What's up with the noble pen shells of Blanes?
What are the noble pen shells?
The noble pen shell (Pinna nobilis) is the largest bivalve mollusc of the Mediterranean sea and one of the World’s largest. It can reach over a meter long. However it lives half buried in the sand, so it is difficult to appreciate its actual length. It is found between 2 and 50m deep in soft-sediment areas overgrown by the seagrasses Posidonia oceanica, Cymodocea nodosa, Zostera marina and Zostera noltii. It feeds on plankton by filtering the surrounding water which it contributes to its transparency. Its predators are sea stars and carnivorous snails. Remarkably, while being alive it already offers a habitat to sponges and worms that colonise its outer shell and, inside, small crabs and shrimps are often found.
Since ancient times its byssus, the turf that keeps it ancored to the sea bed have been greatly appreciated. Till present it is still used to producte the sea silk, an outstanding fabric for its resistance, flexibility and golden colour. More information >>
LEVEL OF PROTECTION: strict protection according to the European Council Directive (92/43/EEC). Fishing is banned.
-Poaching: its shells are appreciated for their size
-Death due to the impact of boat's anchors
-Parasite of the gender Haplosporidium: once it reaches the digestive system it causes its death. First cases were reported during 2016 and presently it is at the category of massive mortality affecting the Mediterranean coast of Spain (ïncluding the Balearic islands) and some populations of France and Italy
In this scenario from S’Agulla we wonder about what is the state of the known population of noble pen shells at Punta Santa Anna (Blanes, Spain).
Presently the area is marked with buoys to prevent yachts getting too close to the shore. As soon as the Summer season is over the survey will begin.