#ocean studies

Scientists warn ocean near tipping point

International ocean scientists have issued a blunt warning to world leaders ahead of the November 2015 climate change negotiations in Paris (COP21).

In a paper published in the journal Science, a University of Queensland oceans expert and a team of international colleagues argue that any new global climate agreement must begin to minimise the mounting toll on the world’s oceans to prevent irreversible damage.

UQ Global Change Institute Director Professor Ove Hoegh-Guldberg said the 2009 negotiations in Copenhagen had underestimated the likely impact of climate change on oceans, and a new more intense focus on oceans was urgently needed.

“There’s compelling evidence that increases in the atmospheric concentration of carbon dioxide and other greenhouse gases  are already resulting in fundamental changes to the physical, chemical, and biological properties of our planet,” Professor Hoegh-Guldberg said.

“This is posing growing risks to human well-being as well as threatening key industries; however, solutions are still possible if we act decisively in Paris,” he said.

French National Center for Scientific Research senior scientist Dr Jean-Pierre Gattuso also voiced his great concern.

“The oceans have been minimally considered at previous climate negotiations. Our study provides compelling arguments for a radical change at COP21,” Dr Gattuso said.

The paper draws on an extensive scientific assessment of the impact of climate change on the world’s oceans completed last year for the Intergovernmental Panel on Climate Change (IPCC).

Professor Hoegh-Guldberg was coordinating lead author for the Oceans section of that United Nations study.

He said the chemical and physical conditions of the ocean were changing at rates which were, in some cases, faster than any seen over the past 65 million years.

“There is also high confidence that many marine organisms and their communities and ecosystems are undergoing fundamental change as the world’s oceans warm, acidify and lose oxygen,” he said.

“While deep cuts in greenhouse gas emissions are a must, we must also agree to rapidly rebuild the resilience of ecosystems and people against the rising tide of change.

“We must work on the urgent issues of adapting to rapid sea level rise, transforming fisheries and the impacts of increasingly strong storms—all of which will help to reduce non-climate stresses on ecosystems and build resilience to climate change-related impacts.”

The Science paper warns that policy options for addressing ocean impacts (mitigate, protect, repair, adapt) are narrowing as the ocean warms and acidifies.

The mesopelagic ‘ocean sunfish’ (Mola mola). Credit: Chris Zielecki

Ninety-five per cent of world's fish hide in mesopelagic zone

Mar 03, 2014 by Geoff Vivian

The article appears on www.phys.org, and does not allow copy-paste of the content, but here is why it's misleading:

1. Scientists have just discovered that there are many more fish in the mesopelagic zone (100m to 1000m deep) than previously thought.

2. Which is a good thing, they seem to think, because 90% of the fish that can be caught above that depth has been fished out [and if we continue commercial fishing, ALL the marine life we are accustomed to eating will go extinct] suggesting this discovery gives us hope that there is much more marine life down there (that we can exploit in the near future).

3. Once a fish population's numbers go below a certain point, the population does not recover (witness the collapse of the Georges Bank Cod fishery); and once a species is extinct, it is lost forever.

4. But apparently, finding new species of fish could be a great alternative to extinction!

5. The scientists were able to make this discovery because they used sonar to count the fish.

6. Sonar may not disorient fish, but it is proven to hurt cetaceans (whales, porpoises and dolphins), who have evolved sonar to get around and communicate. Great. Now it's not just the navies of the world that go around "pinging" for research and driving the remaining marine mammals to their deaths.

7. The article goes on to refer to the 5 Ocean Gyres in glowing terms, as natural wonders of productivity and health, when in effect, those Gyres are now commonly refered to as Garbage Patches, saturated with bits of every kind of plastic in every conceivable size, from original to minuscule (plastic does not dissolve, it just keeps getting smaller), and floats at different depths, and is available to smaller and smaller fish and marine birds, who eventually die of starvation with stomachs full of undigested plastic bits.

8. Finally they congratulate themselves for finding "a pristine stock of fish which happens to be 95% of all the biomass in the oceans" (deliberately excluding the very large percentage of fish we have already killed).