102017-jfwm-087.
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Abstract Information about spawning fish is important to stock-assessment data needs (i.e., recruitment and fecundity) and management (i.e., habitat connectivity and protection). In Lake Erie, information about Lake Sturgeon Acipenser fulvescens early-life history is available for the Detroit River and Lake St. Clair system in the western basin, but fisheries biologists know comparatively little about Lake Sturgeon in the eastern basin. Although researchers have summarized historical spawning areas, no known natural Lake Sturgeon spawning site is described in Lake Erie proper. Researchers documented a remnant population of reproductively mature Lake Sturgeon near the headwaters of the Niagara River in eastern Lake Erie in 2011. Researchers hypothesized that a spawning site was likely in the immediate vicinity of the Niagara River headwaters near Buffalo Harbor, New York; however, its exact location was unknown. We attempted to locate spawning sites near the confluence of the Niagara River using egg traps at three potential spawning sites. We identified Lake Sturgeon eggs at one of these sites using morphological and genetic techniques. Lake Sturgeon eggs collected on one sampling trip began to emerge when placed in preservative, confirming that eggs deposited at this site are fertilized and viable, and that the area supports viable embryos. This discovery fills data gaps in the early-life history for this population, which has domestic and international management implications with respect to proposed recovery targets, stock assessment models, habitat remediation efforts, and status determinations of a protected species in a geographic region designated as an Area of Concern by the International Joint Commission.
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Blair, Gregory R., and Thomas P. Quinn. "Homing and spawning site selection by sockeye salmon (Oncorhynchus nerka) in Iliamna Lake, Alaska." Canadian Journal of Zoology 69, no. 1 (1991): 176–81. http://dx.doi.org/10.1139/z91-027.
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Sockeye salmon (Oncorhynchus nerka) spawn along several island beaches and nearby streams in the eastern portion of Iliamna Lake, Alaska. We investigated the importance of homing, attraction to spawning site characteristics, and attraction to conspecifics in similar reproductive condition as factors influencing spawning site selection. Sockeye were displaced reciprocally between two similar island beaches and a dissimilar nearby stream. Few sockeye successfully homed from one beach to another (11%); those displaced to the stream from a beach displayed intermediate homing (24%) and the best homing was back to the stream (65%). More fish remained at the release site when it was similar to the capture site (25%) than when it was dissimilar (4%). Sockeye that left the release site for a beach were more often missing (68%) than those departing for the creek (30%). The use of ultrasonic transmitters revealed that four of six sockeye that departed for a beach were relocated at a spawning beach other than the capture site. Spawning site characteristics apparently play a role in spawning site selection, but the need to spawn at the capture site was more important. Homing was better to the creek, presumably because it had a unique odor and its flow made it easier to locate than the beaches.
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Snyder, Thomas P., Robert D. Larsen, and Stephen H. Bowen. "Mitochondrial DNA Diversity among Lake Superior and Inland Lake Ciscoes (Coregonus artedi and C. hoyi)." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 9 (1992): 1902–7. http://dx.doi.org/10.1139/f92-210.
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Mitocondrial DNA (mtDNA) of ciscoes from Lake Superior and seven inland lakes in Michigan and New York were analyzed for restriction fragment length polymorphism using 11 informative restriction endonucleases. Five of the 11 enzymes revealed restriction site or size polymorphism among fish. Maximum sequence divergence between mtDNA haplotypes was low (p = 0.006), indicating a maximum divergence time of 300 000 yr. Coregonus artedi and C. hoyi share mtDNA haplotype arrays indicating a more recent divergence. No unique haplotypes exist to separate C. artedi and C. hoyi from single collections, although their arrays of haplotypes are significantly different in frequencies. The lack of qualitative differentiation between C. artedi and C. hoyi noted for mtDNA parallels that previously noted for allozymes and morphology. Introgression between C. artedi and C. hoyi seems unlikely as the cause for this low amount of differentiation because a 100-base pair insertion haplotype present in Lake Superior and inland lake C. artedi is absent in C. hoyi.
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Ovenden, J. R., and R. W. White. "Mitochondrial and allozyme genetics of incipient speciation in a landlocked population of Galaxias truttaceus (Pisces: Galaxiidae)." Genetics 124, no. 3 (1990): 701–16. http://dx.doi.org/10.1093/genetics/124.3.701.
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Abstract Galaxias truttaceus is found in coastal rivers and streams in south-eastern Australia. It spawns at the head of estuaries in autumn and the larvae spend 3 months of winter at sea before returning to fresh water. In Tasmania there are landlocked populations of G. truttaceus in a cluster of geologically young lakes on the recently glaciated Central Plateau. These populations have no marine larval stage and spawn in the lakes in spring. Speciation due to land locking is thought to be a frequent occurrence within Galaxias. To investigate the nature of the speciation event which may be occurring within lake populations of G. truttaceus we studied the mitochondrial DNA (mtDNA) and allozyme diversity of both lake and stream populations. Using the presence or absence of restriction sites recognized by 13 six-base restriction endonucleases, we found 58 mtDNA haplotypes among 150 fish collected from 13 Tasmanian and one south-east Australian mainland stream populations. The most parsimonious network relating the haplotypes by site loss or gain was starlike in shape. We argue that this arrangement is best explained by selection upon slightly beneficial mutations within the mitochondrial genome. Gene diversity analysis under Wright's island model showed that the populations in each drainage were not genetically subdivided. Only two of these stream haplotypes were found among the 66 fish analyzed from four lake populations. Despite the extreme lack of mtDNA diversity in lake populations, the observed nuclear DNA heterozygosity of 40 lake fish (0.10355) was only slightly less than that of 82 stream fish (0.11635). In the short time (3000-7000 years) that the lake fish have been landlocked, random genetic drift in a finite, stable-sized population was probably not responsible for the lack of mtDNA diversity in the lake populations. We infer the lake populations have probably experienced at least one, severe, but transitory bottleneck possibly induced by natural selection for life-history characters essential for survival in the lacustrine habitat. If speciation is occurring in the landlocked populations of G. truttaceus, then it may be driven by genetic transilience.
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Reyjol, Yorick, Philipp Fischer, Sovan Lek, Roland Rösch, and Reiner Eckmann. "Studying the spatiotemporal variation of the littoral fish community in a large prealpine lake, using self-organizing mapping." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 10 (2005): 2294–302. http://dx.doi.org/10.1139/f05-097.
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One of the most fundamental feature of freshwater systems is the spatiotemporal structure of their communities. In the present study, we used an artificial neural network model, i.e., self-organizing mapping, together with a likelihood ratio χ2 statistic for proportions to investigate the influence of each factor of a complex sampling scheme (i.e., site, year, month, and time of day) on the littoral fish community of Lake Constance (south Germany). Based on self-organizing mapping, four clusters of samples were defined characterized by distinct fish communities. The samples gathered in clusters 1 and 2 were significantly related to the factors month and time of the day, while those in cluster 3 were related to the factors month and site and those in cluster 4 to each of the four factors. The results are discussed with regard to the temporal patterns of species succession in lakes and their similarities with the spatial patterns observable in streams, the importance of plasticity with regard to the fish nycthemeral preferences, the partitioning of habitat at a large spatial scale and its importance for the coexistence of species, and the effects of the reoligotro phica tion process in lakes.
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Borgstrøm, Reidar, Knut Bergum, Trond Erik Børresen, and Martin A. Svenning. "Gillnet catchability of brown trout Salmo trutta is highly dependent on fish size and capture site." Fauna norvegica 39 (May 9, 2019): 30–38. http://dx.doi.org/10.5324/fn.v39i0.2536.
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Use of experimental gillnet fleets is common both in scientific studies of fish populations and in fishsampling for management purposes. Fish catchability may vary considerably with fish and gillnet meshsize, and catches obtained by gillnet fleets composed of nets with different mesh sizes may give lengthand age distributions that deviate considerably from the length and age structure of the population.We have estimated the absolute catchability of allopatric brown trout (Salmo trutta) in the littoral andpelagic habitat of a small lake based on a mark-recapture experiment. The brown trout catchabilityvaried considerably both with fish size and habitat type, probably due to a size-related variation inswimming distance per time unit and a size-related use of the different lentic habitats. The samplingbias in experimental gillnet fishing may be reduced by operating the gillnet fleets in all possible lentichabitats and most fundamentally, by use of catchability data obtained from populations with ‘known’length and age structures. By reducing this sampling bias, more realistic estimations of the age andlength distribution for a given population will be possible.
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Snucins, E. J., R. Allen Curry, and J. M. Gunn. "Brook trout (Salvelinus fontinalis) embryo habitat and timing of alevin emergence in a lake and a stream." Canadian Journal of Zoology 70, no. 3 (1992): 423–27. http://dx.doi.org/10.1139/z92-064.
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We assessed redd characteristics of brook trout in a lake and a stream and alevin emergence in the lake. Both populations spawned over upwelling groundwater. In the lake site fish deposited eggs 7–19 cm in the sediment in an egg pocket that contained large-particle substrate. A similar vertical distribution of eggs (16–20 cm) and substrate occurred in the stream; however, in addition to the digging action of the female, the flow conditions in the stream appeared to produce coarser surface sediment conditions. Groundwater offered a high concentration of dissolved oxygen and, relative to lake water, less variable temperature and pH regimes for incubating eggs. Alevin emergence extended over a 71-day period, coinciding with the spring thaw and an episodic pH depression.
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Purwitasari, Diah, Luh Gde Sri Astiti, and Supriadi Supriadi. "Identification Of Migratory Birds And Their Spesific Characteristics Of Habitat In The Salt Water Lake Of Gili Meno, North Lombok Distric." Biology, Medicine, & Natural Product Chemistry 3, no. 1 (2014): 25. http://dx.doi.org/10.14421/biomedich.2014.31.25-30.
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The aim of this research was to identify the species of migratory birds in the ecosystem of salt water lake of Gili Meno and their specific characteristics of habitat. Data collection for birds, mangrove and fish species has been carried out in September and October 2013. In this study, a Shannon-Wiener Diversity Index and Importance Value Index (IVI) of mangrove vegetation were calculated to identify carrying capacity of mangrove population in the form of specific habitat in salt water lake of Gili Meno. This research has identified 17 species of birds which are divided into 5 families: Scolopacidae, Charadriidae, Ardeidae, Meropidae and Alcedinidae. Moreover, 3 species of mangrove were discovered that are <em>A. marina, A. lanata </em>and <em>E. Agallocha</em>, as well as one species of fish (Mujair fish/<em>O. mossambicus</em>). <em>N. Nycticorax </em>and <em>B. Striatus</em> were well-known to have higher population than other bird species. The Diversity Index showed that mangrove vegetation in the ecosystem of salt water lake of Gili Meno has a low species diversity (0.565). This is due to higher dominance of one species than the others. What is more, the IVI of <em>A. marina </em>demonstrated a fairly significant value compared to that of other species (189,01). Mangrove vegetation which surrounds the ecosystem of salt water lake of Gili Meno has formed a unique habitat and and an ideal stopover site for migratory birds. The ecosystem not only provides shelters from predators but also supplies for various abundant feeding sources. The lake it self is rather shallow and muddy around the shore which gives advantages for the migratory birds to obtain plenty small fish from the lake.
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Villamagna, Amy M., Brian R. Murphy, and Sarah M. Karpanty. "Community-Level Waterbird Responses to Water Hyacinth (Eichhornia crassipes)." Invasive Plant Science and Management 5, no. 3 (2012): 353–62. http://dx.doi.org/10.1614/ipsm-d-11-00085.1.
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Water hyacinth is among the most widespread invasive plants worldwide; however, its effects on waterbirds are largely undocumented. We monitored site use by waterbirds at Lake Chapala, the largest lake in Mexico and recently designated Ramsar site, to evaluate the potential influence of water hyacinth cover on species composition and aggregate measures of the waterbird community, including waterbird density, species richness, and Simpson's index of diversity. We examined the response of waterbirds to changes in percent water hyacinth cover at 22 independent sites around the lake during six study seasons from May 2006 to February 2008. We found little evidence to suggest that percent water hyacinth cover affected aggregate community measures; however, multivariate analysis of relative species composition suggested that water hyacinth cover corresponded with seasonal species composition (Canonical Correspondence r = 0.66, P = 0.007) when seasonal site cover averaged 17.7 ± 4.67% (winter 2007). Several migratory species were not observed during this season, which could suggest that some small-bodied migratory species avoided Lake Chapala during the winter of high water hyacinth cover. We suspect that observed changes in the waterbird community are in response to species-specific tolerances for water hyacinth and indirect abiotic and biotic effects of its presence (e.g., invertebrate and fish composition).
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Menconi, Vasco, Maria Vittoria Riina, Paolo Pastorino, et al. "First Occurrence of Eustrongylides spp. (Nematoda: Dioctophymatidae) in a Subalpine Lake in Northwest Italy: New Data on Distribution and Host Range." International Journal of Environmental Research and Public Health 17, no. 11 (2020): 4171. http://dx.doi.org/10.3390/ijerph17114171.
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The genus Eustrongylides includes nematodes that infect fish species and fish-eating birds inhabiting freshwater ecosystems. Nematodes belonging to the genus Eustrongylides are potentially pathogenic for humans; infection occurs after the consumption of raw or undercooked fish. In the two-year period 2019–2020, a total of 292 fish belonging to eight species were examined for the occurrence of Eustrongylides spp. from Lake San Michele, a small subalpine lake in northwest Italy. The prevalence of infestation was 18.3% in Lepomis gibbosus, 16.7% in Micropterus salmoides, and 10% in Perca fluviatilis. The other five fish species (Ameiurus melas, Ictalurus punctatus, Squalius cephalus, Carassius carassius, and Scardinius erythrophthalmus) were all negative for parasite presence. There were no significant differences in prevalence between the three fish species (Fisher’s exact test; p = 0.744). The mean intensity of infestation ranged from 1 (M. salmoides and P. fluviatilis) to 1.15 (L. gibbosus), and the mean abundance ranged from 0.1 (P. fluviatilis) to 0.28 (L. gibbosus). There were significant differences in the infestation site between the four muscle quadrants (anterior ventral, anterior dorsal, posterior ventral, and posterior dorsal) and the visceral cavity (Kruskal–Wallis test; p = 0.0008). The study findings advance our knowledge about the distribution and host range of this parasite in Italy.
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Matveeva, Natalia P. "Seasonal Site of Shadrinsky Maslozavod of Russian Migrants in the Ishim Steppe Region." Vestnik NSU. Series: History and Philology 20, no. 3 (2021): 93–101. http://dx.doi.org/10.25205/1818-7919-2021-20-3-93-101.
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Purpose. The sites of the Russian colonization period continued to stay insufficiently known in Western Siberia. The author considers new materials of excavation of two Russian migrant dwellings for studying local and chronological dynamic of life-support. Results. This site was localized at the bank of Shadrinskoye Lake in the steppe region of Ishim River valley in the Western Siberia region. Buildings stood alone and were not synchronic. They were small in size – 10 m2 and 18 m2, of rectangular form, and of varying depth. They had plank floors, a gable roof and access to the lake. After the fire, a shallow half-dugout dwelling with a larger area was built in place of the deep dugout, which eventually burned down too. The iron axes, traces of drying of nets with sinkers arranged in the complexes, the bones of domestic animals and fish were found. It is interesting that the sinkers are of different forms: biconic, cylindrical, trapeziform with one hole and flat oval form without a hole. The last type was used with wrapped birch bark. Two pots looked like 18th century brown Russian professional pottery. Despite fishing of the habitants, the bones of animals from food leftovers show the developing cattle breeding with predominant livestock and pig breeding in the local community. The chronology of this site was defined based on the periods of function of iron axes with the wide and the rounded off blades, ceramic and adobe clay brick (which had not been imported until much later) at the beginning of the 18th century. Conclusion. The site is interesting as a source of the early stage of Russian development of Siberia and as an ordinary life-supporting complex. It shows the combination of production branches with the development in fishing and game bird hunting in their natural habitat in the ecological lake systems of the steppe zone. Fishing for smaller fish was conducted for the purposes of diversifying the food ration.
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Appleford, P., T. A. Anderson, and G. J. Gooley. "Reproductive cycle and gonadal development of Macquarie perch, Macquaria australasica Cuvier (Percichthyidae), in Lake Dartmouth and tributaries of the Murray - Darling Basin, Victoria, Australia." Marine and Freshwater Research 49, no. 2 (1998): 163. http://dx.doi.org/10.1071/mf97012.
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The gonadal development, reproductive cycle and growth of Macquarie perch, Macquaria australasica Cuvier, in Lake Dartmouth and selected tributaries of the Murray–Darling River Basin in south-eastern Australia were evaluated. Gonadosomatic index (GSI) and histological analysis were used to determine gonadal development and age and size at first maturity in the resident Lake Dartmouth population. GSI analysis was also used to determine age and size of Macquarie perch at first maturity in the inflowing Mitta Mitta River and other riverine populations within the Goulburn River catchment. Males appeared slightly smaller at first spawning than females at all sites; both sexes were fully mature at four years of age. Differences in size at first maturity were found between the lake and river populations; both males and females of river populations tended to mature at a much smaller size than the fish resident in the lake. Spawning occurred around November. Ovarian and testicular development in this species follows a pattern similar to that of other native Australian percichthyids. The implications for management of recreational fisheries based on minimum size regulations is discussed in relation to site-specific differences in growth rates and size of first maturity of fish.
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Veenstra, J., S. Nolen, J. Carroll, and C. Ruiz. "Impact of net pen aquaculture on lake water quality." Water Science and Technology 47, no. 12 (2003): 293–300. http://dx.doi.org/10.2166/wst.2003.0659.
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A 3-year study was conducted by the U.S. Army Corps of Engineers assessing water quality related impacts of aquaculture of 250,000 channel catfish (Ictalurus punctatus) in floating net pens in the Rock Creek Arm of Lake Texoma, Oklahoma/Texas. Five large nylon nets suspended from a floating framework of galvanized metal anchored in open water 100 m offshore made up the net pens with fish stocking densities varying from 88 to 219 fish/m3. Water quality sampling was conducted biweekly from April to September and monthly from October to March at three locations. On all sampling dates field measurements of water temperature, pH, dissolved oxygen, and conductivity were recorded at 1 m depth intervals and water samples were collected at a depth of 0.5 m and near the bottom of the water column at each site. Sample analyses included: total alkalinity, total hardness, turbidity, chloride, sulfate, orthophosphate, total phosphorus, nitrate-N, nitrite-N, total Kjeldahl nitrogen, total organic carbon, dissolved organic carbon, biochemical oxygen demand, and chlorophyll a. The results showed statistically significant decreases in water temperature and dissolved oxygen and significant increases in field conductivity in surface waters near the net pens relative to other sampling sites. The most dramatic water quality effect observed during the study was decrease in dissolved oxygen levels near the net pens following lake turnover in the second year.
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Karrow, Paul F., Arthur L. Bloom, Jean Nicolas Haas, et al. "The Fernbank interglacial site near Ithaca, New York, USA." Quaternary Research 72, no. 1 (2009): 132–42. http://dx.doi.org/10.1016/j.yqres.2009.02.008.
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AbstractThe Fernbank interglacial site, on the west side of Cayuga Lake, New York, has been recently subjected to more detailed study. To a lengthened mollusc list are added ostracodes, insects, fish, pollen, and plant macrofossils. Of these, plants are well preserved and diverse, whereas other groups are poorly preserved and incomplete. Nevertheless, all support the interglacial assignment (Sangamon), which is further supported by minimum age radiocarbon dates (>50,000 14C yr BP) and a TL date of 81 ± 11 ka. In the plant record near the top of the sequence, abundant tree charcoal indicates forest fires. Like the Toronto interglacial record, the plants show a declining July mean temperature from 24 to 18°C (according to transfer functions) through the sequence, from mixed deciduous forest to boreal forest.
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Quinn, Thomas P., Eric C. Volk, and Andrew P. Hendry. "Natural otolith microstructure patterns reveal precise homing to natal incubation sites by sockeye salmon (Oncorhynchus nerka)." Canadian Journal of Zoology 77, no. 5 (1999): 766–75. http://dx.doi.org/10.1139/z99-028.
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Experimental results suggest that anadromous salmon and trout learn (imprint) the odors of their natal site just prior to or during seaward migration. In contrast, information on the life histories of several species and the genetic structure of populations indicate that they must imprint earlier in life, probably during incubation in the gravel or when they emerge as free-swimming fry. To test the hypothesis that sockeye salmon (Oncorhynchus nerka) home to their incubation-emergence sites (rather than just to the lake where they reared before migrating to sea), we took advantage of the natural variation in otolith microstructure caused by differences in thermal regimes during incubation. We collected otoliths from adult sockeye salmon that returned to discrete spawning areas in Iliamna Lake, Alaska, and Lake Washington, Washington, and, in blind trials, these were classified based on comparison with otoliths from juveniles from the same sites and using information on site-specific thermal regimes. Our analysis showed that the salmon were much more likely to return to their natal incubation site than would have occurred by chance. Estimated straying rates were about 0.1% from the Woody Island population to the Pedro Pond population in Iliamna Lake and about 1% from the Cedar River population to the Pleasure Point population in Lake Washington. The results were consistent with genetic evidence for fine-scale structure of salmon populations and with conservation based on spatial scales appropriate for the early life history of the fish.
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Gibson, Katherine N., John P. Smol, and Jesse Ford. "Chrysophycean Microfossils Provide New Insight into the Recent History of a Naturally Acidic Lake (Cone Pond, New Hampshire)." Canadian Journal of Fisheries and Aquatic Sciences 44, no. 9 (1987): 1584–88. http://dx.doi.org/10.1139/f87-191.
Full textAbstract:
Cone Pond, New Hampshire, is an acidic (pH = 4.5) clearwater lake that is currently fishless. Historical records indicate declining fish populations between 1951 and 1966, but paleolimnological work using diatoms failed to find evidence for further recent acidification of this naturally acid site. We initiated new paleolimnological studies using mallomonadacean chrysophytes to further our understanding of Cone Pond's recent past. Our stratigraphic analyses indicate recent striking changes in the chrysophyte flora of this lake, with Mallomonas hindonii, a species only common in recently acidified lakes, replacing M. crassisquama, a cosmopolitan species that dominated the flora over the preceding 8000 yr; this recent change parallels the declines in fish populations. Because chrysophytes often bloom in early spring and are known, in other lakes, to experience changes in community composition before those expressed by the diatom community, a possibility is that chrysophytes track transient excursions of lake water chemistry associated with early snowmelt conditions. In this scenario, chrysophytes would respond to a constellation of specific short-term chemical changes including, but not restricted to, pH. Such pH associated changes could include changes in concentrations, speciation, or complexation of metals mobilized from the catchment or sediments, all of which are known to affect both chrysophytes and fish.
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Brind'Amour, Anik, and Daniel Boisclair. "Effect of the spatial arrangement of habitat patches on the development of fish habitat models in the littoral zone of a Canadian Shield lake." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 4 (2006): 737–53. http://dx.doi.org/10.1139/f05-249.
Full textAbstract:
We developed fish habitat models in a Canadian Shield lake using (i) a sampling-site approach based on analytical units having a surface area equal to that of sampling sites (S ~ 200 m2), (ii) a constant-multiple approach in which the analytical units constituted grouping of adjacent sampling sites in units of increasing sizes (e.g., 2S or 3S), and (iii) a habitat-patch approach in which only contiguous sampling sites with similar environmental characteristics were merged. The best models explaining within-lake variations in fish density, biomass, and community structure on the littoral zone were obtained using the constant-multiple approach, but the predictive power of these models was highly variable (0 < R2 < 0.9) compared with the habitat-patch approach (0.27 < R2 < 0.49). For these approaches, intrinsic variables (estimated inside the analytical units) explained on average 16%27% of the variations of fish descriptors compared with 6%32% for extrinsic variables (observed outside analytical units or related to the spatial arrangement of habitat characteristics). Our study suggests that habitat patches are reliable analytical units with which to develop fish-habitat models. Our study also indicates that inclusion of variables that refer to landscape characteristics may significantly improve the predictive power of fish habitat models.
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Kennedy, C. R. "Establishment, survival and site selection of the cestode Eubothrium crassum in brown trout, Salmo trutta." Parasitology 112, no. 3 (1996): 347–55. http://dx.doi.org/10.1017/s0031182000065872.
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SUMMARYPopulation dynamics, site selection, growth and maturation of the cestode Eubothrium crassum in a natural population of Salmo trutta in a small lake were studied over a period of 1 year, the life-span of a cohort in fish. Infection of fish commenced in spring but peaked in July. Small, plerocerciform parasites initially located in the intestine, but then some moved into the pyloric caecae whilst others, the majority in heavy infections, were lost from the fish causing a fall in abundance from 460 to 10 over 2 months. This mortality was density dependent. Initially, parasites were distributed more evenly throughout the caecae but as time increased larger parasites were found preferentially in the anterior caecae before moving back into the intestine when gravid, preparatory to being lost in the following summer. Only a small proportion of the infrapopulation became gravid. Although the proportion of caecae occupied was initially density dependent, by the time of maturation several preferred anterior caecae remained unoccupied and mean intensity always exceeded unity. Neither growth nor maturation was affected by intraspecific competition. It was concluded that caecal availability did not set a limit or threshold of infrapopulation density, and in this respect E. crassum–S. trutta differed from some acanthocephalan-fish systems but was similar to others. Heavy infection followed by heavy mortality appeared to be typical of this parasite-host system in other localities, and of several other cestode-fish systems. The implications of this for population regulation are discussed.
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Jones, Nicholas Edward, and Ian Charles Petreman. "The Capacity to Detect Change Stream Fish Communities Characteristics at the Site-Level in the Lake Ontario Basin." Environmental Management 50, no. 1 (2012): 77–88. http://dx.doi.org/10.1007/s00267-012-9859-9.
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Haynes, Trevor B., Amanda E. Rosenberger, Mark S. Lindberg, Matthew Whitman, and Joel A. Schmutz. "Method- and species-specific detection probabilities of fish occupancy in Arctic lakes: implications for design and management." Canadian Journal of Fisheries and Aquatic Sciences 70, no. 7 (2013): 1055–62. http://dx.doi.org/10.1139/cjfas-2012-0527.
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Studies examining species occurrence often fail to account for false absences in field sampling. We investigate detection probabilities of five gear types for six fish species in a sample of lakes on the North Slope, Alaska. We used an occupancy modeling approach to provide estimates of detection probabilities for each method. Variation in gear- and species-specific detection probability was considerable. For example, detection probabilities for the fyke net ranged from 0.82 (SE = 0.05) for least cisco (Coregonus sardinella) to 0.04 (SE = 0.01) for slimy sculpin (Cottus cognatus). Detection probabilities were also affected by site-specific variables such as depth of the lake, year, day of sampling, and lake connection to a stream. With the exception of the dip net and shore minnow traps, each gear type provided the highest detection probability of at least one species. Results suggest that a multimethod approach may be most effective when attempting to sample the entire fish community of Arctic lakes. Detection probability estimates will be useful for designing optimal fish sampling and monitoring protocols in Arctic lakes.
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Seilheimer, Titus, Anhua Wei, and Patricia Chow-Fraser. "Changes in Fish Communities of Lake Ontario Coastal Wetlands before and after Remedial Action Plans." ISRN Ecology 2011 (May 5, 2011): 1–11. http://dx.doi.org/10.5402/2011/820529.
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We conducted a change-detection analysis to determine if improvements in the habitat quality of coastal wetlands could be attributed to Remedial Action Plans (RAPs) of Lake Ontario. We used a 5-km buffer relative to each recent site to “resample” an existing database of spawning/nursery habitat from the early 1980s to derive a “historic” species list associated with thirteen representative wetlands sampled in 2001-2002. For each wetland, we calculated Wetland Fish Index (WFI) scores, which are relative measures of wetland quality having scores ranging from 1 to 5, indicating worst to best conditions, respectively. The mean WFI score of 3.16 for the recent era was significantly higher than that for the historic era of 2.79 (Wilcoxon sign-rank test; P=.04), and this is consistent with the conclusion that lakewide RAPs have been effective in recovering some of the ecological functions of degraded coastal wetlands of Lake Ontario.
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Osei, L. K., R. Asmah, S. Aikins, and A. Y. Karikari. "Effects of Fish Cage Culture on Water and Sediment Quality in the Gorge Area of Lake Volta in Ghana: A Case Study of Lee Fish Cage Farm." Ghana Journal of Science 60, no. 1 (2019): 1–16. http://dx.doi.org/10.4314/gjs.v60i1.1.
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The study determined the impacts of fish cage farming on the gorge area of Lake Volta. Water and sediment samples were collected from six sites in the Lee Cage Farm; four from sections with cages and two from about 1300 m upstream of the farm which served as the control. Water quality variables monitored were pH, temperature, dissolved oxygen, nitrate-nitrogen, ammonia-nitrogen, orthophosphate, faecal coliforms and total coliforms. Variables monitored in the sediment were organic matter, total carbon, total nitrogen and total phosphorus. There were variations in water quality between the farmed and control sites but the differences were not significant (p > 0.05). The mean counts of total coliform in the water ranged from 940 - 3318 cfu/100 ml while faecal coliforms ranged from 113 - 552 cfu/100 ml at the farmed site. The mean total coliform count at the control site ranged from 837 - 6960 cfu/100 ml while the faecal coliforms ranged from 48 - 120 cfu/100 ml. Therefore, there was significant variation between the faecal coliforms count at the two sites (p = 0.046). The results suggest that the general microbiological quality of the water at the study area was unacceptable.
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Lavin, P. A., and J. D. Mcphail. "The evolution of freshwater diversity in the threespine stickleback (Gasterosteus aculeatus): site-specific differentiation of trophic morphology." Canadian Journal of Zoology 63, no. 11 (1985): 2632–38. http://dx.doi.org/10.1139/z85-393.
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To assess interpopulation levels of morphological variability populations of Gasterosteus aculeatus were sampled from lakes within the upper Cowichan River system (Vancouver Island, British Columbia). Phenotypic divergence between populations is assumed to be a postglacial event. Nine characters were scored; eight were related to feeding and the ninth character was lateral plate number. All populations were the low plate morph; however, populations of Gasterosteus in lakes lacking piscivorous fish had significantly fewer lateral plates than populations in lakes with predatory fish species. Two distinct trophic "morphotypes" were identified, each one associated with a specific lake environment. Populations inhabiting benthic-dominated environments were found to possess reduced gill raker number and reduced gill raker length but increased upper jaw length relative to populations from limnetic environments. We propose that the interpopulation variability in trophic morphology is a response to trophic resource differences between lakes.
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Matthews, Kathleen R., and Haiganoush K. Preisler. "Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)." Canadian Journal of Fisheries and Aquatic Sciences 67, no. 2 (2010): 243–55. http://dx.doi.org/10.1139/f09-172.
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From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs ( Rana sierrae ) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied habitats, we used multistrata models (with water bodies as the strata) and potential function analyses. The probability of returning to previously used water bodies during all activity periods was typically greater than 80% and always greater than the probability of moving to other water bodies. Site fidelity models (with lake-specific movement transitions) were favored over those models that held movement transitions equal between lakes. Potential function analyses demonstrated that frogs were most strongly attracted to their original capture lakes rather than moving to the nearest available breeding or overwintering lake. Under current disturbances in high-elevation Sierra Nevada lakes (exotic trout, climate change), site fidelity is problematic because frogs return to lakes subject to drying or those with fish rather than dispersing to other lakes. Future recovery of declining species will need to focus efforts towards restoring habitats when animals maintain strong site fidelity even when their habitats deteriorate.