Boost to fish protection as sea currents track path of fish offspring
Posted on 25 November 1997
Dr Callum Roberts of the Environment Department at the University of York, says that mapping the sea's surface current patterns can help unravel the mystery of how populations of marine life link up with each other.
"Currents carry the offspring of fish away from where they were spawned," he says. "Tracking the routes of currents can reveal the pathways of transport and how far offspring travel. This in turn helps us determine where to put marine reserves and how closely we should space them."
Marine reserves are an effective way of preserving fish stocks and other marine life, including coral reefs. Temperate and tropical oceans are suffering from over-fishing, a trend which affects not only the quality of catches but the whole ecosystem of the ocean.
Tracking the routes of currents can [help] us determine where to put marine reserves
Dr Callum Roberts
"Establishing reserves with no fishing has great potential to solve these problems," says Dr Roberts. "They protect fish from capture and act as reproductive 'hot-spots', flooding surrounding fishing grounds with offspring. The need for these 'no-take' marine reserves is so great that the American Association for the Advancement of Science has called for 20 per cent of the seas to be declared no-take by 2020. This call has been taken up by conservationists and fishermen alike."
The management of marine reserves is complicated by the transport of eggs and larvae to other areas by ocean currents. Populations of marine species straddle international borders and collaboration is vital. Dr Roberts' maps show how partner nations can be identified so that they can form management coalitions.
"The ocean floor more closely resembles a ploughed field than the shellfish encrusted wilderness of popular imagination," says Callum Roberts. "We need to act quickly to establish no-take marine reserves and international partnerships to manage them before the richness and diversity of the ocean population becomes just a memory."
ENDS
Notes to editors:
- Dr Roberts' findings on mapping surface current patterns are published in Connectivity and Management of Caribbean Coral Reefs in Science, 21 November 1997.