Convention on biological diversity
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CETACEANS AND THE CONVENTION ON MIGRATORY SPECIESWilliam F. Perrin3 The Convention on Migratory Species has addressed cetaceans since its inception. Very early additions to its Appendix I (migratory species that are endangered) included the blue, humpback, bowhead and right whales. As of February 2001, Appendix I includes six cetacean species and Appendix II (species that have an unfavorable conservation status and/or would benefit from international cooperation through an inter-governmental regional agreement) contains 33 species. One of the first regional agreements to be completed under the CMS umbrella was ASCOBANS (the Agreement on Small Cetaceans of the Baltic and North Seas; came into force in 1994). The second major agreement, ACCOBAMS (Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area) has not entered into force but it is expected to do so shortly. Activities are underway to promote similar agreements in other regions, including Southeast Asia, southern South America, and West Africa. Cetaceans as Migratory AnimalsMany people are familiar with the migrations of the great whales, e.g., the annual trek of gray whales from feeding grounds in the Bering Sea to calving grounds in Mexico, and the movements of blue, fin, sei, minke, humpback and right whales from low latitudes to the Southern Ocean to feed on summer blooms of plankton. However, we know less about migration in the small cetaceans (some 70 species, all the cetaceans other than the baleen whales and the sperm whale), which have been the main emphasis in the CMS agreements. This is mainly because they have not been the targets of large-scale commercial exploitation as the great whales have been. There have been a few exceptions. For example, we know that harbor porpoises once migrated en masse seasonally in and out of the Baltic Sea, because large numbers of them were harvested during their autumn migrations (likely to the point of depletion of the population) in the early to mid 20th Century. Small cetaceans are difficult to observe in the wild and difficult to tag, and it is only recently that progress in tracking telemetry has begun to enable us to follow the movements of individual animals. For the most part, our knowledge of small cetacean migrations is limited to observations of their seasonal presence or absence in certain areas. In other cases, populations of wide-ranging pelagic small cetaceans exist in waters shared by several nations (e.g., the Black Sea). It appears certain that they must frequently move in and out of the jurisdictional waters of any one of the nations. For these reasons, the cetacean agreements developed under CMS to date have not stipulated that the cetacean species included be known to be migratory in the sense of the CMS definition ("the entire population or any separate part of the population of any species or lower taxon of wild animals, a significant proportion of whose members cyclically and predictably cross one or more national jurisdictional boundaries"). The assumption is that all or most of them will eventually be proven to be migratory, wholly or in part. For example, ACCOBAMS applies to "all cetaceans that have a range which lies entirely or partly within the Agreement area or that accidentally or occasionally frequents the Agreement area." ASCOBANS covers all small cetaceans in the Agreement area. Similarly, Appendix II of CMS has been expanded to include a number of regional populations of small-cetacean species (e.g., spinner, spotted, Fraser's and bottlenose dolphins in Southeast Asia) not yet documented to be migratory but under threat and thought to likely be shared by two or more nations. The United Nations Convention on the Law of the Sea (UNCLOS) also recognized that most whales, dolphins and porpoises are presumably migratory in specifically naming (in Annex I) seven families of cetaceans as highly migratory and needing greater international attention and management. The CMS COP recognized the dearth of critical information on migration in small cetaceans and recommended in 1994 that the Parties to the Convention carry out and report on the necessary research to obtain such information, giving priority to species and populations of threatened or uncertain status. The CMS Secretariat is currently undertaking a review of available information on small cetaceans migration. ASCOBANS also has recognized the need and in 2000 asked that parties and range states support further work to elucidate temporal and spatial aspects of distribution of small cetaceans in the ASCOBANS area. Whether these recommendations will be followed by adequate research to delineate migrations remains to be seen. Such research is extremely expensive, involving vessel charters and satellite-based radio tracking, and in general is not high on the lists of national research priorities. Beyond the doubt more research is needed to assess and reduce immediate population threats, such as by-catch in fisheries and effects of pollution (discussed below). However, that should not preclude the full compliance of the precautionary approach. Cetacean DiversityApproximately 85 species of whales, dolphins and porpoises are currently recognized (see Table 1). Some occur nearly from pole to pole, and others are restricted to small seas or single river drainages. This number does not fully reflect diversity in the group, however, because most of the species exhibit geographic differentiation into races and subspecies (named and unnamed). The world cetacean landscape is a complex mosaic of forms morphologically and behaviorally adapted to local ecological conditions. For example, in the eastern tropical Pacific, coastal spotted dolphins are larger and have proportionately larger teeth than their conspecifics offshore that feed on smaller, more elusive pelagic prey. Genetically distinct groups of killer whales in the U.S. Pacific Northwest feed on different kinds of prey, some only on fish and others only on marine mammals. Given the fine-grained nature of this diversity, it is likely that the number of recognized evolutionarily significant units (ESUs) globally would eventually run into the thousands. In addition, undifferentiated local populations contribute to the structure and diversity of ecosystems, and the conservation of these is also important. Unrecognized until recently has been the role of learning and culture in such cases; an extirpated local population of migratory whales may not be replaced simply because there are no longer any adult animals who know about the particular breeding or feeding ground. The Status of CetaceansThe stocks of great whales were depleted by commercial whaling. Some populations were driven to extinction; others were almost wiped out and even now although under full protection for decades have only begun to recover. At present there is a moratorium on commercial whaling by the parties to the International Convention for the Regulation of Whaling (implemented by the International Whaling Commission), although one member, Norway, is taking whales under a legal objection to the moratorium, and another, Japan, harvests hundreds of whales annually under a scientific research permit. The status of whales worldwide is under review by the IWC, and a revised management scheme to ensure conservation when exploitation resumes is nearly completed. It is unlikely that any future exploitation under this scheme will adversely affect the stocks or prevent their further recovery. For the small cetaceans, however, it is another story completely. Like the great whales, their status ranges from critically endangered (the baiji or Chinese river dolphin and the vaquita or Gulf of California harbor porpoise) to unknown but presumably healthy (many of the pelagic dolphins and small toothed whales). What is different is that the threats are more numerous and diverse and far from under control. Small cetaceans are harvested directly and unsustainably, killed incidentally in fisheries in huge numbers, and greatly affected by habitat degradation. There is no single international body dedicated to their global conservation. As compared with the great whales, small cetaceans are particularly vulnerable to threat for a number of reasons. They are highly vulnerable to hunting because of their small size and, in some species, their habit of riding the bow wave of vessels. They can be captured with small-scale equipment and are more easily killed in fishing nets because they do not have the strength to break loose. Their habitats can be easily damaged; rivers can be dammed, rivers and estuaries are easily polluted, and coastal development can degrade adjacent habitats. By-catch in fisheries can be converted to deliberate take as markets develop. Incidental kills and small directed takes are difficult to monitor and regulate, because the animals are often killed or caught by a large number of small vessels (thousands in some cases, e.g., China) that operate independently and land their catches in a large number of places, including undeveloped beaches. All of these factors have operated to lead to adverse conservation status, often cryptic, of many small-cetacean populations. Direct harvests of small cetaceans are generally declining as marine mammals come under increasing legal protection but continue around the world. Belugas are taken in Greenland, Canada, Russia and the U.S.; in some cases the takes have been unsustainable or of unknown impact. A seasonal hunt in Greenland took roughly 1000 harbor porpoises annually between 1950 and 1970 and continues today, but its present magnitude and impacts are unknown. A large-scale seasonal drive fishery for pilot whales continues in the Faeroe Islands. In Japan, a wide variety of directed fisheries harvest dolphins, porpoises and small whales. In some cases, e.g., for the Baird's beaked whale, an effective management scheme is in place, but in others, the impact of harvest has been adverse or is unknown. For example, the population of the striped dolphin is thought to have declined significantly under exploitation, but takes continue. Other directed fisheries, legal and illegal, of various sizes and impacts exist in Indonesia, the Caribbean, the Philippines, Peru, Chile, Sri Lanka, India and elsewhere. The greatest threat to the status of small cetaceans is incidental kill in fisheries. By-catch in purse seines, bottom set nets, drift gillnets and trawls has led and is leading to depletion of many populations. In the eastern tropical Pacific, incidental kill in tuna purse seines of millions of dolphins since the early 1960s, mainly pantropical spotted dolphins and spinner dolphins, has reduced two populations to a third or less of their original size. In recent years the kills have been reduced greatly, but the populations have not shown signs of recovering. Potentially unsustainable kills of porpoises and dolphins of several species in pelagic salmon and squid driftnets in the North Pacific largely ceased when a U.N. resolution banned the large-scale fisheries in the 1990s, but significant by-catch of small cetaceans continues in smaller-scale national driftnet fisheries around the world. In many places, the data on fishing effort and cetacean by-catch that would allow assessment of the impacts of the by-catch do not exist; this is true for even some of the more developed regions, e.g., the North Atlantic and Baltic Seas, where by-catch is thought to have led to decrease in abundance of harbor porpoises but assessments are difficult and incomplete. For the less-developed countries, of course, the difficulties are the greatest; the resources for research and monitoring are scanty. For example, in Southeast Asia, virtually nothing is known of the involvement and status of small cetaceans in the many industrial fisheries that have developed there in recent decades. The very few studies that have been carried out do not lead to optimism about the situation; e.g., incidental kill of spinner dolphins in tuna driftnets in the central Philippines has been shown to be unsustainable. Thus many small-cetacean populations around the world may be in trouble due to by-catch without our knowing about it. CMS recognized the importance of dealing with incidental kill in the conservation of cetaceans and other marine animals in a 1999 resolution calling on member nations to assess by-catch and minimize it to the maximum extent possible through technological research and mitigation measures. Pollution is also a threat to cetaceans, although the evidence is less direct and harder to come by. Cetaceans are top predators and thus subject to bioaccumulation of contaminants, particularly organochlorines. Levels of these pollutants in whales and dolphins are some of the highest that have been recorded for mammals. The effects are sub-lethal, but most of the evidence is circumstantial, as it is difficult or impossible to conduct controlled physiological experiments with these animals. One of the most important suspected effects is immuno suppression. High correlation has been found between organochlorine burden and morbidity during epizootics, such as in a recent mass die-off of striped dolphins in the Mediterranean. Other possible and likely effects include chemical/hormonal interference with reproduction and early development, direct induction of cancer and other pathology, and alteration of behavior. Acoustic disturbance is yet another issue of serious concern, as more acoustic disturbance is being observed and some empirical evidence is showing its effects on whales. Likewise low frequency sonars appear to be used more now and they may be an issue with potential serious impacts4. The Role of CMSBeyond listing some species in Appendix I early on, CMS has not given much attention to the great whales but rather (like CITES) deferred to the IWC as a more specialized international organization with broad responsibility for them. A recent review of the Appendices by the World Conservation Monitoring Centre (of IUCN and UNEP) recommended that the fin and sei whales be considered for addition to Appendix I, but the CMS Scientific Council recommended against this, and no action was taken. In its recent workings, the CMS has effectively limited its active consideration to the small cetaceans. ACCOBAMS applies to all cetaceans, but it is expected that its attentions too will focus on the small cetaceans. At present, only one small cetacean, the franciscana or La Plata river dolphin, is included in Appendix I. This dolphin is thought to migrate between the waters of Brazil, Uruguay and Argentina and is threatened by incidental capture in a number of fisheries. CMS has supported regional consultations to develop joint research to assess the population(s) and the impacts of the fisheries. Most of the activities of CMS on small cetaceans has consisted of identifying and listing on Appendix II those species and populations that could benefit from international cooperation in research and management in particular regions. This is followed up by efforts to establish regional agreements. Proposals for listing are submitted by the parties. Following a global review of the conservation of small cetaceans mandated by the CMS COP in 1990, 22 species recommended by the review for listing were added to Appendix II. For some of these species, only particular geographic populations were listed. Subsequent additions as geographical areas suitable for regional agreements were identified brought the total to the present 33 (Table 2). The geographic areas thus considered have been four: the North and Baltic Seas, the Mediterranean and Black Seas, southern South America, and, most recently, Southeast Asia. Of these areas, two, the North and Baltic Seas and the Mediterranean and Black Seas, have since become the focus of regional agreements. The CMS Secretariat played a major role in drafting these agreements and bringing them into fruition. In addition to identifying and listing species and populations that would benefit from regional cooperation, the CMS has promoted the concept of regional cooperation by funding small "seed-money" projects involving two or more nations in a region ripe for such cooperative conservation research and action. These have included a cooperative training workshop and census survey of the Sulu Sea involving Malaysia and the Philippines, an international workshop on cetacean conservation and management in West Africa, and fieldwork to assess small-cetacean abundance and fisheries involvement in Senegal, the Gambia and Guinea-Bissau. A cooperative workshop and survey of dolphin populations shared by Indonesia and Australia in the Timor and Arafura Seas is underway. Upcoming initiatives include training/survey activities in the Celebes Sea (Philippines and Indonesia) and in Ghana and Togo. ASCOBANSASCOBANS came into force in 1994 and has been ratified by Belgium, Denmark, European Community, Finland, Germany, the Netherlands, Poland, Sweden and the United Kingdom. (Remaining non-members in the area are Norway, Russia, Estonia, Latvia, Lithuania, and France). The Secretariat is located in Bonn. There have been three meetings of the parties, the most recent in 2000 in Bristol, UK. The Advisory Committee has met seven times. An early major accomplishment of ASCOBANS was participation by members in SCANS (Small Cetacean Abundance in the North Sea), the first coordinated survey of small cetaceans in the region. This resulted in estimates of 353,000 harbor porpoises (CI 267,000-465,000) and 7,900 (CI 4,000-13,300) white-beaked dolphins in the North Sea and adjacent waters. Accurate population estimates are essential to assessment of the impacts of by-catches. Further surveys are planned for coming years. In the current Work Plan, the highest priority is given to by-catch assessment and mitigation, with focus on the harbor porpoise. In this area Denmark has taken the lead among the members, in developing and implementing a program to reduce by-catch, including mandatory acoustic alarms in some fisheries. The U.K. has also put a program into place, the UK Conservation Strategy for the Harbour Porpoise. An ASCOBANS-commissioned study on possible mitigation measures and related case studies has been produced. Attention is also being given to integrating ASCOBANS by-catch objectives into fishery policies, through discussions with national fishery agencies, NGOs and the European Commission. A recovery plan for the harbor porpoise in the Baltic Sea is in development. It is hoped that the area of the agreement will be extended to the west and south to include the waters of Ireland, Spain and Portugal. ACCOBAMSThe Agreement on Conservation of Cetaceans of the Black and Mediterranean Seas and Contiguous Atlantic Area has been ratified by the European Community, Monaco, Morocco, Spain, Croatia, Romania, Bulgaria and Malta. The agreement will enter into force shortly. Remaining nations in the agreement area who are not yet members include Portugal, France, Corsica, Italy, Slovenia, Bosnia-Herzegovina, Yugoslavia (Montenegro), Albania, Greece, Turkey, Ukraine, Russia, Georgia, Syria, Israel, Cyprus, Egypt, Libya, Tunisia, and Algeria. Of these, Albania, Cyprus, France, Greece, Israel, Italy, Portugal, Tunisia, and Ukraine signed the original agreement in 1996. One project that is making progress deals with the creation of a Franco-Italo-Monegasque marine mammal sanctuary in the Ligurian Sea; Monaco and France have already ratified the agreement on the sanctuary. Development of a work plan for ACCOBAMS will proceed upon entry into force and establishment of a scientific committee. It is expected that heavy emphasis will be placed on assessment and reduction of by-catch in fisheries. A CAUTIONBoth ASCOBANS and ACCOBAMS prohibit deliberate take (of small cetaceans in the former and all cetaceans in the latter). This arguably limits the scope and effectiveness of the agreements, because not all the countries in the agreement areas agree with the concept of full protection. For example, Norway commands a significant portion of the North Sea but is unlikely to join ASCOBANS while engaged in commercial whaling (albeit of great whales). Norway's position is that sustainable development includes responsible harvest of marine mammals. This sticking point may prevent other major players in the agreement regions from ratifying the agreements and should be carefully considered in any future agreements. However, it should be noted that Norway, though not a member of ASCOBANS, is a party to CMS and has been attending ASCOBANS meetings as an observer and participating in activities of the Advisory Committee dealing with the harbor porpoise). SUMMING UPThe impact of CMS on the conservation of cetacean diversity is just beginning to be felt. One regional agreement is in place and its objectives are starting to be realized. A second agreement is on the verge of coming into force, and further potential agreements are being explored and promoted. The premise of a regional approach has proven its worth, and effective international cooperative research and conservation action on small cetaceans is now becoming a reality. Table 1. List of cetacean species currently recognized by the International Whaling Commission. Scientific name Common name ------------------------------------------------------------------------------------------------------------------------------- Suborder Mysticeti (baleen whales or mysticetes) Family Balaenidae Eubalaena glacialis1 N. Atlantic right whale Eubalaena australis1 Southern right whale Eubalaena japonica2 N. Pacific right whale Balaena mysticetus bowhead whale Family Neobalaenidae Caperea marginata pygmy right whale Family Eschrictiidae Eschrichtius robustus gray whale Family Balaenopteridae Balaenoptera acutorostrata common minke whale Balaenoptera bonaerensis Antarctic minke whale Balaenoptera borealis sei whale Balaenoptera edeni3 Bryde's whale Balaenoptera musculus blue whale Balaenoptera physalus fin whale Megaptera novaeangliae humpback whale Suborder Odontoceti (toothed whales or odontocetes) Family Physeteridae Physeter macrocephalus sperm whale Family Kogiidae Kogia breviceps pygmy sperm whale Kogia sima dwarf sperm whale Family Platanistidae Platanista gangetica South Asian river dolphin Family Pontoporiidae Pontoporia blainvillei franciscana Family Lipotidae Lipotes vexillifer baiji Family Iniidae Inia geoffrensis boto Family Montodontidae Monodon monoceros narwhal Delphinapterus leucas white whale Family Delphinidae
hump-backed dolphin Sousa teuszii Atlantic hump-backed dolphin
Sotalia fluviatilis tucuxi Lagenorhynchus albirostris white-beaked dolphin Lagenorhynchus acutus Atlantic white-sided dolphin
Lagenorhynchus obscurus dusky dolphin Lagenorhynchus obliquidens Pacific white-sided dolphin
Lagenorhynchus cruciger hourglass dolphin Lagenorhynchus australis Peale's dolphin Grampus griseus Risso's dolphin Tursiops truncatus common bottlenose dolphin
Tursiops aduncus Indian Ocean bottlenose dolphin
Stenella frontalis Atlantic spotted dolphin Stenella attenuata pantropical spotted dolphin
Stenella longirostris spinner dolphin Stenella clymene Clymene dolphin Stenella coeruleoalba striped dolphin Delphinus delphis short-beaked common dolphin
Delphinus capensis long-beaked common dolphin
Lagenodelphis hosei Fraser's dolphin Lissodelphis borealis northern right whale dolphin
Lissodelphis peronii southern right whale dolphin
Cephalorhynchus commersonii Commerson's dolphin Cephalorhynchus eutropia Chilean dolphin Cephalorhynchus heavisidii Heaviside's dolphin Cephalorhynchus hectori Hector's dolphin Peponocephala electra melon-headed whale Feresa attenuata pymy killer whale Pseudorca crassidens false killer whale Orcinus orca killer whale Globicephala melas long-finned pilot whale Globicephala macrorhynchus short-finned pilot whale Orcaella brevirostris Irrawaddy dolphin Family Ziphiidae Tasmacetus shepherdi Shepherd's beaked whale Berardius bairdii Baird's beaked whale Berardius arnuxii Arnoux's beaked whale Indopacetus pacificus Longman's beaked whale Mesoplodon bidens Sowerby's beaked whale Mesoplodon densirostris Blainville's beaked whale Mesoplodon europaeus Gervais' beaked whale Mesoplodon layardii strap-toothed whale Mesoplodon hectori Hector's beaked whale Mesoplodon grayi Gray's beaked whale Mesoplodon stejnegeri Stejneger's beaked whale Mesoplodon bowdoini Andrew's beaked whale Mesoplodon mirus True's beaked whale Mesoplodon gingkodens gingko-toothed beaked whale
Mesoplodon carlhubbsi Hubbs' beaked whale Mesoplodon peruvianus pygmy beaked whale Mesoplodon bahamondi Bahamonde's beaked whale
Ziphius cavirostris Cuvier's beaked whale Hyperoodon ampullatus northern bottlenose whale
Hyperoodon planifrons southern bottlenose whale
------------------------------------------------------------------------------------------------------------------------------- 1Listed on CMS Appendix I as subspecies of Balaena glacialis; recent genetic work has indicated full species status is appropriate. Eubalaena is preferred over Balaena for the right whales. 2In CMS Appendix I, subsumed in Balaena glacialis glacialis. Recent genetic work indicated species-level separation from the North Atlantic right whale. 3May include more than one species, but taxonomy still unsettled. Table 2. Cetacean species and populations on Appendix II of CMS. Platanistidae Platanista gangetica gangetica1 Pontorporiidae Pontoporia blainvillei (also on Appendix I) Iniidae Inia geoffrensis Monodontidae Delphinapterus leucas Monodon monoceros Phocoenidae Phocoena phocoena (North and Baltic Sea, western North Atlantic and Black Sea only)
Delphinidae Sousa chinensis Sousa teuszii Sotalia fluviatilis Lagenorhynchus albirostris (North and Baltic Seas only) Lagenorhynchus acutus (North and Baltic Seas only) Lagenorhynchus obscurus |