In a new biological opinion, the National Marine Fisheries Service increases the total number of turtles that the Hawai`i-based longline fleet can take as incidental catch. From a total of 847 set in the previous biological opinion (issued in 1994), the fleet will now be able to catch 955 a year (of which up to 184 are presumed to die from the encounter). Unless these catch rates are exceeded, the opinion is good through the end of the year 2001, at which time consultation over the impact of the fishery on endangered species is to be reinitiated.
The allowed takes are broken down into species, and further distinguished between “all takes” (including animals injured and those killed) and “mortalities.” The take limit for some turtle species has been diminished, while for others, it has increased. For example, under the new biological opinion, the number of leatherback turtles that can be taken has decreased to 244 a year (from the previous level of 271). Allowable leatherback kills, previously set at 23, now are set at 19.
Loggerheads are less fortunate. The number of allowable takes increases to 489 from 355, while the number of kills included in that figure rise from 46 to 103.
No Jeopardy
The long-awaited report — some three years in the making — concludes that the fleet’s continued operation “for 1998-2001 is not likely to jeopardize the continued existence and recovery of loggerhead, leatherback, olive ridley, green or hawksbill turtles or adversely modify critical habitat.”
After reviewing statistics on turtle interactions with the longline fleet in the years since the previous biological opinion was issued, NMFS came up with an “anticipated turtle take” by the fleet for the years 1998-2001. Should the actual catch exceed these anticipated levels, then the process of consultation, set forth in the federal Endangered Species Act, must be reinitiated.
In a November 3, 1998, letter to Gary Matlock, director of NMFS’ Office of Sustainable Fisheries, Hilda Diaz-Soltero, director of NMFS’ Office of Protected Resources (and former administrator of NMFS’ Southwest Region, which includes Hawai`i), expresses several reservations her office has concerning the biological opinion. Among other things, Diaz-Soltero notes that the anticipated take levels are based not on the actual point estimates of past takes of turtles in the longline fishery, but are, instead, based on the top-end of the confidence-bar range that accompanies estimates of takes.1 Thus, instead of reinitiating consultation at the point where the turtle takes reach past thresholds, the authors of the biological opinion have proposed that consultation be triggered at a much later point.
Diaz-Soltero observes: “we are concerned that the dramatic increase in expected take (in some species the expected mortality has doubled) will preclude NMFS from reinitiating consultation when appropriate.”
Several mandatory conditions are attached to the biological opinion. First, NMFS and the Western Pacific Regional Fishery Management Council are required “to continue efforts to reduce the incidental take and mortality of loggerhead, leatherback, olive ridley, and green turtles” in the Hawai`i-based fishery. Such efforts would include “evaluation of gear modifications, implementation of turtle-handling recommendations, evaluation of fleet effort reduction, and investigation of time-area closures.” Another condition requires the immediate review by NMFS of “ANY incidental take of a leatherback sea turtle which results in serious injury or mortality” — this despite the fact that the biological opinion permits the hooking of up to 244 leatherbacks a year, with up to 19 of them resulting in the death of the animal.
Other conditions imposed by the biological opinion on NMFS require the agency to “develop and implement, within two years, studies” on fishing gear that might reduce turtle interactions or mortality; to continue with its observer program and ensure that observer coverage is “sufficient to produce statistically reliable estimates of total sea turtle takes and mortalities and to evaluate the accuracy of logbook data submitted for this fishery.”
Recommended measures include increasing observer coverage to 20 percent of the fleet (it is now around 10 percent) and encouraging bilateral and multilateral research and conservation efforts on sea turtles affected by Pacific basin fisheries.
Declining Numbers
Of all the turtle species that interact with the longline fishing fleet in Hawai`i, leatherbacks are probably the most endangered. These giant creatures (they can weigh up to a ton) “follow bathymetric contours over their long pelagic migrations and typically feed on medusae (jellyfish) and siphonophores [hydroids]. In contrast to other sea turtles, leatherbacks are capable of deep dives, exceeding 1,000 meters,” the biological opinion notes. It continues:
“Leatherbacks are declining at all major Pacific basin rookeries. The nesting population at Terraganu, Malaysia has declined from 3,103 females estimated nesting annually (FENA) in 1968 to 2 FENA in 1994. The nesting populations in Irian Jaya and New Guinea are also reported to be declining. Fewer than 1,000 FENA were estimated for the Pacific coast of Mexico during the 1995-96 season. Spotila et al. reported estimates of 800-1,000 and 30-240 FENA for two areas in Costa Rica.”
Among reasons for the dramatic declines cited in the biological opinion are egg harvesting (both legal and illegal), direct takes of adults in nesting areas, and entanglements in fishing gear. Leatherbacks are common visitors in Hawaiian offshore waters, the biological opinion notes: “There is a strong indication that the pelagic zone surrounding the Hawaiian Islands constitutes regularly used foraging habitat and migratory pathways for this species.” While Hawai`i is not a traditional nesting site for this species, the biological opinion reports that in 1997, a leatherback female nested on Lana`i; no eggs hatched.
Just what impact the take of 244 leatherbacks — and deaths of up to 19 — will have on declining populations is not described in the biological opinion. However, an earlier NMFS study on the impact of Hawai`i longliners on Pacific turtle populations (prepared by the Southwest Fisheries Science Center and published in August 1996), sets forth in some detail the different impacts on the population’s reproductive health made by deaths of juvenile animals, on the one hand, and those of adults, on the other.
In that study, scientists calculated the effect of what is called the Potential Biological Removal (PBR) of leatherback turtles from three areas believed to contribute to the population found in waters fished by the Hawai`i fleet. Scientists concluded: “The Potential Biological Removal of adult leatherback turtles was calculated to be 13 adults from the Pacific Island nesting colonies; 0 adults from the principal Malaysian nesting colony; and 12 adults from nesting colonies in Mexico and Costa Rica. It appears, however, that leatherback interactions with Hawai`i longline gear chiefly involve immature turtles. If incidental mortality is restricted to the immature turtles rather than affecting adults as assumed above, the PBR will be higher. As with loggerheads, the PBR calculation for leatherbacks should be stratified by age or size.”
The just-released biological opinion makes no distinction between takes of juveniles or adults, nor, in fact, does it contain any discussion about the disparate impact on these small populations of taking adult versus juvenile animals.
Inaction on Seabirds Comes Under Fire
Fishing fleets in Alaska and Hawai`i inflict a heavy toll on seabirds, especially albatross. In Alaska, the North Pacific Regional Fishery Management Council has required boats to employ any of several mitigation measures intended to reduce the catch of albatross. The requirement was imposed with some urgency two years ago, after a short-tailed albatross was hooked. (The short-tailed albatross is an especially rare species, with the global population estimated to consist of roughly 1,000 birds.)
Short-tailed albatross are known to range in the waters fished by the Hawai`i-based longline fleet, but to date, the Western Pacific Regional Fishery Management Council has not required vessel operators to adopt any special bird avoidance measures. Instead, the council has recently concluded a workshop on black-footed albatross population dynamics and is contracting with a consultant to experiment with several types of bird-avoidance devices. In the past, it has also attempted to get boat owners to employ bird-avoidance measures through friendly suasion and education (to no visible effect).
Both councils are coming under increasing pressure from national and international organizations and bird experts who regard the councils’ efforts as ineffective and half-hearted. The Alaska regulations do not require that fishers use proven means of avoiding birds, but allow fishers to use de minimis efforts, including simply dragging a board behind the vessel. As one observer puts it, “A toothpick could be towed from the stern and the vessel would still be in compliance.” All this is done in the name of supporting research on bird-avoidance techniques.
One such critic is Charles F. Wurster, professor emeritus of environmental sciences at the State University of New York at Stony Brook and a board member of the national group Defenders of Wildlife. In a recent letter to Kim Rivera, protected resources coordinator for NMFS’ Alaska region, Wurster faults NMFS for “not effectively execut[ing] its responsibilities” by failing to take the lead internationally in adopting measures to reduce bird-fishery interactions. As a result, he writes, “thousands of pelagic birds continue to die in American waters and at the sterns of American longlining ships.”
“NMFS,” he continues, “has focused on the research, as though little was known about methods for saving these birds, while simultaneously issuing ineffective regulations in Alaska and none in Hawai`i. Research became a substitute for effective action to protect the birds.”
The Convention on the Conservation of Antarctic Marine Living Resources requires vessels from signatory nations (including the United States) to adopt bird-avoidance devices — specifically, tori poles (which support streamers that scare birds away from the vessel’s stern) and increased weights on line, causing them to sink faster (and reduce the birds’ window of opportunity to snatch the hooked bait). Although such techniques are effective, Wurster notes, “NMFS went forward with its choice of measures in the final regulations [for Alaska]. Differences between Southern and Northern hemispheres were excessively emphasized by NMFS, research became the central focus, and too little emphasis was given to implementing known techniques for protecting pelagic birds.”
The imminent listing of the short-tailed albatross as endangered in its U.S. range may force both councils to take stronger action. Though a fluke, the short-tailed albatross, although globally endangered, was never recognized as endangered by the U.S. government in its U.S. range (an area that includes the Northwestern Hawaiian islands and waters fished by the Hawai`i fleet, as well as the North Pacific and Bering Sea).
Just recently two, and possibly three, short-tailed albatross were killed after ingesting bait on fishhooks deployed by boats that are using avoidance measures approved by the Alaska council. With the Alaska fishery allowed an incidental take of four short-tailed albatross every two years, the incentives for more earnest bird-avoidance efforts have risen substantially in the Bering Sea and North Pacific. Should the allowed incidental take be exceeded, it is possible that NMFS could shut down the fishery.
Humpback Entanglements Are Reported On Rise
Humpback whales in Hawaiian waters are becoming increasingly entangled in natural-fiber and synthetic lines. The trend, described in a report by scientists from the Hawai`i Institute of Marine Biology and from the National Marine Fisheries Service, began in 1992. By 1996, the last year considered in the report, death and entanglements of humpbacks in Hawai`i had risen three-fold from 1992 levels.
The report, “Deaths and entanglements of humpback whales, Megaptera novaeangliae, in the main Hawaiian Islands, 1972-1996,” was published in the journal Pacific Science. Authors are L. Mazzuca and Sharon Atkinson of HIMB and Gene Nitta of NMFS.
“The annual frequency of deaths and entanglements over the past 25 years rose sharply in 1996. Significantly, none of the entanglements occurred before 1992, whereas 60 percent of reports in subsequent years were entanglement in natural fiber and synthetic lines,” the authors write. “[A]ll but two of the deaths and entanglements reported in 1995 and 1996 are related to human activity, including a direct strike, possibly two, from a moving vessel.”
Most deaths and entanglements involved calves (15 incidents). Juveniles accounted for five; adults, six.
Bombs Away At Hapuna Bay
On the morning of October 15, the Navy detonated ordnance found in Hapuna Bay left over from World War II. This was the third such detonation in as many years at the popular recreational site. Ordnance was found and detonated in 1995 and 1997.
Explosive artillery is continually being found throughout the Pacific, at times entrenched in coral beds. Such was the case in the Northern Marianas, where the Navy’s blasting of World War II ordnance caused $82 million worth of damage to reef resources (see the August 1998 article “[url=/members_archives/archives_more.php?id=823_0_26_0_C]Bombs Old and New Devastate Reefs In the Northern Mariana Archipelago[/url]” from Environment Hawai`i for details).
Currently, the National Marine Fisheries Service works with the Navy’s Explosive Ordnance Disposal (EOD) to mitigate damage to fish species and reefs when the ordnance is deemed too dangerous to move and must be detonated in place.
The most desirable option is to transport the materiel to a site on shore for disposal. If that is not possible, the next option is to relocate the ordnance to an area that has a sandy bottom, then detonating it with the lowest possible charge. If detonation must be done in place, NMFS recommends that sandbags be used to minimize the explosive concussion.
The ordnance found in Hapuna Bay has been “small,” as John Naughton of NMFS puts it, and includes things like machine gun bullets and 60-80 millimeter mortar rounds. Most have been found by recreational snorkelers. A follow-up search by the Navy uncovered more artillery that was not visible from the surface, for a total of eight sites.
According to Bill Walsh and Bob Nishimoto, the marine biologists with the Department of Land and Natural Resources who scoped out the area before detonation, the ordnance was located relatively close to shore in areas not especially rich with fish or coral.
Nishimoto added that some fish probably died — no post-detonation studies were done — but no live corals were harmed.
- 1. With every “point estimate,” or specific number, that statisticians provide for a given occurrence, they also usually give a confidence bar, or error bar, that shows a much wider range of numbers within which the correct number could fall. As an example, the total incidental take of loggerhead sea turtles for 1994 was estimated to be 476, but with a 95 percent confidence limit of 237, on the low side, and 558, on the high side. This means that the scientists developing these figures are 95 percent certain that the loggerhead turtles taken by the fishery in that year numbered at least 237, but did not number more than 558.
— Teresa Dawson
Volume 9, Number 6 December 1998