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Environment| Environment

Environment| Environment

close-up of a porpoise, showing its rounded head and lack of a beak


Scientists who have been studying the DNA and biology of the world’s smallest cetacean (and rarest marine mammal), the vaquita porcoise have made a sweet and surprising discovery.

close-up of a porpoise, showing its rounded head and lack of a beak
A vaquita porpoise believed to have been killed in an illegal gillnet Photograph: Omar Vidal/WWF/AFP/Getty

Conservationists believed that the mammal had a small population of less than 10 individuals remaining. This means that it is at the same risk of harmful mutations or inbreeding as other species of small gene pools.

However, international researchers from the University of California Los Angeles (UCLA), National Oceanic and Atmospheric Administration Fisheries(NOAA), and other institutes discovered that the porpoises were not (in fact, they were) (in fact, they were).Phocoena sinusThey are more likely to avoid the dangers of inbreeding and have less harmful mutations.

The animals have a small geographic range and are restricted to the upper Gulf of California. They are endangered by illegal fishing. These nets, known for trapping turtles and whales, are suspended vertically in the ocean and used for illegal fishing. Experts say that the species is likely to die if it doesn’t stop immediately.

A man in camouflage with a gun walks behind two men carrying a large net on a beach
As part of efforts to save the vaquita, a Mexican marine and fisheries officials confiscated an illegal net in Baja California in March. Photograph: G Arias/AFP/Getty

Christopher Kyriazis (a UCLA doctoral candidate in ecology) said that the vaquita was not doomed because of genetic factors such as harmful mutations. These tend to affect many other species whose genes have decreased to a similar extent. Their greatest threat remains outlawed fishery.

The small porpoises are approximately 1.2-1.5m (4-5ft) in length and often get entangled in the large mesh nets used by poachers to hunt the totoaba. This endangered fish fetches thousands of dollars on China’s black market for its medicinal properties. Although Mexico has banned totoaba fishing in Mexico and the use of vaquitas habitat gillnets, many claim that the ban is not always enforced.

The genomes of 20 vaquitas were analysed by the researchers. They then used models to predict its extinction over 50 years. They concluded that gillnet fishermanship should be stopped immediately to ensure that the vaquita does not suffer the genetic consequences from inbreeding. However, if the practice is continued, even moderately so, the prospects for recovery are less.

Science is publishing the research..

Kirk Lohmueller is a senior co-author and an associate professor of ecology at UCLA. He stated: The prevailing view in population genetics and conservation biology is that small populations can accumulate deleterious mutants. Our results show that the vaquita is more likely to have fewer highly deleterious mutations than the population, which bodes well in their eventual recovery.

Researchers said that the vaquita’s habitat and small population make it the marine equivalent to an island species.

The decline in population from 576 to 7 or 8 over the past decade is due to the Illegal totoaba trade is on the rise.

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