Technical Report

Main Channel Fisheries Monitoring - 2015 Report: Metrics for Adaptive Management of Habitat Restoration Sites for the Rio Grande Silvery Minnow

URL: https://webapps.usgs.gov/mrgescp/documents/SWCA%20Consultants_2015_Main%20Channel%20Fisheries%20Monitoring%20Year%20Two%20Draft%20Report%20Metrics%20for%20Adaptive%20Management%20of%20Habitat%20Restoration%20Sites%20for%20the%20RGSM.pdf

Date: 2015/04/01

Author(s): SWCA Environmental Consultants

Publication: Prepared for U.S. Army Corps of Engineers. Prepared by SWCA Environmental Consultants, 132 p.

Abstract:

Habitat restoration is needed to the reduce risk of extinction and to increase recovery potentials for the Rio Grande silvery minnow (Hybognathus amarus; silvery minnow) in the Middle Rio Grande of New Mexico. Several restoration approaches have been implemented to improve habitat for the species, including bankline lowering, channel widening, backwater construction, and high flow side channel construction. One metric for evaluating the effectiveness of habitat restoration projects is through monitoring for silvery minnow and the Middle Rio Grande fish community during spring runoff and post-runoff. How the fish community and the silvery minnow respond in the vicinity of habitat restoration projects in the months following recruitment provides a broad measure of project utilization. The use of catch per unit effort metrics during post-runoff monitoring allows for general comparisons among sites and provides an opportunity to assess the effectiveness of the various treatment types.

This report presents results from the 2013 and 2014 collection of baseline main channel fish monitoring data in the vicinity of Middle Rio Grande habitat restoration projects. Additionally, the question persists whether using a beach seine for monitoring the Middle Rio Grande fish community adequately describes relative abundance and size distribution of either the silvery minnow or the Middle Rio Grande fish community. To help address this question, a beach seine and bag seine were used in combination to collect relative abundance fisheries data from main channel habitats adjacent to artificial floodplain habitat restoration sites in the Middle Rio Grande. Samples were collected by rapidly drawing the beach seine in a downstream direction up to the larger oversized bag seine.