Castlewellan Lake ASSI

Protected area type: Areas of Special Scientific Interest
Feature type: 
  • Habitat
  • Down
Council: Newry, Mourne and Down
Guidance and literature: Castlewellan Lake ASSI

The site, Castlewellan Lake, is a mid-altitude lake that lies in the valley between Slievenaslat and Slievebeg, within the grounds of Castlewellan Forest Park.

It has been declared as an ASSI because of its aquatic flora and fauna, which are dependent on the unpolluted water and low levels of nutrients. 
The diverse substrate of the lake ranges from boulder and rock, to sand and gravel on the deeper waters. This provides a variety of niches for a wide range of plants and animals.

Such lakes are becoming increasingly rare in Northern Ireland due to pollution.

The floral interest in the site is focused on the aquatic plant community which is dominated in the shallows by shoreweed, while the rare quillwort is found in the deeper waters. Pondweeds and alternative water-milfoil form submerged beds. The site is also valuable for wetland animals including birds and invertebrates. There is evidence that otters regularly frequent the site.

Back to top