Spatial patterns of rainbow smelt energetic condition in Lakes Huron and Erie in 2017: Evidence for Lake Huron resource limitation

Journal of Great Lakes Research
By: , and 

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Abstract

Rainbow smelt (Osmerus mordax) is a key planktivore and prey fish in Lake Huron. Given the declining offshore productivity in the lake since the early 2000s, we described the energy content of rainbow smelt in 2017 across five different regions (North Channel, Georgian Bay, Saginaw Bay, northern main basin, southern main basin) where phytoplankton and zooplankton productivity likely varied. To increase contrast across the productivity gradient, rainbow smelt energy content was also estimated from western Lake Erie. Within the North Channel where large fish (≥90 mm, total length) were sampled most frequently, mean energy density (kJ/g wet weight) varied seasonally: 4.29 in April (month of spawning), 3.86 in June, 3.99 in July, and up to 4.35 in September. Energy density of rainbow smelt from higher productivity western Lake Erie was 37% (large fish ≥90 mm) to 60% higher (small fish <90 mm) than that of fish from Lake Huron. Within Lake Huron, energy density of rainbow smelt from North Channel was slightly higher than those from other regions; rainbow smelt from Georgian Bay generally had the lowest energy density. Across regions, including western Lake Erie, energy density increased with chlorophyll a concentration. Compared with Lake Huron studies prior to 2004, when oligotrophication had not yet accelerated, energy density of rainbow smelt in 2017 was up to 31% lower. The decline in rainbow smelt energy density is likely the result of declining primary and secondary pelagic production and increased resource limitation for planktivorous fish.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Spatial patterns of rainbow smelt energetic condition in Lakes Huron and Erie in 2017: Evidence for Lake Huron resource limitation
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2019.06.001
Volume 45
Issue 4
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Great Lakes Science Center
Description 10 p.
First page 830
Last page 839
Country Canada, United States
State Michigan, Ohio, Ontario
Other Geospatial Lake Erie, Lake Huron