Humpback whales are typically migratory that's why the Arabian Sea population is a mystery to researchers after they found that particular humpback whale has stayed in the same place for 70,000 years.
Researchers from the American Museum of Natural History and the Wildlife Conservation Society collaborated to study the Arabian Sea humpback whale, analyzing samples from 67 whales to check their nuclear and mitochondrial DNA. These humpback whales have originally been hard to study because limited data was available. Fortunately, researchers were able to get their hands on samples, allowing them to take a closer look at Arabian Sea humpback whale. Tissue samples were taken from 1999 to 2004 during small-boat surveys and all included permits issued by the Sultanate of Oman's Ministry of Regional Municipalities, Environment and Water Resources' General of Nature Conservation.
Published in the journal PLoS ONE, the study arrived at the conclusion that the Arabian Sea humpback whale is genetically distinct from its cousins in the North Pacific and the Southern Hemisphere. In fact, analyzing gene flow led researchers to the discovery that the Arabian Sea humpback actually came from the Southern Indian Ocean but was isolated and has been in the same place for 70,000 years.
Researchers admitted that it's going beyond the scope of their study but provided a hypothesis just the same to explain the Arabian Sea humpback whales decision to stay in the same place for tens of thousands of years.
According to them, conditions in the Arabian Sea were simply more conducive to breeding and living than other parts of the ocean, abundant in nutrient supply and just the right temperature.
Unfortunately, the Arabian Sea humpback whale met other threats, dropping in population from at least 400 individuals 50 years ago to just 82 to 142 based on mark-recapture and genetic data. With population below 250 mature individuals and an average continuing decline of at least 25 percent every generation, with a drop in the population amounting to more than 80 percent over the course of three generations, the researchers recommended that the conservation status of the Arabian Sea humpback whale on the International Union for Conservation of Nature's Red List of Threatened Species be changed to "critically endangered."
Titled "The World's Most Isolated and Distinct Whale Population? Humpback Whales of the Arabian Sea," the study was authored by Howard Rosenbaum, Robert Baldwin, Louisa Ponnampalam, Matthew Leslie, Ken Findlay, Gianna Minton, Tim Collins, Ana Amaral and Cristina Pomilla.
