Table – recreation and disturbance to wildlife

Disturbance to seals

A considerable amount of research has been undertaken on the disturbance effects of recreation. This is summarised below. A list of key sources of research is provided in the Appendices.

Land-based recreation can disturb species both through presence of participants and also through direct interference. Liddle (1997) suggests that there are three levels of disturbance which may affect a species:

• the species is aware of the physical presence of the recreational participant but there is no contact (e.g. wildlife watching) and it may or may not alter its behaviour as a result.

• the species may have its habitat physically modified by an activity (e.g. pathway creation, camping activities). The consequences of this disturbance may be positive or negative for the species.

• the species may come into direct and damaging contact with humans (e.g. wildfowling, fishing or vehicle collision).

Different types of recreational activities have different levels of interaction with species and therefore different levels of disturbance or impact. The table below is taken from Duffus and Dearden (1990) and links recreational activities to the types of wildlife disturbance identified by Liddle (as 1,2,3 above). It suggests that the provision of recreational infrastructure such as toilets, roads and visitor centres has a much greater potential to disturb wildlife than the recreational activity itself. However, it also indicates that recreational activities involving dogs or vehicles have the greatest potential to cause impacts.

Table - Recreation and disturbance to wildlife

Duffus and Dearden (1990)

1= low effect

5= high effect

B 0= hunting unsuccessful

B 3 = animal injured

B 5 = animal killed

Within the mSAC demonstration project the only designated species susceptible to land-based recreational disturbance are Common and Grey Seals. The following section identifies disturbance issues associated specifically with these two species.

Tourism and recreation based wildlife watching is a growing and lucrative business and is presently unconstrained by specific legislation. The attraction of seal watching is increasingly promoted by companies and individuals involved in these activities.

Seals are quite elusive in the water and so are most commonly visible whilst ashore. Here they can be very susceptible to disturbance, particularly while resting, breeding and rearing young. Seal watching activities can contribute to disturbance on land, especially as people can have direct and often unrestricted access to them while they are out of the water.

A recent report to SNH by Brown and Prior (1998) concluded that the most significant source of human disturbance to breeding sites on Mousa SAC was from recreational activities.

A research study looking at the effects of human disturbance on the maternal behaviour of grey seals at Donna Nook in Lincolnshire (Lidgard, 1996) showed that females preferred to give birth in areas of low disturbance and that pups born in such areas gained weight more quickly than pups born in areas of greater disturbance levels. However, the study was unable to conclude that these differences in weight gain were as a direct result of human impacts. During periods of high human disturbance, females were more protective towards their pups and the pups were more vigilant. The study suggests that these behavioural changes may divert energy away from the pup leading to reduced growth rate and increased pup mortality. In conclusion the report suggested that:

"Overall it does not appear that the Grey Seal population at Donna Nook is in jeopardy from human disturbance. The colony has dramatically increased in size since 1990, the mortality rate of pups is similar to that reported in other UK colonies and the weaning and growth rate of pups is higher than those reported in other colonies" Lidgard (1996).

The breeding season is an important consideration as it coincides with the ‘low’ season for most recreational activities. However, in the Scilly Isles, the breeding season for Grey Seals begins in July, whereas in South West England it begins in late August to early September and becomes progressively later in a clockwise direction around the country. As a result, the Grey Seal breeding season may actually coincide with summer activities in certain locations or areas. In the breeding and pupping season, the species is more vulnerable to disturbance than at other times of the year and therefore, even with fewer recreational participants, the potential for disturbance to have an impact is greater. Common seals are particularly vulnerable to recreation as their breeding and moulting season lasts from June to August coinciding with the ‘peak’ tourist and recreational season.

The study by Brown and Prior (1998) found that recreational participants who carried cameras or camcorders approached the seals much more closely than those without, and that the closer approaches resulted in greater levels of disturbance. This study also showed that not all people visiting the site caused disturbance. Almost 40% of the visitors observed caused no disturbance at all. However, 40% did cause serious disturbance resulting in the seals abandoning the haul out site for a period of time.

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