U.S. Fish and Wildlife Service has announced a new cap for how many Rio Grande silvery minnows could be lost this year without harming the minnow population, due to ongoing river maintenance and water operations. The allowed mortality limit for the silvery minnow is 265,935 retroactive to April 1.
The Rio Grande dries intermittently during the summer months. Biologists constantly monitor river conditions and salvage minnows from drying pools. Despite these and other precautionary measures, silvery minnows die.
The Endangered Species Act prohibits killing endangered species but also recognizes that species could die during the normal course of conducting legal activities. The Service quantifies how much mortality can occur without significantly impacting the species? long-term persistence in the middle Rio Grande. This number is based on a formula that considers annual population monitoring data from October, indexes spring flows and includes the number of minnows stocked into the river during the previous year.
The Service provides a permit to the two federal agencies that manage river conditions, the Bureau of Reclamation and the U.S. Army Corps of Engineers, that includes the incidental take number and outlines many required measures that benefit the endangered fish.
Last year's mortality limit was 10,440. Monitoring and salvage efforts have documented substantial increases in minnow numbers. Last spring the Rio Grande overflowed into the bosque, providing outstanding nursery habitat for young silvery minnows. Biologists, who do annual monitoring in October, estimate the silvery minnow population increased fifty-fold as a result of last summer's productive spawn.
The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million-acre National Wildlife Refuge System, which encompasses 546 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 69 national fish hatcheries, 64 fishery resources offices and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.
-http://southwest.fws.gov-
