|
|
|
|
|
|
Testimonies
|
|
|
|
|
Pirate Fishing Impacts Pirate fishing by large international companies harms delicate ocean ecosystems with many sea creatures being caught as bycatch. Amongst these are the Green turtles which nest on Ascension Island
FIONA: OK, I'll tell you about the background of the project. The Darwin Initiative was set up at a Conference in Rio in the '90s and their main aim was to give money to countries that couldn't afford to have scientists to study their endangered species. So Ascension was targeted and the University of Swansea put in a grant proposal to get some money to study the turtles. The main idea was basically to study the population. Swansea got enough money for two years for a postdoctoral position. So my bosses, who run a turtle project in Cyprus, got the job. They did a job share because they're a couple. The girlfriend fell pregnant and was due to have a baby at the worst possible time, which was February and so they were looking for somebody that could work out in Ascension and I came out here last year in May for a couple of months to do a project on the hatchlings and I was just about to start a Ph.D. with them as my bosses. So I got the job, which was good, so that's how it all came about. G: So how long have you been here now? F: Four or five months, about that. G: What's the history of turtles on this island, what's the significance of turtles to Ascension island? F: Well, thanks for that question! It's a good job I went into the museum today for the first time, isn't it? I think the history is that there were ships arriving on Ascension and this was their main source of meat at the start and then of course they took turtles back to Britain. So, the turtle ponds, you probably walked past them on the way to the beach. They got the turtles off the beach, flipped them on their back, dragged them up and left them in the turtle ponds until the ship was ready to go and then put these turtles on the ship and left them alive and took them back to Britain or wherever they were going. G: What is the turtle breeding season here? F: December through to May is the nesting time, with peak nesting being in March. Hatching really lifts off in May, that's the peak then, with a 50-60 day incubation period for the nests on Ascension. So, very few nests in December, started to increase in January. The peak was about a month, a month and a half ago. G: Right, so those are the ones that are all hatching now. F: Pretty much, yes. G: So there's much more hatching going on now than nesting. F: Far more, I mean you're lucky. Twenty tracks last night is nothing to what we were used to. A hundred and twenty was the peak. And it's quite sad that they're all gone home, back to Brazil. Because at one point you could stand on the beach and you'd have ten, fifteen turtles all around you and you could just sit there and watch them all. It was great! Now you're tramping up and down looking for them, going oh, not good! G: So are there turtles here at all after May? Or are there no turtles here then at all? F: Yes, spits and spats. The ones and twos that will carry on to June and then that's it. G: There's no population here year round. F: No, there's
a juvenile hawksbill population. No one's ever done a count of it. Must
be quite low, but they don't nest. They seem to move around the Atlantic.
Most turtles as juveniles are thought to do that, feeding, getting bigger
until they reach maturity and then start to nest G: The Green Turtles here, they're resident in Brazil for the rest of the year? F: Yes, same for the males, the males come from Brazil as well. In fact, we managed to attach a transmitter to a male and we used a new type of transmitter. What we normally do is have ones with aerials. This was a new type with no aerial. So it should cause very little drag resistance. And it hasn't worked, well it's worked, but we haven't had many satellite uplinks from it because of no aerial. So unfortunately, the first two males that we've ever managed to get a transmitter on, it hasn't worked that well. So they're hoping to try it again. They're moving to Brazil to have a look at the turtles there. We're trying to do a study of the body condition of the female. A female would have to be extremely fit when she leaves Brazil, because they don't feed around here, there's no food for them. So, basically once they've left Brazil, that's the last food they'll eat before they get back which can be four to six months. What we've been looking at is size and weight of turtles and looking to see if we can estimate how much weight they would lose around Ascension and thus work it up and say well, a turtle in Brazil, if she's 250 kilos in weight in December she's more likely to migrate to Ascension, rather than a 150 kilo weight turtle. So that's one of our projects. We did weigh a few turtles, just to get an index, but that's quite hard going. G: What sort of size and weight of turtles do you get here? F: At the start of the season, we very rarely got a turtle under 170 kilos in weight. Most of the turtles are about a metre wide by a metre and a half long. Now if we were to do it, we would probably get very few turtles over 170 kilos. They lose, we've estimated about 200g a day whilst they're off Ascension. They can lay maybe four or five nests a season. Their inter-nesting interval is two weeks. G: What do they do in that two weeks? F: They dive for an hour and they come up and take two or three breaths and then go back down. They just rest. G: Wish I could do that! F: Whereas the males are far more active - they come up to breathe every 15 minutes and go back down. They don't rest - there's no point in them resting, they're here to mate. G: Do they stay here for the whole season? F: No one's
quite sure what they do. The advantage for a male would be to leave Brazil
as early as possible, to get the first females coming and work through
every female that arrives. I would have thought that maybe slow, poorer,
older males would get here later in the season and mate with the last
few females. Also, with the fact that nobody quite knows if there's sperm
competition within the females, if a female mates with more than one male,
if she uses the first male's sperm, if she uses a combination. So I selected
14 nests, I took a genetic sample from G: Have you done any work on how many of the turtles that leave Brazil actually make it here? That must be quite a high risk activity, to travel all the way across the Atlantic to breed and then back again each year. Do they do it each year? F: No, every 4 years. They follow a very similar route from the tracking work that we've done. G: Do you know how long it takes them? F: Not quite
sure. I think that our estimates from the transmitter work is that they
can manage to cover about 3 km an hour if they are moving fast away from
Ascension and then they slow down the nearer they get to Brazil, although
one of the turtles moved at 6km an hour, so G: What predates on the turtles here now? F: On land, the main problem is themselves. With so many nests laid, for example on Long Beach you can find 2000-3000 nests laid on that beach. Or if you go to English Bay or Comfortless, these beaches are 10, 20 metres long with maybe 100, 200, 300 nests laid on them. So a turtle comes up now and goes to dig a hole, not necessarily even to lay in that hole, andhe'll dig up another nest and ruin that. So the main mortality factor in turtles on the island is themselves, they dig up one another's nests. Secondary problems are frigate birds, once the hatchlings come out onto the beach, the frigates take them, in the daytime anyway. At night, the land crabs on NE Bay take these hatchlings on the way to the sea. Fish will be a huge problem. No one's ever done a study on how bad the predation is, but it must be huge with all the grouper and blackfish off Long Beach, just waiting there at night with their mouths open. So I think that the biggest predation problem is the fish. I think, 7 out of the 8 species of turtle are considered endangered. This is something I'm not 100% sure about. I think there has been a lot of debate about whether the Hawksbill's classed as endangered or not. But the green is. Ascension is the second largest nesting colony in the world, Costa Rica being the first. People that come to Ascension don't realise how few turtles there are in the world. If you go to the Med, then you can spend all night on the beach and you'll not see a turtle. In fact,
it's ridiculous, the incidental catch by fishermen isn't it, in the Mediterranean?
We get a few turtles every year washed up on Northern Cyprus, with their
heads caved in because they've been caught in a net. There's a paper that
is out from Turkey and Northern Cyprus, where people have gone along interviewing
fishermen about if they catch a turtle, what do they do with it. But of
course, people aren't going to own up about that sort of thing. Northern
Cyprus is getting better in the fact that if people find a turtle now,
or if they catch a turtle, they will release it. G: Are they protected in the Med? F: Heavily protected - the numbers are so low there - greens and loggerheads. You come here and you're spoilt. Got to the Mediterranean, go to Turkey and you probably won't even see a turtle on the beach even though it's the most important beach in that country. So it's quite shocking. In northern Cyprus last year, we had seven green nests on our most important beach. G: Yes, it's not good. We've done a lot of campaigns there on driftnets on the bycatch of dolphins and whales in driftnets and so on. That's how I originally got involved in Greenpeace. More on Turtles:
|
|
|
