Does Flipper Need a Flak Jacket? A Review of Dolphin Mortality and Stress in the The Eastern Tropical Pacific Tuna Purse Seine Fishery.
Abstract
Over the past thirty years, perhaps no marine conservation issue has
aroused as much public interest as the drowning of dolphins in purse seine nets used in the
Eastern Tropical Pacific (ETP) to harvest yellowfin tuna. For a generation that grew up watching
Flipper on television, graphic video footage of dolphins hauled to their deaths in tuna nets was
simply too much to bear. The United States tried, but found that it had little power under the
Marine Mammal Protection Act unilaterally to protect dolphins and marine life in the
international waters of the ETP. Despite consumer-driven boycotts of canned tuna and the United
States' embargoes on tuna imports, dolphins were still dying in the ETP purse seine fishery for
yellowfin tuna.
The U.S. Congress adopted measures to label only tuna caught without
encircling dolphins as "dolphin-safe" and to prohibit the import of non-dolphin safe tuna into
the U.S. The international response to these actions was the adoption of the voluntary La Jolla
Agreement within the Inter-American Tropical Tuna Commission to reduce dolphin mortality in the
ETP tuna fishery. The cumulative result of the embargoes, the La Jolla Agreement, and to a
lesser extent the dolphin safe label, was a 98% decline in the number of dolphins killed in the
ETP tuna fishery. Remarkably, however, encirclement of dolphins by tuna fishers remained at
virtually the same level as before the adoption of dolphin-safe restrictions--evidence that the
dolphin-safe label was not driving the reduction in mortality. The data clearly indicated that
the dolphin-safe label hadn't stopped the intentional encirclement of dolphins, it wasn't
stopping dolphins from dying, and it certainly wasn't protecting marine life or the marine
environment. In fact, it was causing greater environmental damage through the increased bycatch
of sharks, sea turtles, swordfish, food fish for dolphins and juvenile tuna. In short,
"dolphin-safe" was neither dolphin safe nor ocean safe.
In reality the drastic decline of dolphin mortality was due to the
remarkable display of innovation and commitment to solving an environmental problem and public
relations nightmare by ETP tuna fishers. Operating under the La Jolla Agreement, these fishers
perfected fishing methods to allow the encirclement and safe release of dolphins while catching
tuna.
In the mid-1990s, twelve nations adopted the Panama Declaration, a blueprint
for developing a legally binding and enforceable agreement within the Inter-American Tropical
Tuna Commission to reduce dolphin mortality further, with the goal of eventually eliminating
dolphin deaths entirely. These nations then negotiated and ratified the Agreement on the
International Dolphin Conservation Program (AIDCP), a scientifically sound international
agreement to protect dolphins and all marine life in the ETP. It locks in progress made under
the voluntary La Jolla agreement, progress that had reduced dolphin deaths from 100,000 in 1989
to fewer than 1,400 in 1999. The AIDCP provides protection for each individual dolphin stock or
species to ensure its continued growth and recovery; requires that measures be adopted to avoid
and reduce the discard of other marine species caught by the fishery such as sea turtles, sharks
and billfish; and mandates actions that will guarantee the sustained health of the tuna fishery
and the marine ecosystem of the ETP.
An obstacle to the full implementation of the AIDCP, however, is the
statutory definition of "dolphin-Safe" under the U.S. law implementing the AIDCP. This law calls
for the definition of "dolphin-safe" to be revised from its current meaning of "no encirclement
of dolphins" to the more meaningful "no dolphin mortality." This proposed change in the
definition of "dolphin-safe" has sparked a heated debate between the animal protection community
and the conservation community. But the change in definition will only occur if the United
States government can demonstrate that the chase and encirclement of dolphins in the ETP purse
seine fishery is not causing significant adverse impacts at the population level to any depleted
dolphin stocks.
Therefore, the question shifts from mortality to stress. Scientists must
quantify the magnitude or phase of stress--alarm, adaptation or compensation, and
maladaption--and evaluate whether the evidence or indicators of stress are having significant
adverse impacts on a depleted dolphin stock (i.e., preventing that dolphin stock from
recovering) The studies will require state-of-the-art analyses of dynamic physiological and
immunological responses to chase and encirclement. The investigation into the impacts of chase
and encirclement on dolphin biology, physiology, and health is critical to determine whether
dolphins are entering the Maladaption Phase of stress.
The results and interpretation of these studies have sweeping political
implications. On the one hand, a revised definition of "dolphin-safe" could result in further
reductions in dolphin mortality and potentially marry the label to an international tracking,
verification, and certification program that will protect dolphins, marine life, and tuna and
will likely achieve what the old label purported to do. Moreover, it could bolster consumer
confidence, in that the "dolphin-safe" label would guarantee that neither dolphins nor the
ecosystem were harmed to catch that tuna. On the other hand, maintaining the status quo
definition of "dolphin-safe"--i.e., no encirclement--would, at best, require a renegotiation of
the AIDCP and, at worst, result in a total breakdown of the agreement and lead to increased
dolphin deaths in a fishery over which we have no control.
The presentation will review the history of efforts under the U.S. Marine
Mammal Protection Act to reduce dolphin mortality' the development and implementation of the
"dolphin-safe" label; international efforts to reduce dolphin mortality; the impacts of
implementing the AIDCP on dolphins and marine life in the ETP; the ongoing research program to
evaluate stress associated with the chase and encirclement of dolphins in the ETP; and how the
results of these stress studies relate to the current and potential future definitions of
"dolphin-safe" under U.S. law and the implementation of the AIDCP.