Ocean acidification refers to the lowering of the ocean’s pH due to the uptake of anthropogenic CO2 from the atmosphere. Coral reef calcification is expected to decrease as the oceans become more acidic. Dissolving calcium carbonate (CaCO3) sands could greatly exacerbate reef loss associated with reduced calcification but is presently poorly ...

Ocean acidification, a product of increasing atmospheric carbon dioxide, may already have affected calcified organisms in the coastal zone, such as bivalves and other shellfish. Understanding species’ responses to climate change requires the context of long-term dynamics. This can be particularly difficult given the longevity of many important species in ...

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). ...

The continental shelf region off the west coast of North America is seasonally exposed to water with a low aragonite saturation state by coastal upwelling of CO2-rich waters. To date, the spatial and temporal distribution of anthropogenic CO2 (Canth) within the CO2-rich waters is largely unknown. Here we adapt the multiple ...

Acidification has sparked discussion about whether regulatory agencies should place coastal waters on the Clean Water Act 303(d) impaired water bodies list. Here we describe scientific challenges in assessing impairment with existing data, exploring use of both pH and biological criteria. Application of pH criteria is challenging because present coastal ...

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 ...

The shell calcification rates of small hard clams in five size classes (0.39, 0.56, 0.78, 0.98, and 2.90 mm shell height) decreased with increasingly severe ocean acidification conditions (pH 8.02, 7.64, and 7.41). Clams in the larger sizes were able to deposit new shell material even under corrosive conditions. However, ...

The shells of eastern oysters from the Chesapeake Bay dissolved at faster rates when exposed to increasingly severe ocean acidification conditions. Oysters with fresh shells dissolved at the fastest rate, followed by oysters with weathered shells and those with dredged shells. (Laboratory study)

Eighteen marine species exposed to ocean acidification conditions for 60 days exhibited a wide range of responses. Ten of the 18 species were affected negatively with lower rates of net calcification and, in some cases, net loss of shell. Those species included temperate corals, pencil urchins, hard clams, conchs, serpulid ...

This article provides an overview of how rivers, which tend to be acidic compared to the ocean, affect shellfish, with a focus on the Gulf of Maine.