WILD IDEAS

Isle ofSEALS

SEAL DISTURBANCE WITHIN A SPECIAL AREA OF CONSERVATION BY MARIA PÉREZ TADEO Ireland hosts breeding populations of grey and harbour seals, protected under the Wildlife Act 1976 and listed under Annex II of the European Union’s Habitats Directive. Therefore, their populations must be monitored and their habitats assessed for designation as Special Areas of Conservation (SACs). These species are found in a range of coastal habitats including intertidal sandbanks and rocky shores. Grey seals can also be found in remote areas, such as caves and sandy beaches on offshore islands, as is the case for one of the largest colonies in the country, located in White Strand beach on the Great Blasket, the biggest of the Blasket Islands, off the coast of County Kerry.

Located off the west coast of the Dingle Peninsula, this magical archipelago is a SAC for grey seals and harbour porpoises. It is also a transient area for other species, presenting suitable habitats for common dolphins, bottlenose dolphins, Risso’s dolphins, minke whales, and humpback whales. Basking sharks are also

encountered within the area during the summer months. Due to their ornithological relevance, the Blasket Islands are also designated as a Special Protection Area, supporting breeding colonies of seabird species such as Manx shearwaters, storm petrels, and puffins. While always beautiful, this is a dreamlike place on a fine summer day, where you can witness one of the most wonderful wildlife scenes in Ireland. Therefore, it is no surprise that the area has quickly become a popular tourist destination in the last few years.

During 2018 and 2019, I had the opportunity to conduct part of my PhD research on the Great Blasket, for which I felt extremely fortunate. This research intended to assess whether disturbances caused by the daily tourism activities, taking place in the area from April to October, were having an impact on the behaviour of grey seals.

I remember my first trip to the island. Accompanied by my PhD supervisor and loaded with fieldwork equipment, we took the ferry from Dunquin Pier with Billy O’Connor (The Great Blasket Island Experience), who made this possible thanks to his great help and hospitality.

We encountered some common dolphins when crossing the Blasket Sound and finally, when we were approaching the island, we spotted the seal colony, with hundreds of seals hauled out on the shore. I realised how special this place was during my first stay on the island. At night, I could hear the noise of the seals vocalising quite loudly, as well as the eerie, strident calls of the Manx shearwaters on their return from the sea. Those sounds accompanied me during the summer nights on the island.

Every day, I woke up in the early morning with that mystical view, I headed down the island to have a first look at the grey seal colony and I set up my camera and scope at the top of the cliff surrounding the beach. During my trips, I enjoyed the island life but I also witnessed how hundreds of seals were regularly leaving their resting site and quickly entering the water due to visitors approaching too close to them to take photos, or moving fast and loud, dogs, drones and, on some occasions, visitors intentionally running towards them. Imagine 800 seals resting peacefully until someone decides that running towards them while filming was a good idea! Vessels passing close to the colony while moving along the beach, increasing their speed at times, also triggered seals to abandon their haul out site. This felt extremely sad and frustrating.

Our study revealed that grey seals were clearly affected by ecotourism, especially by visitors on the beach where seals were hauled out as well as vessels passing along the colony. Approaching vessels at a distance between 250 and 500m also had effect. These activities resulted in seals entering the water, an increase in their vigilance behaviour, a decrease in seals resting, and overall, less seals hauled out.

This is concerning due to several reasons. Grey seals present ‘site fidelity’ (i.e. they don’t easily move to another site) and are highly dependent on these sites to rest after foraging at sea, mate, breed, nurse their offspring and moult. Disturbances could prevent seals from conducting these essential life functions and ultimately lead to habitat displacement.

Where are the seals going when they are disturbed and forced to leave the beach? This is potentially more detrimental to breeding seals and their pups. In Ireland, grey seals breed from September to December, so the tourist season overlaps with part of the breeding season. Disturbances could lead to a decrease in resting and nursing, increasing the energetic demands of mothers and potentially affecting pup survival. Disturbances could also lead to the abandonment of pups, as these cannot enter the water until three weeks after birth.

Despite being a SAC, there are no management plans or regulations in place to avoid disturbances caused by ecotourism, which has continued to grow extensively in the Blasket Islands. This highlights the urgent need for a strict code of conduct for tourists and boats. Our recommendations include reducing vessel speed when approaching the colony and keeping a distance of at least at 250m. Visitors should remain at least at 100m away, avoid all interactions and, during the breeding season, sealwatching should only occur from the top of the cliff surrounding the beach.

The Blasket Islands are undoubtedly a special area, but it is time to move towards better management of SACs and enforcing regulations based on empiricalbased recommendations, so we can give a proper meaning to the ‘conservation’ part as well.

Maria did her PhD in the Marine and Freshwater Research Centre, at the Atlantic Technological University (ATU) in Galway. Her research is published in the journal Aquatic Mammals: Pérez Tadeo, M., Gammell, M., & O’Brien, J. (2021). Assessment of anthropogenic disturbances due to ecotourism on a Grey Seal (Halichoerus grypus) colony in the Blasket Islands SAC, SW Ireland and recommendations on best practices. Aquatic Mammals, 47 (3). https://doi. org/10.1578/AM.47.3.2021.268