THREATS & LEGISLATION

Fishing
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. Increased amounts of angling line can cause abrasion, facilitating colonisation by epibionts and necrosis.

A code of practice should be introduced for anglers, highlighting consequences of discarding line. An example of the damage that can be caused by discarded fishing line is pictured above.

For video evidence of sites both before and after scallop dredging see below:

View the latest damage to the Lyme Bay Reefs

Scallop dredge damage to reef_Video by Colin Munro

Lyme Bay reef pre-scallop dredging (1995) and post dredging (June 2006) Video by Colin Munro

Video footage of scallop dredging by Jason Hall-Spencer, University of Plymouth

Climate Change
The effects that climate change may have on the current UK distribution of this species are not known. Natural environmental factors affecting pink sea-fan populations globally need to be identified in order to differentiate them from local, anthropogenic impacts. Increases in sea temperatures may encourage spread of Eunicella, but could also increase epibiont and bacterial growth, and the spread of the warm-water barnacle Solidobalanus.

Boat Damage
Dredge/Spoil and anchor damage. Particularly from dive boats.

Biological Factors
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).

The prosobranch predator Simnia patula	Tritonia nilsohdneri, which feeds on the sea fans	The rare anemone Amphianthus dohrnii, another BAP species which lives exclusively on seafans.
Dogfish egg attachment	Algal growth	Aggressive settlement by fouling organisms

The cause of necrosis that is killing off pink seafans on the southwest coast of Britain has been identified by marine biologists from the University of Plymouth.

Scientists from the university have established that colonies of the pink seafan, have become infected with a species of bacteria known as Vibrio splendidus. This is killing the cold-water corals by producing enzymes that attack their tissue. Some scientists suspect that the disease may be linked to higher water temperatures which stress the corals and reduce their natural resistance, or help harmful bacteria to thrive.

Diseases increasingly affect tropical corals but this is the first record of disease affecting cold-water corals. What triggers the disease is still unclear, but it could be due to extreme temperatures or pollution.

Left: Bacterial infection, which may be exacerbated by climate change or pollution.