Terry Done, an Australian Institute
of Marine Science biologist, describes the impacts rising ocean temperatures
can have on coral reefs.
BETTY ANN BOWSER: Talk to me about what you did yesterday on mid-reef (in Pandora Reef) and what kind of shape is that one in?
TERRY DONE: ... It's five years away from being beautiful because it had a lot of damage done, but it's also five years into the future. I expect them to look beautiful again. And the reason I say that is in the last few years, since the crown of thorns started, which is a great big spiky starfish which consumes the coral in very large areas, did just that on mid-reef and now after five years, we're seeing corals from this size up to this size.
So I've seen this in the past on that size reef in the early '90s. It was damaged in the mid-90s, while in the mid-90s it was looking beautiful again. It was damaged at the end of the '90s and I expect by 2010, it'll look pretty good.
BETTY ANN BOWSER: Do you think it'll come back?
TERRY DONE: I think it will, yeah.
BETTY ANN BOWSER: Given all the pressures that coral reefs are under today, which of all of them do you think is the most dangerous, the most potentially devastating say 20, 30 years down the road?
TERRY DONE: Twenty to 30 years down the road it's hard to look past global warming, I'm afraid to say it because it's the hardest to do anything about. And it seems pretty likely that we'll see an increasing frequency and severity of the summer heat waves which in '98 and in 2000, or in '98 and 2002 did quite a bit of damage to coral reefs in this area.
|Global warming's impacts on reefs|
BETTY ANN BOWSER: So, that one thing alone, global warming, is enough to make a mess of things?
TERRY DONE: Well, it's going to change things and I think we saw and kindly surmised about how those changes will pan out over that time frame. For example, we know at the moment that the most vulnerable of corals are also the most abundant corals, so when you have a massive wasting event on a particular reef, it takes out the things which occupies most of the space now.
On mid-reef yesterday we went to a place where we saw a lot of the tapa corals and their genus varieties and they're bighead corals like I showed you this morning, also some encrusting ones and some finger ones that seem to be very strong and very resilient to things like global warming or locally, hot water, and also crown of thorn starfish.
BETTY ANN BOWSER: Given the fact that these things have been around forever, coral reefs, how can they have gone down so fast in such a short period of time?
TERRY DONE: Well, it's a good point. Being around forever means that they've been in periods of very hot water in the past. They've been in periods of low sea level during the Ice Ages, that we seem to be seeing now is the fastest rate of increase that's ever occurred in the history of coral reefs that we know of.
Nonetheless, you could say I've been there in terms of sea temperatures before. They'll be OK. I think the important thing is that humans are part of the equation, and in geological time, when geologists say, it's OK because I've been through this and they bounce back, they're talking about being thrown and bounced back over periods of hundreds to thousands of years.
And in terms of our human experience, without global climate change, it would be a reasonable expectation for us to think that reefs would be continuing to (inaudible) with the natural disturbances and bounce back to something like we've expect to see in our lifetimes. And what scientists are concerned about with global warming is that that ability to bounce back will be taken away, simply because the insult will become too frequent and too severe.
BETTY ANN BOWSER: Why can something as small, or what seems small to a layperson like myself, one degree or a half a degree temperature in the ocean, how can something as small as that be so damaging. What happens?
TERRY DONE: Yeah, if it was half of one degree, I don't think it would be quite as rife. And I may seem to be drawing fine distinctions here. But two degrees, which is on the cards for the end of this century, most likely by the end of this century, very possible by the middle of this century, that refers to the average summertime temperatures, and around this average, you have this variability.
So you know there will always be times where we can say, oh, we had a cool summer. These guys on their climate change are obviously crazy, but if you look over 10, 20-year periods, these peaks are going to be getting dismarginally hotter and hotter and their concern is that the corals and other places of the reef are not adapted in the new territory that these temperatures are going into.
BETTY ANN BOWSER: What actually takes place down on the reef when the water temperature increases?
TERRY DONE: Well the hot water is a stress for the symbiosis between the coral animal and the microscopic plants, single cell plants which live by the millions per square centimeter -- in every square centimeter of coral tissue. And these tiny, single-cell plants rely on the sunlight, the photosynthesis and they translate a lot of their products to the coral animal, but if the temperature gets too hot, they spin a bit too fast, and also some of the biochemistry is damaged.
And if you think of photosynthesis, it has two combs, hooked in with one another -- this one continues to rope, but this one is broken and can't pick up the products of the first one, and one of those products is trioxygen radicals, which cause damage to all animal tissue, including our own.
So this is why we're encouraged to take antioxidants to deal with those. The antioxidants in corals are produced over here, and that's damaged. And so there's chemical damage to the animal tissue, there's also a loss of the energy powerhouse, which is tied up in these plant cells. So there's two problems to the coral.
They're having all these toxic oxygen molecules flying around and doing physical damage and they no longer have their primary food source. They can deal with that for periods of days to maybe even a couple of weeks, but they can't deal with it for many weeks at a time, and the projects about the future, they are going to have to deal with it. And we're not at all sure that at least many coral species are able to.
|Loss of coral reefs|
BETTY ANN BOWSER: What is mankind potentially to lose here?
TERRY DONE: Well, mankind stands to lose simply one of the wonders of nature, which is very, very important. We stand to lose opportunities to benefit in more mercenary ways, from this fantastic biodiversity.
The biodiversity, when you think about it, in a given acre of coral reef, you've got thousands of things trying to occupy this given acre. And the way they do that is through some very noble chemical defenses, and these are, you can see, very poorly understood by science.
And if you think of the chemistry which goes on it, could be the same source of chemistry and the same sort of compounds which may be helpful again in medicine. A cure for cancer, the cure for AIDS, not to mention other products, they're useful in industry and agriculture.
In this vast competition for space, it's plant against plant or it's plant against animal. We're dealing with those things on the land and in our agriculture all the time. So if there's some novel compounds to manage, the proliferation of weeds, for example, which have evolved in the sea, that can be made to work on the land, this is a potentially huge benefit to us in their agriculture. So from that point alone, there's a great deal to lose.
BETTY ANN BOWSER: We talked a little bit about global warming, but what is man doing to the reefs that sort of adds insult to injury?
TERRY DONE: Well, that's a good question. Man's been on the same for a long time and you know in fact, you can say man has been part of the coral reef ecosystem for a long time, but man is now here in much greater numbers than ever before.
We occupy the coast next to where the coral reefs occur and we've been treating them as our food powers for centuries. In the olden days, when population numbers were low, these pressures were relatively small in extracting the fish.
But these days, fast access and good gear, fishing gear, (inaudible) technology, geographic positioning systems, the fish have gotten nothing on their side. So it is quite easy to know the fish of coral reef. The fish which live on coral reefs are abundant, but once you take them out, they tend to be slow to replace themselves. They also have roles on the reef, ecological roles which we fully understand but it's certainly important in maintaining the resilience of this system at large.
Now, that's fishing. The other one I mentioned before is runoff from the land. We've had agriculture going on in the coastal lands. We have grazing going on up in the mountains that (inaudible) Great Barrier Reef.
Both of those contribute sediment and silts and fertilizers to the reef system, and while their effects would be minimal or invisible right here, where we're 80 miles off the coast, they certainly affect the qualities of the water close to the coast. And, you know, we need to make sure that the soils and the fertilizers are kept on the land as much as possible.
BETTY ANN BOWSER: How much do you think this new conservation program here in Australia, where you're setting aside 33 percent, is that potentially going to save the Great Barrier Reef?
TERRY DONE: I'm hopeful that it will. Clearly it can't save it from global climate change. But in terms of the way it works, the closing of 22 percent of the coral reefs and all of the other habitats on the Great Barrier Reef area, I think gives us the best chance of anyone has ever had.
BETTY ANN BOWSER: So this new conservation program that's been adapted, what are your thoughts about how it's going to save the Great Barrier Reef?
TERRY DONE: Well, I think it can give us a bit of breathing space, because there's a lot we don't understand, but there are three main components as I see it to the conservation program here, is the creation of no take zones, where no fishing, no harvesting of anything happens. There's a water quality protection plan which mainly focuses on the land and good land where the farmers and the grazers don't lose all their precious soils and fertilizers into the coastal seas. And there's a bucket of (inaudible) coral, ecosystem by fishing management. And they all interact with one another. ...
Now, I think the magnitude of the effort in Australia is not the token. It is a very serious, 33 percent of an area about half the size of Texas, is closed to fishing. And I firmly believe that is a very important thing, and I think it's only over a ton of years that we scientists will be able to convince some of the skeptics that that is the case.
Fish have critical roles on reefs which we are aware of that we have finally been able to prove that the role is to condition and interact with one another to sort of maintain the conditions for all of the reef life. It's sort of a feedback system. And so when we talk about sustainable fishing on coral reefs, we talk of it as if the issue is if I take one out, well, they ought to come back next year and then in 10 years' time and take out the same number. I don't think that's the issue at all. The issue is, if I take some out, is there some lost in function of the reef system which will prevent that system as a whole bouncing back.
So, it's interesting that the no take zones in the Great Barrier Reef are set up, not as a fisheries management issue, but as a biodiversity conservation tool. It's a recognition that the Australian public recognize that all the biodiversity's important, it's not just test fish. ... And we also believe that that provides the best basis for sustainable fisheries in those adjacent areas where fishing can take place.
BETTY ANN BOWSER: Global warming is something you really can't do much about. But there are a lot of other things that people can do, and would you talk a little bit about what some of those things are and where in the world people should be exploring these possibilities?
TERRY DONE: The three basic elements that Australia has adopted I think apply to coral reefs anywhere in the world. Don't overfish them. Don't allow bad stuff to run off on the land into them. This could be pollution from cities or industry as well as agriculture. Control, don't overheat them. And obviously the answer to that is to impress global warming at the highest political levels around the lands and around the world. ... Set some aside so that we have as a human race, the opportunity to just learn how these things work.
We tend to treat them in life as just another production system like agriculture and as you saw this morning, they're a little bit more special than just another system to produce food. Because they're fantastic resorts for tourism. We're out here on a cruising vessel with three other vessels who are just marveling at this wonderful place. ... The beauty itself is worth big bucks.
BETTY ANN BOWSER: What is the lesson to be learned about this particular reef (Willow Reef)?
TERRY DONE: Well I think the lesson is green zones can work. And I'd be foolish to say they will always work. The green zone is Australian lingo for no take. This has been no take for 15 years and you saw how tame these big fish were and you saw how full the sea was of fish.
There's so many places where I go which have been open to fishing forever, since through the period where the Queensland population has increased from a million to several million. You just don't see the fish and we all know intuitively, even if not scientists, that these things do have roles. They're not just on reefs to fill out planters.
And so what I'm seeing here is a reef which is in my way of looking, it's intact as well as being stunningly beautiful. It's somehow ecologically intact. It's got all the options open to it for feedback, symbiosis, redundancies. If one species goes down there's very likely something with a similar function that you'll be able to climb up.
We need to give a lot more reefs the opportunity for those sorts of holds, original balances to be reestablished. And I think the package of conservation measures on the Great Barrier Reef, give it a great chance.
BETTY ANN BOWSER: Do you think people are waking up to this? I mean if this is this great treasure we have around the world and it's something that needs to be saved, or do you think people are feeling complacent about it?
TERRY DONE: I think, you know in the Western World, people are definitely working up to it. Like remember we met some fishermen last night. We asked them, what do they think of the no-take? Oh, no, fishermen who were out there to take fish, feed their family. Their attitude was no, we like the idea. We think it's a good thing. We love our fishing, we love the day on the reef, we love being out in nature, but we appreciate that the regulations which are put in front of us are to the benefit of our kids and their kids.
And that attitude is very widespread ... and it's fairly widespread even amongst the group of society of fishers who are being asked to bear the most direct burden of it. If you put yourself in the context of Southeast Asia, Indonesia, the Philippines, I'd look at you and say, what are you talking about? I mean I feed my family off this fish. I have to go out. I have to take stuff of this reef, you know. So there's two worlds there. And I've been talking about the Western World, and I think countries like the U.S. and Australia have the opportunity and we're duty bound to go down this path.
BETTY ANN BOWSER: ... Are you optimistic?
TERRY DONE: I'm hopeful. The difference is my optimism requires a belief that this treatment space is going to be civilized enough and it's not enough to do all the things we know need to be done, including the big one of slowing down the rate of global warming.
All the other things are laced insatiably doable. The controlling run-off, the controlling fishing and the creation of more no-take marine parts. The big one is do we have the will globally to slow down the rate of global warming. It's considerable, yes, certain amounts of warming are locked in there. We have to live with them and hope that we end up towards the low envelope of the projections which people are making.
And some of my own work suggests that that lower end may not be too bad in terms of us being able to come back out here, I don't expect it to come back in 3050, but perhaps some of my descendants will and have a similar experience to what we did today, at the lower end. But at the upper end of the projections, it's very hard to imagine we're going to have anything quite as beautiful as we saw today.
BETTY ANN BOWSER: Describe what we saw today.
TERRY DONE: We saw one of the nicest spots on the planet in my humble opinion and it's a classic coral reef of a picture postcard with very large and almost entirely living corals of every shape and size if you can imagine. Big, big head corals you know which I showed you one which is 500 years old, at least, 12 foot high and 20 foot across.
And then plates, cups, saucers, all these corals, and then swimming amongst those corals go what we call walls of nubs. These walls of fishes just filling the sea and we had an exciting experience of the local dive master calling in over sharks. Twenty-two sharks in one field of view at one time. This doesn't happen (in) too many places around the place.
It's interesting that this happened in the green no-take zone on the Great Barrier Reef. We've chartered that yesterday, nothing. Not a single shark. And unfortunately the loss of sharks is symptomatic of the deterioration of coral reef ecosystems and marine ecosystems around the world.
BETTY ANN BOWSER: Why is that? When you see sharks, you know what?
TERRY DONE: Well I guess sharks, in, in the simplest of terms, sit at the top of the tropic pyramid. So in a sense if sharks actually live around here permanently, if they were there, made everything below you see is in order, in a simple sense, you know.
And of course there are many places around the world where sharks are killed just for their fins. Harvest the fins and let the rest of the animal sink below because they have a rather small boat, they've been out for a long time and that's all they can deal with. The whole ecological function of that function is now gone, and not to be replaced for some years. And so, you know they're important parts of this system, not just exciting to look at.
BETTY ANN BOWSER: Why is this issue, coral reefs, more important than say someone who wants to try and save the redwoods in California and climbs up and sits in a tree, they call them tree huggers, you know, or people that would march around saying that you shouldn't make fur coats out of pets, and all those other kinds of issues about the environment and animals and so forth. How is this one different?
TERRY DONE: Yeah, it's different. But I don't know if it's necessarily more important, but it's as important now on many levels. ... We're seeing symptoms out here which we're quite certain are symptomatic of hot water. And since people have stopped arguing that the hot water is to anything but an indication of the warming climate. This is a symptom of climate change. We're seeing it, and we're seeing it in areas like we saw today. ... After all those corals have died and you're reaction would be quite different. You still have the shapes, but you don't have the profusion of life.
So there's many of the aesthetic arguments are the same as for the redwood forests or the Grand Canyon. They're just awe-inspiring places. There's the monetary side. They are worth a lot. ... People come from around the world to just simply see them, and that brings money to tourism, etc.
They are potentially and currently many for sustainable fishing of various types that can go on, but of course, it's going to be a balancing act.