Easy Target

Fish just outside the boundaries of marine reserves may be easier to catch, offering a potential boon to fishers, according to a study in Ecology Letters.

Fish in protected areas haven’t been exposed to the dangers of fishing, so they may not be as quick to avoid threats such as spearguns. Previous research showed that it might be easier to nab protected fish than unprotected fish, and the study authors wondered if this naive behavior would “spill over” to areas outside the reserves.

The team studied fish at three marine reserves in the Philippines, surveying an area up to 200 meters outside each reserve. To determine how naive the fish were, a diver approached fish until they darted away. The researchers then measured how close the diver got before the fish fled.

Fish in the Acanthuridae and Scaridae families, which are frequently targeted by fishers, were less cautious near the reserve. The fish close to the reserve boundary allowed the diver to come closer than the fish farther away from the boundary, the team found.

This spillover effect “may provide a previously undocumented benefit to local fishers through greater access to catchable fish,” the researchers write. Fish farther away from the reserve might have learned their lesson when they narrowly escaped a spearfisher or sensed chemical signals released by wounded fish. Roberta Kwok | 19 November 2012

Source: Januchowski-Hartley, F.A. et al. 2012. Spillover of fish naivete from marine reserves. Ecology Letters doi: 10.1111/ele.12028.

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