Amistad Reservoir 2018 Survey Report media download(PDF 783.2 KB)

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Amistad Reservoir - 2018 Survey Report

Prepared by Randall A. Myers and Mitchell Nisbet
Inland Fisheries Division - San Antonio District

This is the authors' summary from a 35-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Amistad Reservoir were surveyed in 2018-2019 using electrofishing and gill netting since the last report (2017). Anglers were surveyed from January through June in 2018 using a creel survey. Historical data are presented for comparison. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.

Reservoir Description

Amistad Reservoir (63,680 acres when full) borders Mexico and was constructed in 1969 on the Rio Grande River. It is managed by the International Boundary and Water Commission to provide water for irrigation and hydro-electric power generation. Boat and angler access are excellent; the National Park Service (NPS) maintains 9 public boat ramps. Water level declined from full pool in 2011 to 61 feet low in 2013. Water level subsequently increased and remained 26-37 feet low since 2015 with water level fluctuating 12.9 feet annually on average. Aquatic vegetation occurrence decreased and hydrilla occurrence increased slightly in 2018 compared to in 2016. Three water samples from the reservoir tested positive for Zebra Mussel DNA in December 2018, further water tests have tested negative and monthly shoreline surveys have not found any adult mussels.

Management History

Important sport fishes include Largemouth Bass, Smallmouth Bass, catfishes, Striped Bass, and White Bass. Striped Bass were stocked in most years since 1974. Florida Largemouth Bass (FLMB) were stocked periodically from 1975 to 2006 and annually since 2010 to improve FLMB introgression and trophy Largemouth Bass potential. Angler harvest of all sport fishes has been regulated according to statewide size and bag limits. Since 2004, the NPS has regulated Largemouth Bass tournaments via a tournament permitting program.

Fish Community

Management Strategies

Sport Fish Restoration Logo

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-221-M-2 Inland Fisheries Division Monitoring and Management Program