redOrbit Staff & Wire Reports – Your Universe Online
The first clear evidence that no-take protected areas can help restock exploited fish populations on neighboring reefs was presented at the International Coral Reef Symposium today.
These answers will help resolve a long-running discussion worldwide about whether areas blocked off to all forms of fishing help replenish fish numbers outside the marine protected areas (MPAs).
“Using DNA fingerprinting technology, we now can clearly show that the benefits of MPAs spread beyond reserve boundaries, providing a baby bonus to fisheries,” Geoff Jones, from the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and James Cook University, who led the study commented.
Jones presented his team´s evidence as part of a media meeting on fish larval spreading and the connectivity between reefs entitled “Reef Connections.” International Coral Reef Symposium which is held every 4 years is the premier global coral reef conference and a breeding ground of the latest advances in coral reef science. The research and findings presented at ICRS2012 are imperative in informing national and international policies and the sustainable use of coral reefs globally.
Others joining Jones was Leanne Fernandes, Director and Principal Consultant, Marine and Coastal Resource Management, Earth to Ocean, Australia; Stephen D. Simpson, Marine Biologist & NERC KE Fellow, School of Biological Sciences, University of Bristol, United Kingdom; and Bob Warner, Professor of Marine Biology at the University of California, Santa Barbara.
A full video of the presentation, with each panelist´s discussion of the current science presented at ICRS and management applications of fish larval research is available online at www.icrs2012mediaportal.com.
The groundbreaking study was carried out in the Keppel Island group on Australia´s Great Barrier Reef by researchers from the ARC Centre of Excellence for Coral Reef Studies (CoECRS), in conjunction with other leading research institutions.
“The implications for local fishing communities around the world are huge,” said Fernandes, who was the manager of the Representative Areas Program in Australia that established one-third of the Great Barrier Reef as no-take protected areas. “It´s never easy to protect areas from fishing because, so often, the fished areas are very important for local communities for food, livelihoods and lifestyles. So fishermen need to know for sure it will work.”
Fernandes said that Jones´ research also shows that MPAs can be effective on small scales, which has implications worldwide. For many communities, particularly in the developing world that depend on small areas of reef for food and income, there are limited options for closing areas to fishing.
“The MPAs weren´t tens of kilometers across. Some were about two kilometers cross or even 800 meters across, and they still worked,” she said. “This is great news for local fishing communities around the world because protecting areas about this size might be possible for them; protecting really big areas is just too hard.”
Using DNA samples, the team of scientists tracked the dispersal pathways of juvenile coral trout and stripey snappers larvae from MPAs in the Keppel island group. They found that a very large proportion of juveniles, 65 percent, settled in nearby areas that are open to fishing. Most of the baby fish settled within one to five kilometers of reserves but a significant proportion dispersed 10 kilometers or more to find a new home.
In addition, the study found that the six marine reserves, which cover only 28 percent of the total reef area of the Keppels, had generated 50 percent of the total juvenile fish, both inside and outside of the reserves. “So 28 percent of the area protected equals 50 percent of the baby fish produced. This means there would have been a lot less fish if the no-take areas weren´t there,” Fernandes said.
Warner said that research into fish larvae behavior is tremendously important to developing successful management approaches. Fish larvae, which are microscopic fish babies, normally are dispersed in the open ocean after they are born, living for days or weeks, before the lucky survivors make it back a reef.
“This poses immense problems for management. How do you manage fish populations if the young produced are scattered out to sea like dandelion puffs drifting in the wind?” he said. But Jones has addressed this critical issue by showing that these fish babies do return to their home reefs, which means that local actions to protect
fish can have direct local benefits, he said.
Simpson added that recent research has shown that fish larvae have highly developed senses, included smell and hearing, and can actively swim back to their home reefs. But that means the reef habitat and adult fish populations need to be intact for them to find their way home. That´s exactly what MPAs can provide, with spillover benefits for neighboring reefs.
“This research is the strongest support for management strategies that adopt marine protected areas as a fundamental tool for sustaining fish populations,” Simpson said.
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