CYNGOR CEFN GWLAD CYMRU
COUNTRYSIDE COUNCIL FOR WALES
SITE OF SPECIAL SCIENTIFIC INTEREST: MANAGEMENT STATEMENT
YNYS MÔN GLANNAU PORTHAETHWY
Date of Notification:
Site Area: 67.6 ha
This management statement contains CCW’s opinion of the way in which the SSSI should be managed in order to maintain its special interest. It also provides a basis for future discussions and decisions on the conservation management of the SSSI. It is important that any works described in this statement are fully discussed with and formally consented by CCW, before any of these management activities are started.
The document sets out a vision for the features of interest; it describes the key issues affecting those features and outlines any management considered necessary to safeguard the features.
It is very important to recognise that management may need to change with time. Problems that we are aware of today may be resolved or completely removed and new unforeseen problems may arise. New improved management techniques may also become available. Consequently the management outlined in this document is considered appropriate for the short term but may need to change in the long term.
Features of Special Scientific Interest:
The greatest diversity of marine plant and animal communities on this type of shore between Bardsey Island and Great Orme’s Head.
Five communities of restricted national distribution:
Sponges, sea-squirts and serrated wrack on tide-swept lower shore rock.
Sponges, sea-squirts, red seaweeds and serrated wrack found on a tide-swept mixture of mud, sand, cobbles and pebbles.
Oarweed, sea-squirts and sea-mats on tide-swept lower shore rock.
Knotted wrack with sea-squirts and sea-mats on tide-swept mid-shore rock.
Lower shore muddy gravel inhabited by a diverse group of small marine worms.
Five species-rich specialised communities of marine plants and animals:
Seaweeds in sediment-floored rockpools.
Sponges, sea-squirts and sea-mats on bedrock overhangs.
Sea-firs, ephemeral seaweeds and periwinkles in mixed sediment tide-pools.
Sponges and shade-tolerant red seaweeds on bedrock overhangs.
Brown seaweeds (fucoids) and kelps in deep rockpools
The most comprehensive example of sheltered rocky shore community zonation in this area.
The most extensive wave-sheltered rock shore between Bardsey Island and Great Orme’s Head.
As well as the features listed above, Glannau Porthaethwy SSSI has other habitats that are essential to the maintenance of the special wildlife interest. These include maritime cliffs, grassland and small islands. This diversity of habitats similarly supports a wide range of species and these too are a key component of the special interest of the site. Unless it is specified below, management of this site should aim to look after these habitats as well as the listed features of interest.
The greatest diversity of the communities present on shores in the area.
Fifty-one marine communities have been recorded at the site, making it the most diverse example of wave-sheltered rock shores in this area. This range of communities should be maintained, subject to natural variation in the marine environment.
Five communities of restricted national distribution.
The important tide-swept communities should continue to be found on the site and should not decrease significantly in extent, subject to natural variation in the marine environment.
Five species-rich communities of marine plants and animals.
The rockpool and bedrock-overhang communities on the site should continue to be found here. Each contains at least seven major groups (‘phyla’) of plants and animals (such as worms, sponges, red seaweeds, shelled-animals) and the overall diversity of species in each community is high. The presence and diversity of these communities should be maintained, subject to natural variation in the marine environment.
The most comprehensive example of community zonation patterns.
Complete zonation of twelve typical rocky shore communities (up to nine at any one point) currently covers over 300 m of the site. The extent of this zonation and the range of communities involved should be maintained, subject to natural variation in the marine environment.
The most extensive sheltered rock shore in the area.
The area of this rocky shore should be maintained at the level recorded in CCW’s survey of 2001, subject to natural changes. The quality of the component communities, as described above, should also be maintained.
Key Management Issues:
Communities on this shore are subject to natural fluctuations in distribution, extent and species composition, attributable in part to random events such as storms and other seasonal and temporal changes. It is important to monitor the communities carefully so that natural cycles can be distinguished from human influences.
The shore’s diversity and proximity to the University of Wales, Bangor’s School of Ocean Sciences, based in Menai Bridge, has resulted in a heavy demand on the area for both field work and the collection of biological specimens. This usage of the area has been taking place since the 1960’s, but demand has increased substantially in recent years. Areas subject to intensive trampling or collecting on such trips may be adversely affected, through damage to or removal of species that contribute to the site’s diversity. Whilst CCW supports continued study of this area, we plan to work with the School of Ocean Science to develop a programme whereby education studies undertaken on the shore contribute to the understanding and management of this site. This would provide a framework of collaboration and consultation where CCW can advise on the fragility of certain habitats, identify any particular issues of concern and identify the most appropriate ways of minimising impact on the shore.
Trampling, as a result of intense visitor pressure, can have a detrimental impact on shore communities. However, it is not thought that recreational use of the shore is detrimental to the marine features at present. If trampling is perceived to be a factor in future, CCW will work with owners, occupiers, interested parties and other agencies to provide information to visitors regarding the biological sensitivity of the site, with the intention of minimising disturbance to important features.
The collection of bait for fishing is recognised as a legitimate activity on this shore. Boulders in certain areas of this site are turned over on the shore by anglers searching for “peeler crabs” (crabs that have recently shed their shell, so are soft to touch) to use as bait. Low intensity, small-scale collection is unlikely to have marked long term impacts on the shore’s diversity, so long as boulders are returned to their original positions. As such, it is not thought that use of the shore for bait collection is of detriment to the marine features at present.
However, an increase in the level and intensity of bait collection (boulder turning) at this site may have a detrimental impact on the marine animals and plants of the under-boulder communities. As part of the management of the site, therefore, the scale of boulder turning should be monitored, to enable better understanding of the extent of this activity and its likely impact. CCW is concerned about the sustainability of bait collecting in the Menai Strait as a whole. We consider that sustainable management of bait collection throughout the Strait could be achieved most effectively through the interested groups and individuals agreeing practices that balance the needs of bait collectors with those of other interests, including habitat and species conservation. The needs of commercial bait collectors must also be recognised and accommodated in the Strait in appropriate locations.
The placement and use of boat mooring structures can cause localised damage to the soft sediment communities of interest on this shore, but it is considered that the existing moorings do not pose a significant threat to the integrity of the site. If further moorings are required they should be sited in the least sensitive habitats at the site, in consultation with CCW.
There is currently no evidence that recreational fishing (angling, shrimping etc) is having any detrimental effect on the marine communities of special interest on this site.
There is currently no significant commercial fishing within the site. If any such operation is proposed CCW will work with the relevant bodies to avoid damage to the features of importance.
Coastal protection works
Coastal protection structures have been built along most of the shore, and in places provide a suitable substrate for marine lichens and seaweeds. As erosion is a natural process that is integral to the quality of the shore, however, the building of further sea defences will be discouraged. Issues of overriding public interest will, however, be considered on a case-by-case basis. CCW should be consulted over any plans to conduct works on existing coast protection structures.
The marine communities are vulnerable to pollution from land and sea, such as oil spills, sewage outfalls and fertiliser run-off from farmland. Nutrient enrichment of the shore could adversely affect the diverse balance of life in the marine communities for which the site is notified and should, therefore, be prevented or, in the case of outfalls and drains, carefully sited after liaison with CCW. Precautionary measures to guard against such pollution will be encouraged by CCW working together with other statutory organisations with responsibility for pollution control, e.g. the Environment Agency. CCW, together with a number of other statutory agencies and other organisations is already involved in pollution contingency planning work and would work with these groups to try to minimise the impact of a pollution incident.