Fisken og havet, special edition 2–2010 Marine Mammals Fisken og havet, special edition 2-2010 Marine Mammals Editors: Arne Bjørge Christian Lydersen Mette Skern-Mauritzen Øystein Wiig Photo editors: Kjell-Arne Fagerheim Arne Bjørge www.imr.no The photographs on the front page were taken by Arne Bjørge and George McCallum 3KRWRJUDSKVRQÀUVWSDJHRIHDFKFKDSWHU Chapter 1: Kjartan Mæstad Chapter 2: George McCallum Chapter 3: Kjell-Arne Fagerheim Chapter 4: George McCallum Chapter 5: Aerial photographs: FotoNord Chapter 6: Kjell-Arne Fagerheim Chapter 7: Kjartan Mæstad Chapter 8: George McCallum The drawings of whales were done by Arne Bjørge Siri Hartvedt and Nils Øien have created the maps in Chapter 5.4 ISSN 0802 0620 Editing completed in May 2011 Graphic design: Harald E. Tørresen, The Institute of Marine Research Graphic production: John Ringstad, Ringstad Design 3ULQWLQJ$**UDÀVN Contents Introduction 5 5.2 Harp and hooded seals on thin ice? 49 T. Haug Chapter 1 What are marine mammals? 5.3 Arctic seals – from pup production 1.1 Which groups and species to sealing quotas 51 are considered marine mammals? 8 T. Haug and T.A. Øigård A. Bjørge 5.4 Whale counts and population estimates 54 1.2 Adaptation to a life in water 9 N. Øien A. Bjørge 5.5 Grazing baleen whales in the Barents Sea: Mostly krill or a bit of everything? 58 Chapter 2 The evolution of whales and their relationship M. Skern-Mauritzen to each other 5.6 Svalbard's resident marine mammals 2.1 Baleen whales 12 and the climate threat 64 A. Bjørge C. Lydersen and K.M. Kovacs 2.1.1 Right whale and pygmy right whale 13 5.7 The bowhead whale – our most 2.1.2 Grey whale 13 threatened whale population 68 2.1.3 Fin whales 14 Ø. Wiig, K.M. Kovacs and C. Lydersen 2.2 Toothed whales 14 A. Bjørge Chapter 6 Harvest and management 2.2.1 Sperm whales 15 of whales and seals 2.2.2 Beaked whales 15 6.1 The history of whaling 72 2.2.3 River dolphins 15 A. Bjørge 2.2.4 High-Arctic toothed whales 16 6.1.1 Ancient coastal whaling 72 2.2.5 Dolphins 17 6.1.2 The Basques hunting of right whales 2.2.6 Porpoises 17 in Biscay 73 6.1.3 Hunting bowhead whales Chapter 3 The evolution of seals and their in the North Atlantic 73 relationship to each other 6.1.4 Sperm whale hunting 73 3.1 Eared seals 20 6.1.5 Modern whaling 74 A. Bjørge 6.1.6 Norwegian whaling for minke whales 75 3.2 Walrus 21 6.2 International regulation of whaling 76 A. Bjørge A. Bjørge 3.3 True seals 21 6.2.1 The International Whaling A. Bjørge Commission (IWC) 76 6.2.2 Protection and the growth Chapter 4 Important species in Norwegian waters of research whaling 77 4.1 Blue whale 24 6.2.3 The IWC's Revised Management N. Øien and A. Bjørge Procedure (RMP) 78 4.2 Fin whale 26 6.3 The history of sealing 79 N. Øien and A. Bjørge A. Bjørge 4.3 Minke whale 28 6.3.1 The hunt for luxury – N. Øien and A. Bjørge the tragedy of fur seals 79 4.4 Humpback whale 30 6.3.2 Elephant seal – an oil source N. Øien and A. Bjørge in a time of scarcity 80 4.5 Killer whale 32 6.3.3 Sealing in the North Atlantic 80 A. Bjørge 6.4 International regulation of sealing 4.6 Porpoise 34 in the North Atlantic 82 A. Bjørge 4.7 Harp seal 36 &KDSWHU 6FLHQWLÀFDGYLFH T. Haug and A. Bjørge for management in Norway 4.8 Hooded seal 38 The Marine Mammal Advisory Board 84 T. Haug and A. Bjørge The Board's discussions, 4.9 Grey seal 40 conclusions and recommendations 85 K.T. Nilssen and A. Bjørge Recommendations on research 4.10 Harbour seal 42 and management 90 K.T. Nilssen and A. Bjørge Chapter 8 Table of all living Chapter 5 Current research topics species of marine mammal 5.1 Coastal seals – a threat to the 8.1 The order Cetacea – whales 92 ¿VKLQJLQGXVWU\" 46 8.2 The order Sirenia – sea cows 94 K.T. Nilssen 8.3 The order Carnivora – carnivores 94 Marine Mammals deals with a subject in which there is both a great deal of interest and a great need for factual information. Some marine mammals are important renewable resources that can be harvested in a sustainable manner, others are important components of the ecosystems. There are also species that are extremely few in number and very threatened. Marine mammals are charismatic animals and, in the international arena, they are important symbols RIWKH¿JKWIRUWKHHQYLURQPHQWDQGFRQVHUYDWLRQ0DULQHPDPPDOVJHWSHRSOHLQYROYHGDQGZHRIWHQ see strong opinions in the news media, both for and against hunting and conservation. The Institute of Marine Research hopes that this report will contribute towards putting this debate within the framework of factual knowledge. The report will show trends and provide the retrospective glances that are necessary in order to understand today's situation. The current management of marine mammals, both internationally and in Norway, will be presented in the form of brief outlines. In addition, the report contains seven articles about research topics of current interest. In Chapter 7, the new Marine Mammal Advisory Board, which will assist the Institute of Marine Research in providing advice to the authorities on research and the management of marine mammals in Norway, is introduced. Finally, a complete table of all the species of marine mammal LQWKHZRUOGLVSURYLGHGZLWKVFLHQWL¿F(QJOLVKDQGZKHUHWKHUHLVRQH1RUZHJLDQQDPHV We believe that Marine Mammals will be useful not only in education but also for decision-makers in resource and environmental management. Hopefully, the report will also make interesting and enlightening reading for the community-oriented public. The Institute of Marine Research is not alone in carrying out research on marine mammals. For this reason, we have invited experts from other specialist environments to contribute material and take part in the edit- ing. All the articles in this special edition have been quality assured by being read and commented on by at Introduction least one peer. The editorial staff would like to thank Nils Øien and Tore Haug for assisting with this work. The editorial staff for Marine Mammals has consisted of Arne Bjørge, Kjell-Arne Fagerheim, Christian Lydersen (the Norwegian Polar Institute), Mette Skern-Mauritzen and Øystein Wiig (University of Oslo). Bjørge, Lydersen, Skern-Mauritzen and Wiig have edited and quality assured the factual content. Fager- heim and Bjørge have picked and edited the photographic material. The proofreading has been done by Marie Hauge and Ingunn E. Bakketeig. John Ringstad and Hege I. Svensen has carried out the graphical production. The report is also available on the Institute of Marine Research's webside www.imr.no. Happy reading! Tore Nepstad Managing Director This report should be cited as: Bjørge, A., Fagerheim, K.-A., Lydersen, C., Skern-Mauritzen, M. & Wiig, Ø. (eds) 2010. Sjøens pattedyr 2010 [Marine Mammals]. Fisken og havet, special edition 2-2010. 5 Chapter 1 Chapter What are marine mammals? Somewhere between 35 and 60 million years ago, animals liv- ing on dry land left in favour of the sea. Since then marine mam- mals have adapted their bodies and bodily functions, to different degrees and in different ways, to a life in the wet element. Arne Bjørge [email protected] arine mammals live in and A life in the sea has, however, led to a mainly live under the surface of the sea need obtain their food from the number of special adaptations. On land, to return to the surface to breathe. The ability sea. But, just like other mammals need a skeleton and four (or two) to absorb and store oxygen is, therefore, Mmammals, marine mammals legs to keep themselves erect and move critical for how long at a time they can be are warm-blooded; they have lungs and about. Submerged in water, the body gets submerged. Marine mammals live in water they breathe air. The give birth to living support and buoyancy. The skeleton is pri- that is usually at a much lower temperature young that are dependent on milk from marily a foundation for the muscles that ani- than the animals' body temperature. The WKHLUPRWKHUXQWLOWKH\DUHVXI¿FLHQWO\ZHOO mals use to move around. Moving through ability to limit heat loss from the body to developed to catch their own food. The ZDWHUFDXVHVVLJQL¿FDQWO\PRUHIULFWLRQWKDQ the water is, therefore, also important. Land structure of a marine mammal is generally through air and a streamlined shape thereby mammals often use their sense of vision to the same as that of land mammals; the becomes much more important. Land ani- ¿QGIRRG$WJUHDWGHSWKVWKHUHLVOLWWOHOLJKW internal organs and main elements of the mals have few restrictions on how often they and marine mammals need alternative ways skeleton are the same. can draw their breath. Marine mammals that RI¿QGLQJIRRG 1.1 WHICH GROUPS AND SPECIES ARE CONSIDERED MARINE MAMMALS? Photo: A. A. Bjørge Photo: There are considered to be three main sea cows, individual species that belong to Figure 1.1.1 groups of marine mammals: whales, seals the land mammals in terms of genus are Californian sea otter. and sea cows. Whales and sea cows are also considered marine mammals in some placed in their own orders: Cetacea and contexts. This includes, for example, the Sirenia1. The seals are called Pinnipedia. Californian sea otter (Figure 1.1.1) and This is a sub group of the carnivore order the polar bear.