Life in the Balance: Coral Reefs Are Declining

Government Report Says Pollution and Climate Changes Threaten Coral Reefs

As reported by ABC News
Clayton Sandell

Coral reefs — a key element in ocean ecosystems that provide not only coastline protection but billions of dollars in benefits from tourism, as well as ingredients used in cutting-edge medicines — are increasingly threatened from the effects of global warming and other hazards, according to a new U.S. government report.

Photo Credit (Getty Images)

The report estimates that nearly half of the coral reefs in areas from the Caribbean to the Pacific “are not in good condition and are continuing steadily on a long-term decline.”

“It’s a pretty alarming situation,” said Jeannette Waddell, the report’s co-editor and a marine biologist with the National Oceanic and Atmospheric Administration’s National Ocean Service. “Coral reefs around the world are confronted by the same types of threats. In some places it is worse. In some places, it’s slightly better. But we’re finding that even remote reefs are showing signs of decline,” she told ABC News. The NOAA report looked at the health of coral reefs in 15 areas under the jurisdiction of the United States and a group of countries called the Pacific Freely Associated States, which include Palau, the Marshall Islands and Micronesia.

A major threat facing corals is climate change, the report says, which affects coral reefs in multiple ways.

First, warmer ocean temperatures cause corals to expel the colorful living algae in their tissues, leaving them with a “bleached” white look.adsonar_placementId=1280605;adsonar_pid=42753;adsonar_ps=-1;adsonar_zw=165;adsonar_zh=220;adsonar_jv=’ads.adsonar.com’;

“It really stresses out the coral and makes them more susceptible to things like disease,” Waddell said.

A major bleaching and disease event in 2005 devastated coral reefs across the Caribbean. In the U.S. Virgin Islands and Puerto Rico, scientists say an average of 50 percent of the coral was lost. Some areas lost 90 percent of their coral.

Another problem for corals is that human-induced climate change is altering the chemistry of the oceans, making them more acidic. It happens as fossil fuels are burned, releasing carbon dioxide into the atmosphere. Much of that carbon dioxide is absorbed by the ocean, which becomes more corrosive.

“If the ocean continues to acidify, it’s possible that it would preclude corals from growing, because they won’t be able to draw the nutrients and elements out of the water that they need to create the structures that they produce as coral colonies,” Waddell said. “It’s also possible that ocean acidification may become so extreme that it may begin to dissolve the corals that already exist, which would spell disaster for coastal communities.”

A 1997 report in the science journal Nature estimated that the resources and economic benefits derived from coral reefs are worth $375 billion a year.

“Coral reefs only cover about one percent of the world’s surface, but they are a very diverse and important environment or ecosystem,” said Mark Monaco, a marine biologist with NOAA’s National Centers for Coastal Ocean Science.

“They provide us fisheries, they provide us culture from the cultural resources, they provide us pharmaceuticals, and they provide us protection from storm events,” he told ABC News.

In areas that have been hit by severe tsunamis, experts point out that damage is usually less severe in places with intact coral reefs just offshore.

Scientists who study the medical benefits of coral reefs say there are about 20 compounds in clinical trials derived from the corals themselves or the many organisms that depend on them.

“That biodiversity is holding the key to treatment of diseases current and future,” said William Gerwick, a professor of oceanography and pharmaceutical sciences who holds a dual appointment at the Scripps Institute of Oceanography and the University of California San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences.

“As we disturb that biodiversity, and reduce the species’ richness, we change that equation dramatically,” said Gerwick, who was not involved in the NOAA report.

Gerwick points to a drug compound derived from a species of sea squirt — small, colorful organisms that live on coral reefs — that has been approved by the European Union for treating soft tissue cancers. The drug, marketed under the name Yondelis in Europe, is in clinical trials in the United States.

Some corals have recently gotten better protections from the federal government. In 2006, two coral species were designated as “threatened” under the Endangered Species Act.

Climate change isn’t the only threat to coral reefs. Tropical storms, coastal pollution, even boats and their anchors are serious concerns.

“The declining conditions that we’re seeing is exacerbated by having a number of threats work together to cause the decline,” Waddell said.

The report — the work of 270 contributors — is being presented today at the International Coral Reef Symposium in Fort Lauderdale, Fla.

“I think if we don’t change the way we’re going with these reef ecosystems we can’t expect them to get better,” Monaco said. “So we’re going to have to make some hard choices — society-wise, political-wise, economic-wise — to protect these ecosystems.”

Oceans on the Precipice: Scientist Warns of Mass Extinctions

For Immediate Release

Oceans on the Precipice: Scripps Scientist Warns of Mass Extinctions and ‘Rise of Slime’

Threats to marine ecosystems from overfishing, pollution and climate change must be addressed to halt downward trends

Scripps Institution of Oceanography/UC San Diego

Human activities are cumulatively driving the health of the world’s oceans down a rapid spiral, and only prompt and wholesale changes will slow or perhaps ultimately reverse the catastrophic problems they are facing.

Such is the prognosis of Jeremy Jackson, a professor of oceanography at Scripps Institution of Oceanography at UC San Diego, in a bold new assessment of the oceans and their ecological health. Publishing his study in the online early edition of the Proceedings of the National Academy of Sciences (PNAS), Jackson believes that human impacts are laying the groundwork for mass extinctions in the oceans on par with vast ecological upheavals of the past.

Jeremy Jackson, Scripps Professor of Oceanography

He cites the synergistic effects of habitat destruction, overfishing, ocean warming, increased acidification and massive nutrient runoff as culprits in a grand transformation of once complex ocean ecosystems. Areas that had featured intricate marine food webs with large animals are being converted into simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.

Jackson, director of the Scripps Center for Marine Biodiversity and Conservation, has tagged the ongoing transformation as “the rise of slime.” The new paper, “Ecological extinction and evolution in the brave new ocean,” is a result of Jackson’s presentation last December at a biodiversity and extinction colloquium convened by the National Academy of Sciences.

“The purpose of the talk and the paper is to make clear just how dire the situation is and how rapidly things are getting worse,” said Jackson. “It’s a lot like the issue of climate change that we had ignored for so long. If anything, the situation in the oceans could be worse because we are so close to the precipice in many ways.”

In the assessment, Jackson reviews and synthesizes a range of research studies on marine ecosystem health, and in particular key studies conducted since a seminal 2001 study he led analyzing the impacts of historical overfishing. The new study includes overfishing, but expands to include threats from areas such as nutrient runoff that lead to so-called “dead zones” of low oxygen. He also incorporates increases in ocean warming and acidification resulting from greenhouse gas emissions.

Jackson describes the potently destructive effects when forces combine to degrade ocean health. For example, climate change can exacerbate stresses on the environment already brought by overfishing and pollution.

“All of the different kinds of data and methods of analysis point in the same direction of drastic and increasingly rapid degradation of marine ecosystems,” Jackson writes in the paper.

Jackson furthers his analysis by constructing a chart of marine ecosystems and their “endangered” status. Coral reefs, Jackson’s primary area of research, are “critically endangered” and among the most threatened ecosystems; also critically endangered are estuaries and coastal seas, threatened by overfishing and runoff; continental shelves are “endangered” due to, among other things, losses of fishes and sharks; and the open ocean ecosystem is listed as “threatened” mainly through losses at the hands of overfishing.

“Just as we say that leatherback turtles are critically endangered, I looked at entire ecosystems as if they were a species,” said Jackson. “The reality is that if we want to have coral reefs in the future, we’re going to have to behave that way and recognize the magnitude of the response that’s necessary to achieve it.”

To stop the degradation of the oceans, Jackson identifies overexploitation, pollution and climate change as the three main “drivers” that must be addressed.

“The challenges of bringing these threats under control are enormously complex and will require fundamental changes in fisheries, agricultural practices and the ways we obtain energy for everything we do,” he writes.

“So it’s not a happy picture and the only way to deal with it is in segments; the only way to keep one’s sanity and try to achieve real success is to carve out sectors of the problem that can be addressed in effective terms and get on it as quickly as possible.”

The research described in the paper was supported by the William E. and Mary B. Ritter Chair of Scripps Institution of Oceanography.

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