The seafloor before and after drilling activities

Offshore drilling activities can impact several environmental compartments, and in particular the seafloor. After placing a drilling rig and a drilling well, drilling can commence. Drilling muds are applied and cuttings are produced in this process. Wageningen Marine Research studied whether the composition of seafloor life has changed after drilling activities on the North Sea.

The area where the drilling took place (a6a), is situated inside a protected Flora and Fauna Habitat area. Drilling activities are not allowed to have an impact on this area. This has to be assessed using survey data. Wageningen Marine Research therefore drew up a plan before the drilling activities even took place. Samples were also taken prior to the drilling (2011) at and around the drilling site and at a reference location some 10 km away. Afterwards (2014) the same locations are sampled and analysed again, using the same techniques. Differences that where found between the samples before and after the activities are so small, that they fall within natural variability (for this the reference location was used) and could not be attributed to the drilling activities.