You are here:
A survey of the St. Louis River estuary with emphasis on non-indigenous species and habitat structure
Citation:
Barker, J., Greg Peterson, J. Hoffman, A. Trebitz, T. Billehus, W. Barsch, AND J. Kelly. A survey of the St. Louis River estuary with emphasis on non-indigenous species and habitat structure. Presented at St. Louis River Estuary summit, February 26 - 27, 2013.
Impact/Purpose:
not applicable
Description:
As part of a larger study to develop a monitoring network for aquatic non-indigenous species (NIS), a comprehensive multi-gear survey of larval fish and macroinvertebrates in the St. Louis River estuary was conducted during summer 2012. A total of 139 larval fish samples and 118 benthic macroinvertebrate samples were collected in the lower estuary, randomly allocated throughout St. Louis, Superior, and Allouez bays. Analysis of samples is not yet complete. To date, larval fish samples have yielded 18 different species, 4 of which were previously observed NIS. Among the four types of larval fish sampling equipment used (tucker trawl, beach seine, neuston net, light trap) light traps collected the lowest abundance of larvae, while tucker trawl samples contained unique species (lake herring and bloater) compared to other gears. Differences observed in species collected among gear and sample period indicates differences in species spawning patterns. Water quality data (temperature, pH, turbidity, conductivity, and dissolved oxygen) and habitat data (sediment type, vegetation type and cover) collected in conjunction with larval fish and macroinvertebrate collection offer insight on differences in habitat quality of the estuary both before and after the June flooding.