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Worthington, T.A., S.K. Brewer, T.B. Grabowski, and J. Mueller.2013. Evaluating the sampling efficiency of the Moore egg collector. North American Journal of Fisheries Management 33:79-88.

Abstract

Quantitative studies focusing on the collection of semibuoyant fish eggs, which are associated with a pelagic
broadcast-spawning reproductive strategy, are often conducted to evaluate reproductive success. Many of the fishes in this reproductive guild have suffered significant reductions in range and abundance. However, the efficiency of the sampling gear used to evaluate reproduction is often unknown and renders interpretation of the data from these
studies difficult. Our objective was to assess the efficiency of a modified Moore egg collector (MEC) using field and laboratory trials. Gear efficiency was assessed by releasing a known quantity of gellan beads with a specific gravity similar to that of eggs from representatives of this reproductive guild (e.g., the Arkansas River Shiner Notropis girardi) into an outdoor flume and recording recaptures. We also used field trials to determine how discharge and release
location influenced gear efficiency given current methodological approaches. The flume trials indicated that gear efficiency ranged between 0.0% and 9.5% (n = 57) in a simple 1.83-m-wide channel and was positively related to
discharge. Efficiency in the field trials was lower, ranging between 0.0% and 3.6%, and was negatively related to bead
release distance from the MEC and discharge. The flume trials indicated that the gellan beads were not distributed
uniformly across the channel, although aggregation was reduced at higher discharges. This clustering of passively
drifting particles should be considered when selecting placement sites for anMEC; further, the use of multiple devices may be warranted in channels with multiple areas of concentrated flow.

 

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Status

Published
January (1st Quarter/Winter) 2013

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Unit Authors

Texas Cooperative Fish and Wildlife Research Unit Cooperators

  1. Texas Parks and Wildlife
  2. Texas Tech University
  3. U.S. Fish and Wildlife Service
  4. U.S. Geological Survey
  5. Wildlife Management Institute