7. Other impacts on seals
7.1 Welfare of seals
Conditions on the seal licence dictate the method of killing that may be used and detail the type of firearm and ammunition, weather conditions and distance from the animal. The licence also states that the marksman should 'take all reasonable steps to take away suffering of injured seals, by locating and humanely killing such animals as soon as possible, and without delay, following their being injured'.
One of the purposes for which carcass recovery is required is to ensure that seals are being killed in compliance with these conditions and in the most humane way possible. As discussed earlier, recovery of carcass killed under licence is rare meaning that this duty cannot be fulfilled.
Since February 2015, 38 seal carcasses (30 grey, six harbour and two unknown) have been collected (i.e. found stranded or collected from site) by SMASS. Of these, SMASS has undertaken full post-mortem on five individuals; one juvenile harbour seal, three juvenile grey seals and one pregnant female grey seal. All reported results indicated seals had been shot correctly and died instantaneously, with indicators of otherwise healthy animals (e.g. recent feeding). SMASS is only able to collect and post-mortem a small proportion of seal carcasses however an additional grey seal carcass is awaiting post-mortem.
7.2 Impacts on seal populations
The total numbers of seals for which licences have been issued in each Seal Management Area have not reached a level that may adversely impact on local seal populations. The number of seals killed or taken, by species, over the licensing scheme is shown in Figure 8. The number of seals killed compared to the annual PBR is shown in Table 4, indicating the number of seals killed is substantially below the PBR for each species.
|Grey seals||Harbour Seals|
Overall, less harbour seals than grey seals are killed or taken. The likely reason for this is that the grey seal population in Scotland is around three times larger than the harbour seal population, and the low PBR for harbour seals in certain management areas (Morris et al., 2020). In the review period, the number of seals killed or taken has remained broadly constant.
Each year, the Special Committee on Seals (SCOS), on behalf of UKRI provides advice to all UK administrations of the status of seals. According to the latest advice from SCOS counts of harbour seals in Scotland have increased from 20,800 in the 2007-2013 survey period to 26,900 in the 2015-2018 period (Duck et al., 2020). This equates to an estimated total minimum population in Scotland of 37,300 seals. Grey seal pup production in Scotland has also increased from approximately 44,100 in in 2010 to 54,750 in 2016, equating to an estimated total population of 122,500 grey seals in Scotland in 2018 (SCOS, 2020).
7.3 Seals in cages
The SCOS 2019 advice (SCOS, 2020) provided information on the potential options for removal of seals which have entered and become trapped in fish farm cages. Historically this has been a rare occurrence, therefore no tested methods exist for removing seals which have entered fish farm cages without killing them. It is possible that providing an escape route could be an option. However it is not clear how this would work in practice, without also allowing escapes of fish. Inside cages, seals have the potential to damage large numbers of fish very quickly, so fast removal is crucial to minimise risk to salmon and seals. Methods to lure a seal into an escape route are likely to be prove difficult due to the stressed nature of the seal. Capture of a seal is also likely to prove risky for both the animal and staff, so is therefore unlikely to be a desirable option.
SCOS therefore recommended that ensuring cages are adequately protected with physical barriers is the best way to mitigate against seals entering cages, as it is unlikely that an effective method of non-lethal removal will be developed in the near future.