Batman River fish feared extinct spotted in Turkey after near 50-year absence - The Washington Post

Batman has returned — the Batman River loach, that is.

The tiny freshwater fish was last seen by scientists in southeastern Turkey in 1974. The yellow-and-brown-striped loach, which grows to only around 1.4 inches, is the Middle East's smallest loach species. Categorized as critically endangered, it once populated the streams and tributaries around Batman River, which feeds into the Tigris.

For nearly five decades, ichthyologists — zoologists focused on fish — have been searching for the loach.

They've scoured shallow, rocky and fast-flowing parts of rivers, the fishes' favorite climate, using tightly woven nets meant to catch tiny critters, according to Shoal, a London-based conservation initiative involved in these efforts. The Batman River loach was one of Shaol's "10 Most Wanted Lost Species" of fish that its partners prioritized trying to find.

And then — they did.

On a recent expedition, 23 fish turned up in the nets of Cüneyt Kaya, a fish taxonomist, and Münevver Oral, a geneticist, who had been working to narrow down possible streams where the fish could still be.

"I've been researching this area for 12 years and this fish was always on my wish list," Kaya, an associate professor at Recep Tayyip Erdogan University, told the Guardian. "It's taken a long time. When I saw the distinctive bands on the fish, I felt so happy. It was a perfect moment."

Kaya and Oral told the Guardian that more work needed to be done to analyze the existing loach communities and what threats they face.

Loach, due to their size, were never commercially fished by humans, whose heavy consumption of other fish species has contributed to their depletion.

But the scientists do suspect that the construction of the Batman Dam in the 1980s and '90s, along with pollution, drought and invasive species, probably led to the fishes' decades-long disappearance.

"It is obvious that the establishment of the dam caused shifts in biodiversity due to degradation of the lower part of the habitat needed by the species," Kay said in a statement on Shoal's website. "I can say this because the species' preferred habitat is shallow streams, with medium or fast-flowing stones or gravel."

"As far as I know, there is no industrial pollution above the points where we identified the species," she added. "We must ensure that it does not happen in the future."

The Batman River loach is the first of Shoal's priority lost fish to be found.

While critically endangered or thought-to-be-extinct species do occasionally reappear, it is relatively rare compared to the continued loss of wildlife.

In September, the U.S. Fish and Wildlife Service announced it was declaring 23 more species extinct and removing them from the endangered list.

"Human activity can drive species decline and extinction by contributing to habitat loss, overuse and the introduction of invasive species and disease," the agency said in a statement at the time, CNN reported. "The growing impacts of climate change are anticipated to further exacerbate these threats and their interactions."

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