NCMC OPPOSES FLAWED LONGLINE “RESEARCH” PLAN

August 2007 -- Swordfish longliners were shut out of southern coastal waters in 2001 to limit their catch of overfished and prohibited species. The closures work. Catch and dead discards of juvenile swords, billfish and sharks are down 40-75 percent from bycatch levels of the late 1990s. So you’d think the National Marine Fisheries Service (NMFS) would be careful about letting longlining resume in these areas. But it seems the agency is prepared to let the industry decide when they’re ready to return and under what conditions; namely now, and for no better reason than to up their take of swordfish from the closed areas.

The National Coalition for Marine Conservation opposes issuance of exempted fishing permits (EFPs) for 13 pelagic longline vessels to fish in the Florida East Coast and Charleston Bump closed areas. At an April 3rd meeting with NMFS chief Bill Hogarth, held at the request of NCMC, we told NMFS we are against the permits because the “scientific experiment” they propose to perform (evaluating bycatch reduction alternatives to the closures) is seriously flawed and features no criteria for judging success. As a result, it amounts to little more than a foot-in-the-door attempt by industry to re-enter the closed areas to longline for swordfish, tuna, dolphin (mahi-mahi) and sharks.

“Because the research proposal was initiated by the longline industry and developed without input from the scientific community and members of the public,” says NCMC president Ken Hinman, “the EFPs, if approved, could undermine the current and future conservation benefits of the closed areas. We are urging NMFS to withdraw the proposal and start over. To issue this EFP at this time, based on a false urgency to catch more swordfish and fill our quota, would be both a misuse of the EFP process and a missed opportunity to conduct bona fide bycatch reduction research.”

Circle Hooks Alone are Not Bycatch Reduction Research

The EFP application, submitted by Blue Water Fisherman’s Association, is based on the notion that the use of circle hooks by the pelagic longline fleet can replace closures as a means to limit bycatch. There is a wide range of species that would be taken by longlines in the Charleston Bump/Florida East Coast areas, including juvenile swordfish, white marlin, blue marlin, sailfish, dolphin-fish, large coastal and pelagic sharks. Although circle hooks have been shown effective in reducing bycatch of some species, especially on rod-and-reel, there is no evidence of reductions in bycatch mortality for fish caught on longlines that remain on the hook for up to 12 hours and more. Nor is there evidence indicating a reduction in post-release mortality for fish released after being on the hook for so many hours.

NCMC is insisting that any real research into the use of circle hooks on longlines must also study the effect of various shortened soak times. In fact, one study indicates that, even using circle hooks, mortality of bycatch species increases significantly with each hour after hook-up. Berkeley and Edwards (1998) used hook-timers in the Gulf of Mexico yellowfin tuna longline fishery to compare mortality with the time the fish spent on the hook. The tuna longliners used circle hooks almost exclusively (over 90 percent). The mortality rate for billfish surpassed 50 percent - that is, more than half the fish brought up dead - after they’d been on the hook for about 8 hours. Swordfish (including juveniles that cannot be landed) surpassed the 50 percent mortality mark less than 2 hours after hook-up.

To meaningfully measure reductions in bycatch mortality attributable to circle hooks, the experiment must also test different soak time lengths (e.g., three hours, six hours, nine hours) and compare survival rates. In addition, released fish should be tagged with pop-up archival tags to assess post-release mortality of fish caught on circle hooks at varying set-lengths. Because the mortality rate for fish taken on circle hooks increases in the hours after hook-up, it is also likely that fish released alive have been stressed enough that post-release mortality may be significant.

Without Strict Performance Criteria, “Success”
Could Mean a Net Loss of Conservation

Blue Water says the “circle hook performance data” will allow comparison with longline logbook data from 1997-99, prior to implementation of the closures. These data, they say, could then be used to consider “re-opening selected traditional swordfish fishing grounds.”

But the ultimate measure of bycatch reduction success is the effectiveness of the current closed areas with no longlining. Any lesser standard would mean a decrease in conservation benefit for a number of species that are severely overfished and the object of long-range rebuilding efforts (white marlin, blue marlin, numerous large coastal sharks), as well as juvenile swordfish, whose survival and growth is still critical to the long-term recovery of swordfish.

In the three years following full implementation of the time-area closures (2001-03), the following bycatch reduction rates were achieved as compared with the pre-closure period 1997-99:

These bycatch reduction rates are the standard against which the performance of gear modifications, as a possible substitute for the closed areas, must be measured. The longline industry suggests only the most minimal standard, that is, comparison to bycatch rates before the closures.

“Within the context of a proposal whose ultimate goal is to ‘allow the U.S. pelagic longline fleet to catch more of the U.S. quota’ of swordfish,” says Hinman, “the public can have no confidence in management decisions made based on this research unless the criteria for assessing the results are clearly spelled out. Because the closed areas are benefiting a wide range of species, the goal of any bycatch reduction program that might be considered as a substitute for closed areas must be to achieve at least the same level of conservation. Otherwise, we – and the fish – will lose.”

Read the update on this issue.

View a map of all areas on the US east and gulf coasts closed to longlining since 2000.