FISH AND INVERTEBRATE SIZE-SPECTRA IN EASTERN U.S. STREAMS: SEARCHING FOR A LATITUDINAL GRADIENT IN LOTIC SIZE STRUCTURE
Scaling relationships between body mass and abundance, or ‘size-spectra’, have been reported in diverse aquatic ecosystems, though few efforts have been made to detect or explain regional scale patterns in size-spectra parameters. Such regional patterns are plausible given that production and diversity, which underlie the distribution of biomass among species, often exhibit regional gradients. We therefore hypothesized that the slopes and intercepts of size-spectra models may exhibit latitudinal trends, mirroring latitudinal production and diversity gradients. To test this hypothesis, we collected quantitative estimates of fish (3-pass depletion sampling) and benthic invertebrate (10 replicate Hess samples) abundance in four eastern U.S. streams, distributed along a latitudinal gradient from ~39°N (Front Royal, VA) to ~33°N (Moundville, AL). Fish and invertebrate data are now being combined with linear regression to build multi-trophic level size-spectra models for each of the four sites. Analysis of covariance will then be used to determine whether the size-spectra slopes and intercepts change in a consistent, directional way with latitude.
Serena Moncion (Primary Presenter/Author), University of Virginia, email@example.com;
Daijona Revell (Co-Presenter/Co-Author), Virginia Commonwealth University, firstname.lastname@example.org;
Raquel Wetzell (Co-Presenter/Co-Author), Virginia Commonwealth University, email@example.com;
Felisha Walls (Co-Presenter/Co-Author), Virginia Commonwealth University, firstname.lastname@example.org;
Daniel McGarvey (Co-Presenter/Co-Author), Virginia Commonwealth University, email@example.com;