Humpback Whale - Conservation

Conservation

The worldwide population is at least 80,000 humpback whales, with 18,000-20,000 in the North Pacific, about 12,000 in the North Atlantic, and over 50,000 in the Southern Hemisphere, down from a prewhaling population of 125,000.

This species is considered "least concern" from a conservation standpoint, as of 2008. This is an improvement from vulnerable in the prior assessment. Most monitored stocks of humpback whales have rebounded well since the end of commercial whaling, such as the North Atlantic, where stocks are now believed to be approaching levels similar to those before hunting began. However, the species is considered endangered in some countries, including the United States. The United States initiated a status review of the species on August 12, 2009, and is seeking public comment on potential changes to the species listing under the Endangered Species Act. Areas where population data are limited and the species may be at higher risk include the Arabian Sea, the western North Pacific Ocean, the west coast of Africa and parts of Oceania.

Today, individuals are vulnerable to collisions with ships, entanglement in fishing gear, and noise pollution. Like other cetaceans, humpbacks can be injured by excessive noise. In the 19th century, two humpback whales were found dead near sites of repeated oceanic sub-bottom blasting, with traumatic injuries and fractures in the ears.

Once hunted to the brink of extinction, the humpback has made a dramatic comeback in the North Pacific. A 2008 study estimated the humpback population, which hit a low of 1,500 whales before hunting was banned worldwide, has made a comeback to a population of between 18,000 and 20,000. Saxitoxin, a paralytic shellfish poisoning from contaminated mackerel has been implicated in humpback whale deaths.

The United Kingdom, among other countries, designated the humpback as a priority species under the national Biodiversity Action Plan. The sanctuary provided by US National Parks, such as Glacier Bay National Park and Preserve and Cape Hatteras National Seashore, among others, have also become major factors in sustaining populations.

Although much was learned about humpbacks from whaling, migratory patterns and social interactions were not well understood until two studies by R. Chittleborough and W. H. Dawbin in the 1960s. Roger Payne and Scott McVay made further studies of the species in 1971. Their analysis of whale songs led to worldwide media interest and convinced the public that whales were highly intelligent, aiding the antiwhaling advocates.

In August 2008, the IUCN changed humpback's status from Vulnerable to Least Concern, although two subpopulations remain endangered. The United States is considering listing separate humpback populations, so smaller groups, such as North Pacific humpbacks, which are estimated to number 18,000-20,000 animals, might be delisted. This is made difficult by humpback's extraordinary migrations, which can extend the 5,157 miles (8,299 km) from Antarctica to Costa Rica.