Future biological and ecosystem impacts of ocean acidification and their socioeconomic-policy implications

Anthropogenic carbon dioxide (CO2) emissions to the atmosphere and subsequent uptake by the ocean are changing seawater chemistry, a process known as ocean acidification. Research indicates that as ocean acidification continues, reflecting increasing CO2 emissions, it is likely that although some species will be tolerant it will impact many marine organisms and processes, including composition of communities and food webs. Whilst there may be local actions to limit acidification from local sources the root cause of ocean acidification, CO2 emissions, is a global issue requiring global action through United Nations bodies.

Ocean acidification mediates photosynthetic response to UV radiation and temperature increase in the diatom Phaeodactylum tricornutum

Increasing atmospheric CO₂ concentration is responsible for progressive ocean acidification, ocean warming as well as decreased thickness of upper mixing layer (UML), thus exposing phytoplankton cells not only to lower pH and higher temperatures but also to higher levels of solar UV radiation. In order to evaluate the combined effects of ocean acidification, UV radiation and temperature, we used the diatom Phaeodactylum tricornutum as a model organism and examined its physiological performance after grown under two CO₂ concentrations (390 and 1000 µatm) for more than 20 generations. Compared to the ambient CO₂ level (390 µatm), growth at the elevated CO₂ concentration increased non-photochemical quenching (NPQ) of cells and partially counteracted the harm to PSII caused by UV-A and UV-B. Such an effect was less pronounced under increased temperature levels. As for photosynthetic carbon fixation, the rate increased with increasing temperature from 15 to 25 °C, regardless of their growth CO₂ levels. In addition, UV-induced inhibition of photosynthesis was inversely correlated to temperature. The ratio of repair to UV-induced damage showed inverse relationship with increased NPQ, showing higher values under the ocean acidification condition against UV-B, reflecting that the increased pCO₂ and lowered pH counteracted UV-B induced harm.

NOAA scholarship awarded to Jan Vicente to study the impact of ocean acidification on marine sponges

The world’s corals are at risk of disintegrating thanks to increasingly acidic ocean waters, but what about the sponges? Graduate student Jan Vicente at the Institute of Marine and Environmental Technology has been awarded the National Oceanic and Atmospheric Administration’s prestigious Dr. Nancy Foster Scholarship to find out.

The program recognizes outstanding scholarship and encourages independent graduate level research in oceanography, marine biology and maritime archaeology. Vicente is working towards his Ph.D. in the laboratory of sponge expert Dr. Russell Hill of the University of Maryland Center for Environmental Science. The scholarship provides substantial support for Vicente’s graduate studies over the next four years.

Global research centre on ocean acid launched

A malnourished sea lion pup (L) and several harbour seals at a facility caring for sea lions poisoned by domoic acid, the result of a bloom of microscopic ocean algae that sickened and killed California birds, sea lions and dolphins in 2007. The UN nuclear agency announced on Monday the creation of a new centre in Monaco to help coordinate efforts to research and combat ocean acidification.

The UN nuclear agency announced on Monday the creation of a new centre in Monaco to help coordinate international efforts to research and combat the serious environmental problem of ocean acidification.

“During the past five years, numerous multinational and national research projects on ocean acidification have emerged and significant research advances have been made,” the International Atomic Energy Agency said.

UN expert warns of ocean acidification, threat to marine ecosystems

A United Nations expert has warned of the consequences of the phenomenon “Ocean acidification,” which can threaten the marine ecosystems.

“Ocean acidification is one of the most important issues facing us today. It’s a new phenomenon, but an undeniable phenomenon,” says Wendy Watson-Wright, Assistant Director- General and Executive Secretary of the UNESCO Intergovernmental Oceanographic Commission (IOC).

Rio+20: the threat from ocean acidification

Richard Feely, Senior Scientist at U.S National Oceanic & Atmospheric Administration talks to Pavilion TV about the problem of the acidification of the world’s oceans in terms of sustainable life of the marine species and ensuring the continued availability of fish for peoples’ diets.

Persistent carry-over effects of planktonic exposure to ocean acidification in the Olympia oyster

Predicting impacts of global environmental change is challenging due to the complex life cycles that characterize many terrestrial and aquatic taxa. Different life stages often interact with the physical environment in distinct ways, and a growing body of work suggests that stresses experienced during one life stage can “carry over” to influence subsequent stages. Assessments of population responses to environmental perturbation must therefore consider how effects might propagate across life-history transitions. We investigated consequences of ocean acidification (decreased pH and carbonate saturation) for early life stages of the Olympia oyster (Ostrea lurida), a foundation species in estuaries along the Pacific coast of North America. We reared oysters at three levels of seawater pH, including a control (8.0) and two additional levels (7.9 and 7.8). Oysters were cultured through their planktonic larval period to metamorphosis and into early juvenile life. Larvae reared under pH 7.8 exhibited a 15% decrease in larval shell growth rate, and a 7% decrease in shell area at settlement, compared to larvae reared under control conditions. Impacts were even more pronounced a week after settlement, with juveniles that had been reared as larvae under reduced pH exhibiting a 41% decrease in shell growth rate. Importantly, the latter effect arose regardless of the pH level the oysters experienced as juveniles, indicating a strong carry-over effect from the larval phase. Adverse impacts of early exposure to low pH persisted for at least 1.5 months after juveniles were transferred to a common environment. Overall, our results suggest that a stringent focus on a single phase of the life cycle (e.g., one perceived as the “weakest link”), may neglect critical impacts that can be transferred across life stages in taxa with complex life histories.

L’AIEA ouvre un centre pour lutter contre l’acidification des océans (in French)

L’Agence internationale de l’énergie atomique (AIEA) a annoncé, lundi 18 juin, l’ouverture cet été dans la principauté de Monaco d’un nouveau centre pour répondre aux problèmes engendrés par l’acidification des océans. Le centre aura pour but d’aider et de promouvoir les recherches de scientifiques.

 

Acid test for marine life

In Rio de Janeiro this week, environmental leaders from many nations are addressing one of our planet’s most serious yet still vastly under-recognized challenges: ocean acidification.

Ocean acidification, a process in which seawater chemistry changes when the ocean absorbs rising levels of atmospheric carbon dioxide, is profoundly affecting global waters and their ecologically and economically vital marine life. It is literally causing a sea change and threatening the fundamental chemical balance of ocean and coastal waters from pole to pole.

Because the consequences can be destructive to so many species, acidification is dubbed the “osteoporosis of the sea.” To build essential skeletons and shells, many marine plants and animals require calcium carbonate, an important mineral in seawater. But ocean acidification, if it continues unabated, could eventually inhibit the ability of oysters, clams, corals and other marine life to make hard protective shells and skeletons. In polar and other waters, the corrosive effect may also dissolve shells and skeletons already built.