Quantifying fishing impact in MPAs

Helping improve the evidence base of fishing impact in designated areas

The Government's revised approach to managing commercial fisheries in European Marine Sites (EMSs) in English waters requires assessment of fishing activity and its impact on protected features. We developed and trialled a range of methodologies to maximise the potential for evidence-based approaches to these assessments, incorporating information from the fishing industry where possible.

Specifically, this involved:

  • Improving the evidence on the distribution and intensity of fishing activities through analysis of VMS data and interviews with inshore fishermen
  • Quantifying the effects of fishing gears on habitats, through modelling physical impacts of gears (penetration and resuspension of sediment)
  • Sensitivity assessment of habitats and species
  • Modelling levels of natural disturbance

Ensuring there is an appropriate evidence base is crucial to the successful management of Marine Protected Areas that benefits both conservation interests and the future of the fishing industry.

Three case studies were carried out:

  • Flatfish beam trawling in North Norfolk Sandbanks and Saturn Reef SCI
  • Shrimp beam trawling in The Wash and North Norfolk Coast SAC
  • Otter trawling in Margate and Long Sands SCI

Exposure to fishing was calculated for individual gear components. VMS ‘footprint polygons’ were created based on tracks between consecutive ‘fishing’ pings which were buffered to reflect the width of individual gear components. This allowed a clear distinction to be drawn between the different pressures caused by individual gear components and their spatial extent. Frequency of exposure was considered based on the number of tracks between consecutive ‘fishing’ VMS pings that crossed each cell of a grid.

Subtidal sandbanks are typically subject to high levels of natural disturbance by tidal flows and/or waves. These natural processes are important to the maintenance of subtidal sandbank features and the benthic invertebrates living in these environments are adapted to high levels of natural physical disturbance. Modelling the mobility of seabed sediments was carried out to allow fishing disturbance to be considered in the context of natural disturbance.

The data and methods developed through this project help address a number of key data gaps for assessments of fisheries in MPAs in relation to the extent, intensity and frequency of impact for both under- and over-15m vessels. This has improved the evidence base on which the assessments are based, reducing the level of uncertainty and the need for precaution to be used in managing fishing activities.

We concluded that assessments of fishing in MPAs should be based on impacts and exposure at the level of individual gear components. The methods developed under this project provide an approach for implementing this, and are repeatable for other sites. There is potential for further development of the methods to assess exposure, to obtain a more accurate picture of the actual footprint of fishing activity on the seabed.

The project was undertaken by ABPmer and Ichthys Marine Ecological Consulting Ltd on behalf of the National Federation of Fishermen’s Organisations and funded by the Sea Fish Industry Authority and the European Fisheries Fund.

Report downloads

Supporting Risk-Based Assessments of Fishing in MPAs – Main Report [PDF, 2MB]

Assessment of Beam Trawling Activity in North Norfolk Sandbanks and Saturn Reef SCI [PDF, 10MB]

Assessment of Shrimp Trawling Activity in The Wash and North Norfolk Coast SAC [PDF, 8MB]

Assessment of Otter Trawling Activity in Margate and Long Sands SCI [PDF, 14MB]

See also

New research to aid sustainable fisheries management in marine protected areas - NFFO

Improving the evidence for fisheries management decisions in marine protected areas - NFFO

ABPmer routinely advises marine sectors on regulatory and policy matters and has a long history supporting government and its agencies in developing the evidence base against which policy decisions are made.

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