Dr Helen Scales, science writer and conservationist based in Cambridge
Part of the show Invasive Species, Conservation and the Last Giant Tortoise
Chris - Now Helen, you're a marine biologist. What are the key problems if we look at the sea at the moment?
Helen - I guess the most obvious and pervasive problem in the ocean is that we're taking too much out of them. We're catching far too many fish and too broad a range of species and it's becoming more and more of a problem.
Chris - Why should that be such an issue? Why don't we just, say, catch a certain species and let the others recover? Or is that impossible to police?
Helen - Well I think the problem is that there are so many fisherman out there. Henry's already been talking about one island in the middle of the Pacific and one species that the fisherman were after. I'm sure that now the sea cucumbers in the Galapagos are declining, they are finding something else to catch. They might be trying to catch sharks and take their fins off, which also supplies a high value trade. That's one issue with the sea that the things we can catch are worth a lot of money. Fishermen can make a lot of money from shark fins for shark fin soup. Sea horse are also fished a lot for Chinese Traditional Medicines. The oceans for some people are just a very large source of money, a treasure trove if you like, and something to be exploited. The other problem with the oceans is that we feed ourselves from them. The statistics are something like half the world's population lives within 60 kilometres of the coastline and essentially rely on fish for their main protein source.
Chris - What could we do at the moment to rescue cod because that's pretty much facing instant jeopardy.
Helen - Cod are in a terrible state depending on exactly where you look and which populations. A cod fishery collapsed off of Canada in the 1980s and hasn't reopened simply because there aren't enough fish left. So yes, cod is in trouble and lots of other species are too. But we do have one thing that might be able to help us, and that's marine protected areas, marine parks, marine reserves or whatever you like to call them. We do know now that it's fairly obviously that if we leave a bit of the ocean and don't fish it, that lets the fish recover. It gives them the chance to reproduce. Not only can we find that marine parks help in terms of biodiversity and preserving species, but they can also feed the fisheries that we're relying on for luxury species and to just feed ourselves. So it's a kind of win - win situation really.
Chris - And very briefly Helen, there's an example of how NASA are helping to save fish because of the no - go zone that's been created around the Kennedy Space Centre.
Helen - That's right. The way we know it's working is that Americans are quite into their sport fishing, especially around Florida. What they've found is that the record breaking enormous fish have gone up and up since they stopped fishing around the Kennedy Space Centre, so it works.
Chris - So that's why we should be establishing more marine reserves to preserve fish stocks and big fish which are more fertile, have more babies and healthier babies.