Salmon mediated contaminant biotransport
Salmon can be a vector for the transport of contaminants. The Great Lakes have a extensive history of environmental contamination resulting from the discharge of organic pollutants such as PCBs and DDT and Mercury from industrial emissions. These chemicals bioaccumlate in the fatty tissue and muscle of fish. The influx of salmon eggs and carcass material provides a high quality food source for invertebrates and fish that can have a high contaminant burden. Thus, spawning salmon are capable of delivering contaminants accrued in the Great Lakes to streams where they spawn. My current research seeks to quantify how salmon spawners and landscape and watershed variables interact to influence stream fish contaminant loads. This Great Lakes Fishery Trust funded research focuses on the intersection of aquatic ecology, environmental chemistry, and fisheries management (Projects 2007.857 and 2012.1244). Currently, I study interactions between introduced and native species with respect to resource subsidies and contaminants. My research is broadly relevant to Great Lakes ecology, dam removal, management of regulated river systems, environmental change, statistics, and modeling. |
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Pacific Salmon in the Great Lakes
Pacific salmon were first stocked in the Great Lakes in the late 1960's to create a world-class recreational fishery and provide a biocontrol agent for invasive alewife that colonized the Upper Lakes. Salmon obtain over ~95% of the body mass in the Great Lakes and migrate each fall from the Lakes to streams and rivers to spawn. All Pacific salmon exhibit a semelparous life history which means they die shortly after spawning. This unique life history allows salmon to significantly impact stream ecosystems. See Dettmers et al. 2012. Fisheries 37:495–501 for more information regarding the history and current state of salmon in the Upper Great Lakes.
Pacific salmon were first stocked in the Great Lakes in the late 1960's to create a world-class recreational fishery and provide a biocontrol agent for invasive alewife that colonized the Upper Lakes. Salmon obtain over ~95% of the body mass in the Great Lakes and migrate each fall from the Lakes to streams and rivers to spawn. All Pacific salmon exhibit a semelparous life history which means they die shortly after spawning. This unique life history allows salmon to significantly impact stream ecosystems. See Dettmers et al. 2012. Fisheries 37:495–501 for more information regarding the history and current state of salmon in the Upper Great Lakes.
Ecological Effects of Spawning Salmon
Spawning salmon have many consequences for stream ecosystems. Salmon can supply large quantities of dissolved nutrients (Nitrogen and Phosphorus) and energy (e.g. eggs and carcass material) that are utilized by primary producers and stream consumers (e.g. invertebrates and fish). This influx of salmon derived material may positively impact stream ecosystems in some areas by increasing primary production and providing a high quality food resource for consumers . Salmon also have a large disturbance effect. Salmon dig redds (nests) to deposit their eggs into during spawning. Redd digging mobilizes large amounts of sediment and gravel which can cause large reductions in primary producers such as algae and consumers including aquatic insects. Within the Great Lakes, salmon exert a much stronger disturbance effect than enrichment effect reflecting the smaller stream substrates (e.g. sand, small gravel) and higher background nutrient concentrations found in the region. Understanding the role of environmental complexity has led our group to focus on how "context" or the biological, physical and chemical characteristics of a stream interact to modulate how stream organisms are influenced by salmon. See Chaloner et al. 2002 Canadian Journal of Fisheries and Aquatic Science, 59:1257-1265, Tiegs et al. 2009. Freshwater Biology, 54: 1864-1875, Janetski et al. 2009 Oecologica, 159:583-595, Janetski et al. 2014 Canadian Journal of Fisheries and Aquatic Science, 71: 502-513 for information regarding the ecological role of spawning salmon in streams.
Spawning salmon have many consequences for stream ecosystems. Salmon can supply large quantities of dissolved nutrients (Nitrogen and Phosphorus) and energy (e.g. eggs and carcass material) that are utilized by primary producers and stream consumers (e.g. invertebrates and fish). This influx of salmon derived material may positively impact stream ecosystems in some areas by increasing primary production and providing a high quality food resource for consumers . Salmon also have a large disturbance effect. Salmon dig redds (nests) to deposit their eggs into during spawning. Redd digging mobilizes large amounts of sediment and gravel which can cause large reductions in primary producers such as algae and consumers including aquatic insects. Within the Great Lakes, salmon exert a much stronger disturbance effect than enrichment effect reflecting the smaller stream substrates (e.g. sand, small gravel) and higher background nutrient concentrations found in the region. Understanding the role of environmental complexity has led our group to focus on how "context" or the biological, physical and chemical characteristics of a stream interact to modulate how stream organisms are influenced by salmon. See Chaloner et al. 2002 Canadian Journal of Fisheries and Aquatic Science, 59:1257-1265, Tiegs et al. 2009. Freshwater Biology, 54: 1864-1875, Janetski et al. 2009 Oecologica, 159:583-595, Janetski et al. 2014 Canadian Journal of Fisheries and Aquatic Science, 71: 502-513 for information regarding the ecological role of spawning salmon in streams.