Investigating the Influence of Land Use, Water Chemistry, Invasive Species, and Spatial Patterns on the Production of Algae Along the South-East Shoreline of Lake Huron

In Lake Huron, oligotrophication of the offshore waters and periodic algal blooms in the nearshore have raised questions as to the relative importance of recent changes in land use and the introduction of invasive species on water quality and algae production. Our project examines the influence of water chemistry, land use, spatial patterns, and invasive species on nearshore algae production in Lake Huron using extensive surveys collected by the Ontario Ministry of Environment and Climate Change. We found that local lake nutrient levels, shoreline development, watershed land use, and invasive dreissenid mussels explain the most variation in algae production. Our results were consistent with the nearshore shunt hypothesis, stressing the role that dreissenid mussels are playing in the growth of benthic algae in Lake Huron. Our findings highlight the need to incorporate spatial patterns and invasive dreissenid mussels in water quality and benthic algae production modelling

A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

Improvements in fish polychlorinated biphenyl and other contaminant levels in response to remedial actions in Hamilton Harbour, Ontario, Canada

<p>Hamilton Harbour, located in Ontario, Canada at the western end of Lake Ontario, is recognized as one of the most anthropogenically-impacted regions within the Great Lakes and is currently listed as an Area of Concern. One of the Beneficial Use Impairments for the harbour has been restrictions on fish consumption due to elevated contaminant levels. In this study, we examined past and recent fish contaminant data collected by the Ontario Ministry of the Environment and Climate Change in partnership with other agencies to evaluate temporal trends in fish contaminant concentrations. Measurements for both resident and migratory sport fish as well as juvenile/forage fish were considered, with analysis focused on polychlorinated biphenyls, the group of chemicals identified as the major contaminant of concern. Current contaminant levels were evaluated against fish consumption advisory benchmarks used by Ontario Ministry of the Environment and Climate Change, and compared with corresponding observations for other locations across the Great Lakes, including other Areas of Concern. The results show statistically significant improvements in fish contaminant levels within Hamilton Harbour, with recent fish mercury concentrations below the first advisory benchmarks for all species included in this study. Polychlorinated biphenyl concentrations declined by 59–82% from historical levels, although this decline was not statistically significant in Brown Trout, Common Carp, Freshwater Drum and White Sucker. Further, all species exhibit recent polychlorinated biphenyl concentrations above the first consumption advisory benchmark of 105 ng g⁻¹. Compared to other Great Lakes locations, including other areas of concern, Hamilton Harbour polychlorinated biphenyl concentrations remain amongst the highest. The results suggest that recovery of Hamilton Harbour is still on-going.</p

A global database of lake surface temperatures collected by in situ and satellite methods from 1985-2009

Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues