Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems

PLoS ONE
By: , and 

Links

Abstract

Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2–3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width:depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems
Series title PLoS ONE
DOI 10.1371/journal.pone.0096599
Volume 9
Issue 5
Year Published 2014
Language English
Publisher PLOS
Contributing office(s) Coop Res Unit Atlanta
Description e96599: 9 p.
Country United States
State Oklahoma
Other Geospatial Canadian River, North Canadian River
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details