Earth & Sky

The following individual was interviewed for today’s show. Our thanks to:

Dr Callum M. Roberts
Environment Department
University of York
York, United Kingdom

Interview with Callum R. Roberts:

ES:

CR: My name’s Callum Roberts, and I’m senior lecturer in Marine Conservation Biology in the Environment Department in the University of York in England.

ES: Fully protected marine reserves are places which are closed to all forms of fishing. There are very few places in the sea like that at the moment, something like 1/10,000th of the surface of the oceans is currently encompassed in fully protected marine reseves, although we have more of the oceans that’s classed as marine protected areas, they are places that are generally protected against only one or a few different threats from human activities like oil-drilling, for example. The difference here is that in fully-protected marine reserves, what we’re trying to do is to address one of the major impacts to the marine environment, which is fishing. Most people when they think about impacts in the sea they think of pollution first. But one of the most profound influences that humanity has had on the oceans is fishing. And we have literally caused the rapid decline of many of the fish stocks that fomerly were abundant and highly productive and supported thriving coastal communities of fisherman and their families. What we’re finding in recent years is that fishery management techniques that we’re currently applying were just simply not working. One of the reasons is that fisheries management is trying to treat the marine environment in a piecemeal fashion. So we’re trying to manage each of the different fish species that we target seperately from each other and seperatly from the habitats that they live within. And this is proving to be a flawed approach. It’s not preventing the decline of fish stocks. It’s in fact been largely ineffective in controlling fisheries and promoting their sustainability. What we’re finding with marine reserves is that they are very effective tools for rebuilding fish stocks. When you establish an area that’s off limits to fishing, then the fish live longer, they grow larger, and large fish produce many, many times more eggs than small fish do. And those eggs get transferred out of the reserve and into the surrounding fishing grounds when they drift away on ocean currents. And as fish stocks build up inside reserves, there also tends to be the beginning of export of fish into the surrounding fishing grounds, there’s a net movement of fish from the reserves to the fishing ground. And there’s evidence for both of these processes going on from existing marine reserves. And it’s proving to be a very promising approach to supporting fisheries. Because reserves are essentially acting as nurseries or productive areas for the surrounding fisheries. What’s exciting about marine reserves is that they are able to perform a dual role. They can protect coral or other kinds of marine life inside the reserve. They can protect the fish inside the reserve. They offer a refuge from fishing for things that are very vulnerable to being impacted by the fishing process, such as some of the sensitive marine life that lives on the sea bed and can be damages by trolling, just as an example. And at the same time though, they can support an extractive industry, the fishing industry. And they can do this because the fishing industry benefits in surrounding areas. This is a major difference between marine reserves and protected areas on land. Because when you set up a protected area on land, then in general that means keeping out the loggers, for example. You can’t protect the trees and harvest them at the same time. Wheras in the sea, it’s possible to protect the productive stock of fish inside reserves and expect it to supply surrounding fisheries.

ES:

CR: After a marine reserve has been in place for a number of years, and the fish stocks inside it build up to quite high levels, in the Carribean we’ve been studying a marine reserve in St. Lucia, and we’ve seen in just 6 years of protection, stocks of exploited fish species like groupers and snappers have rebounded to four times the abundance that there was when the reserves were established. And as these stocks build up inside the reserve, so the conditions tend to become more crowded, and the reserves begin to export fish across their boundaries. The fish leave the reserves in search of less crowded conditions. And in doing so, they become available to the fishery and they’re able to be caught. We’ve seen in the < a href=“http://merrittisland.fws.gov//index.html>Meritt Islands National Wildlife Refuge, which is a wildlife refuge which is the security zone around the Kennedy Space Center at Cape Canaveral, that an area that’s been protected from recreational fishing for the last fourty years has started to export world record sized fish to the surrounding fisheries. There are now very large black drum, red drum and spotted sea trout being caught in the waters nearby the reserve. And these are fish that are being exported by a reserve into the surrounding fishery. It’s a spillover that’s one of the benefits reserves can provide to fisheries.

ES: Is it fair to judge the increased fish populations in marine reserves over the short time they’ve been established? It seems like if there’s been a lot of damage done long ago to fish stocks, you might not see that huge an improvement over the limited time that marine reserves have been around.

CR: There are two strands to that. Most marine reserves that exist at the moment are relatively small. And they are only going to have a very limited impact upon surrounding fishing grounds. It’s not really sensible to expect a reserve that covers just 1% of the fishing grounds to supply very many fish at all to those fisheries. But what you have to do if you expect to derive a benefit to the fishery is to scale up those reserves. And in places that reserves have been established to a suffient size, we’ve seen spectacular effect on the fishery. For example, in St. Lucia, 35% of the coral reef habitat was protected from fishing in 1995. And in just five years we’ve seen a doubling in the fish catches in the adjacent areas. And so here’s an area where the local people decided to give reserves a try and they were bold and ambitious with that objective of trying to rehabilitate a struggling fishery. They gave up a third of their fishing grounds, and it’s really paid off. Another example that you can see a payoff to a fishery is beginning to occur is in the areas of the Georges Bank in New England, where as a result of decades of fish stock decline, managers moved in in 1994 and protected 17,000 square kilometers of the fishing grounds for ground fish species from all kinds of fishing that could threaten those species. And what we’ve seen is that in just five years, again, the fish stocks are beginning to recover more rapidly, the scallop populations really rebounded in these closed areas and began to supply scallops to the surrounding fisheries. And single-handedly these protected areas in New England have rehabilitated what was a languishing fishery for scallops and I believe that the fishers in New England have recently enjoined the best scalloping season they’ve had in many years.

The second strand I think to your question is: how quickly can you expect to see marine reserves benefitting fisheries. The case in New England indicates one of the factors that is involved, and that is how fast the species your interested in turns over.