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In the last few years we have likely lost a species, the baiji (Chinese river dolphin), while others are hanging on by the slimmest of margins. The North Atlantic right whale may have been reduced to less than 450 individuals. The New Zealand Maui dolphin may now number less than 55 individuals and yet they are still dying in fishing nets. In the Pacific Ocean, the western gray whale is down to fewer than 130 individuals (although the eastern gray whale is doing well), with oil exploration a major issue in its habitat. Some species of porpoise are also under threat, with the vaquita, found only in the Gulf of California in Mexico, numbering less than 100 individuals. River dolphins in Asia (South Asian river dolphin) and South America (Amazon River dolphin) are also under enormous pressure as human activity encroaches on many of their key habitats.
What do we mean by endangered?
The dictionary definition is 'a species whose numbers are so small that the species is at risk of extinction.'
This definition can apply to any animal species, but with highly social and widely distributed creatures such as whales and dolphins we should perhaps also consider endangered populations. The loss of any one distinct population of whale or dolphin may have dramatic long-term effects on what remains of the species.
It’s estimated that hundreds of thousands of whales and dolphins are dying annually in fishing nets worldwide with few countries successfully addressing this issue. In the United States, the Marine Mammal Protection Act prohibits “takes” of marine mammals and the Act includes specific processes to assess fishery bycatch and mitigation. Unfortunately, the US metric of Potential Biological Removals’ (PBR), a model developed to identify populations who are significantly impacted by humans as a means to prioritize actions to reduce impacts, has been taken out of context by some countries. Sadly, we are concerned that the UK and potentially the whole of Europe may be attempting to use a similar mathematical approach as way to measure ‘sustainable removal rates’, i.e. how many whales and dolphins can be killed without harming the population. WDC does not support the isolated use of PBR or an similar approach as a means to consider any injuries or deaths of whales and dolphins as sustainable. We have provided more details to EU Member States on what efforts are required to reduce bycatch towards zero, including through implementation of an EU Action Plan for cetacean bycatch reduction, through both ASCOBANS and ACCOBAMS.
Most conservation efforts have sought to limit individual threats to cetaceans, but the chance of long term success are hard to quantify for such long-lived species. Indeed, some of the most successful attempts in whale conservation in the last thirty years have been where we have ‘simply left’ populations and species alone. The 1982 International Whaling Commission (IWC) moratorium, despite the best (or should we say, worst) efforts of the commercial whaling interests, has meant that some populations of certain species are, far from the reach of mankind, slowly stabilizing and some even starting to recover - see the eastern population of gray whales noted above. The USA’s National Oceanic and Atmospheric Administration (NOAA) estimates that southern hemisphere humpback whales (Megaptera novaeangliae) may have recovered from previous whaling to some 25,000 individuals. However, it should be noted that the pre-whaling population was estimated to be some 100,000 individuals, so the concept of ‘recovery’ is of course relative.
Contrast this with the efforts of the New Zealand Government and the protection of the Maui dolphin. New Zealand has one of the best records internationally in the field of cetacean conservation, but the Maui dolphin (Cephalorhynchus hectori maui), a sub-species of the Hector’s, or New Zealand dolphin, is now believed to number less than 55 individuals. Accidental entanglement in gill nets, and trawl fisheries, is the biggest threat to the New Zealand Dolphin and where cause of death is known, over 60% are attributed to bycatch.
Species that find themselves in so-called ‘developing countries’ such as the baiji (Lipotes vexillifer), (which is/was found only in China), face even harder struggles. Indeed, as recently as 2007 the baiji has been described as ‘functionally extinct’, most likely due to unsustainable by-catch in local fisheries. This represents the first global extinction of a large vertebrate for over 50 years, only the fourth disappearance of an entire mammal family since AD 1500. The other river and freshwater dolphins face similar threats and potentially a similar fate unless we do something to help them and soon. For example a small population of Irrawaddy dolphins in the inner Malampaya Sound, Philippines, classified as “Critically Endangered” in the IUCN Red List, is currently threatened by bycatch in the local crab net/trap fishery.
The Critically Endangered western gray whale population is threatened by oil and gas development in its feeding ground on the Sakhalin shelf (Russian Federation). This population has likely fewer than 130 of the critically endangered whales left – including possibly only 26 breeding females.
We have destroyed some 80% of the biomass of whales and dolphins in the world's oceans and rivers. Let's not be the cause of any more such losses, - let us be the generation where we changed things for the better.