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Marine Bycatch

In addressing the tuna-dolphin issue in the eastern tropical Pacific (ETP) Ocean as a case study in bycatch, the authors of “Thinking like an Ocean” (Fall 2002) incorrectly attribute the fishery’s problems to efforts to protect dolphins. For starters, contrary to the authors’ assertion, the ETP purse seine tuna fishery is, in terms of bycatch, one of the world’s ten least wasteful fisheries, with 0.18 animals discarded per landed target catch weight (1). Moreover, the authors fail to note the twin problems of vessel storage overcapacity and overharvesting, both of which have occurred under the aegis of the Inter-American Tropical Tuna Commission (IATTC). From 1992 to 1999, according to the IATTC’s 1999 report, “Considerations Regarding Limitations on the Growth in Carrying Capacity of the Tuna Purse-Seine Fleet Fishing in the Eastern Tropical Pacific Ocean,” the total vessel capacity in the ETP purse seine fleet increased from 100,000 tons to 158,837 tons, an increase of almost 60 percent in less than a decade. The IATTC itself has stated that a sustainable fleet storage capacity is “no more than 135,000 tons” and “most likely significantly less.”

Likewise, the authors only cursorily address the problem of fishing effort, which has increased to the level that, in the IATTC’s own words, “nearly all of the major tuna stocks of the world are fully exploited.” The total estimated catch of the ETP tuna fleet in 1998, the year in which the international agreement implementing the Panama Declaration was signed, was 446,152 metric tons, the second highest since recordkeeping began in 1961 and exceeded only by the 473,778 tons in 1997 (2). Harvest of yellowfin tuna in 1998 was 264,426 metric tons, the highest since 1990, just before major reforms were instituted by the U.S. fishing industry and Congress that year (2). In fact, according to the IATTC’s 1999 report, “Assessment of Yellowfin Tuna in the Eastern Pacific Ocean,” the IATTC reports that overall yellowfin tuna fishing effort in the ETP has increased at least 27 percent during the years 1994-1999, with observed catch of yellowfin tuna also significantly higher. For example, in 1999, the catch of 270,000 metric tons in the IATTC’s yellowfin tuna regulatory area exceeded the 240,000 metric tons recommend-ed as the maximum by IATTC scientists (3, 4).

Most incredibly, the authors fail to acknowledge the increase in all types of purse seine net sets — not just on dolphins but also on floating objects and free-swimming tuna — that have occurred since the signing of the Agreement on the International Dolphin Conservation Program in 1998. In fact, 1998’s total number of 28,333 sets was the highest in history (2). Especially disturbing are the spikes in dolphin sets, from 6,987 in 1993 to 11,430 in 1998, which is the highest number since 1989 (2). Likewise (and unaddressed by the authors), sets on floating objects — conventionally believed to result in the greatest amount of bycatch — have increased, from an average of 3,000 sets during the 1980s to 1990s, to an all-time high of 7,308 in 1997, before dipping only slightly to 6,425 in 1998 (2). Astonishingly, the IATTC continues to raise the annual catch limit for yellowfin tuna, with 2001’s limit of 310,000 metric tons bound to perpetuate the ETP’s overfishing problems.

In short, the bycatch problems in the ETP tuna fishery are more complex than the authors indicate and can hardly be blamed on efforts to protect dolphins. To the contrary, they indicate a fishery that is out of control and plagued by increases in sets, harvests, and vessel storage capacity. Far from pursuing an “emotionally-driven,” single-species protection, environmentalists seek to protect the entire ETP marine ecosystem, including dolphins, birds, sea turtles, and the fish species themselves.

Literature Cited:

1. United Nations Food and Agriculture Organization. 1994. A Global Assessment of Fisheries Bycatch and Discards: UN FAO Fisheries Technical Paper #339. United Nation’s Food and Agriculture Organization, Rome.

2. Inter-American Tropical Tuna Commission. 1999. The 1998 Fishing Year. Inter-American Tropical Tuna Commission, La Jolla, CA.

3. Inter-American Tropical Tuna Commission. 1999. Resolution for Implementing the Catch Limit for Yellowfin Tuna in 1999. Inter-American Tropical Tuna Commission, La Jolla, CA.

4. Inter-American Tropical Tuna Commission. 1998. Assessment of Yellowfin Tuna in the Eastern Pacific Ocean. Inter-American Tropical Tuna Commission, La Jolla, CA.

WILLIAM J. SNAPE, III

Vice President and Chief Counsel, Defenders of Wildlife

KUMAR VASWANI

Walter Kuhlmann Legal Fellow, Defenders of Wildlife

The author responds:

The article addresses the matter of bycatch, which is a very significant issue in the management of fisheries but not the only one. After reducing dolphin mortality by 99 percent and eliminating it as a serious conservation concern, the member nations of the IATTC have begun focusing their attention on the bycatch of sets on floating objects. The fact that the fishery was rated as one of the “cleanest” in the past reflects the fact that the predominant method of fishing (on dolphins) was extremely clean. In the three years previous to the start of the “dolphin-safe” policy, there were annual averages of around 12,000 sets on dolphins, 8,000 sets on unassociated schools, and 3,000 sets on floating objects. In the past three years, these have changed, and the seiners have made around 9,000 sets on dolphins, 10,000 on unassociated schools, and 5,000 sets on floating objects. Given the differences in bycatch rates shown in the article, it is clear that the increase in floating object sets has increased the bycatch.

The number of sets for all seiners has declined by 15 percent between 1998 and 2001 (IATTC Annual Report for 2001, and www.iattc.org), contrary to the assertion of Defenders of Wildlife. Also, a group involved in conservation should recognize that the issue of bycatch cannot be addressed in global percentages and biomasses alone. If the bycatch rate is only one percent, but this level of bycatch is driving a species to extinction, there is a conservation problem. In the case of the fishery on floating objects, we do not have adequate abundance data for most of the sharks, billfishes, and other species involved to determine if the mortality rate is sustainable. But the member countries of IATTC have adopted a precautionary approach and have passed a series of recommendations, including management actions, proposed experiments, etc., aimed at reducing bycatches.

These actions are separate from those addressing the fishing capacity, in which progress is being made. The figure of 158,000 m³ has been used since 1999 as the desired target capacity for the purse-seine fleet. In recent years, capacity has oscillated between 180,000 and 190,000 m³, or 15-17 percent over the desired target.

If you visit any fishing port in the eastern Pacific today, you will see an unusual sight. Dozens of purse seiners are anchored and will remain anchored for the whole month of December in compliance with an IATTC resolution implemented by its member nations to reduce fishing effort. This illustrates the fact that overcapacity is an economic rather than an ecological problem. In June of 2002, the Commission agreed to a measure which, in essence, caps the purse-seine capacity at current levels with some small exceptions. It is not a perfect solution but a work in progress, and it is the only significant fishing capacity control measure adopted by any regional fishery management organization in the world so far as we are aware.

MARTÍN HALL

Head of the Tuna-Dolphin Program at the Inter-American Tropical Tuna Commission