Cadmium concentrations of crustacean zooplankton of acidified and nonacidified Canadian Shield lakes

1990 ◽  
Vol 24 (9) ◽  
pp. 1367-1372 ◽  
Author(s):  
Norman D. Yan ◽  
Gerald L. Mackie ◽  
Peter J. Dillon
Keyword(s):  
Canadian Shield ◽  
Crustacean Zooplankton ◽  
Shield Lakes

Calibration of the zooplankton community size spectrum as an indicator of change in Canadian Shield lakes

2019 ◽  
Vol 76 (12) ◽  
pp. 2268-2287
Author(s):  
Lauren Emily Barth ◽  
Brian John Shuter ◽  
William Gary Sprules ◽  
Charles Kenneth Minns ◽  
James Anthony Rusak
Keyword(s):  
Zooplankton Community ◽  
Canadian Shield ◽  
Rate Of Change ◽  
Crustacean Zooplankton ◽  
Size Spectrum ◽  
Community Size ◽  
Mean Values ◽  
Sampling Protocols ◽  
Stable Characteristic ◽  
Shield Lakes

Developing the crustacean zooplankton community size spectrum into an indicator of change in lakes requires quantification of the natural variability in the size spectrum related to broad-scale seasonal, annual, and spatial factors. Characterizing seasonal patterns of variation in the size spectrum is necessary so that monitoring programs can be designed to minimize the masking effects that seasonal processes can have on detecting longer-term temporal change. We used a random effects model to measure monthly, annual, and interlake variability in the slope (i.e., relative abundance of small and large organisms) and centered height (i.e., total abundance) of the crustacean zooplankton normalized abundance size spectrum from 1981 to 2011 among eight Canadian Shield lakes. Consistent with theoretical predictions, the slope was a relatively stable characteristic of the zooplankton community compared with the height, which varied significantly among lakes. We identified a seasonal signal in height and slope and used a mixed effects model to characterize the linear rate of change from May to October; there was an overall decline in height and an overall increase in slope. Seasonal variance was greater than annual variance for both the height and the slope, suggesting that long-term monitoring of lakes and interlake comparisons using zooplankton size spectra should be based on temporally standardized sampling protocols that minimize the effects of seasonal processes. We recommend sampling the zooplankton community in midsummer because this results in size spectrum estimates close to seasonal mean values.

Evaluation of the responsiveness of the crustacean zooplankton community size spectrum to environmental change and an exotic invader in a sample of Canadian Shield lakes

2020 ◽  
Author(s):  
Lauren Emily Barth ◽  
Brian J. Shuter ◽  
W. Gary Sprules ◽  
Charles K. Minns ◽  
James A Rusak
Keyword(s):  
Time Series ◽  
Environmental Change ◽  
Canadian Shield ◽  
Ecosystem Change ◽  
Crustacean Zooplankton ◽  
Size Spectrum ◽  
Zooplankton Size ◽  
Shield Lakes ◽  
Change In Mean

We evaluated the crustacean zooplankton size spectrum as an indicator of lake characteristics and ecosystem change. First, we used time-series from seven Canadian Shield lakes to identify the factors associated with among-lake and among-year variability in the spectrum slope (relative abundance of small and large zooplankton) and centered height (total abundance). Second, we used time-series from an invaded and three control lakes to assess change in mean and variability in slope and height due to a Bythotrephes invasion. We found that the slope and the height reflected among-lake predictors related to morphometry. The slope was responsive to long-term declining lake phosphorus levels, whereas the height reflected both increases in dissolved organic carbon and decreases in ice duration. We detected a significant increase (i.e. flattening) in mean slope and substantial (up to 120%) increases in the CV of height after Bythotrephes invaded Harp Lake. Thus, the zooplankton size spectrum was responsive to long-term environmental change and a strong top-down perturbation can be detected through regular and frequent monitoring programs.

Relating crustacean zooplankton community structure to residential development and land-cover disturbance near Canadian Shield lakes

2008 ◽  
Vol 65 (12) ◽  
pp. 2689-2702 ◽  
Author(s):  
Malorie Gélinas ◽  
Bernadette Pinel-Alloul
Keyword(s):  
Land Cover ◽  
Human Disturbance ◽  
Variation Partitioning ◽  
Zooplankton Community ◽  
Residential Development ◽  
Canadian Shield ◽  
Crustacean Zooplankton ◽  
Zooplankton Community Structure ◽  
Intermediate Element ◽  
Shield Lakes

We applied the land-cover cascade (LCC) concept to evaluate whether human disturbance affects crustacean zooplankton community in 13 nutrient-poor lakes of the Laurentian region along a gradient of residential development and land-cover disturbance. Zooplankton biomass responded indirectly to residential disturbances within the watershed based on path analysis. In most LCC models, total phosphorus enrichment was a strong intermediate element linking residential disturbances to increased biomass of small crustaceans ( Bosmina , Ceriodaphnia , and Diaphanosoma ) and Daphnia species ( D. g. mendotae , D. dubia , and D. ambigua ). Zooplanktivory index was also an intermediate element in LCC models of crustacean functional groups and an independent element in daphnid-based LCC models. Low zooplanktivory was associated with higher biomass of large Daphnia ( D. pulicaria and D. catawba ). However, residential disturbance and select environmental factors (phosphate enrichment, zooplanktivory index, lake depth, littoral macrophytes) explained only 42% and 57%, respectively, of among-lake variation in crustacean community and Daphnia assemblages. Variation partitioning analysis suggested that planktivory had a similar or greater influence than human disturbance and phosphate enrichment. Our study improves the knowledge of crustacean zooplankton responses to increasing residential development and land-use disturbances near Canadian Shield lakes.

The impact of calcium decline on population growth rates of crustacean zooplankton in Canadian Shield lakes

2017 ◽  
Vol 63 (2) ◽  
pp. 602-616 ◽  
Author(s):  
Shakira S. E. Azan ◽  
Shelley E. Arnott
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Canadian Shield ◽  
Crustacean Zooplankton ◽  
Population Growth Rates ◽  
Calcium Decline ◽  
Shield Lakes ◽  
The Impact

The differing crustacean zooplankton communities of Canadian Shield lakes with and without the nonindigenous zooplanktivore Bythotrephes longimanus

2003 ◽  
Vol 60 (11) ◽  
pp. 1307-1313 ◽  
Author(s):  
Stephanie A Boudreau ◽  
Norman D Yan
Keyword(s):  
Zooplankton Biomass ◽  
Canadian Shield ◽  
Crustacean Zooplankton ◽  
Bythotrephes Longimanus ◽  
Cladoceran Species ◽  
Zooplankton Communities ◽  
Shield Lakes ◽  
Total Zooplankton Biomass ◽  
Harp Lake

The nonindigenous predatory cladoceran Bythotrephes longimanus is spreading rapidly among Canadian Shield lakes, but only one case study of its impacts exists. In Harp Lake, the abundances of several cladoceran and one cyclopoid species fell after the invasion, and far fewer species benefited. To determine if Harp Lake provides typical results, we compared the summer crustacean zooplankton communities of 17 invaded and 13 noninvaded (reference) lakes in Ontario. The communities of the two lake groups differed. Average species richness was 30% higher in the reference (15.3 species) vs. the invaded lakes (11.8 species). Total zooplankton biomass was significantly lower in the invaded lakes, mainly because of lower abundances of all common epilimnetic cladoceran species. As these results were quite similar to those of Harp Lake, it is apparent that current summer zooplankton communities of Canadian Shield lakes with Bythotrephes differ substantially from noninvaded lakes.

Long-term trends in zooplankton of Dorset, Ontario, lakes: the probable interactive effects of changes in pH, total phosphorus, dissolved organic carbon, and predators

2008 ◽  
Vol 65 (5) ◽  
pp. 862-877 ◽  
Author(s):  
Norman D Yan ◽  
Keith M Somers ◽  
Robert E Girard ◽  
Andrew M Paterson ◽  
W. (Bill) Keller ◽  
...  
Keyword(s):  
Species Richness ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Phosphorus ◽  
Canadian Shield ◽  
Interactive Effects ◽  
Crustacean Zooplankton ◽  
Multiple Stressor ◽  
Zooplankton Communities ◽  
Shield Lakes

Time trends in abundance, body size, species richness, and species composition indicate that crustacean zooplankton communities of southern Canadian Shield lakes changed between 1980 and 2003. Total abundance did not decline despite reductions in total phosphorus, but all other metrics changed. Species richness declined in Harp Lake (Ontario, Canada) following its Bythotrephes invasion, but richness increased in three other lakes. Average cladoceran body length increased from 0.6 to 1.0 mm in seven of the lakes, as larger-bodied taxa replaced smaller ones. Correlations with water quality and fish metrics suggest that cladoceran size increases were attributable to many factors: a decline in food availability following declining phosphorus levels increasing the competitive advantage of larger herbivores, a decline in acidity favouring the larger, acid-sensitive daphniids, and reduced risk of planktivory linked to a rise in dissolved organic carbon levels and changes in predation regimes. Zooplankton communities on the Canadian Shield are changing, and these changes are best viewed in a multiple-stressor context. Key anthropogenic stressors have also changed and may do so again if Ca concentrations continue to decline.

Crustacean zooplankton species richness: single- and multiple-year estimates

1998 ◽  
Vol 55 (7) ◽  
pp. 1573-1582 ◽  
Author(s):  
Shelley E Arnott ◽  
John J Magnuson ◽  
Norman D Yan
Keyword(s):  
Spatial Scales ◽  
Species Pool ◽  
Crustacean Zooplankton ◽  
Zooplankton Species ◽  
Asymptotic Approach ◽  
Sampling Programme ◽  
Temporal And Spatial ◽  
Shield Lakes ◽  
The Relationship ◽  
Temporal Extent

Richness estimates are dependent on the spatial and temporal extent of the sampling programme and the method used to predict richness. We assessed crustacean zooplankton richness in eight Canadian Shield lakes at different temporal and spatial scales using three methods of estimation: cumulative, asymptotic, and Chao's index. Percent species detected increased with the number of spatial, intraannual, or interannual samples taken. Single samples detected 50% of the annual species pool and 33% of the total estimated species pool. This suggests that previous estimates of zooplankton richness, based on single samples in individual lakes, are too low. Our richness estimates for individual lakes approach the total number of zooplankton found in some regions of Canada, suggesting that each lake has most taxa at some time, the majority being very rare. Single-year richness estimates provided poor predictions of multiple-year richness. The relationship between richness and environmental variables was dependent on the method of estimation and the number of samples used. We conclude that richness should be treated as an "index" rather than an absolute and sampling efforts should be standardized. We recommend an asymptotic approach to estimate zooplankton richness because the number of samples taken influenced it less.

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