Fishers are among the biggest commercial resource users in the marine environment. In order to meet international, national and local policies, the UK has to designate a suite of marine protected areas (MPAs) and reach marine renewable energy (MRE) targets. Inevitably, there will be conflict between these two industries and marine conservation. This study uses a multi-disciplinary approach to examine evaluate the suitability of various sources of data, which could be used to detect, assess, and ultimately predict, fishing effort displacement within the different sectors of the > 15 m fleet in the South West of the UK. Gear-specific Vessel Monitoring System (VMS) data from 2005-2008 was used to assess potential effort displacement due to Haig Fras, a proposed MPA and Wave Hub, a marine renewable energy installation (MREI). The spatial distribution of fishing activity was highly heterogeneous and distinct areas of intense fishing could be identified for all gear-types. A closure of Haig Fras would have the greatest impact on gillnetters. Scallop dredgers also occasionally use the area. The current closure at Wave Hub has the greatest impact on potters and whelkers whose geographic specialisation is most pronounced and who use the area extensively. Longliners also use the area disproportionately would be affected. A simple index of variability was developed in order to determine baselines and two other sources of data were used. High resolution seabed data and low resolution catch data. A semi structured interview was conducted with forty fishers to elicit further information on the challenges, barriers to progress and priority issues in relation to MRE those fishers face. The theme of discontent with the consultation process scored highly throughout. Fishers’ Knowledge (FK) another source of data also scored highly, although further work must be carried out to identify what aspects of this data are useful in assessment of fishing effort displacement.