ocean acidification

Yesterday ABC's World News Tonight aired a segment about ocean acidification featuring the lead author, Ellycia Harrould-Kolieb, of our new Acidification Report, Acid Test.

In the segment, Harrould-Kolieb says that if we reach 450 parts per million of carbon dioxide in the atmosphere, "We can pretty much say goodbye to coral reefs." Right now we're at 385 ppm.

Corals, lobsters, and many other ocean creatures are unlikely to withstand the increasing acidity of the oceans brought on by global warming, according to a new report from Oceana.

Our new report, "Acid Test," examines the far-reaching consequences of the accumulation of heat-trapping gases, particularly carbon dioxide, in the world's oceans.

High levels of carbon dioxide (CO2) in seawater deplete the carbonate that marine animals need for their shells and skeletons. Creatures that are at risk if trends continue include corals, commercial fish, including shrimp and lobster; and pteropods, or swimming sea snails, which are an important part of the base of polar and sub-polar food chains.

We are calling for a reduction of CO2 emissions in industrialized countries by 25 to 40 percent below 1990 levels by 2020.

The key findings of the report include:

Until recently, models analyzing the effects of global warming on coral bleaching have been strictly based upon thermal stress projections, but a new study highlights the added impact of ocean acidification, yielding startling results.

Through experimental research, Dr. Ken Anthony led a team of scientists who found that the productivity and calcification rates of corals and important coral reef builders, crustose coralline algae, significantly decline under higher temperatures coupled with increased CO2 and high light exposure, suggesting that high CO2 levels may exacerbate coral bleaching events in warmer waters.

The International Maritime Organization’s recent decision to adopt tighter emission rules for the global shipping fleet is a step in the right direction in an industry where emissions have been practically unregulated. Ship emissions are blamed for 60,000 deaths worldwide each year – a sincere public health threat.

The new rules, however, only address sulfur and nitrogen oxide emissions. Meanwhile, carbon dioxide emissions from the same ships remain a major, and often overlooked, contributor to global warming.

The world’s shipping fleet comprises 300,000 ships, each a city block in length, and transports 90 percent of the world’s trade. In 2007, the fleet emitted nearly twice as much carbon dioxide as all of America’s cars combined. If the fleet were a country, it’d be ranked as the sixth largest producer of CO2, between Japan and Germany.

Not to mention that these ships use the dirtiest fuel available, creating a high percentage of unusable sludge that must be burned.

Some marine animals may be able to cope with ocean acidification, but not without sacrifice.

A recent study revealed that one such creature, the brittlestar, which is capable of regenerating lost arms, is able to replace lost appendages more quickly in acidic seawater than in normal seawater because it increases calcification and metabolic rates to compensate for rising acidity.

But while arms sprouted faster than usual, they also sprouted thinner than usual. In brittlestars exposed to acidified seawater, muscle mass declined in both the already present, undamaged arms and in newly generated ones.

Cold-water corals (also known as deep-sea corals) are in as much danger from the corrosive effects of ocean acidification as those found in tropical waters.

Scientist James Orr recently found that population reductions in Arctic cold-water corals were analogous to those expected to occur in tropical corals. Orr and other scientists determined that by 2100, more than two-thirds of cold-water corals will be in waters corrosive to their calcium carbonate skeletons.

In further noisy ocean news this past week, our nation's highest court heard oral arguments in the dispute over the Navy's use of mid-frequency active sonar off the coast. The sonar has been associated with whale injury and beach strandings; meanwhile, the Navy argues that halting or restricting sonar training exercises in any way harms national security.

According to the Natural Resources Defense Council (NRDC), the plaintiff in the case, many whales that have been beached as a result of sonar have suffered physical trauma, including bleeding around the brain, ears and other tissues.

In addition, many have shown symptoms akin to a severe case of "the bends" -- the illness that can kill scuba divers who surface quickly from deep water, implying that the whales' dive patterns are altered. Sonar has also been shown to disrupt feeding and other vital behavior and to cause a wide range of species to panic and flee. The NRDC case is specific to training exercises in the Pacific Ocean and whether the Navy has to be environmentally responsible in its routine trainings by reducing their impacts to whales.

A new report looks at the effects of increased ocean acidity on how sound travels in seawater, which scientists have long suspected to be influenced by pH.

The report found that drops in pH affect the ocean's chemical balance and consequently lower its sound absorption, especially to frequencies below 10 kilohertz (kHz). The researchers say that by the 1990s, the oceans absorbed 15% less sound than during the previous century, which will likely affect the communications of ocean wildlife as well as military operations, by making sound travel farther and increasing the ocean's ambient noise level. Already, scientists have discovered that blue whales, which normally communicate below1 kHz, have started calling at lower frequencies.

News from Miriam at the Oyster's Garter: There's a new documentary about ocean acidification coming in early 2009.

A Sea Change follows "retired educator and concerned grandfather Sven Huseby back to stunning ancestral sites (Norway, Alaska the Pacific Northwest) where he finds cutting-edge ocean research underway. His journey of self-discovery brings adventure, surprise and revelation to the hard science of acidification."

Ocean acidification is one of those climate change nasties that most people have a general idea about. But when it comes to its long-term consequences, they're blissfully ignorant, which is why a documentary like this has the potential to be a great thing, in my opinion (and if Al Gore has anything to say about it.) Watch the trailer below:

Poor coral.

With global warming-generated ocean acidification already hindering the essential production of the calcium carbonate (CaCO3) skeletons in coral species, scientists now suspect another threat to corals and reef ecosystems caused by climate change.