In this month’s Manx Wildlife Trust column, Peter Duncan takes a look at the Manx Marine Nature Reserve of Baie ny Carrickey (Carrick Bay).
The Baie ny Carrickey (or Carrick Bay) Marine Nature Reserve is centred in Port St Mary in the island’s south, and has a total area of 11.4 km2.
The history of the area as a marine protected area actually dates back to around 2012, when the bay was closed to mobile fishing gear (trawls and dredges) as a mechanism to reduce fishing gear conflict between dredges and creels.
The perception was that the heavy, towed gears used for scallop fishing were damaging both the rocky reef habitats and also the valuable lobsters that lived among them. The solution was to separate the two types of fishing on either side of the boundary, a successful situation that still exists today.
Subsequently, when the designation of marine nature reserves was being considered, the wide range of important species and habitats within the area, and that bottom-towed gears were already excluded, meant that it was an obvious candidate.
Baie ny Carrickey is characterised by the local, rocky geology, and three hard-rock habitats that highlight the reserve’s diversity are the sea stack, known as the Sugarloaf, the fossil-bearing limestone of Port St Mary ledges, and the rocky seabeds that support the dense kelp forests of the bay itself.
The Sugarloaf is a seastack on the eastern side of Baie Stacka and is one of the most important seabird nest sites on the island, and probably within the Irish Sea as a whole.
From around April to late summer, hundreds of pairs of guillemots, razorbills and kittiwakes make this rock their home, raising their chicks and feeding and resting offshore.
This spectacular annual sight can be viewed best from the Chasms, or by taking a boat trip around Bay Stacka, perhaps as part of a trip to the Calf.
Moving further along the coast, the remains of a 300 million year old sub-tropical lagoon form the famous limestone ledges.
For various reasons, chiefly wave exposure, the rocks themselves are bare, but below the tidal range there are luxuriant kelp forests off Port St Mary.
However, there is still interest in the bare rocks, where ancient sea creatures can be found embedded in the limestones. Notably some of the fossil animals are the ancestors of living animals still living in Carrick Bay.
Carrick Bay itself is characterised by rocky habitats which were mapped by Bangor University and produced a report on the bay, which you can find at http://sustainable-fisheries-iom.bangor.ac.uk/index.php.en
A seabed map shows the progression from rock and kelp dominated seabed in the outer, southern part of the bay to finer mixed sediments and sand closer to the beach.