Dolphin Researchers Focus on Alboran Sea

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"Over the last decade Ana has collected the most extensive data set—in terms of duration and areas covered—on cetaceans in the Mediterranean," said Hammond. "They [Ana and Ric] have done this project very cheaply, on a shoestring, and they have still come up with the best data."

In 1990 Canadas and Sagarminaga came to the Mediterranean to study a sea turtle nesting ground in Tunisia. Later that year they turned to investigating a massive dolphin die-off that stretched from Spain to Greece.

To help sustain their research, the couple founded Alnitak, a non-profit University of Madrid-linked environmental organization. Earthwatch has funded Alnitak since 1999.

A Noisy Underwater World

The Mediterranean has suffered heavily from overfishing and the effects of pollution—hydrocarbons, heavy metals, debris, sewage from tourist sites and noise from maritime traffic.

Although the dolphin population in the Alboran seems healthy, the creatures may face a new threat from the fisheries. The industry is stepping up the sardine catch to feed farm-raised tuna.

"We don't know whether this is a problem for the dolphins or whether their spectrum of prey is broad enough to compensate," Canadas said.

In 1997 Canadas and Sagarminaga expanded into bioacoustics, using a hydrophone—an underwater microphone—to study dolphin communication.

The couple launched genetic studies in 1999, collecting tissue samples from stranded animals or those caught up in fishermen's nets.

Today, aboard the Toftevaag, with a crew of four researchers and up to eight volunteers, Canadas and Sagarminaga are taking a hands-on approach.

When curious dolphins swim around the boat, the team launches an inflatable boat. The researchers reach out to the dolphins with a sponge-tipped pole and try to swab them. The flakes of skin on the sponge go into a tube for DNA analysis.

The Toftevaag also eavesdrops on the dolphins. Manolo Castellote, a visiting bioacoustics researcher, sits with headphones on, staring at a computer screen showing digital imaging of dolphin clicks—"sort of k-k-k-k-k-k, rhythmic sounds," he said.

But manmade sounds drown out the dolphins—"this kind of beep-be-deep, beep-be-deep, that's VHF interference made by ships," said Castellote. "The Mediterranean is a very acoustically polluted sea."

"All these species use the same frequencies of sound as the engines of big ships," Castellote said. The engine sounds may somehow interfere with the dolphins' communication or possibly deafen the animals with high background noise.

The Alboran may be noisy and chaotic but the dolphins thrive there. Canadas and Sagarminaga want that vitality to continue—and to extend ever easterly.

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