(2) Pink Sea-fan (Eunicella verrucosa)
Species Action Plan 1999
Pink Sea-fan (Eunicella verrucosa)
• Current status
• Current factors causing loss or decline
• Current action
• Action plan objectives and targets
Proposed actions with lead agencies
• Policy and legislation
• Site safeguard and management
• Species management and protection
• Advisory
• Future research and monitoring
• Communications and publicity
• Links with other plans
• Lead partner
• Local implementation
• Publication details
Current status
The pink sea-fan Eunicella verrucosa is widely distributed in south-west Britain between north Pembrokeshire and Portland (Dorset). In the Bristol Channel the eastward extent is to approximately Combe Martin (north Devon). The pink sea-fan also occurs on the west coast of Ireland and southwards into the Mediterranean.
Sea-fans attach to the rocky seabed usually on upward-facing bedrock or stable boulders at depths below the limit of algal domination (as shallow as 3 m in the turbid waters of north Devon, but more generally deeper than about 15 m). The sea-fan, a passive suspension feeder, is attached to the seabed by a broad base extending to a column. The column may be up to 8 mm in diameter and branches profusely from approximately 20 to 40 mm above the base. The thickness of the branches increases with age and annual growth rings are present in the axis. Branching is usually in one plane, which is orientated at right angles to predominant water currents. At some locations in Southwest England, sea-fans occur in 'forests' but in most locations, individuals are widely separated. The species appears to recruit infrequently and large specimens may be as much as 40 years old.
The pink sea fan may be found in the following JNCC Marine Nature Conservation Review (MNCR) biotopes: Alcyonium digitatum with massive sponges (Cliona celata and Pachymatisma johnstonia) and Nemertesia antennina on moderately tide-swept exposed circalittoral rock (ECR.AlcMaS) (usually in local shelter); Phakellia ventilabrum and axinellid sponges on deep exposed circalittoral rock (MCR.PhaAxi); Erect sponges, Eunicella verrucosa and Pentapora foliacea on slightly tide-swept moderately exposed circalittoral rock (MCR.ErSEun); Cushion sponges (Polymastia boletiformis, Tethya), branching sponges, Nemertesia spp and Pentapora foliacea on moderately exposed circalittoral rock (MCR.ErSPbolSH).
The pink sea-fan is a host species for another BAP priority species: the sea anemone Amphianthus dohrnii. The pink sea-fan is protected under Schedule 5 of the Wildlife and Countryside Act 1981 against killing, injuring, taking possession and sale.
Current factors causing loss or decline
The collection as souvenirs, including commercial collection, occurred during the late 1960s and may have reduced populations in the long term.
The effects that climate change may have on the current UK distribution of this species is not known. Natural environmental factors affecting pink sea-fan populations globally need to be identified in order to differentiate them from local, anthropogenic impacts.
The long-term effects of intensive potting and netting on local populations are not known and need further investigation. However, entanglement in fishing nets and line is a problem in some areas; it is known to damage soft tissue and may ultimately severely damage or kill colonies. Fin-strike damage by scuba divers on pink sea-fan colonies may also be detrimental.
Sea-fans can die whilst still attached to the seabed after becoming smothered by other organisms (such as by ephemeral seaweeds at shallow depths during early summer).
Current action
The awareness amongst recreational divers of the long life and slow growth of the sea-fan has been promulgated since the mid 1970s and it is important to retain this education.
Part of the study on the impacts of potting was directed at establishing the importance of bottom gear on the survival of the pink sea-fan. This provided valuable information in determining management measures to protect the species.
The zoning schemes for Lundy and Skomer Marine Nature Reserves (MNRs) were both established to, in part, reflect the sensitivity of the pink sea-fan to various factors. This approach should be extended to other marine protected areas.
Action plan objectives and targets
Ensure that the pink sea-fan maintains its current abundance from the 1998 baseline.
Ensure that the pink sea-fan maintains its current geographical distribution from the 1998 baseline.
Proposed actions with lead agencies
Policy and legislation
None proposed.
Site safeguard and management
Ensure that the management of Special Areas of Conservation (SACs) and Marine Nature Reserves (MNRs) takes account of the pink sea-fan. (ACTION: CCW, NE)
Ensure that areas with significant populations of pink sea-fan in non-statutory (voluntary) marine protected areas are identified as being of appropriate sensitivity within management zoning schemes. (ACTION: CCW, NE)
Undertake management measures to ensure human activities do not compromise known populations of the species. (ACTION: NE, SNH)
Species management and protection
Investigate causes of decline and take the appropriate management response where human activities are implicated. (ACTION: CCW, NE)
Advisory
Increase awareness among coastal zone management groups, divers and inshore fishermen of the sensitivity of the pink sea-fan in locations where it is known to exist. (ACTION: CCW, NE)
Future Research and Monitoring
Continue to monitor the abundance and condition of sea-fans as a part of established monitoring work and ensure that they are included in SAC monitoring programmes, where appropriate. (ACTION: CCW, NE)
Undertake a programme of spot surveys in three years between 1999 and 2004. The surveys are to be conducted at locations where pink sea-fan are known to occur, from ‘forest’ areas to areas where abundance is sparse. Sites at the present limit of distribution should also be included. This can be linked to long-term monitoring of climate change. The data to be recorded should include density, size structure, colour, ‘fouling’, percentage ‘infestation’ by predators (the seaslug Tritonia nilsodhneri, and the prosobranch Simnia patula). Data is also required on the occurrence and density of the sea-fan anemone Amphianthus dohrnii (often found attached to the pink sea-fan). (ACTION: CCW, NE, NERC)
Research the factors which affect recruitment and survival of pink sea-fan. Report by end of 2004. (ACTION: NERC)
Communications and Publicity
Provide information on the pink sea-fan and Amphianthus dohrnii. Distribute as appropriate to recreational divers and lobster potters through leaflets, posters, displays and talks. (ACTION: CCW, NE)
Consider including in public aquaria (with Amphianthus dohrnii) to increase general awareness of marine biodiversity. (ACTION: CCW, NE)
Synthesise and disseminate data from existing sea-fan monitoring and research programmes as appropriate. (ACTION: CCW, NE)
Links with other action plans
None given.
Local implementation
The following LBAPs are working on Eunicella verrucosa:
A Local Biodiversity Plan for Pembrokeshire
Action for biodiversity in the South-West, a series of habitat and species plans to guide delivery
Cornwall’s Biodiversity vol 1, 2 and 3
Devon Biodiversity Action Plan
Teignbridge BAP
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume V: Maritime species and habitats (October 1999, Tranche 2, Vol V, p85)
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