Tuna, dolphins, and purse seine fishing in the eastern tropical Pacific: the controversy continues.

• Author: O'Connell, Denis A.

Like peace, the real work of saving the ocean is not only carried out in diplomatic chambers and government offices. It is carried out in the hearts and hands of the people. (2)

INTRODUCTION: DOLPHIN DEATHS AND THE MARINE MAMMAL PROTECTION ACT

During the early 1970's, a historic peak in the environmental movement, fueled by public outrage and activism, resulted in the passage of several new U.S. laws designed to protect the environment. Congress enacted the Marine Mammal Protection Act (MMPA) (3) in 1972 to address, among many problems concerning marine mammals, the large number of dolphins killed by the purse seine method of fishing for yellowfin tuna in the eastern tropical Pacific Ocean (ETP), (4) a 5 to 7 million square-mile area of ocean that extends roughly from Southern California to the Chilean coastline, and west to Hawaii. (5)

The MMPA established a moratorium on the taking (or killing) and importation of marine mammals, including dolphins, except those taken incidentally during commercial fishing operations. (6) Recent MMPA amendments have reiterated the fundamental views of Americans and the original intent of Congress that marine mammals "have proven themselves to be resources of great international significance, esthetic and recreational as well as economic, and it is the sense of the Congress that they should be protected ..." (7)

It was the voice of an entire nation that pressured Congress to enact the MMPA, but it was the acts of one man that brought public attention to the decimation of dolphin populations in the ETP as a result of the yellowfin tuna industry's fishing practices. In 1988, American marine biologist Sam LaBudde undertook a daring and dangerous mission: he enlisted as a cook on a Panamanian tuna vessel and secretly filmed purse seine fishing activities. (8) LaBudde was the first person to successfully capture this slaughter on film. (9) LaBudde's widely publicized images depict the brutal annihilation of dolphins then commonplace in purse seine fishing. (10)

LaBudde's pictures were the catalyst for a shifting debate regarding dolphins and the ETP purse seine tuna fishing industry. (11) In the beginning, it was purely a domestic dispute concerned with the large number of dolphin deaths. After the MMPA and its amendments successfully lowered dolphin mortality rates, the debate's focus shifted. The issues of recovery of dolphin populations, protection of marine biodiversity, international relations, and consumer fraud have now largely replaced dolphin mortality as the debate's central issues. (12) The debate also broadened from a domestic outlook to an international one with the passage of treaties such as the La Jolla Agreement and the Panama Declaration.

Along with this shift in focus, a schism has occurred in the previously united environmental community. Several environmental groups have backed what they believe to be a workable balance between the economics of fishing and dolphin mortality. Other organizations have taken a hard line approach against any dolphin mortality and have brought lawsuits against the U.S. government challenging legislation ratifying recent international agreements. This paper will provide a history of the tuna-dolphin debate, beginning with an analysis of the tuna-dolphin relationship. A chronological overview of both domestic and international legislative developments regarding ETP purse seine fishing follows. Finally, two recent court cases, Brower v. Evans (13) and Defenders of Wildlife v. Hogarth, (14) are discussed and analyzed for their potential impact on the continuing debate.

TUNA, DOLPHINS, AND PURSE SEINE NETS IN THE ETP

Yellowfin tuna is the most economically significant tuna species caught in the ETP. (15) Yellowfin can grow to be 6 feet long (180 cm), and generally weigh anywhere from 11 to 44 pounds (5 to 20 kg). (16) Their size makes yellowfin well fit for solid packing in cans and causes the market demand to be greater for yellowfin than it is for other fish species. (17) Approximately 30 percent of the world's yellowfin harvest is taken from the ETP. (18) For reasons that are still scientifically unexplained, yellowfin swim below dolphin schools in this oceanic area. (19) Because dolphins must surface to breathe, this tuna-dolphin relationship has provided an easy means for fishermen to locate yellowfin (20)

Prior to 1959, fishermen catching tuna rarely harmed dolphins because they predominantly fished by using a baited hook-and-line. (21) Then, U.S. fishing vessels began to encircle dolphins with large purse seine nets to capture the yellowfin tuna swimming beneath them. (22) Purse seine nets are up to a mile long, and may hang as deep as 600 to 800 feet beneath floats on the ocean surface. (23) The process known as "setting on dolphins" begins shortly after a dolphin school is sighted. Speedboats are launched to chase, tire, and herd the dolphins into a tight group that can easily be encircled. (24) Explosives, helicopters, and other devices are also sometimes used to herd the dolphins into the center of the nets. (25) Chase and herding activity lasts an average of 20 minutes, with some extreme chases lasting more than an hour. (26) During the chasing and herding, yellowfin tuna remain below the dolphins on the surface. (27)

The fishermen surround the dolphin school with the net, with a small boat holding one end of the net stationary. (28) Upon encirclement, the bottom of the net is drawn together ("pursed") by cables to keep the tuna below from diving underneath the net to escape. (29) The fishermen then haul the net on board to recover the tuna. (30) Dolphins are released through a back-down procedure, where the fishermen reverse the vessel's direction after about half of the net has been taken onboard. (31)

A variety of factors can cause dolphin mortality on the ocean's surface during purse seine operations. Sudden strong currents can collapse the net, catching dolphins inside. (32) Dolphins sometimes panic at the sight of the boats and net and become entangled in the net's sides. (33) When setting the nets at night ("sunset sets"), it is difficult for fishermen to see the dolphins or predict their movements, and dolphins can become entangled in the net as it is set. (34) Additionally, nets lost or abandoned in rough weather ("ghost nets") can continue to trap dolphins as they float unattended through the ocean. (35)

The Earth Island Institute and Humane Society claim that encirclement methods harass, injure, and potentially kill dolphins, whether or not dolphins are brought on board the ship. (36) In addition to direct surface mortality, hidden dolphin mortality resulting from encirclement has also been an important concern to these organizations. (37) Dolphins are often injured during chase and herding activities and, even if released alive, are more vulnerable to predator attack and death from their injuries. (38) During the confusion of the chase, young dolphins may be separated from their mothers, resulting in an increased chance of death from predator attack or starvation. (39) The Humane Society also claims that chase and encirclement repress dolphins' reproductive output to the point where population numbers are not recovering from the massive mortality that has taken place in the past. (40)

Although it is undisputed that purse seine net fishing has taken a toll on ETP dolphin populations, the estimates of dolphin mortality have varied over the last thirty years. (41) By some counts, over seven million dolphins have died as a direct result of contact with the yellowfin tuna fishery since the advent of purse seine fishing in 1959. (42) In the early 1970's, the U.S. fishing fleet alone was responsible for the slaughter of over 300,000 dolphins annually. (43)

Even though direct dolphin mortality has largely been curtailed, ETP dolphin population sizes are not returning to their pre-1950's levels. One explanation for the lack of recovery is that dolphin populations are thought to grow slowly, and the measures of abundance trends are designed to be long-term indicators and are insensitive to short-term changes. (44) An alternative explanation, as discussed above, is that stress to individual dolphins during encirclement hinders their reproductive output, thus also hindering the recovery of the dolphin population. (45)

CONGRESS ADDRESSES DOLPHIN MORTALITY CAUSED BY FOREIGN VESSELS: THE 1988 MMPA AMENDMENTS

In the early 1980's, the MMPA had successfully reduced dolphin mortality in the ETP caused by the U.S. tuna boat fleet, but the growth of foreign fleets offset that reduction. (46) One reason for the reduction of U.S.-caused dolphin deaths was the decreased numbers of U.S. fishing vessels in the ETP. (47) Over the years, the size of the U.S. tuna fleet had diminished from 35 vessels to 6. (48) Most U.S. vessels moved to the western Pacific (an area where purse seine net use is still not regulated), were inactivated, or were sold to foreign companies. (49) The U.S. dominance of the ETP tuna fishing industry fell to Mexico, Ecuador, Venezuela, Vanuatu, and Colombia. (50) Dolphin slaughter by fishing vessels from these and other countries remained a growing problem because there were no international regulations governing tuna fishing. (51)

Through amendments to the MMPA in 1984 and 1988, Congress enacted specific standards intended to ensure that foreign tuna fishing fleets in the ETP would reduce the number of dolphins they killed. (52) Congress chose to bring about dolphin mortality rate reductions by imposing a mandatory embargo on the importation of yellowfin tuna from countries whose fleets failed to meet certain standards. (53) The embargo caught the attention of other tuna-fishing nations because the U.S. tuna market had been expanding for years, with per capita tuna consumption more than doubling between 1950 and 1965 until, by 1974, more than one quarter of all fish consumed in the U.S. were tuna...