Science Snapshot: Down but Not Out

Researchers catch and release a vaquita in 2017.

Researchers catch and release a vaquita in 2017, obtaining genetic information used in the current study.

VaquitaCPR

Mother and calf vaquita

Mother and calf vaquitas. As the world’s smallest cetaceans, adults will only grow to be about 150 centimeters (just shy of 5 feet) long.

Paula Olson

Juvenile female vaquita in the water

A female juvenile vaquita was photographed in 2017. When fully grown, she’ll weigh around 55 kilograms (120 pounds).

RichardLadkani/TerraMaterStudios/NationalGeographic

For many animals, genetic diversity is crucial to survival because it affords the population some flexibility when encountering changes in the environment. Individuals may be lost, but variation helps protect whole populations from being wiped out in one fell swoop. Enter the vaquita (Phocoena sinus): the world’s smallest cetacean. These happy-looking porpoises, which occupy a small area in the Gulf of California, are critically endangered, with only 10 individuals estimated to remain in existence, giving conservationists doubts about the species’ survival due to genetic inbreeding.

A study published yesterday (May 5) in Science examined genomic data from archived vaquita tissue samples and found that genetic diversity has been low yet stable among the animals for the last 1,000 years or so, indicating that the current lack of variation should not drive the species to extinction. The biggest threat to the vaquita’s continued existence is fishing, as they often become entangled in illegal gillnets. 

Source: the-scientist.com

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