Traditional community-run marine reserves and fisheries can play a big role in restoring and maintaining fish numbers in stressed developing nations’ coral reef fisheries.
Using genetic ‘fin-printing’, an international team of scientists has gathered the first clear proof that small, traditional fishing grounds, effectively managed by local communities, can help re-stock both themselves and surrounding marine areas.
The finding has big implications for hundreds of millions of people around the world who depend on coral reefs for food and livelihood.
In an article in Current Biology the researchers report that the offspring of protected coral trout breeding in community-managed areas in Papua New Guinea were plentiful – in the managed area and in surrounding fishery tenures.
“This is a really important finding, because it shows that small, community-run fisheries can preserve their fish stocks and can boost fish stocks in a radius of 30 kilometres or more,” said lead author Dr Glenn Almany of the ARC Centre of Excellence for Coral Reef Studies and James Cook University.
Dr Richard Hamilton from The Nature Conservancy said that the finding was “proof that traditional local fishery management pays off – and that is particularly critical in countries around the world where government fisheries schemes are lacking or poorly enforced.
“Some of this traditional marine management has operated for centuries. We’re providing the hard scientific evidence that it works,” he said.
Local fisheries in countries such as Indonesia, the Philippines, Malaysia, Papua New Guinea, Solomon Islands and East Timor (the six countries forming the Coral Triangle, the world epicentre of marine biodiversity) feed hundreds of millions of people and are under growing stress from development, overfishing and climate change.
However the principles also extend to coral reefs in countries such as Australia.
Dr Almany said local marine reserves and traditional fishing tenures have been widely posed as a solution – but so far there had been a lack of proof, and public confidence, that they benefited local fishers and communities.
Working with local fishers on Manus Island in PNG, the team took fin samples from a spawning aggregation of coral trout in a tiny marine reserve. They then collected similar samples from juvenile fish up to 33km away and used DNA parentage analysis to see how many were the offspring of the parent group.
“We wanted to see where the young fish went, and what was the effect of the marine reserve on both its surrounding fishery and others nearby,” Dr Almany said.
They found 17-25 per cent of all juveniles collected in the managed area were from this particular group of parent fish, as were 6-17 per cent of all juvenile groupers caught in four neighbouring fishery areas.
“It is a really exciting result. It’s the most compelling evidence yet that traditional, community management of fisheries really works,” Dr Almany said.
The researchers project from their findings that the offspring of this one bunch of coral trout could be spreading as far as 80km from the breeding site of the parents.
“This gives us a really great handle on how different fishery areas interconnect, and can support one another. It shows that the community that bears the cost of operating a marine reserve also derives the greatest benefit,” Dr Hamilton said.
“We didn’t have to explain our results to the local fishers – they got it at once,” he said. “It gives them the confidence they need to get behind traditional fisheries management or government-introduced marine parks, because more fish will be caught locally.
“Importantly too, the same management principles can work in places like Australia’s Great Barrier Reef, where many of our favourite species like snapper, emperor and coral trout form spawning aggregations.”
The results of the research are published in the latest issue of the journal Current Biology in an article entitled “Larval dispersal from a grouper spawning aggregation and the spatial scale of fisheries replenishment” by Glenn R. Almany, Richard J. Hamilton, Michael Bode, Manuai Matawai, Tapas Potuku, Pablo Saenz-Agudelo, Serge Planes, Michael L. Berumen, Kevin L. Rhodes, Simon R.Thorrold, Garry R. Russ and Geoffrey P. Jones.
“Our results can empower people in the Coral Triangle region and throughout Oceania, where millions of people rely directly on coral reef fisheries and desperately need improved management, to take effective local actions that help ensure their own food security,” the scientists conclude.
Issued: April 1, 2013
Jim O’Brien, James Cook University Media Office, +61 (0)7 4781 4822 http://www.coralcoe.org.au/