Following the Deepwater Horizon/BP oil spill in the Gulf of Mexico, there was understandable concern for a variety of species that inhabit the area, particularly those whose numbers were fragile and in decline to begin with. The Atlantic bluefin tuna was one such example, not only because its number worldwide are perilously low but because it is the Gulf of Mexico where the Western Atlantic bluefins go to spawn from March to June.
Pelagic longlining (PLL), one of commercial fishing's most indiscriminate methods, also occurs in the Gulf and with some scientists saying that as much as 20% of juvenile Atlantic bluefin tuna population was killed by the oil spill, many organizations are seeking to have the spawning grounds placed off limits to all PLL fishing during the spawning season. Their position is that, with a perilous population already weakened by the direct effects of the oil spill, to allow longlining to take place would spell disaster.
Equally as tragic is the fact that the focus of the longliners in the Gulf is not bluefin tuna. They are after the smaller yellowfin tuna, swordfish, and other species - making the bluefin merely accidental bycatch. Is it possible for the large and powerful bluefin tuna to be released if caught? Apparently not. There is a high mortality rate because the elevated levels of stress when caught, combined with the animals high metabolism and the warm waters of the Gulf, often prove fatal before any chance of release could take place.
The National Oceanic and Atmospheric Administration (NOAA) has, to date, recommended that PLL boats use what are called "weak hooks." These are large hooks that are constructed with a smaller diameter wire so that a large and powerful fish like a bluefin tuna will have a fighting chance because the hook will bend, allowing the fish to release itself.
According to the results of field tests with participating longliners from 2008 to 2010, the NOAA Fisheries Service "found a statistically significant reduction in the catch of bluefin tuna of 56%, but no statistically significant difference in the catch of yellowfin tuna, swordfish, dolphin fish, or escolar on weak hooks compared to traditional hooks."
NOAA is considering making the use of weak hooks mandatory for the Gulf PPL fleet, but this has not necessarily won favor with many conservation groups concerned about the overall declining population of bluefin tuna and who have been demanding greater action on the part of ICCAT, the international body that basically regulates the tuna industry but which has continued to set annual catch levels that far exceeds levels recommended by even their own scientific panels.
Additionally, while some Atlantic Bluefin tuna would be spared by the use of weak hooks, there are countless other animals, from sharks to turtles to other unwanted bycatch, that would be needlessly killed just by virtue of the very nature of the longline technique itself.
As the Center for Biological Diversity (CBD) describes it, "The pelagic longline fishery has a long history of deadly interactions with imperiled species. The weak-hook proposal acts as a stopgap measure to allow longline fishing to continue in spite of strict limits on bluefin tuna catch. Closing western Atlantic bluefin tuna breeding grounds during spawning season will not only afford bluefin tuna a greater chance to recover, but will also build a healthy ecosystem by protecting other bycatch species such as sharks, sea turtles and billfish."
CBD is currently waging a campaign through their own efforts and that of a email letter drive to Division Chief Margo Schulze-Haugen of NOAA's National Marine Fisheries Service to have NOAA consider the closure. If you would like to add your voice, click here.
Read NOAA's bulletin on weak hooks.