80 Year-Old Bookkeeping Error Causes First Species to be Fished to Extinction


The Almost-Extinct Flapper Skate. Photo via the Telegraph
Everyone has no doubt heard about how fisheries around the world are in grave danger of being fished into oblivion. Countless species are currently threatened by overfishing, and environmentalists work fiercely to prevent victims like sharks and tuna from disappearing--but no one suspected that a common skate would be the first to go. And it turns out no one suspected anything because of a simple classification mistake made 80 years ago.

It was an error that was made almost 8 decades ago--and it appears to have lead to the seemingly irreversible decline of a now-endangered skate. Here's what happened, according to Science Daily:

From the mid-19th century the common skate was described as two distinct species, the flapper skate, D. intermedia, and the blue skate, D. flossada. However, in an influential work in 1926 R.S Clark recognised only 'D. batis' as a valid species and this classification has largely gone unchallenged since.
So, thanks to Clark, there were two species of skate being lumped in together as Dipturus batis--meaning that there was assumed to be a larger stock of a single species by both fishing companies and environmentalists.

Now, the European common skate--the name accidentally given to both species--has been on the World Conservation Union's Red List of Threatened Species since 2006. Catch limits were then imposed to protect it. Unfortunately, because of the bookkeeping error made 80 years ago, the two species weren't differentiated, and no one could tell that one of them was getting hit much harder--until it was too late.

Thanks to the mix-up, the rarer flapper skate--the world's largest--has now been fished to the brink of extinction. Before mass fishing began, the ill-fated species--along with its twin--was abundant. But now it's been all but entirely depleted from its natural habitats in the Celtic and North Seas, the Skagerrak and the English Channel.

A team of scientists led by Dr Samuel Iglésias, whose research has only now finally uncovered the past mistake, are desperately attempting to create an official distinction in a last ditch effort to save the flapper skate. "Without revision and recognition of its distinct status the world's largest skate, D. cf. intermedia, could soon be rendered extinct," he says.

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Tags: Animals | Conservation | Endangered Species | Fishing