All about coral reefs [4]

Historically, coral reefs have sustained rich local fisheries targeting a range of fish and invertebrate species.

Now, technology has made it easier to reach fishing grounds, to find and catch fish and to keep them in good condition until they reach the market.

In many areas the demand is exceeding the productive capacity of reef ecosystems, particularly where those ecosystems are stressed by other human impacts. In some cases the removal of the most attractive food fish, the top predators, has led to an unbalanced system and major ecological changes in reef ecology.

As fish become hard to catch, fishers in many areas have turned increasingly to destructive techniques such as poisons or explosives, which further damage reef ecosystems.

Experience suggests that most reefs can sustain some level of non-destructive/invasive fishing over very long periods. Yet recent expansion in the amount, type and purpose of fishing, driven by new technologies and new demands, better transport and aquarium technology for the home or restaurant, has built large markets for live fish and invertebrates at prices far beyond those paid in conventional fisheries.

The combination of new and old fisheries has resulted in overwhelming the capacity of reefs in many areas.

There is an urgent need to learn how to manage reefs sustainably with adequate sanctuaries, reference sites and breeding areas free from fishing, and to maintain the species diversity and ecosystem processes of the fished areas.

We have to develop means to manage the demand and trade in reef species. In areas that are not sanctuaries, we must consider increasing the sustainable productivity through aquaculture or sea farming to meet the needs of people in many parts of the tropics.

There are already examples of successful farming of reef products such as seaweeds and shellfish. Other species are likely to be farmed for food, pharmaceuticals or as aquarium specimens.

The challenge is to develop sustainable techniques that do not themselves cause further pollution or introduce disease.