Fishing activity near Wintershall offshore pipelines

On the North Sea bottom lie numerous pipelines to link oil- or gas offshore units, - platforms and processing stations on land. Although pipeline tubes are coated and covered with protective layers (Concrete Weight Coating), the pipelines risk being damaged through man-made threats like fishing activities with bottom trawls (trawling interference), anchoring and dropped objects. IRM Systems performs integrated risk assessments of pipelines for amongst others Wintershall. 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 Wintershall pipelines. Fishing activity has been quantified at a spatial scale of approximate 2500 m2 blocks (50m by 50m) using fishing Vessel Monitoring System (VMS) data for 2016 and 2018. In total, for each year 69 shapefiles specifying the fishing intensity in a buffer area of 100m either side of the pipeline, were delivered. The overall total trawl fishing intensity in 2016 and 2018 along the pipeline trajectories ranges from 0 - 18.83 times per grid cell per year and is the result of combining all beam-trawl fleet activities, though split by large beam trawls and shrimp trawls. There is substantial difference in effort between 2016 and 2018 which varies up to 200% for some pipeline segments. Though, at the North Sea scale, fishing has been relatively stable over the past 10 years. Highest fishing intensities are recorded within the 12nm zone where the effort of the shrimp trawlers is most abundant and has increased almost 5-fold in some areas from 2010 and has not come to a halt yet. At the spatial scale relevant in this study, small spatial differences make for substantial differences though

Fishing intensity around the BBL pipeline

Wageningen Marine Research was requested by ACRB B.V. to investigate the fishing activities around the BBL pipeline. This gas pipeline crosses the southern North Sea from Balgzand (near Den Helder) in the Netherlands to Bacton in the UK (230km). This pipeline is abbreviated as the BBL pipeline. Part of the activities deployed by the owner of the BBL pipeline is to secure the integrity of the pipeline, which includes checking burial status, detecting free-spans and investigating internal and external threats to the integrity of the pipeline. Fishing is considered as one of the external threats to the pipeline where a collision with fishing gear could damage the pipeline, the fishing gear, the vessel or the crew. Therefore in areas with substantial fishing activity, extra care should be taken. Such a risk inventory becomes more and more common day practice of submarine pipeline and cable owners where discussions now focus on how to best spend effort on protecting pipelines and where to relieve specific burial requirements

Impact of fisheries on seabed bottom habitat : fisheries from The Netherlands, Germany, Denmark and Sweden

The Marine Stewardship Council (MSC) released new certification requirements in 2014. The new requirements come with new guidelines for scoring fisheries for several Performance Indicators (PIs). One of the adjusted PIs is PI 2.4.1: the Habitats outcome indicator:“The Unit of Assessment (UoA) does not cause serious or irreversible harm to habitat structure and function, considered on the basis of the area(s) covered by the governance body(s) responsible for fisheries management.”Up to now, the new guidelines for this PI have not yet been translated into an operational performance indicator. An international group of fisheries organisations, from the Netherlands, Denmark, Germany and Sweden, is interested in applying for MSC accreditation or for renewal of existing accreditation. For them it is relevant to know how the new guidelines for PI 2.4.1 translate into a scoring of their fisheries. Therefore, the fisheries organisations requested WMR to develop a methodology for assessing fisheries’ impact on the North Sea seabed which could be used in assessments for MSC accreditation.WMR combined the MSC guidelines with a methodology for assessing fisheries’ impact on the seabed developed in collaboration with partners in the International Council for Exploration of the Sea (ICES). A so-called ‘Population Dynamic’ method was applied, which indicates how bottom trawling affects the biomass of the benthic community relative to an undisturbed situation. Recovery of a habitat is an important aspect in determining whether serious or irreversible harm is caused by a fishery. The benthic invertebrate community consists of many different taxa that differ in their sensitivity to fishing disturbance. This difference in sensitivity is reflected in the parameterisation which distinguishes between an average sensitivity (sensitivity I) and a high sensitivity (sensitivity II). Recovery of Seabed Integrity (SI) is used as an indicator for serious or irreversible harm. This methodology was applied for habitats with status type ‘commonly encountered’. Data that were used are satellite (VMS) and logbook data giving information on the spatial distribution and intensity of the fisheries. Information on North Sea habitats was obtained from EMODnet EU Sea Map and data on recovery rates and gear specific impact rates were obtained from an EU project called ‘BENTHIS’. The methods were applied to 11 UoAs for four different countries, in four different management areas (North Sea, Skagerrak, Kattegat and Eastern English Channel).The analysis comprised of a definition of the current state of seabed integrity (SI), based on historic fishing intensity. For each UoA a study area or ‘footprint’ was defined by gear and management area. Next, for each grid cell (1-minute longitude by 1-minute latitude) the fishing intensity was calculated from VMS data for three different gear groups: Beam Trawl (BT), Demersal Otter Trawls (TR) and Danish Seine (SDN). It was then possible to assess recovery rates for each grid cell (relative increase of biomass per year). The SI was calculated for the moment right after fishing impact and then for respectively 1, 5, 10 and 20 years after ceased fishing. Two indicators were used to assess whether recovery of the habitat to 80% of its unimpacted structure was achieved:- T80% > 0.95K: the top 80% of least impacted grid cells have an SI of at least 0.95 K, meaning that biomass is at more than 95% of the carrying capacity (K).- 100% > 0.80K: all grid cells in the study area have an SI of at least 0.80 K, so biomass is more than 80% of K.For habitats with status type ‘Vulnerable Marine Ecosystem’ (VME) we did not apply the methodology. In order not to cause any serious or irreversible harm to VMEs, the VMEs should not be fished at all. If that is taken into account during assessments for MSC accreditation, it is not relevant whether the VME habitat recovers. We did overlay maps of fishing by UoA with maps of vulnerable habitats (based on either ICES or OSPAR data) in order to see whether VMEs may be a relevant theme during assessments for MSC accreditation.Habitats with status type ‘minor’ were not considered, as with our interpretation these are insignificant in the North Sea and data for carrying out the above (or any) methodology is lacking.The analyses show that for the scenario with Sensitivity I (average recovery rates) none of the UoAs causes serious or irreversible harm to the commonly encountered habitats. I.e. recovery up to 80% is achieved within 20 years for both indicators. If the other Sensitivity is applied (II, with lowest recovery rates), the results are different. The ‘T80% > 0.95K’ indicator always reaches the threshold value within 20 years, but the ‘100% > 0.80K’ indicator does not reach the threshold value for 6 UoA. The 6 UoAs are the TR groups from Denmark (North Sea and Skagerrak), Germany (North Sea), the Netherlands (North Sea) and Sweden (Skagerrak) and the BT group from the Netherlands (North Sea). This may mean – dependant on whether both indicators should reach the threshold value or not – that for these 6 UoA it could be concluded that they do cause serious or irreversible harm to the habitat.Overlaying fishing activities by UoA with VMEs in the North Sea show us that there may be an issue for the German TR unit on the North Sea. This UoA has a minimal overlap with VMEs according to the ICES database. However, if data on threatened and/or declining species and habitats from OSPAR are used, a larger overlap is found. The methodology developed in this study can be a useful starting point for assessing the impact of fishing on the sea bed. It is not yet fully developed to be used in the framework of MSC accreditation: there are still several issues to be dealt with. First of all, a decision needs to be made on which performance indicator(s) to use: the ‘T80% > 0.95K’ indicator or the ‘100% > 0.80K’ indicator, or both. Second, a choice needs to be made about the sensitivity to be used.Another issue that needs to be considered concerns the UoAs. Each UoA may have a negligible impact on the seabed compared to the whole fleet. However, all UoAs together may cause serious or irreversible harm to the seabed. It is therefore important to be aware of the context in which the UoA is practicing the fishery

Overview of the international fishing activities on the Cleaver Bank and Frisian Front : update with Dutch, British, Danish, German, Belgian, Swedish and French data for 2010-2015

In response to a request to Wageningen University & Research from the Dutch Ministry of Economic Affairs an update of the data and analysis on the value of the fishing activities of the Dutch, British, Danish, German, Belgian, Swedish and French fishing fleets on the proposed closed areas on the Cleaver Bank and Frisian Front was prepared. This report uses the method presented in Chapter 5 of ‘Effects of seabed protection on the Frisian Front and Central Oyster Grounds’ (Van Oostenbrugge et al. 2015) to update the reports already published by Wageningen Economic Research on fishing activity on the proposed closed areas on the Cleaver Bank and Frisian Front (Hamon et al. 2013; Oostenbrugge and Hamon 2014). The effort, value and landings by the Dutch, British, Danish, German, Belgian, Swedish and French fishing fleets are presented for a five year period (2010-2015) and show variations over the last years but generally show a decline in effort in both areas. Value of landings and gross value added show an upward trend for the Dutch fishery in the Cleaver Bank (with a low point in 2013) but a downward trend for the British, German and Belgian fleets and for the Frisian Front. Main target species of the Cleaver Bank are plaice, targeted by the beam trawl fleet, followed by mackerel, cod and whiting in the rest of the demersal fleet. On the Frisian Front, gillnets target mainly sole and cod. The total value of landings has remained relatively stable on the Cleaver Bank between €1.6m and €2m over years (with the exception of the low 2013 value at €0.7m) while it remained low for the Frisian Front around €17,000 per year on average for the fleets from the countries considered. Within fleets, the dependency of individuals on the areas to be closed can greatly vary although the value of landings in the proposed closures represent less than 1% of the total value of landings for the Dutch fleet. For the Dutch fisheries about 30 to 40 vessels fish a minor part (less than 10%) of their revenue from the proposed closed areas on the Cleaver Bank and only 1 or 2 vessels get more than 10% of their revenue from the proposed closures. Between 15 and 20 vessels would be impacted by a seasonal closure on the Frisian Front net fishery, of those vessels only one fished more than 10% of its revenue in the proposed closure for one year

Quantifying habitat preference of bottom trawling gear

Continental shelves around the world are subject to intensive bottom trawling. Demersal fish assemblages inhabiting these shelves account for one-fourth of landed wild marine species. Increasing spatial claims for nature protection and wind farm energy suppresses, however, the area available to fisheries. In this marine spatial planning discussion, it is essential to understand what defines suitable fishing grounds for bottom trawlers. We developed a statistical methodology to study the habitat preference of a fishery, accounting for spatial correlation naturally present in fisheries data using high-resolution location data of fishing vessels and environmental variables. We focused on two types of beam trawls to target sole using mechanical or electrical stimulation. Although results indicated only subtle differences in habitat preference between the two gear types, a clear difference in spatial distribution of the two gears was predicted. We argue that this change is driven by both changes in habitat preference as well as a change in target species distribution. We discuss modelling of fisheries' habitat preference in light of marine spatial planning and as support in benthic impact assessments.</p

VMStools: Open-source software for the processing, analysis and visualization of fisheries logbook and VMS data

VMStools is a package of open-source software, build using the freeware environment R, specifically developed for the processing, analysis and visualisation of landings (logbooks) and vessel location data (VMS) from commercial fisheries. Analyses start with standardized data formats for logbook (EFLALO) and VMS (TACSAT), enabling users to conduct a variety of analyses using generic algorithms. Embedded functionality handles erroneous data point detection and removal, métier identification through the use of clustering techniques, linking logbook and VMS data together in order to distinguish fishing from other activities, provide high-resolution maps of both fishing effort and -landings, interpolate vessel tracks, calculate indicators of fishing impact as listed under the Data Collection Framework at different spatio-temporal scales. Finally data can be transformed into other existing formats, for example to populate regional databases like FishFrame. This paper describes workflow examples of these features while online material allows a head start to perform these analyses. This software incorporates state-of-the art VMS and logbook analysing methods standardizing the process towards obtaining pan-European, or even worldwide indicators of fishing distribution and impact as required for spatial planning. -------------------------------------------------------------------------------

Wind op Zee : bepaling van de waarde van geplande windparkgebieden voor de visserij

De ontwikkeling van windparken in de Noordzee heeft economische consequenties voor de visserij. In deze notitie is met behulp van de historische visserijpatronen in de periode 2010-2017 de waarde van de bestaande en geplande windmolenparkgebieden tot 2030 in het Nederlandse deel van de Noordzee voor de visserij bepaald. Daarbij is ook rekening gehouden met de cumulatieve effecten van andere ruimteclaims op de Noordzee op de waarde van deze gebieden. De visserij-activiteiten in de geplande windmolenparkgebieden droegen in de periode 2010-2017 gemiddeld 1.52 mln. euro per jaar bij aan de bruto toegevoegde waarde van de Nederlandse kottervisserij. Dit was 1,36% van de totale bruto toegevoegde waarde van de Nederlandse kottersector en 2,65% van de totale bruto toegevoegde waarde van de Nederlandse kottersector op het Nederlands Continentaal Plat (NCP). De bijdrage varieerde van 1,0 tot 2,5 mln. euro per jaar. Voor individuele schepen was de variatie van de bijdrage uit de geplande windmolenparkgebieden aan de inkomsten veel hoger (0-17%). Het toekomstig belang van de gesloten en te sluiten windmolenparkgebieden voor de visserij wordt mede bepaald door de toekomstige ontwikkelingen in ecologie van de Noordzee, de beleidsmatige en de sociaaleconomische context. Bij sluiting van alle geplande natuurgebieden en windmolenparken in zowel het Nederlandse deel als het buitenlandse deel van de Noordzee zal de bijdrage van de windmolengebieden aan de bruto toegevoegde waarde van de Nederlandse kottersector toenemen tot maximaal 1,57% en bij een 'harde Brexit' tot maximaal 1,93%. De waarde van de gebieden voor de visserij is niet gelijk aan het economisch effect van sluiting van de gebieden voor de visserij. Een nadere analyse van de gedragsveranderingen in de visserij bij sluiting van de gebieden en de resulterende effecten op de kosten en inkomsten is nodig om hier uitsluitsel over te kunnen geven. Gezien alle gebiedsbeperkingen en hun invloed op buitenlandse visserijen, is het daarbij van belang het internationale perspectief niet uit het oog te verliezen