More acidic ocean could spell trouble for marine life's earliest stages

Jul 31, 2008

Increasingly acidic conditions in the ocean—brought on as a direct result of rising carbon dioxide levels in the atmosphere—could spell trouble for the earliest stages of marine life, according to a new report in the August 5th issue of Current Biology, a publication of Cell Press. Levels of acidification predicted by the year 2100 could slash the fertilization success of sea urchins by an estimated 25 percent, the study shows.

" If other marine species respond similarly—and there's no evidence yet that they don't—then we're in trouble," said Jon Havenhand of the University of Gothenburg in Sweden. "The analogies are quite simple: we observed a 25 percent reduction in fertilization success at reduced pH, which is equivalent to a 25 percent reduction in the spawning stock of the species. Apply equivalent changes to other commercially or ecologically important species, such as lobsters, crabs, abalone, clams, mussels, or even fish, and the consequences would be far-reaching. It could be enough to "tip" an ecosystem from one state to another."

However, he emphasized, more data about the response of growing acidic conditions on more species is needed before any such extrapolation can be made.

Widely cited estimates show that the average level of acidity in the oceans has risen by about 25 percent in the last 150 years, since the advent of fossil fuel burning, Havenhand explained. The most recent data show that levels of ocean acidification predicted for the end of this century—about a three-fold increase over current levels—have already been measured in some coastal waters.

More acidic surface waters eventually will sink to the bottom of the ocean, but it's a process that takes some 1,000 to 1,200 years. That long-term overturning circulation of the ocean has accommodated much higher atmospheric carbon dioxide levels in the past without resulting in the pH changes seen today. "The current problem is being caused by the rate of increase of carbon dioxide in the atmosphere, not the absolute level," Havenhand said. "To put it simply, the carbon dioxide is rising too quickly for the ocean's natural buffering system to catch up."

Earlier studies had primarily focused on the responses of adult stages of calcifying taxa including mollusks and corals to gross pH changes more relevant for the years 2200 to 2400. There had been scant evidence for the effects of ocean acidification on the very earliest life-stages (including fertilization) in marine animals, with most previous work examining pH changes far greater than those now tested.

They show that the upper limit of acidity levels predicted in the coming century—which have already been measured in some locations on the US West Coast—significantly reduce the swimming speed and motility of sperm from the sea urchin, Heliocidaris erythrogramma, leading to a 25 percent reduction in their fertilization success.

" We need to begin to respond globally to counteract the coming impacts of ocean acidification, an effort requiring at least as much global participation as current efforts to stem carbon dioxide emissions," Havenhand said. "I really hope I'm wrong about the broader implications of our work. However, the available evidence points to the conclusion that at present acidification is the biggest threat to the long-term viability of our ocean ecosystems and especially to key invertebrate species that maintain many of the marine ecosystems on which we rely for food, protection, and recreation."

Source: Cell Press

Explore further: Free the seed: OSSI nurtures growing plants without patent barriers

add to favorites email to friend print save as pdf

Related Stories

New study outlines 'water world' theory of life's origins

Apr 16, 2014

(Phys.org) —Life took root more than four billion years ago on our nascent Earth, a wetter and harsher place than now, bathed in sizzling ultraviolet rays. What started out as simple cells ultimately transformed ...

Building better soybeans for a hot, dry, hungry world

Apr 16, 2014

(Phys.org) —A new study shows that soybean plants can be redesigned to increase crop yields while requiring less water and helping to offset greenhouse gas warming. The study is the first to demonstrate ...

Warm US West, cold East: A 4,000-year pattern

Apr 16, 2014

Last winter's curvy jet stream pattern brought mild temperatures to western North America and harsh cold to the East. A University of Utah-led study shows that pattern became more pronounced 4,000 years ago, ...

Recommended for you

Plants with dormant seeds give rise to more species

Apr 18, 2014

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

Apr 18, 2014

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.