SAN DIEGO, Nov. 24 (UPI) -- Fishing activities are stunting population growth of a type of Pacific Ocean dolphin despite dolphin-safe practices, U.S. university researchers said.
The study by Scripps Institution of Oceanography at the University of California-San Diego revealed negative impacts from fishing activities remain, despite adoption of regulations and agreements designed to reduce dolphin deaths from "by-catch" in which animals are caught unintentionally along with the intended targets.
The research by the university and the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center showed fishing activities disrupted the reproductive yield of the northeastern pantropical spotted dolphin, the university said in a news release. Researchers note that reproductive output of the eastern spinner dolphin also declined, but finding a direct link to fishing was inconclusive.
The conclusions are based on surveys between 1987 and 2003 conducted by NOAA Fisheries Service designed to assess the size and general health of dolphin populations in the eastern Pacific Ocean.