Skip to main content
U.S. flag

An official website of the United States government

Stream fish colonization but not persistence varies regionally across a large North American river basin

May 3, 2018

Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species distributions and abundances. However, research is lacking that examines how physiography affects the processes underlying metapopulation dynamics. We used data describing occupancy dynamics of stream fishes to evaluate evidence that physiography influences rates at which individual taxa persist in or colonize stream reaches under different flow conditions. Using periodic survey data from a stream fish assemblage in a large river basin that encompasses multiple physiographic regions, we fit multi-species dynamic occupancy models. Our modeling results suggested that stream fish colonization but not persistence was strongly governed by physiography, with estimated colonization rates considerably higher in Coastal Plain streams than in Piedmont and Blue Ridge systems. Like colonization, persistence was positively related to an index of stream flow magnitude, but the relationship between flow and persistence did not depend on physiography. Understanding the relative importance of colonization and persistence, and how one or both processes may change across the landscape, is critical information for the conservation of broadly distributed taxa, and conservation strategies explicitly accounting for spatial variation in these processes are likely to be more successful for such taxa.

Publication Year 2018
Title Stream fish colonization but not persistence varies regionally across a large North American river basin
DOI 10.1016/j.biocon.2018.04.023
Authors Kit Wheeler, Seth J. Wenger, Stephen J. Walsh, Zachary P. Martin, Howard L. Jelks, Mary Freeman
Publication Type Article
Publication Subtype Journal Article
Series Title Biological Conservation
Index ID 70196815
Record Source USGS Publications Warehouse
USGS Organization Patuxent Wildlife Research Center