Marine mammals, back from the brink? Contemporary conservation issues

Abstract

The extensive territorial waters of Australia and New Zealands (NZ) (over 8 million km2 for Australia and a further 4 million km2 for NZ) are home to approximately 49 species of whales and dolphins, 11 species of seals and the dugong. Within Australia, at least eight species are listed as threatened, though there is insufficient information on a further 25 to determine their conservation status, while in NZ eight species are listed as threatened. The relationship between humans and Australasia's marine mammals is culturally diverse and has changed significantly in recent years. Dugongs and stranded whales have been important both spiritually and as a source of nutrition to some Aborigines and Torres Strait Islanders for thousands of years; seals and whales had a similar role for Maori in NZ. In recent history, exploitation of baleen whales, elephant seals and fur seals was an important driver for much of the earliest European settlement of Australasia. The success of the whaling and sealing industries came at the expense of marine mammal populations, leading to the near extirpation of many species by the mid twentieth century. In more recent decades there has been a fundamental shift in public attitudes towards marine mammals, in particular the great whales and dolphins. All marine mammals are protected within Australia and NZ waters. Traditional hunting of dugongs is legal in Australia for Native Title holders. Marine mammal protection is an important platform of government foreign policy with strong bipartisan support. Both Australia and NZ play key roles in the International Whaling Commission and the Commission for the Conservation of Aquatic Marine Living Resources. Despite the strong government and public focus on marine mammal conservation, species remain vulnerable to a number of threats including fisheries interactions, vessel disturbance, coastal and offshore development and climate change. Managing these threats can be particularly difficult for marine mammals as many species are migratory and so only inhabit areas managed by Australia and NZ for part of their life-cycle. Interactions between threats are often poorly understood, and even individual threats can have severe consequences if not well managed. Despite these challenges, marine mammals represent some of the most successful examples of effective conservation in contemporary Australia and NZ, with rapid recovery of many of the great whales and fur seals. Yet some of our most iconic species face an uncertain future. A few are in immediate jeopardy, including the Maui's dolphin and the New Zealand sea lion. Others face a very uncertain future due as much to lack of knowledge of cumulative effects of threatening processes as to any specific threat. To increase the resilience of marine mammals, manageable threats need to be investigated, understood and carefully managed or, where possible, ameliorated.