Assessment of the fisheries activity data
This was undertaken for each approach in 2 parts.
Assessment of over 15m data
This dataset is an amalgamation of logbook and landings data with Vessel Monitoring System ( VMS) data. Logbook and landings data for ICES rectangles where there are protected areas is identified. The VMS data for each corresponding date and vessel in the logbook data is identified. It is filtered by speed (between 0 and 5 knots) to limit it to reports that are indicative of fishing activity. The two data sets are then merged giving each VMS report a notional value. Each VMS report is considered to be worth 2 hours of effort unless it is clear that the reporting frequency is much greater. In that circumstance adjustments have been made.
There are some potential sources of error in this estimate. If the wrong rectangle has been recorded in the logbook then data will be omitted. The total catch value for the trip is divided in proportion with the daily logged amount for a species. Therefore it is impossible to account for possible variations in catch quality which in turn influences the actual daily value.
In some cases a vessel may have a reported position outside an area in consecutive reports. If the intervening time was spent inside an area then this is missed by the analysis. By the same token a vessel may have just entered the area before a VMS report meaning it is included in the analysis.
This resulting dataset is then plotted using a Geographic Information System ( GIS) and VMS reports that would be affected by a particular management approach identified. These are then summarised into the tables in this document for each site detailing the percentage of activity affected.
Assessment of under 15m data
For vessels in the range of 10 to 15m there is a requirement to keep a logbook detailing catches at ICES rectangle level. VMS is presently being rolled out to vessels in this size range but there is no industry wide dataset available yet.
Marine Scotland undertook the Scotmap project to get a better understanding of the distribution of activities by under 15m vessels. The resultant amalgamation of all the data gathered is presented with each ICES rectangle split into 800 cells. However not all vessels participated in Scotmap meaning that the values are an under estimate of total fleet activity.
From the Scotmap data the total value of each ICES rectangle for a particular gear type was calculated. In the same manner the value of each SAC or MPA was calculated. From this the proportion of value from an ICES rectangle that was taken in the MPA could be estimated from the Scotmap data.
This proportion was used to estimate the level of value and effort in each MPA based upon the total catch and effort from the logbook data. For each management approach the proportion of activity affected was estimated using the same percentage identified from over 15m vessels.
There are potential sources of error within this estimate. It assumes that vessels which did not participate in Scotmap have the same distribution of activity in an ICES rectangle. It also assumes that the proportion of fishing effort in the same as the proportion of value. This may not always be the case due to variations in catch quality. Finally for each management approach it assumes that the proportion of activity affected for a gear type is the same as for over 15m vessels.
No attempt has been made to estimate the value of under 10m activities due to the lack of spatial data. However the Scotmap data includes these vessels so it can be seen from these maps whether important fishing grounds will be affected by the management approaches or not.
Any additional information on fleet activity, under 10m in particular, that can be provided during this consultation is welcomed. This would help ensure the final assessment that accompanies the resultant Statutory Instruments is as accurate as possible.
Availability of other fishing grounds
Where some activity is likely to be displaced consideration has been given to where alternative fishing grounds may be. As a general rule grounds within 20 nm have been considered, which would be within reasonable daily reach. It is recognised that some of these grounds may not be suitable for smaller vessels during bad weather.