PI: Allen Curry, Canadian Rivers Institute and Biology Department, UNB Fredericton
The Mactaquac Aquatic Ecosystem Study (MAES) is a whole ecosystem study to understand the structure and function of the Saint John River and the potential implications of removal of the Mactaquac Dam upstream of Fredericton. As part of this multi-disciplinary, multi-institutional project we are assessing the structure of the riverine food web and the contemporary and historical concentrations of metals, hydrocarbons and chlorinated organics (e.g. PCBs) in the sediments of the headpond. These results will be used to support the decisions around dam removal or refurbishment.
Funding: This project is funded by NB Power and by an NSERC CRD Grant.
Collaborators: Paul Sibley, Guelph; Irena Creed, Western; Dave Kreutzweiser, Canadian Forestry Service; John Richardson, UBC
Nearly two-thirds of Canada’s land base is forested, and this forms the basis of one of Canada’s most important resource industries. However, forests are also key suppliers of aquatic ecosystem services (AES), such as serving as critical source areas for much of North America’s sustainable, clean water supplies. However, poor understanding of how forest ecosystem attributes regulate these AES has hindered formal integration of AES into the decision making process.
Experimental manipulations to test the effects of forest management activities on physical, chemical and biological indicators of aquatic ecosystem services from headwaters of forested landscapes. We are exploring the change in physical, chemical and biological indicators of aquatic ecosystem services (AES) across a gradient of forest disturbance and recovery.
Cumulative effects of catchment disturbances on downstream ecosystem services in forested landscapes We are examining the effects of forest management practices on downstream ecosystems and their services, using select regional watersheds (including Black Brook District in New Brunswick) on forested landscapes with a strong history of assessment and monitoring.
Funding: This research is supported by an NSERC Strategic Network Grant and through in-kind support from JD Irving.
Effects of stressors on wetlands
Wetlands provide invaluable ecological services including their capacity to improve water quality, stabilize shorelines, provide habitat for wildlife and act as reservoirs during flooding.
In addition to their loss during development, wetlands in the province are subject to numerous other stressors including runoff of pesticides and fertilizers from agricultural, forestry and military applications.
We are establishing the Long-term Experimental Wetlands Area (LEWA; www.lewa.ca) for conducting whole-ecosystem experiments, and the current focus of the research at this facility is to understand how glyphosate, a commonly used herbicide in agriculture and forestry, and fertilizers affect these aquatic ecosystems.
This study is being done in partnership with the Department of National Defence (DND; CFB Gagetown), Natural Resources Canada (NRC), Environment Canada, and the Universities of Ottawa and Acadia. Funding sources: NSERC Strategic and Discovery Grants, Environmental Trust Fund, DND and NRC.
Whole lake estrogen experiment
Aquatic organisms are being affected by chemicals that mimic natural hormones and interfere with their ability to grow, develop and reproduce. To understand whether effects on individuals can impact population sustainability, we are conducting a multi-year estrogen-addition experiment at the Experimental Lakes Area (ELA) in northwestern Ontario.
After 2 years of baseline study, we added the estrogen used in the birth control pill, 17α-ethynylestradiol (EE2), to Lake 260 in 2001- 2003, and studied its effects on fish, amphibian, zooplankton, benthic invertebrate, algal, and microbial communities. More recently, we are studying the recovery of this lake from EE2 additions.
Results from this study will be used to assess the risks that hormone mimics pose to fish and fish habitat, and to understand the timing and magnitude of the impacts that estrogen-like substances have on aquatic organisms.
Funding sources: Fisheries and Oceans Canada, American Chemistry Council, Canadian Federal Toxic Substances Research Initiative, Schering AG, and the Canadian Water Network.
Accumulation of pollutants through food webs
Some environmental pollutants can concentrate up through food webs to levels in fish that can affect the health of the fish themselves or the fish-eating wildlife and humans.
Even in remote systems with no human activities, mercury and other contaminants can be high in fish.
We have several projects to understand how contaminants are accumulated through freshwater food webs into top predators. In Nova Scotia we are working in Kejimkujik National Park, an area known as a mercury hotspot.
We are studying how mercury moves through the food webs of these acidic lakes and whether it is affecting the health of the fish.
In the Arctic we are sampling lakes around Resolute Bay, Nunavut to understand why some Arctic char are higher in mercury than others.
The group has also completed several studies on stream and lake food webs in New Brunswick to understand where and why fish are elevated in mercury.
These projects have been supported by NSERC Discovery & Strategic Network Grant, Environmental Trust Fund, Wildlife Trust Fund, Northern Contaminants Program, Polar Continental Shelf Project, Environment Canada, Canadian Water Network and Parks Canada.