In his keynote address this morning Kenneth Sherman, of the US National Oceanic and Atmospheric Administration, warned that fish stocks in the Asia-Pacific region are hanging in the balance – a precarious position for a region where people get 80 per cent of their protein from fish.
Sherman was talking about the world’s 64 large marine ecosystems (LMEs), coastal marine ecosystems that are divided by natural boundaries. Research in 2007 found that all LMEs have been degraded by overfishing, pollution, introduced species and the climate – and degraded ecosystems can’t support the fish higher up the food chain that we humans are so keen on.
Three LMEs in the Asia-Pacific region – the South China Sea, the Gulf of Thailand and the Indonesian Sea – are at particular risk, said Sherman, but all LMEs in the equatorial region are susceptible to climate change.
As temperatures rise, nutrients in these warmer LMEs are inhibited from mixing, reducing the productivity of the system – and the number of fish it can support, even as fish catches reported to the FAO are increasing.
Reversing this trend will require political will and nations working together as many LMEs lie off the coasts of multiple countries. The Global Environment Fund and World Bank are now funding a programme in which neighbouring countries agree to work together to restore ecosystems. Seventeen such projects are now in place.
One success story is the beginning of rehabilitation to a ‘dead zone’ in the Yellow Sea. China and Korea have agreed to reduce fishing and are replacing the lost protein with ‘integrated multitrophic mariculture’, a system in which kelp, abalone, scallops and sea cucumbers are grown in a layered pot, with nutrients trickling down from one to another. The system also sequesters carbon and improves water quality.
A collaboration in the Coral Triangle between Indonesia, Malaysia and the Philippines is also being established.
So all is not lost, says Sherman. “We probably were in a downward spiral but we’re in not in one anymore.”
Katherine Nightingale, South-East Asia news editor, SciDev.Net