Fish become smart enough to evade hunters

Fish have got wise to the ways of those who are hunting them with spear-guns. Researchers found that fishes exposed to spear-gun fishing take flight much earlier when a diver approaches compared with those living in protected zones.

“We were studying the effect of the customary reef closures which many groups in the Pacific use,” explains team member Fraser Januchowski-Hartley of the ARC Centre of Excellence for Coral Reef Studies.

The team wanted to know whether the existence of a closed area changed the behaviour of the fish inside it, compared to those outside, reports the journal Conservation Biology.

Their study took place at Muluk in Papua New Guinea.

It looked at fish traditionally hunted by the local people, including snappers, triggerfish, parrotfish and surgeonfish, according to an ARC Centre statement.

“Fish, which are regularly targeted, appeared to have a pretty fair idea of the three metre range of the typical rifle-style spear-gun used by the local PNG (Papua New Guinea) fishers,” explains lead author David Feary of University of Technology.

“Inside protected areas, the fish tended to move off when the diver closed to within 2-3 metres of them. However, those outside the protected zone, where hunting was common, mostly fled when the diver came within 4-5 metres of them.”

“Quite simply, the fish in areas that were fished regularly were more wary and stayed farther away - just far enough that it would be difficult to hit them with the spear-gun technology used locally.”

IANS