Monday, November 7, 2011

Featured Research: by Stephanie Schmidt

Schmidt et al. 2011. Historical and contemporary trophic niche partitioning among Laurentian Great Lakes coregonines. Ecol. Appl. 21:888-896.

An ecologically unique and diverse species assemblage once roamed the deep waters of the Great Lakes, prior to overfishing and non-native species introductions. Now extirpated from Lakes Michigan, Huron, and Ontario (and in low numbers in Superior), the deepwater coregonines were important prey fish for top predators and supported a productive commercial fishery. Rehabilitation of native deepwater fish communities is now a top management priority, yet little is known about their historical ecology.

Stephanie Schmidt and her colleagues collected coregonine tissue samples from museum specimens and from contemporary populations in Lakes Superior and Nipigon. They used stable isotope analysis – a technique that uses carbon and nitrogen information to decipher diet – to reconstruct the food web from the 1920’s to the present.

In each lake, the coregonines were ecologically distinct from one another, their distinctness was maintained throughout a period of tremendous ecosystem change, and the most distinct species was most likely to persist over time. Stephanie suggests that the rehabilitation of ecological diversity be considered in reintroduction programs.