To see the other types of publications on this topic, follow the link: Biota of lakes.
Journal articles on the topic 'Biota of lakes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Biota of lakes.'
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
Macdonald, C. R., and C. D. Metcalfe. "Concentration and Distribution of PCB Congeners in Isolated Ontario Lakes Contaminated by Atmospheric Deposition." Canadian Journal of Fisheries and Aquatic Sciences 48, no. 3 (1991): 371–81. http://dx.doi.org/10.1139/f91-049.
Full textAbstract:
The concentration of 19 PCB congeners was analysed in biota, sediments, water, and suspended solids in four central Ontario lakes in which atmospheric deposition was the major source of PCB contamination. Input from the atmosphere resulted in total congener concentrations of 1–2 ng∙L−1 dissolved in water, 10–50 μg∙kg−1 (dry weight} in sediment, 5–10 μg∙kg−1 (wet weight) in biota from lower trophic levels (i.e. zooplankton, golden shiner (Notemigonus crysoleucas)), and 10–30 μg∙kg−1 (wet weight) in fish from upper trophic levels (yellow perch (Perca fiavescens), smallmouth bass (Micropterus dolomieui)). The dominant PCB congeners in the lakes were the trichlorobiphenyl congeners 31(28} and the hexachlorobiphenyl congeners 153 and 138, consistent with congener distributions reported for vapour- and particulate-bound PCBs in the atmosphere. Discriminant analysis indicated slight differences in congener patterns between the study lakes, but the general pattern for isolated lakes was substantially different from point-source contaminated lakes, primarily due to the high proportion of congeners 31(28). There was no significant difference in the total PCB concentrations in biota (lipid basis) between lakes, but within the lakes, total PCB concentrations were significantly higher in yellow perch than in biota from lower trophic levels.
2
Ovdina, Ekaterina, Vera Strakhovenko, and Emilia Solotchina. "Authigenic Carbonates in the Water–Biota–Bottom Sediments’ System of Small Lakes (South of Western Siberia)." Minerals 10, no. 6 (2020): 552. http://dx.doi.org/10.3390/min10060552.
Full textAbstract:
We studied 46 small, drainless lakes in various landscape types: The sub-taiga (Vasyugan plain), forest–steppe (Baraba lowland), and steppe and subzone of ribbon forests (Kulunda plain). Sampling of lake components (sediments, water, and biota) was performed. The materials were analyzed via a combination of modern analytical methods (atomic absorption spectroscopy, X-ray fluorescence, scanning electron microscopy and X-ray diffractometry). It was found that in the south of Western Siberia, lakes with a bicarbonate-sodium water composition are widespread against the background of general landscape zoning. This composition contributes to the abundant growth of biota in the lakes, which leads to the processes of authigenic carbonate formation from calcite–dolomite series and aragonite on geochemical barriers, i.e., drifting biota–water, submerged biota–water, and water–bottom sediments against a background of terrigenous demolition and organic matter accumulation. The article shows the differences in the composition and structure of low-temperature carbonate minerals formed on various geochemical barriers. It was found that low-magnesium calcite and aragonite are the most common authigenic carbonates in small lakes in the south of Western Siberia and are formed on all three geochemical barriers in lakes. High-magnesium calcites and Ca-excess dolomites are formed only at the water–bottom sediment barrier in lakes with HCO3–Na and Cl–HCO3–Na water composition at pH > 9 and with a total dissolved solids > 3 g·L−1 (in some lakes of HCO3-Na composition with a TDS < 3 g·L−1 and pH > 9).
3
Comin, F. A., and M. Alonso. "Spanish salt lakes: Their chemistry and biota." Hydrobiologia 158, no. 1 (1988): 237–45. http://dx.doi.org/10.1007/bf00026281.
Full text
4
Allen, Erik W., Ellie E. Prepas, Stephan Gabos, William MJ Strachan, and Weiping Zhang. "Methyl mercury concentrations in macroinvertebrates and fish from burned and undisturbed lakes on the Boreal Plain." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 9 (2005): 1963–77. http://dx.doi.org/10.1139/f05-103.
Full textAbstract:
Methyl mercury (MeHg) concentrations in macroinvertebrates and fish were compared among five lakes in burned catchments and five reference lakes on the western Canadian Boreal Plain to determine the influence of forest fire on MeHg bioaccumulation. Two years after fire, MeHg concentrations in five of six aquatic taxa were similar in burned and reference lakes. Among a larger set of 12 lakes, MeHg concentrations in biota were negatively correlated with lake water pH, trophic status, and hardness, reflecting a pre-existing gradient in water chemistry. Biomagnification of MeHg (as determined by regression of MeHg concentration on baseline-adjusted δ15N) was negatively correlated with lake water chlorophyll a concentration. A subsequent logging experiment interrupted by fire provided an opportunity to compare pre- and post-fire MeHg concentrations in aquatic biota. Three months after fire, biota MeHg concentrations had decreased by 32%50%, and lake water ammonium concentrations had increased 11-fold relative to the previous year. In this nutrient-rich setting, fire may lower MeHg concentrations in aquatic biota over the short-term by inducing an increase in lake productivity that dilutes MeHg at the base of the food web.
5
Subehi, L., H. Uno, Imroatushshoolikhah, et al. "Ecological Heterogeneity of Oxbow and Floodplain Lakes Along the Kapuas Riverine System." IOP Conference Series: Earth and Environmental Science 1062, no. 1 (2022): 012019. http://dx.doi.org/10.1088/1755-1315/1062/1/012019.
Full textAbstract:
Abstract Kapuas River in West Kalimantan with over 1,143 km is the largest river in Indonesia. It serves as a main refuge for high potential biodiversity. Oxbow lakes along the Kapuas River are of high ecological essential due to the number and the diversity of habitats they provide. In addition, oxbow lakes are critical components of the floodplain systems of lowland rivers. The objective of this study was to explore the diversity of oxbow lakes and their connectivity to the main river. We conducted fieldwork to measure water quality and ecological components at 12 oxbow lakes along the Kapuas River and two lakes in the Sentarum complex in January - February 2020. We measured the environmental parameters including water depth, water temperature, Secchi/transparency, pH, dissolved oxygen concentration, chlorophyll-a concentration, total nitrogen, and total phosphorus concentrations. Aquatic biota, including phytoplankton and zooplankton community structures, were also observed at 12 oxbow lakes along the Kapuas River and two lakes in the Sentraum complex. The sampling points represented both permanent and non-permanent connectivity of the oxbow lakes to the main river. The result indicates the variability of environmental characteristics between the lakes, based on water quality and biota analysis; for example, water acidity, as indicated by pH, was likely to seem like the main variable determining the oxbow lake biota. Also, the habitat connectivity of oxbow lakes to the main river has significantly influenced the biotic composition.
6
Baccini, Peter. "Metal transport and metal/biota interactions in lakes." Environmental Technology Letters 6, no. 1-11 (1985): 327–34. http://dx.doi.org/10.1080/09593338509384350.
Full text
7
Remucal, Christina K. "Spatial and temporal variability of perfluoroalkyl substances in the Laurentian Great Lakes." Environmental Science: Processes & Impacts 21, no. 11 (2019): 1816–34. http://dx.doi.org/10.1039/c9em00265k.
Full text
8
Vidal, Nicolas, Susanne L. Amsinck, Vítor Gonçalves, et al. "Food Webs and Fish Size Patterns in Insular Lakes Partially Support Climate-Related Features in Continental Lakes." Water 13, no. 10 (2021): 1380. http://dx.doi.org/10.3390/w13101380.
Full textAbstract:
Disentangling the effects of climate change on nature is one of the main challenges facing ecologists nowadays. Warmer climates forces strong effects on lake biota for fish, leading to a reduction in size, changes in diet, more frequent reproduction, and stronger cascading effects. Space-for-time substitution studies (SFTS) are often used to unravel climate effects on lakes biota; however, results from continental lakes are potentially confounded by biogeographical and evolutionary differences, also leading to an overall higher fish species richness in warm lakes. Such differences may not be found in lakes on remote islands, where natural fish free lakes have been subjected to stocking only during the past few hundred years. We studied 20 species-poor lakes located in two remote island groups with contrasting climates, but similar seasonality: the Faroe Islands (cold; 6.5 ± 2.8 °C annual average (SD) and the Azores Islands (warm; 17.3 ± 2.9 °C)). As for mainland lakes, mean body size of fish in the warmer lakes were smaller overall, and phytoplankton per unit of phosphorus higher. The δ13C carbon range for basal organisms, and for the whole food web, appeared wider in colder lakes. In contrast to previous works in continental fresh waters, Layman metrics of the fish food web were similar between the two climatic regions. Our results from insular systems provide further evidence that ambient temperatures, at least partially, drive the changes in fish size structure and the cascading effects found along latitude gradients in lakes.
9
Padilla Gil, Dora Nancy. "The Heteropterans (Gerromorpha and Nepomorpha) of Andean lakes from Colombia." Revista Facultad de Ciencias Básicas 15, no. 2 (2020): 57–68. http://dx.doi.org/10.18359/rfcb.4399.
Full textAbstract:

 
 
 
 The Nepomorpha and Gerromorpha heteropterans are highly diverse, mainly in Neotropical aquatic ecosystems; however, their composition in the lakes of the Tropical Andes is poorly known. This article presents the composition of aquatic and semiaquatic bugs and their geographical and altitudinal distribution in eight lentic ecosystems from the Cundinamarca department, Colombia. The similar aquatic heteropteran composition between these Andean lakes and its relationship with the geographical and altitudinal range from 1,585 to 3,700 m.a.s.l. in the Eastern Andes are also analyzed. To carry out this work, the collections and pertinent literature are reviewed, and biota similarity is compared by applying a upgma analysis. The results show the predominance of Nepomorpha with a total of 12 species, four genera, and two families: Corixidae (6), and Notonectidae (6). The second most common suborder is Gerromorpha with eight species, seven genera, and five families: Gerridae (3), Veliidae (2), Hebridae (1), Hydrometridae (1), and Mesoveliidae (1). The biota similarity is related to páramo ecosystems and forest type. This article is the first to consider aquatic and semiaquatic heteropterans as biota from the Andean and High Andean lakes in Colombia.
 
 
 
10
Yang, Hong, Charles J. Smiley, and Shipu Yang. "Comparative taphonomy of Miocene fossil biotas with soft tissues in lake deposits: Clarkia (Idaho, U.S.A.) and Shanwang (Shandong, P.R. China)." Paleontological Society Special Publications 6 (1992): 319. http://dx.doi.org/10.1017/s2475262200008790.
Full textAbstract:
The recent discovery of Tertiary plant fossil DNA from the Clarkia Miocene lacustrine deposits, northern Idaho, has raised concerns of the taphonomic conditions of preservation of fossil biotas with soft tissues and the further prediction of such occurrence in ancient lake deposits. The exceptionally preserved Clarkia fossil biota is compared with the Shanwang biota in Shandong Provence, eastern P.R.China, another example of Miocene conservative fossil lagerstatten. The comparison shows following similarities between the two extraordinarily preserved Miocene fossil biotas: (1) both were deposited under similar age, geological background, and depositional environment; (2) humid, warm-temperate paleoclimate was inferred in both areas; (3) both deposits contain diverse fossil biotas with soft tissues but having limited benthic organisms; (4) higher similarity coefficient exists between fossil diatoms, higher plants and insects at genus or higher taxonomic levels; and (5) overall similar taphofacies exists between the two fossil biotas.However, following differences appear between the two areas: (1) diverse vertebrate fossils in Shanwang site are sharply contrasted with the Clarkia biota in which terrestrial vertebrates are absent; (2) comparison of taphonomic signatures shows slightly different patterns between the two; (3) the two Miocene lakes originated in different manners, thus differences appear in configuration, stratification, and other paleolimnologic parameters between the two ancient lakes.The comparison of the two extraordinary fossil biotas, coupled with geologic, sedimentologic, paleoecologic and paleobiochemical studies, demonstrates that the formation and preservation of such fossil biotas with soft tissues in ancient lake deposits were strongly controlled by various paleolimnologic, paleoclimatic, taphonomic and compositional parameters.
11
Macdonald, C. R., and C. D. Metcalfe. "A Comparison of PCB Congener Distributions in Two Point-Source Contaminated Lakes and One Uncontaminated Lake in Ontario." Water Quality Research Journal 24, no. 1 (1989): 23–46. http://dx.doi.org/10.2166/wqjr.1989.003.
Full textAbstract:
Abstract PCB congener accumulation in biota and sediments involves several processes, including physical factors characterized by octanol-water partition coefficients and water solubility, and chemical factors which are influenced by the degree of chlorination and the substitution pattern of the individual congeners. The present study was conducted to determine if PCB congeners are distributed in a consistent pattern in two lakes known to have received point-source contamination with PCBs, and a control lake with no known point source. Samples of 4 groups of biota, water and sediment indicated that each lake had a unique pattern of congener distribution which was probably related to the source of the contamination. A comparison of total and individual PCB congener concentrations within each study lake showed that no one species consistently contained the highest residues of PCBs. Smallmouth bass had the highest concentration of PCBs in Rice lake while yellow perch was highest in Lakes Clear and Scugog. Sediments contained lower concentrations of PCBs than biota and did not show enrichment of higher chlorinated congeners, despite having high organic carbon content. Within the contaminated lakes, young-of-the-year (YOY) and older yellow perch had the same congener pattern, and there was no significant difference in their PCB concentration. This indicates that equilibrium concentrations of PCBs are established rapidly in the young fish and that all congeners equilibrate at the same rate.
12
Cera, Alessandra, Luca Gallitelli, and Massimiliano Scalici. "Macroplastics in Lakes: An Underrepresented Ecological Problem?" Water 15, no. 1 (2022): 60. http://dx.doi.org/10.3390/w15010060.
Full textAbstract:
Lakes are the greatest reserve of available superficial inland fresh water and concurrently one of the most threatened ecosystems. Among the many pollutants, plastics contaminate lakes worldwide; notwithstanding that, little is known on the impacts of macroplastics. The aim of this work is to provide the first global overview of scientific articles researching macroplastic pollution in lakes. Articles were selected from Web of Science and Scopus databases. We performed a bibliometric analysis of the results on the publication trend, geographical distribution of study areas, investigated matrix (i.e., water, sediment, biota), as well as abundance and type (i.e., shape, litter category, polymer) of lacustrine macroplastics. We also compared the articles’ methodologies. Fourteen articles were collected (the publication trend is increasing in recent years), showing a diffuse contamination by macroplastics. Research efforts are mostly focused on shoreline assessments. There is a lack of information and methodological standardisation (i.e., macroplastic size definition, sampling protocol, shape, litter categories), which limits the comparison of article outputs. We propose the definition of lacustrine macroplastics as plastics >5 mm and the adoption of the UNEP/IOC protocol to sample lake shoreline. We suggest focusing future investigations on (1) testing the methodological standardisation, (2) understanding the factors influencing macroplastic dispersal, and (3) assessing the impacts on biota.
13
Kidd, Karen A., Michael J. Paterson, Raymond H. Hesslein, Derek CG Muir та Robert E. Hecky. "Effects of northern pike (Esox lucius) additions on pollutant accumulation and food web structure, as determined by δ13 C and δ15 N , in a eutrophic and an oligotrophic lake". Canadian Journal of Fisheries and Aquatic Sciences 56, № 11 (1999): 2193–202. http://dx.doi.org/10.1139/f99-148.
Full textAbstract:
In May 1993 and 1994, northern pike (Esox lucius) were added to eutrophic Lake 227 and oligotrophic Lake 110 at the Experimental Lakes Area in northwestern Ontario. Both lakes were previously dominated by cyprinids, and northern pike additions significantly decreased cyprinid densities in both lakes. Food web relationships were determined pre- and post-manipulation using stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of zooplankton, benthic invertebrates, and fishes. In Lake 110, fathead minnow (Pimephales promelas) shifted from a zooplanktivorous to a zoobenthivorous diet as indicated by a shift in isotopic composition to more depleted δ15N and enriched δ13C values after northern pike additions. It was not possible to direct predator-induced shifts in cyprinid diets in Lake 227. Concentrations of mercury and organochlorines (sum of polychlorinated biphenyls (ΣPCB), dichlorodiphenyltrichloroethane (ΣDDT), and hexachlorocyclohexane (ΣHCH)) in these fish did not change markedly after northern pike introductions despite the shifts in diet for fathead minnow from Lake 110. However, concentrations of all contaminants were lower in biota from eutrophic Lake 227 when compared with Lake 110, which is consistent with previous studies. Our results indicate that nutrient availability, rather than short-term changes in food web structure, determined contaminant concentrations in fish and other biota from these lakes.
14
Keller, W. (Bill), Jocelyne Heneberry, and Brie A. Edwards. "Recovery of acidified Sudbury, Ontario, Canada, lakes: a multi-decade synthesis and update." Environmental Reviews 27, no. 1 (2019): 1–16. http://dx.doi.org/10.1139/er-2018-0018.
Full textAbstract:
The Sudbury region of northeastern Ontario, Canada, provides one of the world’s best examples of the resilience of aquatic ecosystems after reductions in atmospheric contaminant deposition. Thousands of lakes around the Sudbury metal smelters were badly damaged by acid deposition. Lakes closest to the smelters were also contaminated by metal particulates. However, large reductions in atmospheric SO2 and metal emissions starting in the early 1970s have led to widespread chemical improvements in these lakes, and recovery has been observed for various aquatic biota. Studies of Sudbury-area lakes are advancing our understanding of chemical and biological lake recovery; however, recovery is a complicated process and much remains to be learned. Biological recovery has often been slow to follow chemical recovery, and it has become apparent that the recovery of lakes from acidification is closely linked to interactions with other large-scale environmental stressors like climate change and Ca declines. Thus, in our multiple-stressor world, recovery may not bring individual lakes back to their exact former state. However, with time, substantial natural biological recovery toward typical lake communities can be reasonably expected for most but not necessarily all biota. For organisms with limited dispersal ability, particularly fish, human assistance may be necessary to re-establish typical communities. In lakes where food webs have been severely altered, re-establishment of typical diverse fish communities may in fact be an important element aiding the recovery of other important components of aquatic ecosystems including zooplankton and benthic macroinvertebrates. In the lakes closest to the smelters, where historically watersheds as well as lakes were severely damaged, the recovery of aquatic systems will be closely linked to ongoing terrestrial recovery and rehabilitation, particularly through the benefits of increased inputs of terrestrially derived organic matter. The dramatic lake recovery observed in the Sudbury area points to a brighter future for these lakes. However, continued monitoring will be needed to determine future changes and help guide the management and protection of Sudbury-area lakes in this multiple-stressor age.
15
Lescord, Gretchen L., Meredith G. Clayden, Karen A. Kidd, et al. "Assessing the utility of sulfur isotope values for understanding mercury concentrations in water and biota from high Arctic lakes." Arctic Science 5, no. 2 (2019): 90–106. http://dx.doi.org/10.1139/as-2018-0022.
Full textAbstract:
Methylmercury (MeHg) biomagnifies through aquatic food webs resulting in elevated concentrations in fish globally. Stable carbon and nitrogen isotopes are frequently used to determine dietary sources of MeHg and to model its biomagnification. However, given the strong links between MeHg and sulfur cycling, we investigated whether sulfur isotopes (δ34S) would improve our understanding of MeHg concentrations ([MeHg]) in Arctic lacustrine food webs. Delta34S values and total mercury (THg) or MeHg were measured in water, sediments, and biota from six lakes near Resolute Bay, NU, Canada. In two lakes impacted by historical eutrophication, aqueous sulfate δ34S was ∼8‰ more positive than sedimentary δ34S, suggestive of bacterial sulfate reduction in the sediment. In addition, aqueous δ34S showed a significant positive relationship with aqueous [MeHg] across lakes. Within taxa across lakes, [THg] in Arctic char muscle and [MeHg] in their main prey, chironomids, were positively related to their δ34S values across lakes, but inconsistent relationships were found across entire food webs among lakes. Across lakes, nitrogen isotopes were better predictors of biotic [THg] and [MeHg] than δ34S within this dataset. Our results suggest some linkages between Hg and S biogeochemistry in high Arctic lakes, which is an important consideration given anticipated climate-mediated changes in nutrient cycling.
16
Amano, Y., K. Taki, K. Murakami, T. Ishii, and H. Matsushima. "Sediment Remediation for Ecosystem in Eutrophic Lakes." Scientific World JOURNAL 2 (2002): 885–91. http://dx.doi.org/10.1100/tsw.2002.156.
Full textAbstract:
The remediation method — namely, a hybrid system combined with DAF and CRM — is studied in this paper for the size reduction of aqua-ecological circulation and for the elution control in lakes. Results show that two effects on water quality purification, the sediment washout effect and the elution control effect, can be induced by this system, and the biota inhabiting the lake is therefore shifted into an oligotrophic aspect, from blue algae to green algae and/or diatoms.
17
Radke, L. C., K. W. F. Howard, and Peter A. Gell. "Chemical diversity in south-eastern Australian saline lakes. I: geochemical causes." Marine and Freshwater Research 53, no. 6 (2002): 941. http://dx.doi.org/10.1071/mf01231.
Full textAbstract:
This study re-examined hydrochemical data for south-eastern Australian saline lakes using graphical techniques and reaction path models generated by PHRQPITZ. Results showed that the lakes are more diverse than previous studies have implied. Cyclic solute matrices are modified in catchments by rock–water interactions, mineral dissolution, seawater intrusion and cation-exchange reactions, and within the lakes by sulfate reduction, mixing, brine reflux, mineral precipitation and the recycling of the most soluble salts. Three different pathways of the Eugster–Jones–Hardie models are identified. The study is important because the described variations of water chemistry influence the composition of lake biota.
18
Papineau, Madeleine. "Small Lake Water Chemistry in Southern Quebec." Water Quality Research Journal 31, no. 1 (1996): 163–74. http://dx.doi.org/10.2166/wqrj.1996.010.
Full textAbstract:
Abstract Small lakes are an important resource both in terms of number and habitat for aquatic biota. A winter survey of 25 small lakes (&lt;5 ha) was carried out in the area northwest of Quebec City in December 1991 to assess the chemical status of these lakes in relation to acidic deposition. A large number (36%) of lakes in the &lt;5 ha size class have very little acid neutralizing capacity and usually relatively high concentrations of aluminum. The average concentration of hydrogen ions, sulfates, aluminum, colour and dissolved organic carbon is higher in the group of lakes in the &lt;5 ha size class than in a group of nearby lakes in the &gt; 5 ha size class. The addition of chemical information from lakes in the &lt;5 ha class to the estimates of number of lakes in different pH classes increases the proportion of lakes with a pH at or below 5.0 from 4 to 10% and that of lakes with a pH at or below 5.5 from 17 to 24%.
19
Hodgson, D. A., W. Vyverman, and K. Sabbe. "Limnology and biology of saline lakes in the Rauer Islands, eastern Antarctica." Antarctic Science 13, no. 3 (2001): 255–70. http://dx.doi.org/10.1017/s0954102001000372.
Full textAbstract:
The Rauer Islands contain more than fifty shallow lakes and small ephemeral ponds. Despite their proximity to the Vestfold Hills - one of the most diverse and intensively studied lake districts of eastern Antarctica - the lakes of the Rauer Islands have remained undescribed. In this study the physical and chemical limnology and biology of ten lakes is presented and their species-environment relationships explored using multivariate statistics. Analyses of chemical and biological data indicate that the Rauer Islands form a distinct limnological province amongst the lakes of the Prydz Bay oases. Salinities range from hypo- to hyper-saline with an ionic order close to that of seawater. Deviance from this order indicates either an earlier origin for some of the most hypersaline lakes when compared with the Vestfold Hills, more rapid evaporation vs precipitation or differences in the sources of ions resulting from isostatic history. With fluctuating salinities, winter water temperatures below –10°C, seasonal ice and slush formation, desiccation and high levels of solar radiation, the lacustrine environment presents considerable abiotic challenges for biological survival. Results indicate that there is little or no planktonic flora in the lakes and no zooplankton were encountered. Despite this, analyses of pigments, diatoms and other micro-algae revealed an active and diverse benthic biota characterized by filamentous cyanobacteria with interstitial algae. Thirty-eight diatom taxa, and a selection of Chlorophyta and Xanthophyta were detected amongst the cyanobacteria. Clusters in the diatom data correspond to salinity. Further analyses of the relationships between the biota and their environment revealed some of the strategies employed for survival. In particular, the synthesis of scytonemin was detected. This pigment is known to function as an extracellular UV sunscreen which protects cyanobacterial cells against damage by ultraviolet radiation. These results support the hypothesis that environmental extremes and biogeographical isolation control the biology of these lakes.
20
Allan, R. J. "Atmospheric mercury contamination of remote aquatic ecosystems in Canada." Water Science and Technology 39, no. 12 (1999): 173–77. http://dx.doi.org/10.2166/wst.1999.0544.
Full textAbstract:
The long-range atmospheric transport and deposition of metals, particularly mercury (Hg), into lakes has become a subject of increasing interest. In Canada, the sources of anthropogenic, atmospheric Hg are primarily considered to be power stations in the United States and Europe. Increases in deposition of Hg have been recorded in lake sediment cores from many parts of Canada. Where Hg input to lakes from local sources in Canada has been reduced, concentrations in lake sediments and lake biota have declined. However, in many remote lakes, fish consumption advisories are still in effect for Hg. Debate continues over the sources of this mercury, whether long-range anthropogenic, atmospheric or natural. Where studied, the same applies to remote lakes in other parts of the world.
21
Istvánovics, Vera. "The Role of Biota in Shaping the Phosphorus Cycle in Lakes." Freshwater Reviews 1, no. 2 (2008): 143–74. http://dx.doi.org/10.1608/frj-1.2.2.
Full text
22
Yu, Xue, Charles T. Driscoll, Mario Montesdeoca, et al. "Spatial patterns of mercury in biota of Adirondack, New York lakes." Ecotoxicology 20, no. 7 (2011): 1543–54. http://dx.doi.org/10.1007/s10646-011-0717-y.
Full text
23
Prepas, E. E., B. Pinel-Alloul, D. Planas, G. Méthot, S. Paquet, and S. Reedyk. "Forest harvest impacts on water quality and aquatic biota on the Boreal Plain: introduction to the TROLS lake program." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 2 (2001): 421–36. http://dx.doi.org/10.1139/f00-259.
Full textAbstract:
Eleven headwater lakes in Alberta's Boreal Plain were monitored for nutrients and plankton 2 years before and 2 years after variable watershed harvesting (harvesting mean 15%, range 0-35%). After harvesting, variations in annual precipitation resulted in lake water residence times that differed by an order of magnitude from one year to the next. During the first posttreatment year, total phosphorus concentrations increased (overall 40%) in most lakes; however, response was most consistent in lakes that were shallow and the water column mixed or weakly thermally stratified. Chlorophyll a, cyanobacteria (Aphanizomenon-Anabaena), and cyanotoxins (microcystin-LR) increased after harvesting, primarily in shallow lakes. Zooplankton abundance and biomass decreased after harvesting, particularly in stratified lakes where edible phytoplankton biomass declined. In the weakly or nonstratified lakes, declines in zooplankton biomass were associated with higher cyanobacterial biomass and cyanotoxins. Posttreatment change in total phosphorus concentration was strongly related to weather (greatest response in a wet year) and relative drainage basin size (drainage basin area to lake volume, r2 = 0,78, P << 0,01). There was no evidence that buffer strip width (20, 100, and 200 m) influenced lake response. These results suggest that activities within the entire watershed should be the focus of catchment-lake interactions.
24
Beck, Marcus W., and Lorin K. Hatch. "A review of research on the development of lake indices of biotic integrity." Environmental Reviews 17, NA (2009): 21–44. http://dx.doi.org/10.1139/a09-001.
Full textAbstract:
Current methods of ecological health assessment of lakes within the United States are not adequate for meeting the requirements of the 1972 Clean Water Act (CWA) and assessing the condition of aquatic biota. Impairment status of lakes has typically been measured and classified by individual states via eutrophication standards or through the use of total maximum daily load (TMDL) protocols. These measurements often fail to account for effects of anthropogenic disturbances on aquatic biota that are not directly reflected by chemical and physical proxies of environmental condition. The index of biotic integrity (IBI) is a potentially effective ecological health assessment method that is meant to integrate ecological, functional, and structural aspects of aquatic systems. Furthermore, the IBI is meant to meet the requirements of the CWA by directly examining biological components of an ecosystem. The adaptation of the IBI for use in lake monitoring has increased in recent years as managers address the need to directly examine the biota of aquatic systems. This review is meant to examine research related to the development of IBIs in lacustrine environments. Obstacles and shortcomings to index development that are commonly encountered are discussed within the review. Attention is also given to robust methods and lessons learned from inadequate methods. The review will facilitate use of the IBI for lake monitoring efforts with the overall goal of improving water resource management.
25
Kline Jr., Thomas C., John J. Goering, Ole A. Mathisen, Patrick H. Poe, Patrick L. Parker та Richard S. Scalan. "Recycling of Elements Transported Upstream by Runs of Pacific Salmon: II. δ15N and δ13C Evidence in the Kvichak River Watershed, Bristol Bay, Southwestern Alaska". Canadian Journal of Fisheries and Aquatic Sciences 50, № 11 (1993): 2350–65. http://dx.doi.org/10.1139/f93-259.
Full textAbstract:
Biota δ15N and δ13C values (deviations from recognized isotope standards) from lliamna Lake (a major anadromous sockeye salmon (Oncorhynchus nerka) nursery lake supporting peak-year runs > 10 million) and several other anadromous-salmon-free lakes in the Kvichak River watershed, Bristol Bay, southwestern Alaska, were compared to determine the significance of marine-derived nitrogen (MDN) delivered by returning adult salmon. Biota in lliamna Lake had higher δ15N compared with control lakes, verifying a mixing model correlating δ15N with MDN. Periphyton δ15N values reflected localized input from populations of spawning salmon. Juvenile sockeye MDN varied in response to escapement size, suggesting the importance of large escapements (> 10 million) for maintaining a predominantly MDN lacustrine N pool. Other resident fishes showed shifts in δ15N between years of high and low escapement. The dual-isotope approach, using δ15N and δ13C together, suggested that fish production is primarily dependent on limnetic primary and secondary production. The dual-isotope approach indicated that the coast range sculpin (Cottus aleuticus) was the only fish with an appreciable dietary component consisting of salmon eggs or emergent fry.
26
Hicks, Heraline E. "The Great Lakes: a Historical Overview." Toxicology and Industrial Health 12, no. 3-4 (1996): 303–13. http://dx.doi.org/10.1177/074823379601200303.
Full textAbstract:
The Great Lakes are collectively the largest inland body of freshwater on this planet. For more than two hundred years, the Great Lakes basin has been used as a resource for industry, agriculture, shipping, and recreation. The physical characteristics of the basin and the long retention time of chemicals in the lakes combine to make this huge freshwater resource a repository for chemical by-products of these activities. Many of the more than one thousand chemicals detected in the waters, sediment, or biota of the Great Lakes have known toxic effects. This overview will identify the 11 most persistent toxic chemicals known as "critical" Great Lakes pollutants. It also will describe some of the adverse health effects that have been observed in fish and other wildlife because of exposure to these pollutants. Finally. it will discuss some of the early human health studies that 1) have demonstrated a correlation between increased body burdens and fish consumption, and 2) suggest an association between consumption of contaminated Great Lakes fish and adverse human health effects.
27
Shapiro, Joseph. "Lake restoration by biomanipulation—a personal view." Environmental Reviews 3, no. 1 (1995): 83–93. http://dx.doi.org/10.1139/a95-003.
Full textAbstract:
Restoration of over-fertilized, algae-laden lakes and reservoirs has generally been based on removal or reduction of phosphorus inputs and concentrations. However, this approach frequently is not feasible. An alternative is biomanipulation, in which the biota of the water body, particularly the fish population, is manipulated so as to reduce predation on small herbivorous zooplankters. This results in increases in body size of the zooplankters with consequent great increases in grazing rates on the algae. The process, though controversial, has worked in many lakes and offers promise to many more.Key words: biomanipulation, trophic cascade, lake restoration.
28
Ionescu, Venera, Maria Năstăsescu, Lucreţia Spiridon, and Valentin A. C. Bulgăreanu. "The biota of Romanian saline lakes on rock salt bodies: A review." International Journal of Salt Lake Research 7, no. 1 (1998): 45–80. http://dx.doi.org/10.1007/bf02449924.
Full text
29
Minns, C. K., J. E. Moore, D. W. Schindler, and M. L. Jones. "Assessing the Potential Extent of Damage to Inland Lakes in Eastern Canada due to Acidic Deposition. III. Predicted Impacts on Species Richness in Seven Groups of Aquatic Biota." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 4 (1990): 821–30. http://dx.doi.org/10.1139/f90-095.
Full textAbstract:
Linked regional chemical and biotic models predicted that at least 20% of all lakes in 15 of 38 secondary watersheds in eastern Canada had lost at least 20% of their potential species richness given 1980 acidic sulphate deposition levels; 20% of lakes in 15 watersheds represents circa 55 000 lakes. Fish and molluscs were the most affected of seven aquatic taxonomic groups, and rotifers the least. Mean percent loss of potential richness in all of eastern Canada ranged from 5.0 to 9.5% for the seven groups of biota under 1980 acidic deposition. Sulphur dioxide emission reductions of 42% in Canada and the United States were predicted to reduce the number of affected watersheds to seven, leaving circa 25 000 lakes with 20% or more loss of potential richness. Greater acidic deposition reductions will be needed to minimize the biotic damage affecting large areas of eastern Canada.
30
Enache, Mădălin, Takashi Itoh, Masahiro Kamekura, Gabriela Popescu, and Lucia Dumitru. "Halophilic archaea isolated from man-made young (200 years) salt lakes in Slănic, Prahova, Romania." Open Life Sciences 3, no. 4 (2008): 388–95. http://dx.doi.org/10.2478/s11535-008-0034-5.
Full textAbstract:
AbstractWe isolated a number of extremely halophilic archaea from four salt lakes (Red Bath, Green Bath, Shepherd Bath and Bride Cave) located in Slanic Prahova, Romania. The characterization of 12 representative isolates by polyphasic approach revealed that 11 strains were members of the genus Haloferax and only one was a member of the genus Haloarcula. The 11 Haloferax isolates possessed sulfated diglycosylarchaeol-1 as the major membrane glycolipid, and G+C contents of total DNA were 63.4–65.8 mol%. The predominant isolation of Haloferax species from the lakes may suggest that the underground salt deposit possesses Haloferax species as the major biota of ancient origin. To the best of the authors’ knowledge, this is the first paper on the survey of halophilic archaea of man-made young salt lakes.
31
Currie, David J. "Phosphorus Deficiency and its Variation among Lakes." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 6 (1990): 1077–84. http://dx.doi.org/10.1139/f90-124.
Full textAbstract:
The severity of phosphorus deficiency varies greatly among lakes. Is this variation related to particular morphological, chemical, or biological characteristics of lakes? These questions were addressed by sampling 49 lakes in Quebec, Ontario, and the northeastern United States. The rate constant of orthophosphate uptake (k1), a measure of orthophosphate demand:supply, proved to be only weakly related to watershed area and to the total phosphorus (P) concentration of the water (R2 = 0.210). Abundance of the biota and other aspects of water chemistry were all unrelated to the intensity of P-deficiency as it varies among lakes. In contrast, within-lake seasonal variability of the rate constant of orthophosphate turnover (kt, which is approximately equal to k1) is strongly related to temperature and bacterial abundance (R2 = 0.575 to 0.828). The results indicate that the seasonal variation in phosphorus deficiency depends strongly on bacterioplankton activity, whereas inter-lake variability in phosphorus deficiency is determined mainly by factors other than morphometry, plankton abundance, or trophic richness.
32
Kutyła, Sebastian. "Characteristics of water level fluctuations in Polish lakes – a review of the literature / Charakterystyka wahań poziomu wody w jeziorach polskich – przegląd piśmiennictwa." Ochrona Srodowiska i Zasobów Naturalnych 25, no. 3 (2014): 27–34. http://dx.doi.org/10.2478/oszn-2014-0011.
Full textAbstract:
Abstract Water level fluctuations (WLF) in lakes are a natural feature that can be modified by human activities. The article presents a review of literature on the water level fluctuation in Polish lakes, their amplitude, periodicity and trends. WLF controlled by natural conditions and also those induced by human activity were considered. Although anthropogenic water level fluctuations in most Polish lakes seem to fall within the range of natural fluctuations, in some cases economic activities (e.g. the use of lakes for energy generation purposes) can lead to strong disturbances of the hydrological regime, causing an ecological instability that makes it impossible to maintain/achieve good ecological status. This, in turn, makes it necessary to define good ecological potential, being an environmental objective for such water bodies, which is less rigorous compared with good ecological status. The article indicates the need to expand the methods for the assessment of lakes in the country with new biological indicators to assess, in accordance with the Water Framework Directive requirements, the impact of hydrological alterations on biota
33
Denisov, Dmitry B., Svetlana A. Valkova, Vladimir A. Dauvalter, et al. "Limnological research in the Institute of North Industrial Ecology Problems of the KSC RAS." Transaction Kola Science Centre 11, no. 6-2020 (2020): 68–86. http://dx.doi.org/10.37614/2307-5252.2020.6.19.006.
Full textAbstract:
The article gives an overview of the limnological research historyat INEP KSC RAS since the late 1980s. until now. The most important results of complex work are presented, including the study of the hydrochemical composition of water and bottom sediments, as well as biota (plankton, benthos and fish) of the Murmansk region lakes. The prospects for the scientific research development of are shown.
34
Garcia, Edenise, and Richard Carignan. "Mercury concentrations in northern pike ( Esox lucius) from boreal lakes with logged, burned, or undisturbed catchments." Canadian Journal of Fisheries and Aquatic Sciences 57, S2 (2000): 129–35. http://dx.doi.org/10.1139/f00-126.
Full textAbstract:
We measured total Hg and stable isotopes (δ13C and δ15N) in northern pike (Esox lucius) from 19 Boreal Shield lakes with undisturbed, logged, or burned watersheds. Average Hg level in standard 560-mm northern pike, on a dry weight basis, was significantly higher in logged lakes (3.4 µg·g-1) than in reference lakes (1.9 µg·g-1). Average Hg concentrations in burned lakes (3.0 µg·g -1) did not differ significantly from those in logged and references lakes. Concentrations of Hg normalized to trophic position determined from isotopic composition yielded similar results. Mercury levels were above the WHO safe consumption limit in all logged lakes. Mercury in northern pike was correlated with methyl mercury in zooplankton (+), total N (+), pH (-), alkalinity (-), sulfate (+), dissolved organic C loading (+), and light attenuation in lake water (+). Stepwise multiple regressions explained 79% of the variability in Hg in fish and included methyl mercury in zooplankton, pH, and sulfate as independent variables. Explained variability increased to 92% when a second-order lake with an exceptionally large drainage area was excluded. Our results suggest that extensive logging activities may disrupt the natural cycling of Hg in watersheds and increase Hg levels in the aquatic biota.
35
Oikonomou, Anthi, та Konstantinos Stefanidis. "α- and β-Diversity Patterns of Macrophytes and Freshwater Fishes are Driven by Different Factors and Processes in Lakes of the Unexplored Southern Balkan Biodiversity Hotspot". Water 12, № 7 (2020): 1984. http://dx.doi.org/10.3390/w12071984.
Full textAbstract:
Disentangling the main drivers of species richness and community composition is a central theme in ecology. Freshwater biodiversity patterns have been poorly explored; yet, it has been shown that different freshwater biota have different, often contrasting responses to environmental gradients. In this study, we investigated the relative contribution of geographical and environmental (habitat-, climate- and water quality-related) factors/gradients in shaping the α- and β-diversity patterns of macrophytes and fish in sixteen natural freshwater lakes of an unexplored Balkan biodiversity hotspot, the Southern Balkan Peninsula. We employed generalized linear modeling to identify drivers of α-diversity, and generalized dissimilarity modeling to explore commonalities and dissimilarities of among-biota β-diversity. Species richness of both biota was significantly associated with lake surface area, whereas macrophytes had an inverse response to altitude, compared to fish. Both species turnover and nestedness significantly contributed to the total β-diversity of macrophytes. In contrast, species turnover was the most significant contributor to the total fish β-diversity. We found that the compositional variation of macrophytes is primarily limited by dispersal and ultimately shaped by environmental drivers, resulting in spatially structured assemblages. Fish communities were primarily shaped by altitude, highlighting the role of species sorting. We conclude that among-biota diversity patterns are shaped by different/contrasting factors, and, thus, effective/sustainable conservation strategies should encompass multiple aquatic biota.
36
Yan, Norman D., Andrew M. Paterson, Keith M. Somers, and Wolfgang A. Scheider. "An introduction to the Dorset special issue: transforming understanding of factors that regulate aquatic ecosystems on the southern Canadian Shield." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 5 (2008): 781–85. http://dx.doi.org/10.1139/f08-077.
Full textAbstract:
This special issue demonstrates that aquatic ecosystems on the south-central Canadian Shield have changed in many ways over the last three decades. El Niño cycles have synchronized multilake dynamics in lake-water chemistry and in several components of the aquatic biota. Overlain on this cyclic regional pattern, phosphorus, sulphate, and calcium levels have all declined, whereas alkalinity has not yet risen in the most acid-sensitive study lakes, despite large reductions in SO2 emissions. Further, novel and unanticipated stressors have appeared, including nonindigenous predator introductions, Ca decline, salinity increase, and autumn spikes in metals following El Niño induced droughts. The resident biota are clearly responding not only to the familiar historical phosphorus and acid stressors, but also to the interactive effects of changes in multiple stressors in a warming environment. Lakes are best managed with an understanding of dominant limnological trends, their causes, and their responses to past management interventions. The research conducted at the Dorset Environmental Science Centre indicates “progress but no cigar” on acid rain, proof of climate variability as a direct and indirect regulator of south-central Shield ecosystems, and the emergence of novel stressors, the effects of which we cannot yet fully predict.
37
Kullman, Marilynn A., Karen A. Kidd, Cheryl L. Podemski, Michael J. Paterson, and Paul J. Blanchfield. "Assimilation of freshwater salmonid aquaculture waste by native aquatic biotaThis 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): 1965–75. http://dx.doi.org/10.1139/f09-128.
Full textAbstract:
An experimental finfish aquaculture farm was operated in a small lake at the Experimental Lakes Area in northwestern Ontario, Canada. In this study, we used the distinct and enriched carbon and nitrogen isotope ratios (δ13C and δ15N) of rainbow trout ( Oncorhynchus mykiss ) feed and waste to determine whether the operation provided a novel source of energy for native biota. For 1 year prior to and for 3 years during the cage culture, we collected littoral, pelagic, and profundal invertebrates and minnows from the experimental and reference lakes. In both the second and third years of aquaculture, there was a significant increase in δ15N of all organisms sampled in the experimental lake; mean δ15N values of littoral, pelagic, and profundal invertebrates and minnows shifted towards the signature of the fish feed by up to 4.2‰. Significant increases in δ13C of up to 2.6‰ were observed in Mysis , profundal chironomids, and minnows but not in littoral invertebrates or zooplankton. Aquaculture waste became a progressively more important component of minnow diets over the course of this study. The dissolved and (or) particulate wastes of the cage operation became a novel source of energy for the native biota in this experimental lake.
38
Gouramanis, C., P. De Deckker, D. Wilkins, and J. Dodson. "High-resolution, multiproxy palaeoenvironmental changes recorded from Two Mile Lake, southern Western Australia: implications for Ramsar-listed playa sites." Marine and Freshwater Research 67, no. 6 (2016): 748. http://dx.doi.org/10.1071/mf14193.
Full textAbstract:
Numerous saline playa lakes exist across the arid, semiarid and temperate regions of Australia. These playa lakes exhibit a diverse range of hydrological conditions to which the Australian aquatic invertebrate biota have become adapted and which the biota can utilise as refugia in times of hydrological deterioration. Saline playas also yield palaeoenvironmental records that can be used to infer lacustrine and catchment responses to environmental variability. We present a palaeoenvironmental record recovered from Two Mile Lake, a saline playa from southern Western Australia. Dating, based on quartz optical luminescence and 14C accelerator mass spectrometry of biogenic carbonates and organic fibres, suggests that most of the sediment was rapidly deposited at 4.36 ± 0.25 thousand years ago. Ostracods and non-marine foraminifera preserved in the sediment show periods of faunal colonisation of the lake with oscillations between hypersaline and oligosaline conditions. The geochemistry of ostracod valves and foraminifera tests suggests higher-frequency variability within the lake, and palynological changes indicate landscape changes, possibly in response to fire. The Two Mile Lake record highlights the utility of saline playas as archives of environmental change that can be used to guide wetland health management, particularly under the impacts of a changing climate.
39
Maghsodian, Zeinab, Ali Mohammad Sanati, Tebogo Mashifana, et al. "Occurrence and Distribution of Antibiotics in the Water, Sediment, and Biota of Freshwater and Marine Environments: A Review." Antibiotics 11, no. 11 (2022): 1461. http://dx.doi.org/10.3390/antibiotics11111461.
Full textAbstract:
Antibiotics, as pollutants of emerging concern, can enter marine environments, rivers, and lakes and endanger ecology and human health. The purpose of this study was to review the studies conducted on the presence of antibiotics in water, sediments, and organisms in aquatic environments (i.e., seas, rivers, and lakes). Most of the reviewed studies were conducted in 2018 (15%) and 2014 (11%). Antibiotics were reported in aqueous media at a concentration of <1 ng/L–100 μg/L. The results showed that the highest number of works were conducted in the Asian continent (seas: 74%, rivers: 78%, lakes: 87%, living organisms: 100%). The highest concentration of antibiotics in water and sea sediments, with a frequency of 49%, was related to fluoroquinolones. According to the results, the highest amounts of antibiotics in water and sediment were reported as 460 ng/L and 406 ng/g, respectively. In rivers, sulfonamides had the highest abundance (30%). Fluoroquinolones (with an abundance of 34%) had the highest concentration in lakes. Moreover, the highest concentration of fluoroquinolones in living organisms was reported at 68,000 ng/g, with a frequency of 39%. According to the obtained results, it can be concluded that sulfonamides and fluoroquinolones are among the most dangerous antibiotics due to their high concentrations in the environment. This review provides timely information regarding the presence of antibiotics in different aquatic environments, which can be helpful for estimating ecological risks, contamination levels, and their management.
40
Verleyen, Elie, Dominic A. Hodgson, John Gibson, et al. "Chemical limnology in coastal East Antarctic lakes: monitoring future climate change in centres of endemism and biodiversity." Antarctic Science 24, no. 1 (2011): 23–33. http://dx.doi.org/10.1017/s0954102011000642.
Full textAbstract:
AbstractPolar lakes respond quickly to climate-induced environmental changes. We studied the chemical limnological variability in 127 lakes and ponds from eight ice-free regions along the East Antarctic coastline, and compared repeat specific conductance measurements from lakes in the Larsemann Hills and Skarvsnes covering the periods 1987–2009 and 1997–2008, respectively. Specific conductance, the concentration of the major ions, pH and the concentration of the major nutrients underlie the variation in limnology between and within the regions. This limnological variability is probably related to differences in the time of deglaciation, lake origin and evolution, geology and geomorphology of the lake basins and their catchment areas, sub-regional climate patterns, the distance of the lakes and the lake districts to the ice sheet and the Southern Ocean, and the presence of particular biota in the lakes and their catchment areas. In regions where repeat surveys were available, inter-annual and inter-decadal variability in specific conductance was relatively large and most pronounced in the non-dilute lakes with a low lake depth to surface area ratio. We conclude that long-term specific conductance measurements in these lakes are complementary to snow accumulation data from ice cores, inexpensive, easy to obtain, and should thus be part of long-term limnological and biological monitoring programmes.
41
Zullini, Aldo. "Is a biogeography of freshwater nematodes possible?" Nematology 16, no. 1 (2014): 1–8. http://dx.doi.org/10.1163/15685411-00002779.
Full textAbstract:
An attempt was made to detect some possible biogeographic patterns in the distribution of freshwater nematodes. The literature concerning 14 geographic areas (in Eurasia, Africa and America) and seven well studied lakes was examined. Notwithstanding the ubiquity of most freshwater nematodes, some distributional patterns emerge from a multidimensional analysis. Examining the lakes only, nematodes in Lake Baikal appear markedly different from the other lacustrine nematodes from other parts of the world. It is possible to conclude: i) that freshwater nematodes communities show some difference at the continental level only; and ii) that the freshwater nematode biota is divided into two parts with the Lake Baikal community as one part, and the rest of the world community as the other.
42
Mallory, M. L., D. K. McNicol, D. A. Cluis, and C. Laberge. "Chemical trends and status of small lakes near Sudbury, Ontario, 1983-1995: evidence of continued chemical recovery." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 1 (1998): 63–75. http://dx.doi.org/10.1139/f97-213.
Full textAbstract:
We monitored 23 chemical parameters in 161 lakes northeast of Sudbury, Ontario, in most years between 1983 and 1995 to determine whether lake chemistries were responding to reduced local SO2 emissions. Lakes were typically small (median 4.0 ha, 4.5 m deep), rapid flushing, and acid stressed (median pH 5.58, acid-neutalizing capacity (ANC) 7.1 µequiv. ·L-1). Forty percent of the lakes declined significantly in SO4, base cations, and Al levels from 1983 to 1995, but only 12 and 16% increased in ANC and pH, respectively. Chemical trends were influenced by local climate; pronounced improvements occurred in response to drought conditions (1986 and 1987), but rapid deterioration followed the wet year in 1988. With more typical precipitation levels since 1989, a pattern of gradual improvement returned. Connected, rapid-flushing lakes, those on low or moderately sensitive bedrock, and peatlands showed the greatest improvements in pH and ANC whereas glacial headwaters and lakes on highly sensitive bedrock showed the least improvement. These results confirm that some recovery continues to occur following local emission reductions. However, many small Sudbury area lakes remain very degraded and unsuitable for acid-sensitive biota. Further emission reductions, including long-range sources, may be necessary to restore chemical conditions to critical levels sufficient to support further biological recovery.
43
Jeffries, D. S., D. CL Lam, I. Wong, and M. D. Moran. "Assessment of changes in lake pH in southeastern Canada arising from present levels and expected reductions in acidic deposition." Canadian Journal of Fisheries and Aquatic Sciences 57, S2 (2000): 40–49. http://dx.doi.org/10.1139/f00-128.
Full textAbstract:
An integrated acid rain assessment model was used to estimate pH for six clusters of lakes in southeastern Canada and scenarios of sulphate deposition that reflect the situation (a) before implementation of the SO2 emission controls required by the Canada/U.S. Air Quality Agreement, (b) after implementation of Canadian controls, and (c) after implementation of Canadian and U.S. controls. Modelled lake pHs were always less than their estimated original values. To assess the ecological significance of the pH reduction, scenario "damage" was quantified as the percentage of cluster lakes having pH < 6, a threshold criterion sufficient to protect most aquatic biota. Care was taken to account for naturally acidified lakes. The integrated acid rain assessment model predicted that Canadian SO2 controls will reduce damage in Ontario and Quebec but have little effect in Atlantic Canada. Implementation of U.S. SO2 controls will further reduce damage throughout all regions, although it is conservatively estimated that from 5 to 24% of the lakes will still have pH < 6 depending on cluster. Extrapolating to the inventory of acid-sensitive lakes in southeastern Canada suggests that ~76 000 lakes and ~970 000 ha of lake area will remain chemically damaged unless additional reductions in SO2 emissions are implemented beyond those required by the Air Quality Agreement.
44
Marshall, T. R., and P. A. Ryan. "Abundance Patterns and Community Attributes of Fishes Relative to Environmental Gradients." Canadian Journal of Fisheries and Aquatic Sciences 44, S2 (1987): s198—s215. http://dx.doi.org/10.1139/f87-323.
Full textAbstract:
Seventy-five lakes of the Canadian boreal forest were examined for patterns of fish species abundance and community structure in relation to gradients of four environmental variables: (1) lake area, (2) mean depth, (3) Secchi disk transparency, and (4) morphoedaphic index (MEI). Mean depth appeared to exert the greatest control on the relative abundance of the species considered. The remaining variables influenced abundance in unique ways, although, as with mean depth, this influence was mainly a consequence of changes in thermal and nutrient regimes. An examination of lower trophic components indicated that these regimes appear to structure food webs, with distinctly different patterns in food webs occurring in dimictic and polymictic lakes. Major shifts in aquatic biota occur in the transition region between lake types. Lakes with these characteristics are at a lower successional state due to environmental unpredictability, as demonstrated by an increasing importance of r- over K-strategists.
45
Blanchfield, Paul J., Michael J. Paterson, John A. Shearer, and David W. Schindler. "Johnson and Vallentyne’s legacy: 40 years of aquatic research at the Experimental Lakes Area." Canadian Journal of Fisheries and Aquatic Sciences 66, no. 11 (2009): 1831–36. http://dx.doi.org/10.1139/f09-148.
Full textAbstract:
Wally Johnson and Jack Vallentyne played key roles in the establishment of the Experimental Lakes Area (ELA), which comprises a research team, a set of protected lakes, and a field station, with the mandate to quantify anthropogenic impacts to lakes through whole-ecosystem manipulation and monitoring. We begin this collection of papers, celebrating four decades of aquatic research at the ELA, by reflecting on the historical relevance and scientific milestones of the ELA. The remaining papers encompass themes at the core of ELA research: long-term ecological monitoring of unimpacted reference lakes, ecosystem responses to anthropogenic stressors through whole-system experimentation, recovery of manipulated ecosystems from perturbation, and detailed mechanistic studies. Utilizing these approaches, papers in this issue examine a wide variety of anthropogenic impacts on freshwater including the ecosystem effects of climate change, recovery from lake acidification, upland and wetland flooding on methyl mercury levels in biota, endocrine-disrupting chemicals on fish populations, and freshwater aquaculture. These studies emphasize the value of long-term monitoring and experimentation at the ecosystem scale for understanding human impacts on freshwaters.
46
Udayakumar, Muthulingam, and Kanakasanthi Ajithadoss. "Angiosperms, Hydrophytes of five ephemeral lakes of Thiruvallur District, Tamil Nadu, India." Check List 6, no. 2 (2010): 270. http://dx.doi.org/10.15560/6.2.270.
Full textAbstract:
The aim of this study was to document the Angiosperm diversity of five ephemeral lakes of Thiruvallur District of Tamil Nadu South India. Qualitative floristic surveys were carried out during 2005-2007. Herbarium specimens with voucher number, taxonomical and ecological information were deposited to the herbarium, Pachaiyappa’s College (PCH) Chennai, Tamilnadu. Forty five species of hydrophytes belonging to 21 families and 34 genera were documented. Most speciose families were Poaceae with 5 species followed by Polygalaceae and Nymphaeaceae (4) Cyperaceae, Hydrocharitaceae, Najadaceae, and Scrophulariaceae (3 species each). Mean depth of all five lakes shrinking gradually due to severe anthropogenic pressure. Conservation of wetlands is the need of the hour to protect the biota as well as quality of drinking water.
47
Nunes, Josué Ribeiro da Silva, and Carolina Joana da Silva. "Biomass of Eichhornia crassipes, (Mart) Solms. In the Chacororé–Sinhá Mariana, lake System Pantanal of Mato Grosso, Brazil." Research, Society and Development 10, no. 2 (2021): e141029293. http://dx.doi.org/10.33448/rsd-v10i2.9293.
Full textAbstract:
The Pantanal constitutes the biggest floodplain of the world, forming a mosaic of different habitats, sustaining rich aquatic and terrestrial biota. This mosaic of habitats of the Pantanal is well represented in the Barão de Melgaço region by the Chacororé-Sinhá Mariana Lake System, this system of parental lakes of Cuiabá river are recognized by their aquatic productivity and scenically beauty. The aquatic macrophyte are very abundant organisms being considered the most productive community in the aquatic system, with great capacity of accumulate biomass and nutrients. The samples were collected into three stations representing the Chacororé-Sinhá Mariana lakes and the transition between them. This study had as purpose to evaluate the spatial and temporal dynamic of biomass in E. crassipes in the stands of this specie in Chacororé-Sinhá Mariana “baía” system. The results shown that both lakes shown bigger biomass during flood, and that in transition sample area were verified the bigger biomass of studied areas. This research supports another studies realized in the Pantanal about the importance of the “flood pulse” in the temporal variation of the biomass and shown that the variation of the biomass of E. crassipes in the lakes evidence the spatial heterogeneity which exists between those lakes. In this way the aquatic macrophyte can indicate the impacts resulting of the hydrological changes in this system of lakes.
48
Minns, Charles K., James E. Moore, Brian J. Shuter, and Nicholas E. Mandrak. "A preliminary national analysis of some key characteristics of Canadian lakes." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 8 (2008): 1763–78. http://dx.doi.org/10.1139/f08-110.
Full textAbstract:
Knowledge of Canada’s lakes is needed to manage environmental stresses. Lake inventory and lake feature databases were used to build a national impact assessment template and assess regional typology. There are ~910 400 lakes with area ≥ 0.1 km2(10 ha), 37% of the Earth’s total. Lake features (number of lakes by size class, maximum depth, mean–maximum depth ratio, Secchi depth, pH, and total dissolved solids) were modeled regionally by secondary watershed (SWS) using linear regression models. Lake trout ( Salvelinus namaycush ) occurrence was analyzed as a cofactor to highlight regional links between lake characteristics and aquatic biota. Significant (R2from 0.231 to 0.492) regional models were obtained using area or maximum depth, lake trout occurrence, and their cross products as covariates. Analyses of fitted SWS coefficients showed that ecozones were a better predictor of lake characteristics than primary watersheds. The national typology was consistent with previous regional assessments. The regional models were used to estimate the number, area, and volume of lake trout lakes by size class and ecozone. There are ~66 500 lake trout lakes covering ~3 510 000 km2primarily on Boreal and Taiga Shield areas. Regional lake resource models will enable national assessment of stresses such as climate change and invasive species.
49
Metcalfe, Christopher D., and G. Douglas Haffner. "The ecotoxicology of coplanar polychlorinated biphenyls." Environmental Reviews 3, no. 2 (1995): 171–90. http://dx.doi.org/10.1139/a95-008.
Full textAbstract:
Polychlorinated biphenyls (PCBs) have been recognized for over 25 years as global environmental contaminants. However, many PCB congeners may be relatively harmless, while a small group of PCB congeners are highly toxic to biota. The toxic coplanar PCB congeners are chlorinated at meta positions and at one or none of the ortho positions on the biphenyl ring, thus resembling 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in molecular configuration. In vitro and in vivo toxicity tests with rodents, fish, and birds have shown that the coplanar PCB congener 126 is almost as toxic as TCDD. Several coplanar PCBs (e.g., 77, 126, 105, 118) are present in biota at parts per billion concentrations, which is orders of magnitude higher than concentrations of TCDD. Thus, coplanar PCBs may account for over 95% of the dioxinlike toxic activity affecting biota, such as fish-eating birds in the Great Lakes. There is some evidence that the toxicokinetics of coplanar PCBs in organisms differs from that of other PCB homologues. If coplanar PCBs are more persistent than their homologues, they could become enriched in biota as they pass up through the food chain (i.e., trophic enrichment), or as overall PCB levels decline with time (i.e., temporal enrichment). Overall, the available data do not support the concept of trophic or temporal enrichment in the environment.Key words: polychlorinated biphenyls, coplanar, toxic equivalents, kinetics, mixed function oxidase, 7-ethoxyresorufin-O-deethylase.
50
Hebert, C. E., R. J. Norstrom, and DVC Weseloh. "A quarter century of environmental surveillance: The Canadian Wildlife Service's Great Lakes Herring Gull Monitoring Program." Environmental Reviews 7, no. 4 (1999): 147–66. http://dx.doi.org/10.1139/a99-011.
Full textAbstract:
The Great Lakes Herring Gull Monitoring Program has annually provided information concerning levels of environmental contaminants in herring gull eggs since 1974, making it one of the longest running biomonitoring programs in the world. The program was initiated in response to observations of poor reproductive success in colonial waterbirds on the Great Lakes. Initial studies examined the role of halogenated hydrocarbons (HAHs) in causing this reproductive dysfunction. By the late 1970s, reproductive success in herring gulls had improved greatly and emphasis was placed on developing more sensitive indicators to measure the subtle effects associated with HAH exposure. Geographic and temporal trends in Great Lakes contamination were also elucidated. Analysis of herring gull tissues led to the identification of HAHs (mirex, photomirex, polynuclear aromatic hydrocarbons, chlorobenzenes, dioxins) previously undetected in Great Lakes upper trophic level biota. Data collected as part of this program have improved our understanding of contaminant sources and fate in the Great Lakes and have provided us with a means to assess our progress in controlling contaminant inputs. The extensive nature of this dataset has allowed detailed examination of the factors that regulate contaminant levels in this species. Most monitoring programs rely on less extensive datasets for the interpretation of environmental trends and may benefit from the mechanisms identified here. Research has also identified other stressors, e.g., dietary deficiencies, that may affect the success of Great Lakes herring gull populations. Ongoing monitoring of this species will continue to provide new insights into the dynamic Great Lakes ecosystem.Key words: herring gull, Larus argentatus, Great Lakes, environmental monitoring, halogenated hydrocarbons, contaminants.