One of the main goals of the Marine Mammal Protection Act (MMPA) of 1972 was to prevent taking of marine mammals. Taking means “to harass, hunt, capture, or kill, or attempt to harass, hunt, capture or kill”. This was especially true for dolphins, and with the 1994 amendments to the MMPA, people began raising awareness of the relationship specifically between tuna fisheries and dolphins in the eastern tropical Pacific Ocean. The gear types used in Hawaiian fisheries are responsible for many marine mammal deaths and injuries. Gillnets also capture mammals and float lines trap lobsters and sometimes entangle other cetaceans (3).
Congress primarily passed the MMPA in order to keep populations of mammals at their optimum sustainable levels, and to improve stranding and mortality response programs. The 1994 MMPA amendments were signed by President Clinton on April 30th, 1994 and just like the MMPA, continue to protect marine mammals, maintaining population stocks at their optimal population levels, protecting habitats, mating grounds, and other important areas of marine mammals.
One of the biggest concerns has been the interaction between marine mammals and commercial fishing operations. As a result, three new sections were added to the Act related to commercial fishing. These included preparing Stock Assessment Reports (SAR) annually and developing and enforcing Take Reduction Plans. These plans reduce the mortality and injury of marine mammals that interact with fisheries (6). The 1994 amendments included a definition of Potential Biological Removal (PBR)which quantitatively describes anthropogenic impacts on populations.
The revisions also added the “strategic stocks” category. Strategic defines those species that are threatened or endangered under the Endangered Species Act (ESA), stocks that are already depleted under the MMPA, near to being threatened, and for which human-caused deaths exceeds their biological removal. Section 118 of the 1994 amendments of the MMPA requires a SAR annually for each stock of marine mammals in US waters. Report requirements include estimates of human-caused deaths and injuries, and for the strategic stocks, a detailed description of factors that may be harmful to the mammal’s habitats such as interactions with vessels (4).
Other revisions include permission to “take” marine mammals under certain conditions, revised permits for public display, photography and scientific research, and addition of a new transfer of responsibilities of the captive care and management of marine mammals. Additionally, the 1994 Amendments redefined “harassment”. It now means anything that 1) can potentially injure marine mammal stock in the wild (labeled as Level A harassment) and 2) can potentially disturb the behavioral patterns, such as migration, breathing, nursing, breeding, feeding, or sheltering wild marine mammals, which is referred to as level B harassment (5).
Unfortunately, Spinner dolphins are not viewed as endangered or threatened under the Endangered Species Act (1973), nor are they listed as depleted under the MMPA. Furthermore, the Hawaiian Spinner dolphins are not depicted as “strategic stock” under the 1994 Amendments because mortality and injury counts are close to zero (3).
With the recent increase of swim-with-dolphin programs and tourism activities around the main Hawaiian Islands, Spinner dolphins are disturbed from their natural cycles of resting, caring for their young, and avoiding predators in the shallow coves and bays during the day (1). Due to these human disturbances, the dolphins have begun to avoid swimmers by leaving their bays and spending time at the mouth of the bays or in deep water. Nevertheless, with the implementation of the 1994 amendments have come several controversial issues. The most difficult tasks have included implementation of the Take Reduction Plans, to reduce the bycatch of marine mammals in commercial fisheries. This is far behind schedule because it is hard to establish rules that also lessen the adverse effect on the industries (2). There have also been difficulties with implementing and interpreting the definition of “harassment”. Nevertheless, it is important that these laws have raised awareness and continue to educate the public.
Source 1: Norris, K.S., B. Wursig, and R.S. Wells, 1994. The Spinner Dolphin. In K.S. Norris, B. Wursig , R.S. Wells and M. Wursig (Eds.), The Hawaiian Spinner Dolphin. University of California Press, Berkeley. Pp. 14-30.
Source 2: CRS Report for Congress. The Marine Mammal Protection Act: Reauthorization Issues. http://www.nationalaglawcenter.org/assets/crs/RL30120.pdf
Source 3: Spinner Dolphin. (Stenella longirostris longirostris): Hawaiian Islands Stock Complex- Hawaii Island, Oahu/4-islands, Kauai/Niihau, Pearl & Hermes Reef, Midway Atoll/Kure, Hawaii Pelagic. http://www.nmfs.noaa.gov/pr/pdfs/sars/po2010dosp-isl.pdf
Source 5: Woosley, Jamie M. Detailed Discussion of Dolphins Under the MMPA. Michigan State University College of Law, 2002. http://www.animallaw.info/articles/ddusdolphins.html
Source 6: Buck, Eugene H. Marine Mammal Protection Act Amendments of 1994. http://www.netpets.org/fish/legislation/marinemam.html
Photo Credit: Photo taken by the SAPPHIRE Project (Duke and Murdoch Universities) under permit from NOAA Fisheries.