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April 2018    Download the Entire Issue (PDF) Vol. 33, No. 4   RSS Feed for Undercurrent Issues
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Does Your Light Cause Critters Harm?

are high-powered video lights a concern?

from the April, 2018 issue of Undercurrent   Subscribe Now

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It was during early attempts at macro photography at night at Grand Turk's reef wall that I first discovered the hazardous effect of artificial light on small critters. Every time I lined up my camera on one, it would disappear before I had time to record it. It was some time before I realized a big grouper had taken up station next to me and was literally sucking my subjects, mesmerized by the light, out of my picture. In Egypt's Red Sea, lionfish have learned to do the same at night in a commensal relationship with divers' flashlights.

Great hordes of white-tip reef sharks follow divers at night like packs of hounds.

Stéphan G. Reebs of the Université de Moncton, Canada, wrote in 2007 how fishes at night exposed to a bright light suffer 'light shock' -- becoming motionless and often sinking to the bottom [where it is shallow]. "This may give the illusion of sleep when in fact it is only a short-lived reaction to a temporally abnormal stimulus."...

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