Marine reserves, areas of the sea that are off-limits to all fishing, show great promise as a means of rebuilding fish stocks and restoring fishery productivity. They also represent a way of better matching management to local needs, helping to restore the connection between fishers and their local resources. Roberts spoke about these issues with BusinessWeek London Correspondent Kerry Capell recently. Edited excerpts of their conversation follow:
Q: What's behind the decline in the fishing industry globally?
A: The reason the fishing industry has been in decline is because we have provided no refuges for animals from exploitation. We have reached the point that for many of the most commercially valuable species there are no fish surviving to reproductive maturity.
In the past, fisheries management has taken no account of the habitat in which fish live. It has always been assumed that the means to support fish production will be there. Now, we are beginning to realize that this assumption is deeply flawed.
The problem is many of techniques we use to harvest fish destroy the habitat those fish need to survive. By taking a dragger or trawler into the North Sea or Georges Bank [off Cape Cod] what we're doing is mowing down the fish habitat while catching fish. We are catching fish in a way that damages their habitat and compromises our ability to achieve sustainable fisheries.
Q: Why would that be the case?
A: One of the problems is the way we fish: catching bigger animals and leaving little ones behind. The bigger fish are disproportionately more important to reproduction than smaller ones. A big cod produces many more times the number of offspring than a smaller-size cod. So that means it's better to have fewer big fish around than lots and lots of small ones. But the way we fish now means that there are virtually no big fish and lots of small ones. This greatly undermines reproduction and compromises the sustainability of fishing.
Q: What's the new thinking about how to save fisheries and protect marine reserves?
A: It sounds curious from the point of innovation, but the paradigm of fishery management is that all of the seas are open to fishing, and we can exploit everywhere all of the time. We need to turn that assumption on its head and say all of the sea is protected from fishing except for certain places where certain kinds of fishing are licensed.
The best way to improve fishery production is to allow the sea more space to produce. The idea is to set aside large areas of the sea as a refuge from fishing. By large, I mean 20% to 30% of the sea being fully protected.
Marine reserves have in the past been more closely associated with conservation, but evidence is building that they can help sustain fisheries. Marine reserves offer refuges from fishing mortality and the collateral damage done by fishing gears like trawls. Within them, animals live longer, grow larger, and produce more eggs. That production can be exported to fisheries as ocean currents carry eggs and larvae from reserves to fishing grounds.
Q: Why not rely on farming?
A: This just makes the problem in the ocean worse. We use industrial-scale fishing to catch lots of wild fish, then pulp them up, and feed them to fish in farms. This means we are using maybe 4 kilos of wild-caught fish to produce 1 kilo of farmed salmon. That is unproductive, and we are fishing down the food web in the wild.
If we want to improve aquaculture, we would need to farm fish lower in the food web. This would mean trying to grow grass carp or tilapia. These are generally herbivores, and we can farm them without using wild-caught fish to feed them.
Q: Wouldn't marine reserves prove challenging and costly to enforce?
A: No. In the case of large-scale industrial fisheries, we can turn to developing technology in the form of satellite transponders. Since 1994, 25% of Georges Bank is protected from trawling and scallop dredging. [This is done] by putting satellite monitors on the fishing vessels so they can plot exactly where the fishing is being done. Such instruments allowed the location of vessels in New England to be very accurately traced and showed a very high level of compliance with closures by the fleet.
Q: Where does this innovative approach emerge from?
A: The interesting twist is that the innovation and technology transfer in using marine-protected areas to sustain fisheries is coming from developing countries to developed countries. Protected areas were first used to support fisheries in developing countries such as the Philippines, Chile, and South Africa . In these countries, people established marine reserves because it was one of the only options available to them. That's because in many places there's very little control over fishing methods and how much fish they catch.
Q: Wouldn't marine reserves take away a very important source of income and food in developing countries?
A: It wouldn't restrict livelihoods if you did it in the right way. One of the main objections that fishers often have about marine reserves is they will lose a significant proportion of their fishing grounds and fear this will lead to a corresponding decrease in catch. But what we see in marine-protected areas around the world is there can be between two and three times the number of fish after protection than there was before.
In St. Lucia in the West Indies, for instance, they have implemented marine reserves that protect 35% of the coral reef from fishing. Within five years of implementing marine conservation areas, the catch rates of the surrounding trapped fishery increased by 46% to 90%. We monitored how many fish were there prior to establishing marine-protected areas and after protection.
Within the protected areas, fish stock built up to five times the level they were before protection within seven years. In fishing grounds, the number of fish increased by 2.5 times. So this a real success story. By creating areas off-limits to fishing, you're helping to rebuild a diverse and productive marine ecosystem. Moreover, outside those protected areas, you also have a thriving, economically valuable fishery.