The Obama administration said on Friday that it had declined to grant Endangered Species Act protections to the Atlantic bluefin tuna, whose numbers have declined precipitously because of overfishing on both sides of the ocean.

The National Oceanic and Atmospheric Administration said the fish, whose fatty flesh is prized by sushi aficionados, would be classified as a species of concern, however, effectively placing bluefin on a watch list as the agency awaits new data on the impact of a stricter international management regimen.

“The future of this species relies on sound international management,” said Larry Robinson, NOAA’s assistant secretary for conservation and management. The agency’s scientists are also continuing to assess the effect of last year’s Deepwater Horizon oil spill on bluefin spawning grounds in the Gulf of Mexico, officials said, and the agency will revisit its decision by early 2013.

Mr. Robinson said the bluefin tuna did not warrant protection under the Endangered Species Act because it was “not likely to become extinct.”