Reduced sea water pH disrupts resource assessment and decision making in the hermit crab Pagurus bernhardus

The decisions that animals make are based on information gathered from their environment, and can have consequences for their fitness and survival. Such processes can be disrupted by environmental change. Hermit crabs find and select the gastropod shells they inhabit using chemical and visual cues, and tactile assessment. The choice of an optimal shell is important since it provides shelter against environmental extremes and protection against predators; inhabiting a suboptimal shell can also reduce fecundity. Hermit crabs are subject to cyclical reductions in the pH of the water in the intertidal rock pools that they inhabit, and such reductions may be further exacerbated by climate change. Reduced sea water pH, a consequence of ocean acidification and leaks from geological storage sites, has already been shown to disrupt the behaviour of marine animals. We investigated the effects of reduced sea water pH on the shell assessment and selection behaviour of the hermit crab Pagurus bernhardus. Under highly reduced pH conditions (pH 6.8) crabs were less likely to change from a suboptimal to an optimal shell than those in untreated sea water; those that did change shells took longer to do so. Crabs in the reduced pH treatment also showed significantly lower antennular flicking rates (the ‘sniffing’ response in decapods) and reduced movement. Thus, a reduction in sea water pH disrupts the resource assessment and decision-making processes of these crabs, indicating that the ability to acquire a vital resource may be influenced by both naturally occurring environmental cycles and anthropogenically induced environmental change.

Vulnerability of Antarctic marine benthos to increased temperatures and ocean acidification associated with climate change

Metadata record for data from AAS (ASAC) project 3134.

Public
Ocean acidification and warming are global phenomena that will impact marine biota through the 21st century. This project will provide urgently needed predictive information on the likely survivorship of benthic invertebrates in near shore Antarctic environments that is crucial for risk assessment of potential future changes to oceans. As oceans acidify carbonate saturation decreases, reducing the material required to produce marine skeletons. By examining the effects of increased ocean temperature and acidification on planktonic and benthic life stages of both calcifying and non-calcifying ecologically important organisms, predictions can be made on the potential vulnerability of marine biota to climatic change.

Ocean acidification educator workshop evaluation report

In June, 2011, NOAA CRCP organized a series of three workshops in south Florida on its new Ocean Acidification Data-in-the-Classroom module, training over 80 participants in the science behind OA and how to teach it in the classroom. Evaluation assessed participant subject knowledge gains, material intent-to-use, self-reported ability and confidence to use OA data, and workshop rating.

Nutrition and income from molluscs today imply vulnerability to ocean acidification tomorrow

Atmospheric carbon dioxide (CO₂) emissions from human industrial activities are causing a progressive alteration of seawater chemistry, termed ocean acidification, which has decreased seawater pH and carbonate ion concentration markedly since the Industrial Revolution. Many marine organisms, like molluscs and corals, build hard shells and skeletons using carbonate ions, and they exhibit negative overall responses to ocean acidification. This adds to other chronic and acute environmental pressures and promotes shifts away from calcifier-rich communities. In this study, we examine the possible implications of ocean acidification on mollusc harvests worldwide by examining present production, consumption and export and by relating those data to present and future surface ocean chemistry forecast by a coupled climate-ocean model (Community Climate System 3.1; CCSM3). We identify the ‘transition decade’ when future ocean chemistry will distinctly differ from that of today (2010), and when mollusc harvest levels similar to those of the present cannot be guaranteed if present ocean chemistry is a significant determinant of today’s mollusc production. We assess nations’ vulnerability to ocean acidification-driven decreases in mollusc harvests by comparing nutritional and economic dependences on mollusc harvests, overall societal adaptability, and the amount of time until the transition decade. Projected transition decades for individual countries will occur 10–50 years after 2010. Countries with low adaptability, high nutritional or economic dependence on molluscs, rapidly approaching transition decades or rapidly growing populations will therefore be most vulnerable to ocean acidification-driven mollusc harvest decreases. These transition decades suggest how soon nations should implement strategies, such as increased aquaculture of resilient species, to help maintain current per capita mollusc harvests.

Ocean acidification – part 1 (video)