The Circle: Ocean acidification threatening our oceans

Readers of The Circle are accustomed to editorials that frame the issue we’re examining in each edition, along with information about WWF solutions and initiatives.

We pride ourselves on being a solutions-oriented organization. However, ocean acidification is too new and the research too incomplete for us to fully understand how to tackle this growing threat to our oceans.

The Open University: 2011 PhD studentship: Origin and significance of high-Mg calcite for the global carbon budget

1. Project Title
Origin and significance of high-Mg calcite for the global carbon budget

2. List of supervisors and their role in the project
Pallavi Anand (lead supervisor) – chemical analysis techniques and carbonate abundance
Neil Edwards- modelling technique for global calcium carbonate budget calculations
Charles Cockell (University of Edinburgh)- molecular training
Maureen Conte (Bermuda Institute of Ocean Sciences, USA)- Sediment trap samples provider and training in sample collection technique

3. Aspects of the project

• Field work in Bermuda to learn the sediment trap sampling technique and obtain samples for the project.
• Training in chemical and molecular analyses techniques.
• Training in computer modelling of global biogeochemical cycles.
• Investigate role of high Mg calcite in the global carbon cycle.

Testing the waters

Shark humor has its time and place, but not when I’m snorkeling somewhere called Shark Bay. At the Heron Island Research Station, a laboratory on the teardrop-shaped atoll 45 miles (72 km) off Australia’s east coast, the suntanned, chirpy station manager gives a parting wave to the three students who are taking me out for my first look at the legendary corals of the Great Barrier Reef. “Just don’t get eaten, will you?” she says. Ha-ha. Happily, there are no sharks in Shark Bay that morning; in fact, there’s not a whole lot of anything. As I follow the students’ snorkels, we pass over circular beds of brown, monochromatic coral and empty expanses of rippled sand. A handful of small, glimmering fish hover in the water column, but they’re the only life we see during an hour-long swim. Where are the schools of coral trout? The famed Maori wrasse? Wading back to shore, one of the students shrugs: “Sorry there wasn’t more.”

…

Up in the Air
Above the clear water off Heron Island, a single windmill whirs in the breeze, its legs anchored in the shallows while it sends power to a tangle of computers and carefully looped cables perched on floats a few feet away. The computers are measuring, among other things, the pH levels of the water flowing through four plastic chambers mounted on the reef. The information gathered at this lab could give the world a clue as to what’s in store for the Great Barrier Reef — and the other 90% of the world’s corals. The makeshift station is the first experiment to measure how coral responds in its natural environment to ocean acidification, widely thought to be one of the biggest threats today to marine environments. Oceans absorb about half of the carbon dioxide humans produce, and while that helps lessen the effect of fossil-fuel emissions on the atmosphere, it also causes a reaction that makes seawater more acidic.

Atelier de travail Québec-Chine (in French)

Des chercheurs québécois et chinois unissent leurs efforts pour étudier l’acidification des océans

Un atelier de travail dont l’objectif était la mise sur pied d’un programme de recherche conjoint Québec-Chine sur les problèmes liés à l’acidification des océans a eu lieu à Qingdao, en Chine, en décembre dernier. Organisé par Maurice Levasseur, professeur au Département de biologie et directeur de Québec-Océan (Groupe interinstitutionnel de recherches océanographiques du Québec), et Gui-Peng Yang, de l’Université des océans de Chine, cet atelier a réuni une vingtaine de participants.

Think of the pteropods!

The pteropods! Won’t somebody think of the pteropods!

Pteropods are adorable little planktonic sea snails that go swimming about the open ocean looking impossibly cute. They’re also quite important, being a major component of the diets of zooplankton, herring, salmon, whales and other marine creatures.

Unfortunately, pteropods may be facing a rather sudden extinction because of that “other” carbon dioxide problem, ocean acidification.

About a third of the carbon dioxide produced by man is absorbed by the world’s oceans, and the consequences for many marine species look like being catastrophic.When CO2 dissolves into seawater it creates carbonic acid, which makes the seawater more acidic. (Technically, it makes it less alkaline since seawater is on the alkaline side of neutral, but it’s still the same thing). This reduces the availability of the carbonate ions that pteropods and many other marine animals need to make their shells.

CO2 and ocean acidification

Today we’ll look at the work being done by Dr. Grace Saba of Rutgers University. Grace is a postdoc in Oscar Schofield’s lab (remember the gliders) and is studying the effects of the dramatic increase of CO2 in the atmosphere.

Planet Earth – Studying ocean acidification (audio)

Dave Smith, Dave Suggett, University of Essex in Colchester

Chris – Coral reefs are regarded as the rainforest of the sea. They play a vital role in marine ecosystems and now, a new reef research unit at the University of Essex in Colchester has been setup to study them and Planet Earth presenter Sue Nelson has been to meet the Assistant Director Dave Suggett, and the Director Dave Smith.

Dave Smith – We have a central large tank which acts asa whole ecosystem with corals, fish, numerous different types of organisms that make up a coral reef, and then around the outsides of the central system, we have a designated site which we use to fragment corals to grow for experiments. On the other side of the central system, smaller tanks where we can very precisely control the environmental conditions. From light levels to temperature, and in some cases water quality as well.

Sue – We’re in the doorway at the moment. Let’s just go inside where it’s even noisier and take at closer look at this large, central, rather beautiful tank. Can you give me an idea of the range of species that you’ve got?

CO2 and vitamin B12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom

Phytoplankton growth can be limited by numerous inorganic nutrients and organic growth factors. Using the subarctic diatom Attheya sp. in culture studies, we examined how the availability of vitamin B₁₂ and carbon dioxide partial pressure (pCO₂) influences growth rate, primary productivity, cellular iron (Fe), cobalt (Co), zinc (Zn) and cadmium (Cd) quotas, and the net use efficiencies (NUEs) of these bioactive trace metals (mol C fixed per mol cellular trace metal per day). Under B₁₂-replete conditions, cells grown at high pCO₂ had lower Fe, Zn and Cd quotas, and used those trace metals more efficiently in comparison with cells grown at low pCO₂. At high pCO₂, B₁₂-limited cells had ~50% lower specific growth and carbon fixation rates, and used Fe ~15-fold less efficiently, and Zn and Cd ~3-fold less efficiently, in comparison with B₁₂-replete cells. The observed higher Fe, Zn and Cd NUE under high pCO₂/B₁₂-replete conditions are consistent with predicted downregulation of carbon-concentrating mechanisms. Co quotas of B₁₂-replete cells were ~5- to 14-fold higher in comparison with B₁₂-limited cells, suggesting that >80% of cellular Co of B₁₂-limited cells was likely from B₁₂. Our results demonstrate that CO₂ and vitamin B₁₂ interactively influence growth, carbon fixation, trace metal requirements and trace metal NUE of this diatom. This suggests the need to consider complex feedback interactions between multiple environmental factors for this biogeochemically critical group of phytoplankton in the last glacial maximum as well as the current and future changing ocean.

Seawater plus calcium could cut carbon, aid sea life

Seawater and calcium can be used to remove carbon dioxide from flue gas, and the resulting calcium bicarbonate can be pumped back into the sea to help marine life

Limestone scrubbers deployed at natural gas power plants could help reduce carbon emissions as well as lower ocean acidification by pumping a byproduct of the scrubbing process back into the water, according to an experiment conducted by the Energy Department’s Lawrence Livermore National Laboratory.

Greg Rau, a scientist at LLNL and the University of California, Santa Cruz, conducted a series of small-scale lab experiments that found seawater and calcium can be used to remove carbon dioxide from a gas-fired plant. When combined into a limestone scrubber, the mix can be used to remove CO2 in a plant’s flue stream. The resulting calcium bicarbonate can be pumped back into the sea to help marine life, Rau said.

Rising ocean temperatures and acidity may prove a deadly one-two punch for the world’s corals

A recent experiment by scientists at the Smithsonian Tropical Research Institute in Panama has revealed just how rising atmospheric carbon dioxide will deliver a one-two punch to coral reefs in coming decades, potentially knocking them out by preventing growth in juvenile corals. The combination of rising water temperatures and acidity, the experiment demonstrates, essentially starves juvenile coral larvae, creating an environment where more energy is needed to create their calcium skeletons, but where none is available.

Increased acidity of ocean waters will require more work for coral to manufacture calcium, yet higher water temperatures will prevent the symbotic zooxanthalle which live inside coral cells from producing sugars and oxygen at the increased levels the coral will need to survive. In essence, explains Smithsonian Associate Scientist Aaron O’Dea, “the coral needs more food and oxygen to make their skeleton, but is actually getting less because of higher temperatures. Within 50 years or so oceanic conditions could seriously hinder the growth of new corals.”