Polygon

These maps are an update of the previous seal usage maps described in Jones et al. (2015). There are three key updates: (1) The telemetry data have been updated and now include data from 1991 - 2016 (inclusive) resulting in a marked increase (grey seals: 23%; harbour seals: 39%) in sample size for the UK; (2) The count data now include effort data and have been updated resulting in estimates of usage scaled to the estimated population size in 2015; (3) Haulout sites have been clustered together resulting in an increase in the proportion of sites for which there are associated telemetry data and thus increased accuracy of estimated distribution. The estimates reflect the expected mean number of seals in each 5 x 5 km cell at any given time. The estimates do not distinguish between the type of usage (e.g. foraging or travelling behaviour) and similar usage values could be a result of many individuals using a given area a small amount, or a small number of individuals that area intensively. Temporal variation in usage (seasonally or annually) is not represented. The confidence intervals reflect confidence in the estimate of mean usage in each cell, rather than showing the variability in usage. Thus, the confidence intervals are per cell and so do not represent uncertainty in distribution across the maps. Telemetry data were aggregated in order to provide the most complete spatio-temporal coverage around the UK, thus any differences in distribution by sex or age are not reflected. These maps only reflect estimates of usage resulting from seals that haul out in the UK and the Republic of Ireland; usage emanating from continental Europe is not considered.

The Petroleum Act 1987 is the UK law which governs offshore safety zones. A surface safety zone is an area extending 500m from any part of an offshore oil and gas installation and is established automatically around all installations which project above the sea at any state of the tide. Subsea installations may also have safety zones, created by statutory instrument (S.I.) to protect them. These safety zones are 500m radius from a central point. Vessels of all nations are required by law to respect safety zones. It is an offence (under section 23 of the Petroleum Act 1987) to enter a safety zone except under special circumstances.

Measuring fishing effort is important for assessing the environmental sustainability of fish stocks and the socioeconomic efficiency of fishing activity. Fishing effort describes the amount of fishing gear used on a fishing ground over a given unit of time. Effort in this case is defined as number of creels hauled per day per 4 km2. This survey interviewed 198 creel vessel skippers from four regions, two on the west and two on the east coast of Scotland. This analysis has been produced from these SAMPLED vessels only. This IS NOT a census and IS NOT a map of all creeling effort in these waters or in the survey areas. This is an indication of potential fishing effort only and if creeling is not quantified in an area in this map, that DOES NOT mean creeling is not taking place. Equally quantified effort could be higher given some creeling vessels were not surveyed. Fishing effort outside of the surveyed area was not measured.

Measuring fishing effort is important for assessing the environmental sustainability of fish stocks and the socioeconomic efficiency of fishing activity. Fishing effort describes the amount of fishing gear used on a fishing ground over a given unit of time. Effort in this case is defined as number of creels hauled per day per 4 km2. This survey interviewed 198 creel vessel skippers from four regions, two on the west and two on the east coast of Scotland. This analysis has been produced from these SAMPLED vessels only. This IS NOT a census and IS NOT a map of all creeling effort in these waters or in the survey areas. This is an indication of potential fishing effort only and if creeling is not quantified in an area in this map, that DOES NOT mean creeling is not taking place. Equally quantified effort could be higher given some creeling vessels were not surveyed. Fishing effort outside of the surveyed area was not measured.