BACKGROUND Oxygen concentrations in both the open ocean and coastal waters have been declining since at least the middle of the 20th century. This oxygen loss, or deoxygenation, is one of the most important changes occurring in an ocean increasingly modified by human activities that have raised temperatures, CO2 levels, and nutrient ...

Inorganic carbon chemistry data from the surface and subsurface waters of the West Coast of North America have been compared with similar data from the northern Gulf of Mexico to demonstrate how future changes in CO2 emissions will affect chemical changes in coastal waters affected by respiration-induced hypoxia ([O2] ≤ ~ 60 µmol kg−1). ...

Appendicularians are free-swimming tunicates that are common in most oceans, coastal waters, and estuaries. They build delicate, gelatinous houses that they use to filter food from the water. This study found that appendicularian abundance increased with ocean acidification, warmer temperatures, and higher nutrient levels. This suggests that appendicularians will play ...

Copepods produced more eggs in warmer temperatures, but the increase was smaller when copepods were simultaneously exposed to warmer temperature and ocean acidification conditions (lower pH). When pH changed between egg production and hatching, fewer eggs hatched. Warmer egg production temperature induced a positive maternal effect and increased the egg ...

Estuarine waters are more susceptible to acidification because they are subject to multiple acid sources and are less buffered than marine waters. Consequently, estuarine shell-forming species may experience acidification sooner than marine species although, the tolerance of estuarine calcifiers to pH changes is poorly understood. This study analyzed 23 years ...

Thermal sensitivity of spider crabs, as indicated by heart rate, rose under increasing levels of ocean acidification conditions. The results suggest a narrowing of the spider crab's thermal window under moderate increases in ocean acidification. (Laboratory study)

The immune responses of grazing isopods (Idotea balthica) in the Baltic Sea dropped by 60 to 80 percent after the isopods were placed in ocean acidification conditions for 20 days. In addition, isopods from a low salinity site, where their health was already compromised, suffered 100 percent mortality when placed ...

Brittlestar arms regenerated faster in warmer water. However, they did not do so when the temperature increase was accompanied by ocean acidification conditions. This may have occurred because the brittlestars had to devote more of their energy to maintaining calcium carbonate body parts, as calcium carbonate became undersaturated when the ...

The amount of available phosphorus appeared to regulate how much inorganic carbon was used by a red alga grown at different levels of ocean acidification conditions. Growth reflected a balance between carbon and nutrient metabolism. (Laboratory study)

The egg production rate, hatching success, and respiration of a Mediterranean copepod were not affected by ocean acidification conditions. Warming and food availability did have some effects. (Laboratory study)