Annual Report

Rio Grande Silvery Minnow Augmentation in the Middle Rio Grande, New Mexico: Annual Report 2024

URL: https://webapps.usgs.gov/mrgescp/documents/Archdeacon_2025_Fish-Rescue-Annual-Report-2024-Final.pdf

Date: 2025/03/04

Author(s): Archdeacon, T.P.

Publication: U.S. Fish and Wildlife Service report submitted to U.S. Bureau of Reclamation

Abstract:

  • This report covers New Mexico Fish and Wildlife Conservation Office (NMFWCO) Rio Grande Silvery Minnow (RGSM) augmentation activities for the 2024 cohort.
  • Spring runoff in early 2024 was moderate, resulting in a request of 210,000 hatchery-reared age-0 fish to supplement the wild 2024 cohort.
  • Broodstock collections April through July 2024 resulted in 220 RGSM eggs (transported to the Albuquerque BioPark), ~2,500 larval RGSM (transported to the Albuquerque BioPark), and ~750 juvenile RGSM (transported to Southwestern Native Aquatic Resources and Recovery Center). This resulted in approximately 1,800 surviving broodstock, with only 300 housed at Southwestern Native Aquatic Resources and Recovery Center.
  • Based on September 2024 population monitoring, the San Acacia and Angostura Reaches had > 1.0 RGSM per 100m2 but <50% occupied sites and CPUE = 0.07 in the Isleta Reach. Because the Angostura Reach was only slightly above 1.0, the NMFWCO requested additional fish be released there, leading to a final request of 130,000 RGSM for release in the San Acacia Reach.
  • 163,206 hatchery-reared age-0 Rio Grande Silvery Minnows were released in October, November, and December 2024. All were given a red left VIE tag prior to release.
  • VIE-marked fish were recaptured between January and December 2024, all from the 2023 cohort. The majority of recaptures (N = 105) were during fish rescue activities.
  • A pilot mark-recapture study continued in 2024 to determine the feasibility of robust-design mark recapture to estimate monthly survival, movement, and capture efficiency of Rio Grande Silvery Minnow. A total of 962 Rio Grande Silvery Minnow was captured in 2024 with 26 recaptures.

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