Tributary Contribution of Energy to Rivermouths of Whitefish Bay, Lake Superior, MI

Tributary Contribution of Energy to Rivermouths of Whitefish Bay, Lake Superior, MI

"Whitefishes (Coregoninae), native to the Great Lakes, are important culturally and economically. In particular, Lake Whitefish (Coregonus clupeaformis) are part of an important commercial and subsistence fishery in Whitefish Bay, Lake Superior. Tributaries to Whitefish Bay are provide important energy inputs to the rivermouth food web and age-0 Whitefish could be potentially relying on this energy for growth and development. This study identifies contributions of three tributaries to adjacent rivermouth food webs that support Whitefish in Whitefish Bay. Basal resources (seston, fine particulate organic matter [FPOM], and epilithon) and age-0 and adult Whitefish were collected from tributary and/or rivermouth sites every two to three weeks from April-August, 2012. Carbon isotopes (δ13C) of algal and fish tissue were measured to identify uptake of tributary-derived carbon. The mean percent of tributary-derived carbon to epilithon (59.1%) was greater than to seston (27.1 %). Tributary algae and FPOM were less enriched in δ 13C than were rivermouth algae. Age-0 Whitefish showed an intermediate carbon signature to the adult Whitefish and tributary basal resources, suggesting that tributaries are providing resources to age-0 Whitefish in rivermouth food webs, via primarily a benthic pathway. Understanding tributary and rivermouth energy sources to Whitefish can direct management efforts by identifying habitats and processes that are pertinent to Lake Whitefish recruitment and growth."

Mockler, Dan

Biology

Lake Superior State University

2014

Dr. Ashey Moerke

Copyright Dan Mockler: All rights reserved. LSSU use only.

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English

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S20220520001

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