Fishing activity near Petrogas offshore pipelines, 2020

Hintzen, Niels


On the North Sea bottom lie numerous pipelines to link oil- or gas offshore drilling units, - platforms and processing stations on land. Although pipeline tubes are coated and covered with protective layers, the pipelines risk being damaged through man-made hazards like anchor dropping and fishing activities with bottom trawls. Petrogas E&P Netherlands B.V. works towards integrated risk assessment of pipelines. Spatial maps of fishing activity would contribute to this risk assessment. Therefore, WMR was tasked to quantify the amount of fishing activity in the vicinity of Petrogas E&P Netherlands B.V. pipelines. Fishing activity has been quantified at a spatial scale of approximate 3800 m2 blocks (68m by 56m) using fishing Vessel Monitoring System (VMS) data from the year 2020. The results in this study show that larger vessels as well as smaller vessels do operate a fishing in the vicinity of the pipelines located closer to shore. In the northern part of the EEZ, fishing intensity of larger vessels is low and negligible for smaller vessels and shrimp trawlers. The highest fishing intensity (number of times a full grid cell is trawled) is recorded close to the IJmuiden harbour due to shrimp trawling activity and amounts to an estimated 3-4 times trawling intensity around the pipelines. It is however realised with gears substantially lighter than traditional beam trawls. This fishing intensity is below the range of 5-10 times a year estimated in the most intensively fished areas of the North Sea. The indicators calculated in this study, reflecting number of potential interactions (fishing effort) of trawling vessels with the pipelines and the potential severity of these interactions (fishing intensity), may contribute to the risk assessment. It should be noted, however, that owing to seasonal changes in fish distribution and yearly changes in fishing gear characteristics, these maps do not provide an accurate base for the prediction of future fishing impact.