Marine species in the Pacific

• Marine mammals
• Whales
• Dolphins
• Dugongs
• Marine turtles
• Sharks
• Conservation issues
• Pollution
• Fisheries
• What SPREP is doing?

Download the Pacific Islands Regional Marine Species Programme, 2008-2012

Introduction

The Pacific islands region is the largest continuous marine habitat on the planet, the Pacific ocean. It is home to a wide range of large marine animals including mammals like whales, dolphins, porpoise and dugongs and marine turtles. Maintaining healthy populations is essential to maintaining oceanic productivity.

The diversity of these marine creatures is recognized as a fundamental element of Pacific Islands’ culture and heritage. Many Pacific island cultures have legends, stories and traditional uses of marine mammals and turtles, indicating the importance of these creatures in the identities of people, their way of life and their heritage. Polynesian travels throughout the region are often linked with stories of migratory species such as great whales and turtles. Polynesians may have recognized the migratory paths of these species and used them as guides to the seas of the south Pacific.

Marine mammals

Despite efforts in certain areas and on certain species e.g. humpback whales, detailed knowledge of marine mammals is at best extremely limited. This is in part due to limited resources and expertise to undertake research in the region, the vastness of the region itself and the diversity of its marine mammals in it.

Whales

Over half the world’s known species of whales are found in the region. The best estimates of southern hemisphere populations are based on sighting cruises in Antarctic Ocean. Figures are:

The recovery of most large whale species from the impacts of former whaling operations is, for the most part, unknown. Humpbacks are recovering in some areas (e.g. East and West Australia) but recovery rates (if any) in French Polynesia, New Caledonia, Tonga, Cooks are currently unknown. Humpbacks remain rare in other areas of former abundance (e.g. Samoa, Vanuatu, American Samoa and Fiji). Status and trends of other species of large baleen whales in the region is unknown.

In 1993 there was no whale sanctuary in the region, national Exclusive Economic Zone Whale Sanctuaries now total more than 10.9 million square kilometres and range from Melanesia (PNG) through to the far reaches French Polynesia and have been described as a growing bridge to a wider South Pacific Whale Sanctuary. Currently the Cook Islands, Fiji, Papua New Guinea, French Polynesia Samoa and Niue have declared sanctuaries, with other countries actively looking at this e.g. Vanuatu. Furthermore, American Samoa, Tonga and Tokelau all effectively protect whales and are sanctuaries in all but name only.
The hunting of large whales does not currently occur in the region, although there is continuing pressure to resume whaling in Tonga. Currently direct takes of dolphins for meat and teeth take place in the Solomon Islands. In Fiji there is a history of taking dolphins and toothed whales for their teeth, but there have been no recent reports. In Tonga the current Humpback population is approximately 10% of pre-exploitation days. Given that the population clearly has not recovered to pre-exploitation levels of abundance, any renewed hunting pressure would be detrimental to the future of this stock. The research data currently available shows links between Tonga and other island groups in Polynesia and possibly Melanesia. Takes from the Tongan humpback population may thus significantly impact other humpback populations in the region.

Potential impacts of scientific whaling – over 6000 Antarctic minke whales were taken by the Japanese research whaling programme between 1986 and 2003, and some of these animals will have spent some of their lives in the waters of Pacific Island nations. Japanese research whaling operations in the vicinity of the Solomon Islands between 1977 and 1979 took 240 Bryde’s whales. The impact of these removals on the current population in the area is unknown.

In fisheries across the world, sperm whales and a variety of smaller toothed whale species have learned to follow long-line fishing boats and feed off the fish caught on the hooks. This is leading fishermen to look on them as a pest threatening their livelihood. In the south Pacific region, there is no scientific basis for the argument that whales eat fish already caught on long lines, although in some areas, small toothed whales like killer whales, false killer whales and pilot whales are probably involved. Some dolphin species take bait from hooks. This is a significant problem in the region (particularly in Samoa, Fiji, Tonga and PNG).

Large toothed whales usually eat non-commercial prey such as deep-sea squid (of no commercial value). Baleen whales have not been shown to eat large fish. For Bryde’s whales (the only species of baleen whales that feeds in tropical waters), studies of stomach contents from Japanese “scientific whaling” in the Solomon Islands in the 1970s showed that 97% of their diet is plankton. Baleen is a filtering mechanism and baleen whales have no teeth. They are not fast enough to chase and catch large fish, such as tuna.

Dolphins

Dolphins are fast swimming animals that are grouped together with whales under Cetacea. Characteristic features are long snouts and rounded foreheads. Dolphins are threatened by habitat destruction and pollution. Many cultures have hunted dolphin for food. Many are killed when they become entrapped in the huge nets used to catch tuna.

Dolphins are predatory animals and feed largely on fish and squids and in the case of killer whales, other marine mammals, sea turtles and birds. Dolphins rely on echolocation to navigate and locate food especially in muddy estuaries where there is low visibility. Increasing noise pollutions can affect dolphins.

Dolphin species found in the SPREP region includes Risso’s dolphin, bottlenose dolphin, Indo-Pacific humpbacked dolphin, striped dolphin, pan-tropical spotted dolphin, spinner dolphin, Frazer’s dolphin, and Irrawaddy dolphins.

Photo © Peter Bennett/SPREP

Dugongs

The dugong (Dugong dugong) is the only herbivorous mammal that is strictly marine. They are seagrass specialists and frequent coastal waters. Dugong breeding is very sensitive to the availability of its seagrass food. When dugongs do not have enough to eat they delay breeding, making habitat conservation a critical issue. Dugongs are long-lived with low productive rates, low generation time and a high investment in each offspring. A slight reduction in adult survivorship can cause a chronic decline. The dugong is listed as vulnerable to extinction at a global scale by the World Conservation Union (IUCN).

The dugong home range in the region includes the waters of Australia, Papua New Guniea, Solomon Islands, Vanuatu, New Caledonia and Palau. Throughout much of its range in these SPREP member states, relic isolated populations still remain. The region supports the world’s largest remaining populations of dugongs. Of the five world dugong populations tentatively identified, two occur partly in the SPREP region The approximate boundaries of population 1 are Vanuatu on the east and 140º E on the west, and the range includes virtually. all of Melanesia, Papua New Guinea, and the northeast and east coasts of Australia. Population 2 is centred along the northwest and west coasts of the Australia, Irian Jaya, and northwards to the Philippines. The dugongs in Palauan have been described as “the most isolated dugong population in the world.”

Scientific information on dugong distribution and abundance is outdated or non-existent. The status of dugongs is unknown throughout the region. It is likely that dugongs are widely distributed in small numbers in much of PNG, the Solomon Islands and Vanuatu and that larger numbers occur in the PNG waters of Torres Strait. Their reliance on relatively shallow water seagrass beds for food limits the ability of dugongs to travel between islands and continents that are separated by extensive areas of deep water. For this reason, many island populations, including those around Vanuatu and Palau, are essentially isolated. Such isolation makes this groups of dugongs especially vulnerable to extinction.

Dugongs are vulnerable to human influences because of their life history and their dependence on seagrasses that are restricted to coastal habitats, and which are often under pressure from human activities. Threats to the survival of dugong population include habitat loss and degradation, fishing pressure, indigenous use and harvesting, vessel strikes, ecotourism, acoustic pollution, chemical pollutants and diseases.

An urgent issue is the need to address the conservation management of dugongs in the region. Despite a comprehensive global review and some excellent in-country activities, e.g. Palau Conservation Society’s dugong campaign, the status of dugongs remains largely unknown, few effective conservation measures exist and anecdotal evidence gives increased cause of concern for their future.

Marine turtles

The Pacific area supports the world’s largest remaining populations of green, hawksbill and loggerhead turtles. There are six marine turtle species that feed and migrate through the Pacific waters. These are the green turtle, the hawksbill turtle, the leatherback turtle, the loggerhead turtle, the Pacific Ridley turtle and the flatback. There is also one record of the subspecies Chelonia mydas agassi from PNG.

The Pacific island region is a globally significant area for marine turtle breeding and migration. The coastal populations of the Pacific islands have exploited marine turtles for their meat, eggs, shell and oil for centuries. Cultures and traditions, which historically managed sustainable use and promoted ecological balance, are degrading. The loss of traditional values combined with the negative effects of unregulated adult and egg harvest, habitat degradation, commercial trade and mortalities through incidental capture in fishing gear have accelerated the decline of the marine turtle population. The latter half of the 20th century has been marked by catastrophic declines of sea turtle populations throughout the Pacific region. Having existed for thousands of years, most marine turtles are now categorized as “Critically Endangered,” “Endangered,” “Threatened” or “Vulnerable” on the Red List of the World Conservation Union.

Key issues for turtle survival are unsustainable harvesting and habitat degradation. Both of these factors are mainly due to human activities. In the last 10 years concern for turtle conservation and wise use has grown in the region with an increasing number of initiatives being undertaken at local, national and regional levels. This has resulted in the establishment of the Regional Marine Turtle Conservation Programme (RMTCP) and associated active network of government and ngo agencies working together to effect turtle conservation and sustainable use.

Sharks

The Pacific Islands Forum Fisheries Agency (FFA), the Secretariat of the Pacific Regional Environmental Programme (SPREP), the Secretariat of the Pacific Community (SPC) and the Western and Central Pacific Fisheries Commission (WCPFC), in a collaborative effort on behalf of their members, are developing a Pacific Islands – Regional Plan of Action for Sharks (PI-RPOA). The PI-RPOA will provide Pacific Island Countries & Territories with a framework for considering and developing management arrangements for shark species that address regional management obligations.

The above-mentioned regional organisations are seeking a consultant with experience in shark management and/or research to develop the PI-RPOA in collaboration with focal points from each agency. The full details of the consultancy are provided in the terms of reference. Applications to undertake the consultancy should address the terms of reference and include a CV. Applications should be lodged to Mr Steve Shanks via e-mail at steve.shanks@ffa.int before close of business on 27 March 2009.

Conservation issues

In a number of areas of the Solomon Islands, locals hunt dolphins and other small cetaceans. The animals are herded into confined bays where they are killed, with the primary objective of obtaining their teeth and meat. Dolphin teeth have long served as currency throughout Malaita and Makira. They are also woven into collars or headbands used in blood bounties. Necklaces of dolphin teeth remain essential to the payment of bride price amongst some Malaitans and Makirans.

Most of the cetaceans taken in the Solomons are apparently long-snouted oceanic forms, including spinner, pan-tropical spotted, striped, common and rough-toothed dolphins, along with false killer whales. Risso’s dolphins were also taken occasionally, but their low numbers of teeth make them of relatively little value to the Malaitans and Makirans. Melon-headed whales are also reported to have been taken in the past but are rarely taken today.

Although the Malaitans were reported in 1996 to no longer hunt cetaceans, further reports suggest that this practice has been recently reinstated. The civil unrest has caused significant damage to the economy and infrastructure, and dolphin teeth are again being commercially marketed domestically in a number of islands, including Malaita, Makira, the Lau sub-district on the extreme north and northeast of Malaita, as well as Walande and Kwai to the south of Mal

During 2003, a Mexican consortium began buying bottlenose dolphins from villagers in Gavutu in the Solomon Islands. Villagers were reportedly being paid SBD$450 per dolphin. The dolphins are kept in holding pens for transfer to Honiara and onward air transport to Cancun in Mexico where they are apparently trained for sale to marine shows in the United States and elsewhere. Dolphins are listed under the Convention on International Trade in Endangered Species of Fauna and Flora (CITES) but the Solomons is not a CITES signatory. However, Mexico, the importing country was, so they were bound to make sure that the Solomon Islands Government issued export permits that would satisfy CITES requirements. In fact, the Ministry of Forests, Environment and Conservation as the CITES competent authority had issued an export license for 120 dolphins. The Department of Fisheries had also provided a capture licence, reportedly a quota of only 100 dolphins per year.

Dolphins are also captured in the Solomons for traditional shell money and there is the issue of by catch in fishing fleets. The impact of the latter two activities would probably account for far more than 100 dolphins per year.

Dugongs and turtles have been hunted extensively in the region both for traditional and subsistence purposes and more recently for commercial gain. They are now considered endangered throughout their range and many small and/or isolated populations are vulnerable to extinction. Dolphins have also been used as a source of food and resources, often through local drive hunts. These species remain a highly valued food (meat and oil) and medicine (oil). The shells, skin and bones are often used for jewellery and ornaments. Dugong teeth and those of small cetaceans have been important in certain ceremonies, for example in marriages and funerals in New Caledonia, Manus Province, Papua New Guinea and Malaita, Solomon Islands.

While subsistence hunting of dugongs and turtles may have been sustainable in the past, the combination of increasing human populations and the introduction of new technologies, like outboard motors and gill nets, has severely affected several species (especially dugongs and turtles) resulting in fragmentation of populations and even local extinction. However, in the region there is an increasing commitment by countries such as PNG and the Solomon Islands to ensure sustainable rates of subsistence use.

These species are generally long-lived and have low reproductive rates. Unsustainable rates of removal, for example, the trade in turtle eggs, have resulted in many populations becoming threatened, endangered, or even locally extinct. There is, however, a growing awareness of their non-consumptive values for the social, economic and cultural benefit of local communities, e.g., whale watching in Tonga, dolphin watching in French Polynesia, turtle watching in PNG and dugong watching in Vanuatu.

Marine mammal-based tourism is increasing and mirrors global trends where whale watching for example is estimated to be worth more then US$1billion annually. Significantly the development of marine mammal tourism in the region is mostly associated with endangered species, e.g. dugong and/or during parts of the life cycle vulnerable to disturbance e.g. humpback mating and calving.

Pollution

The types of pollution that may impact whales and dolphins in the region include chemical (heavy metals); sewage (nutrient enrichment, disease; heavy metals and pesticides); plastics (ingestion) and persistent organic pollutants.

Sewage discharge could be a problem as it may cause nutrient enrichment and possible habitat destruction; it may also introduce disease and heavy metals and pesticides. A few cases of impact have been recorded from this region, including disease issues in dolphins adjacent to sewage discharge in Western Australia for example. At this stage it is not considered to be a significant issue for the region but needs to be monitored.

Chemical pollution is not considered to be a significant issue in this region, other than persistent organic pollutants, which include pesticides, polychlorinated biphenyls and dioxins, mainly produced in the northern hemisphere, that are potentially a significant threat to cetaceans. These compounds effect hormonal system and can cause low fertility and birth defects. They are transmitted through atmospheric deposition into the ocean and by run-off from land, particularly agricultural chemicals (e.g. pesticides).

The issue of plastics is thought to be a priority pollution threat in this region; the occurrence of plastic bags in the ocean is increasing and it is known that the ingestion of only a few plastic bags can kill juvenile cetaceans, and turtles.

In our lifetime, there has been a growing awareness of the increasingly threatened status of many of these icon species and of the need for a concerted and coordinated approach amongst Pacific Island nations to arrest and reverse declining population trends.

The following link is an interesting children’s education site: http://nmml.afsc.noaa.gov/education/marinemammals.htm

Fisheries

Today as in the past, marine resources retain their traditional importance for the diet, cultures and economies of Pacific island peoples. The Pacific now contains some of the last relatively intact fisheries in the world’s oceans, and as such they are increasingly threatened. The commercial use of living marine resources has increased to rival the combined value of all the region's other renewable resources. For many island countries and territories, fishery resources offer the greatest potential for economic development, given their control of enormous maritime zones. The challenge of managing these resources on a sustainable basis is formidable. For more information on Pacific marine resources, go to: http://www.spc.int/marine.htm

What SPREP is doing.

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