Mass Extinctions And 'Rise Of Slime' Predicted For Oceans

ScienceDaily 13 Aug 08;

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. Jackson believes that human impacts are laying the groundwork for mass extinctions in the oceans on par with vast ecological upheavals of the past.

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 marine 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.

A recipe for saving the world's oceans from an extinction crisis
EurekAlert 13 Aug 08;

Simply enforcing fisheries regulations would go a long way to preventing species extinctions.

Jeremy Jackson, senior scientist emeritus of the Smithsonian Tropical Research Institute and the Scripps Institution of Oceanography, asserts in the Aug. 12 issue of the journal Proceedings of the National Academy of Sciences, that the following steps, if taken immediately, could reverse the demise of the oceans: Establish marine reserves, enforce fishing regulations, implement aquaculture, remove subsidies on fertilizer use, muster human ingenuity to limit fossil fuel consumption, buy time by establishing local conservation measures.

In 2001, Jackson and 18 co-authors published a landmark paper in the journal Science, "Historical Overfishing and the Recent Collapse of Coastal Ecosystems," in which they made the case that environments that we perceive as relatively pristine have, in fact, been radically altered by centuries of human exploitation.

Jackson has been on the lecture circuit since then. "Our amnesia about what is natural is the greatest threat to the environment," said Jackson, in the youTube version of his talk "The State of the Ocean," delivered at Middlebury College, in Vermont, in 2007.

Developing a media-savvy approach, Jackson worked closely with Nancy Baron, Ocean Science Outreach director of SeaWeb/Communication Partnership for Science and the Sea to publicize his work and the work of other ocean scientists.

Later, he collaborated with marine biologist-turned-filmmaker, Randy Olson of "Flock of Dodos" and "Sizzle" fame, to create Shifting Baselines videos for the Web—graphic demonstrations of the way our perception of what a "natural" environment is changes over time.

In this article, "Ecological Extinciton and Evolution in the Brave New Ocean," Jackson reviews a series of studies that bolster initial observations that exploitation and pollution of estuaries and coastal seas, coral reef ecosystems, continental margins and the open ocean continue unabated.

He predicts that overfishing will lead to extinction of edible species and have an indirect effect on other levels of the food chain. Larger dead zones and toxic algal blooms may merge along the coastal zones of all of the continents. Disease outbreaks will increase. Vertical mixing of ocean waters may be inhibited resulting in disrupted nutrient cycles.

"Some may say that it is irresponsible to make such predictions pending further detailed study to be sure of every point. However, we will never be certain about every detail, and it would be irresponsible to remain silent in the face of what we already know."

Despite Jackson's bleak prognosis for a "brave new ocean," he clearly identifies "lack of political will and the greed of special interests" as standing in the way of establishing sustainable fisheries and aquaculture, "Simply enforcing the standards of the Magnuson-Stevens Act and the U.S. National Marine Fisheries Service would result in major improvements in U.S. waters within a decade."

"We have to begin somewhere," says Jackson—who will continue to stir the pot.