Cool Science
Sounds of Alarm

November 30, 2015

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Photo Credit: ©Gill Braulik/WCS

In March of this year, WCS scientists set off from Tanzania to survey local dolphins and whales. Led by Dr. Gill Braulik of the WCS Tanzania Program, they covered over 2,600 kilometers of coastal waters (or 1,600 miles). As part of the research, the team dropped underwater microphones, called hydrophones, below the surface to pick up audio.

They were expecting to hear the sounds of marine mammals. Far more often, they wound up hearing explosions—the result of fishermen catching their quarry with homemade bombs rather than rods and reels. It's a practice called blast fishing, which is illegal in Tanzania. Though they knew it was still happening, the researchers didn't expect to find it to such an extent. Over 36 days, they ended up hearing 318 blasts.

"Not only is this type of fishing harmful to acoustically sensitive species such as marine mammals," Dr. Braulik said, "it indiscriminately kills fish and other marine life, and can seriously damage coral reefs." Check out just how damaging blast fishing can be.

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