Threats
With, as of 2008, between just 300 and 350 North Atlantic right whales remaining, this species' existence lies in an extremely precarious situation (1). Years of whaling, starting in the 11th century and becoming a modern industrial practice in the early 20th century, have left North Atlantic right whale stocks seriously depleted in the western Atlantic (2), and virtually extinct in the eastern Atlantic (1). They were killed in their thousands for their valuable oil and baleen (2), until commercial whaling was prohibited by the International Whaling Commission in 1935 (1). Whilst the North Atlantic right whale is no longer hunted (1), decades of exploitation have left a tragic legacy. The small, remaining population, concentrated along the heavily industrialised coast of north-eastern America (7), is highly vulnerable to the impacts of human activities. Collision with ships is currently the most serious source of mortality threatening the North Atlantic right whale, and was the cause of 16 North Atlantic right whale deaths between 1970 and 1999. This is closely followed by the threat of entanglement in commercial fishing gear, either active gear or nets that have been lost or damaged. Known as 'ghost gear', this fishing equipment continues to wreak havoc on marine species, with three North Atlantic right whales known to have died from entanglement since 1970 and a further eight known to have been seriously injured, most likely with fatal consequences (2). These numbers may sound small, but in a population of just 300 or so individuals, the consequences can be enormous. A number of other threats may also be impacting this imperilled species, including a loss of habitat due to human activity, oil spills, man-made noise which may interfere with communication, intensive commercial fishing having knock-on effects on prey availability, and global climate change (2). As the North Atlantic right whale has a relatively narrow range of prey on which it can feed, and relies on a specific combination of water currents and temperatures to create suitable feeding grounds, changes to ocean temperatures and currents caused by global climate change could have devastating affects (2) (8). Indeed, climate change may be the final factor that pushes this species over the brink to extinction (8).
