Bryozoan colonies were grown at a site in the Tyrrhenian Sea (Italy) where natural emissions of carbon dioxide associated with volcanic activity lower seawater pH to 7.76, simulating levels of ocean acidification predicted for the end of the 21st century. The colonies showed impaired growth and had fewer defensive polymorphs. ...

This study investigated the possible effects of ocean acidification on the calcareous skeleton of a Mediterranena bryozoan by transplanting live and dead colonies into an area of natural volcanic carbon dioxide vents in the Tyrrhenian Sea, Italy. Colonies remained alive at the below-normal and acidic pH sites during the 45-day ...

Four species of intertidal brown seaweeds increased their uptake of carbon dioxide (CO2) as ambient CO2 concentration increased, while one other species did not. The amount of increased CO2 uptake changed seasonally with temperature, and for one species the results indicated that future impacts of increased CO2 would be greatest ...

In the early life stages of a coralline alga, mortality and growth abnormalities increased with small changes in pH. However, rate of growth remained similar, potentially by re-directing energy from other life processes. (Laboratory study)

When embryos of a common estuarine fish—the inland silverside—were exposed to high CO2 levels until one week after hatching, survival dropped by 74 percent and length by 18 percent. The eggs were more vulnerable to mortality than the post-hatch larvae. The CO2 conditions that were simulated in the study are ...

When larvae of blue mussels were kept in ocean acidification conditions predicted for 2100 (pH 7.6) there was no marked effect on fertilization, development, abnormalities, or feeding. However, although the mussel larvae were able to form shells, after two months of exposure they were 28 percent smaller than larvae raised ...

When scientists collected pteropods living in the Southern Ocean, where high levels of CO2 caused low availability of calcium carbonate in the water for building shells, they found that the pteropods' shells had severely dissolved. In the laboratory, pteropods incubated under similar CO2 conditions had equivalent levels of dissolution. ...

Blue mussels exposed to highly acidified seawater for sixty days were able to protect their body tissues involved in reproduction, digestion, and respiration. However, the physiological defenses take energy away from other life processes, meaning that long-term exposure to ocean acidification may result in reduced growth and health of blue ...

Juvenile oysters living in acidified seawater had higher mortality rates and less growth of shell and soft-body tissues. They also had higher metabolic rates, likely because of the higher energy cost of maintaining their body chemistry. The high-CO2 conditions also reduced the hardness and fracture toughness of the shells. (Laboratory ...

Blue mussels in pH 7.1 seawater for 44 days had reduced shell growth, and those in pH 6.8 virtually stopped growing. In less acidified water—pH 7.4 or 7.6—shell growth was not significantly reduced.