Great Lakes Laboratory for Fisheries and Aquatic science

Burlington, Canada

Great Lakes Laboratory for Fisheries and Aquatic science

Burlington, Canada
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Rajakaruna H.,Great Lakes Laboratory for Fisheries and Aquatic science | VandenByllaardt J.,Great Lakes Laboratory for Fisheries and Aquatic science | Kydd J.,Great Lakes Laboratory for Fisheries and Aquatic science | Bailey S.,Great Lakes Laboratory for Fisheries and Aquatic science
Journal of Sea Research | Year: 2017

The International Maritime Organization (IMO) has set limits on allowable plankton concentrations in ballast water discharge to minimize aquatic invasions globally. Previous guidance on ballast water sampling and compliance decision thresholds was based on the assumption that probability distributions of plankton are Poisson when spatially homogenous, or negative binomial when heterogeneous. We propose a hierarchical probability model, which incorporates distributions at the level of particles (i.e., discrete individuals plus colonies per unit volume) and also within particles (i.e., individuals per particle) to estimate the average plankton concentration in ballast water. We examined the performance of the models using data for plankton in the size class ≥. 10. μm and <. 50. μm, collected from five different depths of a ballast tank of a commercial ship in three independent surveys. We show that the data fit to the negative binomial and the hierarchical probability models equally well, with both models performing better than the Poisson model at the scale of our sampling. The hierarchical probability model, which accounts for both the individuals and the colonies in a sample, reduces the uncertainty associated with the concentration estimation, and improves the power of rejecting the decision on ship's compliance when a ship does not truly comply with the standard. We show examples of how to test ballast water compliance using the above models. © 2017.

PubMed | University of Windsor and Great Lakes Laboratory for Fisheries and Aquatic science
Type: Journal Article | Journal: Ecology and evolution | Year: 2015

Quantifying spatial genetic structure can reveal the relative influences of contemporary and historic factors underlying localized and regional patterns of genetic diversity and gene flow - important considerations for the development of effective conservation efforts. Using 10 polymorphic microsatellite loci, we characterize genetic variation among populations across the range of the Eastern Sand Darter (Ammocrypta pellucida), a small riverine percid that is highly dependent on sandy substrate microhabitats. We tested for fine scale, regional, and historic patterns of genetic structure. As expected, significant differentiation was detected among rivers within drainages and among drainages. At finer scales, an unexpected lack of within-river genetic structure among fragmented sandy microhabitats suggests that stratified dispersal resulting from unstable sand bar habitat degradation (natural and anthropogenic) may preclude substantial genetic differentiation within rivers. Among-drainage genetic structure indicates that postglacial (14kya) drainage connectivity continues to influence contemporary genetic structure among Eastern Sand Darter populations in southern Ontario. These results provide an unexpected contrast to other benthic riverine fish in the Great Lakes drainage and suggest that habitat-specific fishes, such as the Eastern Sand Darter, can evolve dispersal strategies that overcome fragmented and temporally unstable habitats.

Bunt C.M.,Biotactic Inc. | Mandrak N.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Eddy D.C.,Biotactic Inc. | Choo-Wing S.A.,Biotactic Inc. | And 2 more authors.
Environmental Biology of Fishes | Year: 2013

Black Redhorse (Moxostoma duquesnei) larval and juvenile habitat was characterized in the Grand River, Ontario from June to September 2007-2012. Similar to adult Black Redhorse and their congeners, larval Black Redhorse were most likely to be located in clean, clear, stable runs with low to moderate flow, over pebble, gravel and cobble substrate, mixed with sand. Areas (n = 22) where 0+ Black Redhorse were observed and collected were 1.4 ± 0.2 m from shore, with a mean water temperature of 22.0 ± 0.5 °C, mean depth of 0.20 ± 0.02 m and mean water velocity of 0.12 ± 0.05 m/s. Larval and juvenile Black Redhorse occupied riffles, runs, pools and backwater areas; however, there was a strong preference for runs. Juvenile Black Redhorse moved upstream in the early evening and at night to overwintering areas in the Grand River in November when water temperature approached 5 °C. The persistence of Black Redhorse populations in the Grand River may be related to the presence of groundwater, which provides refuge from extreme temperature and poor water quality during the summer. © 2013 Springer Science+Business Media Dordrecht.

Bunt C.M.,Biotactic Fish and Wildlife Research | Heiman T.,Great Lakes Laboratory for Fisheries and Aquatic science | Mandrak N.E.,Great Lakes Laboratory for Fisheries and Aquatic science
Copeia | Year: 2013

Adult Black Redhorse (Moxostoma duquesnei) were seined from the Grand River, Ontario and artificially spawned in May 2007 and May 2008. Eggs hatched after 9-16 days at a mean temperature of 20°C, and after 11-25 days at a mean temperature of 17°C. Eggs did not develop fully at temperatures <11°C. Eggs and development of larvae between 9 and 24 mm TL, and juveniles up to 35 mm TL are described. Ontogeny of larval and juvenile Black Redhorse was compared to that of Greater Redhorse (Moxostoma valenciennesi), River Redhorse (Moxostoma carinatum), Golden Redhorse (Moxostoma erythrurum), Shorthead Redhorse (Moxostoma macrolepidotum), Copper Redhorse (Moxostoma hubbsi), and Spotted Sucker (Minytrema melanops). There was significant overlap between most meristic variables compared. However, the majority of Black Redhorse in this study (up to 18 mm TL) generally had higher myomere counts that were different from most other redhorse species. These data, in combination with knowledge of variation in congeneric distributions and differences in spawning windows, may allow identification of Black Redhorse as small as 9 mm TL. © 2013 by the American Society of Ichthyologists and Herpetologists.

Leisti K.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Doka S.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Minns C.K.,Great Lakes Laboratory for Fisheries and Aquatic science | Minns C.K.,University of Toronto
Aquatic Ecosystem Health and Management | Year: 2012

Originally mesotrophic, the Bay of Quinte ecosystem has experienced eutrophication since the 1940s, which resulted in the decline of once-lush submerged aquatic vegetation (SAV) beds in the upper bay by the mid-1960s. Since 1972, twelve SAV surveys have been conducted along ten index transects, recording:% cover, distance SAV beds extended from shore (extent), maximum depth of colonization (Zc), species composition, and, in later years, wet plant biomass. Offshore secchi depth and ε{lunate}par, (the vertical light extinction rate (m-1) for photosynthetically active radiation), were also recorded either weekly or bi-weekly during the growing season since 1972. During this time, two major changes occurred within the bay: the reduction in point-source phosphorus (P-control) loadings in 1978 and the 1993 invasion by Dreissenid Mussel. SAV response to these changes varied temporally and spatially, with the shallow upper bay showing the greatest response, particularly after Zebra Mussels establishment. In the upper bay, mean secchi depth increased by 8% from 1.2 m prior to P-control (pre-P), to 1.3 m after P-control (post-P) and further increased by 46% to 1.9 m after Dreissena establishment (post-D). Upper bay SAV responded to these invasive species with increases in the means of three variables: Zc from 1.6 to 3.5 m, extent from 114 m to 417 m and wet biomass from 50 g m-2 to 962 g m-2. SAV in the middle and lower bays were in better condition in 1972, with pre-P cover in excess of 50% and Zc of 2.6 and 3.7 m, respectively. SAV cover did increase in the post-D (1994 to 2007) period by approximately 25% and Zc increased to 3.7 and 6.5 m, but the narrow fringing strip of shallower water along the shore in these two deeper bays limited substantial increases in bed extent. Both water clarity and basin morphometry strongly influenced SAV distribution and abundance within the Bay of Quinte. © 2012 Copyright Taylor and Francis Group, LLC.

Trumpickas J.,McGill University | Mandrak N.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Ricciardi A.,McGill University
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2011

Changes to native fish assemblages in lakes are commonly associated with introduced predatory fishes. How fish assemblages change as multiple predatory species are introduced is not well understood. This study investigated the relationship between the presence of introduced large-bodied predatory fishes (largemouth bass Micropterus salmoides, pike Esox lucius, rock bass Ambloplites rupestris, smallmouth bass Micropterus dolomieu, walleye Sander vitreus) and the composition of native fish assemblages in littoral areas of 40 lakes in Algonquin Provincial Park, Ontario, Canada. Fish assemblages were compared across lakes of different predator composition, and within lakes before and after recent predator invasions. The presence of an introduced predator was associated with significantly different native fish assemblages across lakes, after controlling for environmental and spatial variables. Native fish assemblages did not significantly vary across lakes with more than one predator species. Furthermore, while declines in native species richness over time were observed in a number of lakes, these were not associated with introductions of additional predators. Several small-bodied species (brook stickleback Culea inconstans, fathead minnow Pimephales promelas, finescale dace Chrosomus neogaeus, and northern redbelly dace Chrosomus eos) consistently showed strong negative correlations with predator presence. The results suggest that predatory fish introductions alter native fish assemblages and that this impact is consistent regardless of the number of predatory species introduced. Copyright © 2011 John Wiley & Sons, Ltd and Her Majesty the Queen in Right of Canada. Copyright © 2011 John Wiley & Sons, Ltd and Her Majesty the Queen in Right of Canada. 21 4 June 2011 10.1002/aqc.1192 Research Article Research Articles Copyright © 2011 John Wiley & Sons, Ltd and Her Majesty the Queen in Right of Canada..

Blanchet S.,French National Center for Scientific Research | Blanchet S.,CNRS Biological Evolution and Diversity Laboratory | Reyjol Y.,ONEMA | April J.,Laval University | And 4 more authors.
Global Ecology and Biogeography | Year: 2013

Aim: We investigated the relationship between geographic range size (GRS), longitude and latitude (Rapoport's rule) in Canadian freshwater fishes. We tested hypotheses regarding the phenotypic and phylogenetic determinants of GRS to unravel processes driving the spatial patterns of GRS in Canada. Because GRS is negatively correlated with extinction risk, we also aimed at identifying biological proxies that may be used to predict extinction risks. Location: North-America, Canadian Shield. Methods: We built a database combining range area, seven ecological traits, and a molecular phylogeny for native Canadian freshwater fishes. We tested latitudinal and longitudinal patterns in GRS by the mean of Pearson correlations. We combined phylogenetic generalized least squares (PGLS) models and a model selection procedure to tease apart hypotheses (and hence ecological traits) that best explained GRS in our dataset. PGLSs were also used to explore relationships between ecological traits, phylogeny, and species mid-range latitude and longitude. Partial regressions were used to determine direct and indirect relationships driving spatial patterns of GRS in Canadian freshwater fishes. Results: There was a significant and positive correlation between GRS, latitude and longitude. According to PGLSs, three ecological traits, related to the habitat use, migratory and thermal tolerance hypotheses, were significantly correlated with GRS, mid-range longitude and mid-range latitude. Two traits related to locomotion were further related to GRS. There was no phylogenetic effect on GRS (i.e. no phylogenetic conservatism). Partial regressions revealed complex direct and indirect relationships between ecological traits, mid-range latitude, mid-range longitude and GRS. Main conclusions: Our results show that traits related to the ability to use dispersal corridors, as well as traits directly related to mobility, are useful in understanding biodiversity patterns such as Rapoport's rule. However, because of a weak explanatory power, we conclude that using biological proxies of GRS to predict species at risk of extinction would be premature. © 2013 John Wiley & Sons Ltd.

Leisti K.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Theysmeyer T.,Royal Botanical Gardens | Doka S.E.,Great Lakes Laboratory for Fisheries and Aquatic science | Court A.,Royal Botanical Gardens
Aquatic Ecosystem Health and Management | Year: 2016

Over the past two hundred years, anthropogenic activities have resulted in the substantial decline of the once extensive wetlands in both Hamilton Harbour and Cootes Paradise. Some of the key stressors for aquatic vegetation have been infilling, sustained high water levels and level regulation in Lake Ontario, and reduced water clarity because of eutrophication and suspended sediments. Designated an Area of Concern in 1985, remediation efforts have included upgrades to the sewage treatment plants discharging into the harbour to reduce eutrophication and the 1996 construction of a fish barrier to exclude large Carp from entering Cootes Paradise to reduce turbidity. Over the past ten years, Cootes Paradise has seen a 120% increase in the areal extent of emergent vegetation, but this still represents less than 20% of the circa 1900's marsh area. Despite substantial reductions in Carp density in Cootes Paradise, submerged aquatic vegetation has been sparse and typically found at depths of less than 0.5 m, likely because of impaired light penetration. Following a significant improvement in water clarity in Hamilton Harbour between 1987 and 1997, submerged aquatic vegetation in the harbour proper expanded, achieving a mean maximum depth of 2.9 m in 2012. Species richness was considerably lower in Hamilton Harbour when compared to Cootes Paradise; however, the species composition in both these areas indicated degraded conditions throughout the time period of our assessment. Using our recent dataset, we tested relationships that had been previously established in the literature between emergent extent and water levels for Cootes Paradise and also the connection between maximum depth of submergent colonization and Secchi depths but simple univariate tests were not significant. A combination of small sample size, simple tests, and a small range for the independent variable may be issues in establishing simplified response relationships and are likely oversimplifications of vegetation response in the area that require more complex modelling. © 2016, Copyright © Crown copyright.

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