Scientists' lights blind deep-sea shrimp.

The pink clothespin-shaped eye spot on the back of a deepwater shrimp appears to go permanently blind when blasted by the light from scientific craft exploring the ocean.

The latest evidence comes from Peter J. Herring and his colleagues at Southampton Oceanography Centre in England. In the March 11 NATURE, they describe shrimp with chalky-white eyes, indicating degraded photopigments, at two fields of hydrothermal vents on the Atlantic seabed.

At one site, most of the shrimp collected were blind. That vent field, called Lucky Strike, had been visited often by light-beaming submersible craft. The other site, called Rainbow, had been visited for the first time only a month before Herring's team sampled the shrimp in 1997. Fewer animals with degraded pigments turned up there.

The damage reminds Herring of problems in the deep-water crustacean Nephrops. Well-intentioned fishers off Scotland tossed undersized catch back into the water, not realizing that surface light had blinded the creatures.

Scientists observing vent shrimp need to be aware that the animals may already have been blinded, Herring observes. "It's a cautionary tale," he says.

The warning is not new to vent scientists (SN: 2/11/89, p. 90; 1/1/94, p. 14). Herring's group has now "stated the case more strongly," says Robert N. Jinks of Franklin and Marshall University in Lancaster, Penn. He and his colleagues in 1995 published descriptions of shrimp eyes and predicted damage.

Jinks favors the idea of setting aside certain vents as dark sanctuaries until scientists develop gentler observation techniques. "I think we need to worry," he says.