20 Mar 2017 - Fish can quickly evolve to get more benefit from the protection offered by marine protected areas, according to research from the University of B.C.
Variation in the natural range of large fish species means that some fish will spend much of their lives in or near areas protected from fishing, while others will range farther and face capture. Because they are less likely to be harvested, less mobile fish are more likely to survive and pass that trait on to their offspring.
“Evolution can be very fast and we’ve seen that many times, when organisms are dying, selection pressure is high,” said co-author Jonathan Mee.
Researchers modelled the ocean movements of species including skipjack and bluefin tuna and great white sharks in a collaboration between UBC’s Biodiversity Research Centre and the Sea Around Us project at the Institute for the Oceans and Fisheries.
“It’s safe to assume that a trait like how much fish move has some genetic basis. In fact, it would be weird if that wasn’t the case,” said Mee.
They found that the movement patterns of tuna could change within 10 years of the creation of a new marine protected area (MPA). The longer-lived Great Whites showed change after 50 years.
‘The boats got bigger and now we can cover the entire range of the tuna. The distance doesn’t protect them, depth doesn’t protect them, nothing protects them except our decision to remove ourselves from certain areas in the form of marine reserves’ — study co-author Daniel Pauly, UBC.
MPAs are parks and conservancies managed under federal and provincial law to protect sensitive ecosystems and species.
Based on the idea of “fisheries-induced evolution,” co-author Daniel Pauly said that expanded “no-take” zones could balance the negative impacts of overfishing outside protected areas, where commercially desirable fish have no place to hide.
“The boats got bigger and now we can cover the entire range of the tuna,” said Pauly. “The distance doesn’t protect them, depth doesn’t protect them, nothing protects them except our decision to remove ourselves from certain areas in the form of marine reserves.”