September 4, 2012
Brazilian Humpback Whale Population Triples Over Ten Years
Brett Smith for redOrbit.com - Your Universe Online
In a victory for conservationists, the Humpback Whale Institute near Salvador, Brazil announced that the amount of humpbacks along the country´s coastline has more than tripled over the past ten years.
According to the Institute, the 10,000 whales that were counted off the coast this past breeding season shows a robust growth for the local whale population that numbered only 3,000 when the researchers began keeping track in 2002.
The report also illustrated the success of policies that banned hunting of the marine mammals in 1966 when the population was estimated to be around 1,000. Institute chief Milton Marcondes said the ban and other conservation efforts have helped the species recover despite global warming and human activity, such as shipping and commercial fishing that negatively affect the population.
About 90 percent of the species are spotted in the winter months around the Abrolhos Archipelago off the coasts of the eastern Brazilian states of Bahia and Espirito Santo where humpback whales breed and raise their young after a year-long gestation period. Starting in July, as the austral winter begins, the Brazilian population of whales migrates toward the Antarctic to feed on krill and small fish.
The Humpback Whale Institute is currently looking to photo-indentify as many members of the whale population as possible.
In the 19th and early 20th century, humpbacks were hunted for their whale oil that was used for street lighting among other things. Some have estimated that 200,000 humpback whales were killed in the Southern Hemisphere during the 20th century alone.
Recent studies conducted in the North Atlantic have indicated that the humpback population is on the mend and approaching levels similar to those before commercial whale hunting began. In August 2008, the IUCN changed humpback whale´s conservation status from Vulnerable to Least Concern.
However, the whales are still considered endangered in some countries, including the United States. That status could change, as the U.S. initiated a status review in 2009 and is seeking public comment on possible changes to the species listing under the Endangered Species Act. One factor that could play into the status is the possibility of listing separate humpback populations, a distinction that would be made difficult by the whale´s wide range.
Today, the worldwide population is at least 80,000 humpback whales, and conservation efforts have been focused on identifying and fostering at-risk localized populations. These populations are typically under threat from human activity.
The humpback whales´ comeback has been tempered by the fact that increasing populations along with bigger and faster boats have resulted in an increase in whale collisions and ship-strikes in coastal waters.
Entanglement in fishing gear is also a global concern for many species of whales, as confirmed reports of entanglements and examination of whale scars off the coast of Hawaii suggest as many as one-third of the whale population there is negatively affected by commercial fishing, according to whaletrust.org. The conservationist website concedes that it is unclear whether the rising trend is the result of an increase in incidents or increased awareness.