By Deborah Zabarenko, Environment Correspondent
WASHINGTON (Reuters) - The U.S. government put the Atlantic bluefin tuna on an environmental watchlist as a "species of concern" on Friday, and will keep checking for any impact on these fish from the 2010 BP oil spill in the Gulf of Mexico.
At this time, the species is not threatened or endangered and so will not be listed as such under the Endangered Species Act, which would trigger immediate protections, officials at the National Oceanic and Atmospheric Administration said in a telephone briefing.
Atlantic bluefin tuna spawn in the Gulf of Mexico in the vicinity of last year's BP Deepwater Horizon spill, but so far there is no evidence that the species is being harmed.
"While the NOAA team found that presently available information did not support listing, it also recognized the need to continue to monitor the potential long-term effects of the spill on bluefin tuna and the overall Gulf ecosystem," Eric Schwaab, of NOAA's Fisheries Service, told reporters.
The time period of the agency's peer-reviewed study did not allow for full consideration of the impact from the oil spill, Schwaab said.
NOAA will revisit this decision by early 2013, when more information about the spill's impacts will be available. There will also be a updated assessment of Atlantic bluefin tuna stocks by the International Commission for the Conservation of Atlantic Tunas (ICCAT), the global agency that monitors the fish's management and conservation.
Susan Lieberman of the Pew Environment Group applauded NOAA's decision to closely monitor the species, but said the agency should close the Gulf of Mexico to long-line fishing for other species to protect Atlantic bluefin tuna's spawning grounds.
"They've got it on a watchlist, they agree it's in trouble and they need to take action," Lieberman said by telephone.
Long-line fishing operations continue to ply the Gulf for yellowfin tuna and swordfish, but now use so-called weak hooks to protect bluefin tuna that spawn in the area, Schwaab said.
Atlantic bluefin tuna can fetch more than $100,000 each in markets such as Japan, though stocks have declined by more than 80 percent since the 1970s due to overfishing.
Last November, ICCAT set fishing quotas for this year at 12,900 tonnes, a reduction of 600 tonnes from the previous year, but a reduction that environmental groups said was too small to ensure recovery of the species in the Mediterranean.
Last week, Europe's fisheries chief called for close monitoring of the trade in bluefin tuna caught in Libyan waters, fearing illegal catches could push the species closer to regional extinction.
(Editing by Eric Walsh)