Can seepage of CO₂ stored in sub-sea geological formations disrupt important behavioural traits in benthic invertebrates

There is ongoing technological development of methods to detect and accurately measure CO₂ seepage from sub-sea geological storage. This project aims to provide important information for interpretation of such data to enhance its value with respect to determining potential impacts from leakages on marine vertebrates that live in association with the sea bed overlying these storage areas. The project will evaluate the potential effects of CO₂ seepage on the behavioural responses of representatives of two key benthic invertebrate groups (bivalve molluscs and crustacean decapods) and is expected to add significantly to the field of knowledge on the extent of impact from such leakages. A key step in this process will be the establishment of the threshold responses of the test organisms to indicate whether leakage events will have a serious impact on marine fauna both close to and more distant from a leakage source. The endpoints to be examined are high level biological processes such that significant alteration away from normal predictable patterns would indicate an ecologically significant change. The central North Sea has had an active sub-sea storage system in use at the Sleipner site since 1986 and the region is also likely to host further storage sites in the future. For this reason it will serve as a suitable case study for examination of the potential effects of CO₂ leakage. Species that form part of the benthic fauna found within the central to northern North Sea area will be used within the project. An exposure system, which has already been successfully used in the laboratory at IRIS, is being used to deliver a stepwise increasing volume of CO₂ gas that will ultimately reduce the seawater pH to 6.0. The system will aim to mimic potential seepage conditions in the field to determine if acute and or chronic exposure at these levels causes changes in behaviour of the exposed animals that could lead to reduced fitness or migration away from affected areas.