Project Title Analysing the fishing patterns on scallop grounds in terms of local vs distant home port fishing activity
Brief
The UK scallop dredge fleet is composed of 281 vessels (96 >15m, and 185
<15m) (UK fleet survey 2014).
Generally, scallop dredging occurs in fairly discrete areas of seabed where there are high stock densities (Figure 1), typically over gravelly and sandy substratum.
Habitat and fishing effort mapping generally shows scallop dredging to occur on areas of seabed that have already changed through decades of fishing. Recent work also suggests that there is an effort threshold (i.e. tows per area of seabed), below which, impact on the epibenthos and infauna found on/ in gravelly and sandy substrata is not significant.
However, another key issue for sustainability of scallop fisheries is the impact of roving vessels that move freely between scallop grounds. A criticism of roving vessels from local fishermen is that they have little incentive to comply with local management regulations/ voluntary measures. Given there is no baseline data on the spatial and temporal scales roving vessels operate, and also scallop grounds roving vessels target, this project will seek to analyse the fishing patterns on scallop grounds (see Figure 1) in terms of local vs distant home port fishing vessel activity.
Figure 1 Stock units of king scallops
How will the student address/contribute to addressing the problem?
Feasibility and possible problems
The student will work closely with fisheries scientists at CEFAS. CEFAS have access to VMS data for 12m vessels and above, and this can be interrogated by trip. The student will conduct spatial analyses using ArcGIS to address the following questions:
1) To what extent is dredge effort on different scallop grounds partitioned between roving and local vessels?
Does a clear dichotomy even exist?
2) What are the effects of season, year, geography (e.g. remoteness), and estimated stock biomass in explaining variation for 1)?
Local port activity will be underestimated if the focus is solely on VMS, so if a student is able to develop a method for mapping the effort of <12m dredge vessels that would be highly beneficial to the project. With regards <12m vessels there is a lot of observational data out there (e.g. from the IFCAs and also aerial surveys) and in Scotland there is at least some information from the ScotMap project.
To narrow the scope of this exercise, a student could potentially focus on a case-study area(s) (e.g. Cardigan Bay).
The main barrier to the analysis is that effort data is only available for vessels >12m. Any additional surveys to map effort would be dependent on fishermen’s willingness to engage, with potentially many already suffering from stakeholder fatigue.
Another issue is data anonymity. With regards to the roving larger vessels fishing patterns, depending on study area, these vessels may be few in number and therefore identifiable.
To deliver in a few weeks the student would have to arrive with excellent big data/GIS skills.
What training or other career benefits will the student get?
The student will further improve their spatial analysis skills in GIS, also learning how to use the statistical programming software R.
Supporting Staff Member Dr Alex Caveen Email Alex.Caveen@seafish.co.uk