Action: Cease or prohibit the deposit of drill cuttings on the seabed
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of ceasing or prohibiting the deposit of drill cuttings on the seabed on subtidal benthic invertebrate populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.
Routine oil and gas drilling activities can impact subtidal invertebrate seabed communities due to the production of drill cuttings. Drill cuttings consist of the fragments of rock that are removed as each oil or gas well is drilled. The drill cuttings are usually discharged onto the seafloor in the vicinity of the platforms to form a cuttings pile, but are often contaminated with drilling fluids, oil and chemical additives which can leach and pollute the sediments. Drill cuttings can also smother and bury organisms under their weight (Henry et al. 2017). Ceasing the deposit of drill cuttings, for instance following protective legislation or changes in activity management, can stop the threat and potentially allow for the community to recover over time. Evidence related to alternative means of disposing of drill cuttings are summarised under “Threat: Energy production and mining - Dispose of drill cuttings on land rather than on the seabed” and “Bury drill cuttings in the seabed rather than leaving them on the seabed surface”.
Henry L.A., Harries D., Kingston P. & Roberts J.M. (2017) Historic scale and persistence of drill cuttings impacts on North Sea benthos. Marine Environmental Research, 129, 219–228.