Disproportionate importance of nearshore habitat for the food web of a deep oligotrphic lake
Hampton SE, Fradkin SC, Leavitt PR, Rosenberger EE. 2011. Disproportionate importance of nearshore habitat for the food web of a deep oligotrphic lake. Marine and Freshwater Research. 62:350-358
In large deep oligotrophic lakes, multiple lines of evidence suggest that the shallow nearshore water provides disproportionately important feeding and breeding habitat for the whole-lake food web. We examined the trophic importance of the nearshore environment, human impacts nearshore, and several approaches to disturbance detection in a deep (190m) oligotrphic lake with relatively modest residential development. In Lake Crescent, on the Olympic Peninsula of Washington (USA), stable isotope analysis demonstrated that apex salmonid predators derived more than 50% of their carbon from nearshore waters, even though this nearshore water accounted for only 2.5% of total lake volume. Unfortunately, it is this land-water interface that is initially degraded as shorelines are developed. We hypothesised that under these conditions of relatively modest disturbance, the effects of residential develpment would be strongly localised near to shore. Indeed, we found striking differences between developed and undeveloped sites in periphyton and associated organic matter, though there were no offshore signals of human impact in water nutrient analysis of paleolimnological investigations. Together, these results suggest that nearhshore biological monitoring should be integrated in lake management plans to provide 'early warning' of potential food-web repercussions before pollution problems are evident in open water and comparatively intractable.
- Type
- Journal Article
- Authors
- Hampton, Stephanie; Fradkin, Steven; Leavitt, Peter; Rosenberger, Elizabeth
- Units
- OLYM
- Keywords
- Freshwater Lake, habitat coupling, Lake Crescent, Littoral Zone, Olympic National Park, Onchorynchus mykiss, Oncorhynchus clarkii, Recreational Fisheries, septic systems