Jump to content

Trying To Save The Coral Reefs


Recommended Posts

Trying to Save the Coral Reefs

Near the close of the 1960s, a squadron of young scuba divers headed out into the warm waters of the South Pacific, tanks of air strapped to their backs and syringes at the ready. Their mission, one lethal injection at a time, was to put a stop to an outbreak of crown-of-thorns starfish, a voracious predator of fragile tropical coral reefs. Those early efforts — along with a big printing of 'Save the Barrier Reef' bumper stickers — helped establish what has since been considered one of the world's best-protected coral reefs.

More than 30 years later, some of those dive bums have grown up to become full-fledged coral ecologists, and what they are seeing today is probably making them long for the halcyon days of the '60s. Rising ocean temperatures, compounded by other man-made factors, like pollution and overfishing, have been catastrophic for the earth's coral. "I grew up diving and snorkeling all over the world," says Gregor Hodgson, executive director of the coral monitoring organization Reef Check Foundation. "Those reefs are all gone."

On August 7, researchers at the University of North Carolina released the world's first comprehensive study on coral in the Indo-Pacific region, which stretches from Japan to Australia and east to Hawaii, and is home to 75% of the world's coral reefs. The outlook is grim. Between 1968 and 2003, more than 600 sq. mi. of reef disappeared in the region — that's 1% a year, twice the pace of rainforest decline — and the losses are hitting well-protected areas like the Great Barrier Reef just as hard as the stressed, overfished reefs that surround crowded countries like the Philippines. "People thought the Pacific was in much better shape," says John Bruno, lead author of the study, which was published online by the Public Library of Science. Scientists assumed that far-flung reefs in the vast waters of the Pacific would be safely isolated from negative human impact. They were wrong. "There is no such thing as an isolated reef from the perspective of climate change," says Bruno.

The UNC report coincides with separate accounts of another widespread scourge: in July, coral reefs in the South China Sea and around the Florida Keys and Caribbean started to bleach — a result of warming waters. Healthy reefs live symbiotically with algae, which takes shelter inside the coral and, in return, passes nutrients to its host. When waters reach an uncomfortably high temperature, coral gets stressed and kicks the algae out, which turns the coral white and essentially starves it to death. Local reef watchers have contacted the U.S. National Oceanic and Atmospheric Association (NOAA) from the northern Philippines to southern Japan, some warning that their coral is bleaching nearly as much as it did in 1998, when El Ni�o–heated waters killed 15% of the world's reefs.

Like the busily receding glaciers in the Arctic, coral reefs are a canary in the global warming coal mine. "They are a sensitive species that are affected first," says C. Mark Eakin, coordinator of NOAA's Coral Reef Watch program, which warns scientists when their part of the world is at risk for bleaching. And though climate change awareness is up, and embattled reefs do get moments of compassion, the public has a short attention span when it comes to ecosystems it can't see. So do policy makers. Bruno says more coral data is being gathered today by non-governmental organizations than universities or government programs, particularly in developing nations where the focus is more on building hospitals and roads than on marine science. But even in the U.S., NOAA's satellite data program, alert system and monitoring are second to the larger network of local groups and governments keeping watch over the U.S. reefs. "Nobody wants to pay for monitoring because it's boring," says Hodgson.

That's why he founded Reef Check. Realizing that one man's chore might be another's hobby, Hodgson decided to fill the information gap by enlisting people who were naturally interested: divers. In 1997 he created a global network of volunteer snorkelers and divers, specially trained by scientists to monitor reefs using a standardized checklist. Over the last 10 years, Reef Check's volunteers have amassed a bounty of data on the world's coral. "In the beginning, people were looking down on us, saying 'Oh, you guys are just volunteers,'" Hodgson recalls. Now, Reef Check has become one of the primary sources of scientific information about coral health.

Why the need to monitor coral so closely? Coral reefs comprise a complex and vast global ecosystem, home to millions of species of plants and fish that people depend on for food and tourist revenue; in some areas, healthy reefs help protect the shore from potentially destructive waves. But arguments about the preservation of biodiversity make eyes glaze over, so Hodgson, who's trying to get coral on the World Conservation Union's red and endangered species lists, likes to point out that several anticancer drugs are derived from reef species. "Maybe one day a coral will save your life," Hodgson tells skeptics. "That gets to people."

Perhaps the single best advocate for the preservation of coral reefs is the reefs themselves. In many parts of the world, conservationists are letting the natural beauty and allure of the reefs — which generate about $1.6 billion annually in tourist dollars — do the talking for them. In one area of the Philippines, for instance, local leaders asked fishermen who had been making a living by blast-fishing, which destroys reefs, to trade in their trawlers for dive boats. They did, the fish came back to the reefs, the local economy flourished and everybody — tourists, residents, and coral ecologists alike — was happy. In cases like these, one hand washes the other, says NOAA's Eakin. "If healthy coral reefs are your bread and butter, you're going to make sure they're in good shape."

It remains to be seen whether local solutions, like ecotourism or the establishment of marine parks, will create lasting changes. No one knows when the warm waters causing the current bleaching epidemic will recede, and once coral starts dying in warm currents, there isn't a lot that scientists can do but sit back and watch. Some reefs may recover, but others won't, and researchers are still trying to figure out why. "I don't think there's any way you can manage for a global effect locally," says Bruno, the author of the UNC report. He thinks the root cause of disappearing coral is, in the end, climate change, which can be addressed only by a worldwide effort to cap fossil-fuel use and pass stringent climate change legislation. "If we only manage locally, [we] will be totally overwhelmed over the next century."

Link to comment
Share on other sites

Here'e another view:

By Peter Ridd

Peter Ridd is a Reader in Physics at James Cook University specialising in Marine Physics. He is also a scientific adviser to the Australian Environment Foundation.

Closer to home, there is a swindle by scientists, politicians and most green organisations regarding the health of the Great Barrier Reef (GBR). We are told that the reef is a third of the way to ecological extinction, is being smothered by sediments, is polluted by nutrients and pesticides, and is being cooked by global warming. Some scientists and organisations give the reef only a couple of decades before it is finished.

In the light of all this dismal news comes a new study by Scientists from the Australian Institute of Marine Science (AIMS) which indicates that the corals are more tolerant to rising waters temperatures than first thought by most people.

Under conditions of extremely high water temperature, corals expel the symbiotic algae called zooxanthelae that reside within the polyp making them appear bleached white. Some coral die from this bleaching and there have recently been some major mass bleaching events in the Great Barrier Reef and around the world, particularly in 1998 and 2002. The AIMS work shows that the corals can adapt to rising water temperatures by using strains of zooxanthelae that make them tolerant to higher temperatures.

In biological circles, it is common to compare coral reefs to canaries, i.e. beautiful and delicate organisms that are easily killed. The analogy is pushed further by claiming that, just as canaries were used to detect gas in coal mines, coral reefs are the canaries of the world and their death is a first indication of our apocalyptic greenhouse future. The bleaching events of 1998 and 2002 were our warning. Heed them now or retribution will be visited upon us.

In fact a more appropriate creature with which to compare corals would be cockroaches - at least for their ability to survive. If our future brings us total self-annihilation by nuclear war, pollution or global warming, my bet is that both cockroaches and corals will survive.

Their track-record is impressive. Corals have survived 300 million years of massively varying climate both much warmer and much cooler than today, far higher CO2 levels than we see today, and enormous sea level changes. Corals saw the dinosaurs come and go, and cruised through mass extinction events that left so many other organisms as no more than a part of the fossil record.

Corals are particularly well adapted to temperature changes and in general, the warmer the better. It seems odd that coral scientists are worrying about global warming because this is one group of organisms that like it hot. Corals are most abundant in the tropics and you certainly do not find fewer corals closer to the equator. Quite the opposite, the further you get away from the heat, the worse the corals. A cooling climate is a far greater threat.

The scientific evidence about the effect of rising water temperatures on corals is very encouraging. In the GBR, growth rates of corals have been shown to be increasing over the last 100 years, at a time when water temperatures have risen. This is not surprising as the highest growth rates for corals are found in warmer waters. Further, all the species of corals we have in the GBR are also found in the islands, such as PNG, to our north where the water temperatures are considerably hotter than in the GBR. Despite the bleaching events of 1998 and 2002, most of the corals of the GBR did not bleach and of those that did, most have fully recovered.

Of course, some corals on the Queensland coast are regularly stressed from heat, viz. the remarkable corals of Moreton Bay near Brisbane which are stressed by lack of heat in winter. A couple of degrees of global warming would make them grow much better.

Even the GBR has seen massive changes in its comparatively short life. Eighteen thousand years ago, the GBR did not exist as water levels were about 100m lower than today. At that time, the Australian coast was about 100km from its present position, and the small hills upon which the reefs were to form dotted a broad and flat coastal plain that would become the GBR lagoon. When the sea level started to rise at the end of the ice age, the coast eroded at a phenomenal rate. The Aboriginal people living on these coastal plains lost land at a rate of about 50m each year as they witnessed the birth of one of the natural wonders of the world.

The reef was born in conditions that most biologists would regard as horrific for corals and far worse than what most of the present GBR would see: rising temperatures, high water turbidity due to the erosion, high nutrient concentrations due to erosion and the closer proximity of river mouths, rising CO2 concentrations, and rapidly rising sea levels (10mm per year). These are all factors presently regarded as threats to the GBR.

A few millennia later, Aboriginal people were to witness the greatest loss of coral ever seen by humans in Australia, for about 5,000 years ago, whilet civilisations were being born around the world, the sea level of eastern Australia started to fall. The coral reefs that had grown rapidly upwards to the low tide level were now exposed to the air and sun during spring tides. They died and formed the extensive dead areas called reef flat that make up a large proportion of many reefs in the GBR. It is ironic that if we see a modest sea level rise of one metre due to global warming, these dead areas of reef will explode into life, potentially doubling the coral cover. Sea level rise will be bad for Bangladesh and Venice but it will be good for the GBR.

Other threats are also overstated. Studies have shown that the quantity of sediment in rivers’ plumes that wash out into the lagoons is much less than sediment that is resuspended from the seabed every time the south-easterly trade winds blow. Pollution due to nutrients is also probably restricted to a few reefs close to a couple of river mouths as the rest of the lagoon receives relatively small nutrient loads from rivers compared to other sources, and the water is rapidly flushed to the Coral Sea.

Fishing pressure is very limited. The coast adjacent to the GBR contains about half a million people compared with 50 million for the similarly sized Caribbean reefs. Most Queenslanders never visit the reef and do not use it as a significant food source unlike most other reefs around the world. The northern 1,000 kilometres of the reef has a population that can be counted in 100’s. It has been barely touched by mankind.

With the exception of Antarctica, I challenge anyone to name an ecosystem better preserved than the GBR. The sheer lack of people pressure on this huge system, and its distance from the coast has saved the GBR from the fate that has befallen the Caribbean and other areas. It did not suffer the equivalent of land clearing for agriculture, cities, dams and roads. It does not have problems with infestations of noxious weeds and feral animals such as cats and cane toads, or the mass species extinctions of the Australian land.

Apart from a reduction in turtles and dugongs, it is doubtful that Captain Cook would notice any difference to the GBR if he sailed up this coast again. Pity we cannot say the same about the land that he visited. Whereas the coral reef that he struck near Cooktown is alive and healthy, the land around Botany Bay would be unrecognisable.

So why have we been swindled into believing this almost pristine system is just about to roll over and die when it shows so few signs of stress. There are many reasons and processes that have caused this and some of them are the same as why we should all be more than a little sceptical about the hypothesis that CO2 is causing global warming.

The first reason is that there is some very bad science around. Second, a mainly biological oriented scientific community seems to take little heed of the geological history of corals. Third, we have many organisations and scientists that rely for funding on there being a problem with the GBR.

Most grant applications on the GBR will mention at some stage that a motivation for the work is the threat to which it is exposed. I confess that I do this in all my applications - it’s the way the game works.

Why does a scientist and environmentalist such as myself worry about a little exaggeration about the reef. Surely it’s better to be safe than sorry. To a certain extent it is, however, the scientist in me worries about the credibility of science and scientists. We cannot afford to cry wolf too often or our credibility will fall to that of used car salesmen and estate agents - if it is not there already.

The environmentalist in me worries about the misdirection of scarce resources if we concentrate on “saving” a system such as the GBR. Better we concentrate on weeds and overpopulation and other genuine problems.

So I’m thinking of asking Martin Durkin to come over to Australia and do another show called The Great Great Barrier Reef Swindle. I’d have to make sure he got all his graphs right and did not talk to anybody who thought smoking didn’t cause cancer, but I reckon he could put a very compelling case that the GBR is in great shape and that there is little to fear, especially relative to other environmental issues, such as overpopulation and invasive species.


Link to comment
Share on other sites

Very interesting article Billfisher.

Two schools of thought....I'd like to think yours is correct and that the GBR flourishes

in a changing climate.

There's certainly a lot we haven't been told about climate change or they just haven't figured it out yet.

It certainly is a remarkable place though.

By the way...THIS IS MY 2000TH POST!!! :yahoo:



Link to comment
Share on other sites

Geologists are certainly more relaxed about climate change Pete, they know that the Earth's climate has always been changing. I'll be seeing the GBR myself next month as I am heading to Cairns for a fishing holiday.

Edited by billfisher
Link to comment
Share on other sites

Geologists are certainly more relaxed about climate change Pete, they know that the Earth's climate has always been changing. I'll be seeing the GBR myself next month as I am heading to Cairns for a fishing holiday.

Enjoy the time up there....Wish it was me.

Be careful not to step on any scientists poking around in the coral spending their grants monies

looking at ways to increase their funding next year. :1prop:

Hope you get amongst some nice fish up there too.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...