Improving non-native fish larvae detection based on temporal habitat use

Session: 34. - Aquatic Habitat Evaluation and Assessment

Greg Peterson, Environmental Protection Agency, peterson.greg@epa.gov
Joel Hoffman, US EPA Office of Research and Development, hoffman.joel@epa.gov
Anett Trebitz, EPA, Trebitz.Anett@epa.gov
Mark Pearson, US EPA, pearson.mark@epa.gov
Chelsea Hatzenbuhler, ORISE participant, US EPA, Hatzenbuhler.chelsea@epa.gov
Hannah Ramage, Lake Superior NERR, hannah.ramage@ces.uwex.edu
Jon Barge, Student services contractor, US EPA, Barge.Jonathon@epa.gov
Will Bartsch, Oak Ridge Inst. for Sci. and Education, EPA-MED, bartsch.will@epa.gov
Jonathan Launspach, CSRA, launspach.jonathon@epa.gov

Abstract

As part of the development of an early detection monitoring strategy for non-native fishes, larval fish surveys have been conducted since 2012 in the St. Louis River estuary.  Survey data demonstrates considerable variability in fish abundance and species assemblages across habitats and temporal scales.  To optimize early detection monitoring we need to understand larval fish patterns of development and dispersion and the environmental factors that influence them.  In 2016 we designed an experiment to assess the temporal variability in larval fish abundance and composition amongst habitats that differed in temperature, turbidity, and vegetation.  We sampled larval fish bi-weekly at nine locations from mid-May to mid-July, including both upper and lower estuary to contrast river versus seiche influenced habitats. Temperature was logged every 15 minutes beginning in early April, and hydroacoustic surveys (Biosonics) were conducted in alternate weeks between fish sampling to quantify the development of vegetation.  Temperature data show that shallow upper estuary habitats warm faster and have less among-site variability than similar habitats in the lower estuary.  These and other habitat patterns are compared to larval fish abundance and assemblage data to assess temporal and spatial relationships that could be exploited for more efficient larval fish monitoring.

1. Keyword
invasive species

2. Keyword
experimental design

3. Keyword
monitoring

4. Additional Keyword
Fish Larvae