Connectivity of stormwater ponds impacts Odonata abundance and species richness.

Context: The successful dispersal of an animal depends, partly, on landscape connectivity. Urbanization poses risks to dispersal activities by increasing hostile land cover types.

Objectives: We investigated how connectivity of urban ponds impacted Odonata communities (dragonflies and damselflies), an order of semi-aquatic insects that actively disperse.

Subfossil Chironomid Assemblages as Indicators of Remedial Efficacy in the Historically Contaminated St. Lawrence River at Cornwall, Ontario.

Long-term data are required to quantify the impacts of historic industrial pollution and subsequent remedial action on the nearshore benthic community in the St. Lawrence River Area of Concern at Cornwall, Ontario. Specifically, high-quality temporal records are needed to understand changes in benthic invertebrate assemblages in response to multiple possible drivers including industrial pollution, environmental heterogeneity, and climate warming.

Plants, water quality and land cover as drivers of Odonata assemblages in urban ponds.

As cities expand, urban ecosystems could either contribute to or impede conservation efforts. To maximize the potential for urban areas to support biodiversity, there is a need to understand how systems in an urban environment can sustain the natural history requirements of species. This study compared the relative importance of local-scale factors (plant communities and water quality) to landscape factors (surrounding land cover) in structuring assemblages of a recognized group of wetland bioindicators.

Nearshore Sedimentary Mercury Concentrations Reflect Legacy Point Sources and Variable Sedimentation Patterns Under a Natural Recovery Strategy.

The St. Lawrence River at Cornwall, Ontario, Canada, received substantial inputs of mercury from local, shoreline-based industries through much of the 20th century. Although emission controls were implemented in the late 20th century to reduce the influx of mercury and other metals entering the river, legacy contamination of riverine sediments continues to be a concern.

Water quality effects on dragonfly and damselfly nymph communities: A comparison of urban and natural ponds.

Cities are increasingly using constructed ponds to mitigate flooding and downstream water pollution from urban runoff. As a result, these stormwater ponds can have poor water quality, yet they can also attract wildlife. In this study, the effects of water quality on dragonflies and damselflies (Odonata) were determined in stormwater ponds (n = 41) and natural reference ponds (n = 10) of similar size across the National Capital Region of Canada.

Cortisol modulates metabolism and energy mobilization in wild-caught pumpkinseed (Lepomis gibbosus).

Acute elevation of cortisol via activation of the hypothalamic-pituitary-interrenal (HPI) axis aids the fish in dealing with a stressor. However, chronic elevation of cortisol has detrimental effects and has been studied extensively in lab settings. However, data pertaining to wild teleosts are lacking.

Mercury Concentrations in Sentinel Fish Exposed to Contaminated Sediments Under a Natural Recovery Strategy Within the St. Lawrence River Area of Concern at Cornwall, Ontario, Canada.

Legacy mercury (Hg) sediment deposits are a long-term issue within the St. Lawrence River (Cornwall) area of concern with three depositional areas along the Cornwall, ON waterfront containing sediments that exceed the Ontario Sediment Quality Guidelines for Hg. Assessing the bioavailability of these Hg-contaminated sediments plays a crucial role in evaluating the effectiveness of the Cornwall Sediment Strategy based on a natural recovery approach.

Predicted impacts of climate warming on aerobic performance and upper thermal tolerance of six tropical freshwater fishes spanning three continents.

Equatorial fishes, and the critically important fisheries based on them, are thought to be at-risk from climate warming because the fishes have evolved in a relatively aseasonal environment and possess narrow thermal tolerance windows that are close to upper thermal limits. We assessed survival, growth, aerobic performance and critical thermal maxima (CTmax) following acute and 21 d exposures to temperatures up to 4°C higher than current maxima for six species of freshwater fishes indigenous to tropical countries and of importance for human consumption. All six species showed 1.

Preferential incorporation of dark, coloured materials into nests by a mound-nesting stream cyprinid.

We compared size and colour characteristics of rocks used by male cutlip minnows Exoglossum maxillingua to build nests to those of streambed background materials. We found that materials used to construct conspicuous, mound-shaped nests were uniform in size and darker and more colour-saturated than background materials of the same size. To our knowledge, this phenomenon is the first reported example of fish selecting nest materials based on colour and has important implications for the conservation of mound-nesting stream cyprinid species.

Dynamic mass balance model for mercury in the St. Lawrence River near Cornwall, Ontario, Canada.

A dynamic mass balance model was developed for the St. Lawrence River near Cornwall, Ontario that predicts and hindcasts mercury concentrations and fluxes in three forms, elemental Hg (Hg(0)), divalent mercury (Hg(2+)), and methyl mercury (MeHg), in a six compartment environment (air, water, porewater, sediment, periphyton, and benthic invertebrates). Our objective was to construct a dynamic mass balance model for mercury in the St.

A comparison of biofilms from macrophytes and rocks for taste and odour producers in the St. Lawrence river.

Given their widespread and prolific annual development in the St. Lawrence River (SLR), macrophytes (i.e.

The species composition and seasonal distribution of mosquitoes in vernal pools in suburban Montreal, Quebec.

A study was conducted in the spring and summer of 1998 to determine the invertebrate community in vernal pools on the western portion of the Island of Montreal. This paper examines the mosquitoes (Diptera: Culicidae) found in 10 pools. Fifteen species in 4 genera (Aedes, Anopheles, Culex, and Ochlerotatus) were collected and the seasonal distribution of each species was determined.