Trends in Lake Erie benthos: 1930-2014

Session: 32. - Long-Term Monitoring: Achievements, Challenges, and Solutions

Lyubov Burlakova, Great Lakes Center at SUNY Buffalo State , [email protected]
Alexander Karatayev, Great Lakes Center at SUNY Buffalo State, [email protected]
Don Schloesser, U.S. Geological Survey, [email protected]
Martin Stapanian, U.S. Geological Survey, [email protected]

Abstract

We combined data from benthic surveys conducted within the Cooperative Science and Monitoring Initiative, Great Lakes Restoration Initiative, historic data sets of western basin assembled by the USGS Great Lakes Science Center, and literature data over the last 80 years to detect trends in the Lake Erie benthic community. Analysis of historic data set from the western basin revealed that benthic density, responding to organic enrichment, increased 4-fold from 1930 to 1961, and further doubled by 1982. This trend was reversed in the beginning of 1990s, resulting in a 3-fold decline in overall benthos density by 2003 along with the recovery of species sensitive to eutrophication. Similar trends were found lake-wide: repeated sampling of stations surveyed in the 1970s confirmed the increase in benthic species diversity, likely due to the combined effects of watershed improvements and increased water clarity due to filtering activity by Dreissena spp. However, we found an escalating dominance of pollution-tolerant Oligochaeta in the recent years, particularly in the central basin which experiences periodic hypoxia. Abundance of Oligochaeta also increased in the last decade in the western basin, potentially indicating a recurring trend toward eutrophication. 

1. Keyword
benthos

2. Keyword
Lake Erie

3. Keyword
monitoring