In 2016, an outbreak of one disease caused the mortality of 99% of its population in Spain. The cause of the disease was a newly discovered
pathogen,
Haplosporidium pinnae, which still poses a serious threat to the survival of the species. By 2019, mortality spots had been detected in
Greece,
Croatia,
Turkey,
Tunisia,
France and
Morocco. In the
Trieste area, considerable efforts have also been made to conserve the deposits since 2020. In the past,
Pinna nobilis faced extinction, due in part to fishing, incidental killing by trawling and anchoring, and the decline in
seagrass fields; pollution kills eggs, larvae, and adult mussels. The noble pen shell has been listed as an endangered species in the Mediterranean Sea. The European Council
Habitats Directive 92/43/EEC, on conservation of natural habitats and the wild fauna and flora, proclaims that
P. nobilis is strictly protected (by the Annex IV of EEC, 1992) – all forms of deliberate capture or killing of fan mussel specimens are prohibited by law. As part of the
Costa Concordia disaster recovery effort in Italy in 2012, a group of about 200
Pinna nobilis was relocated to a nearby area due to the threat posed by subsequent engineering work. The
byssus of
Atrina pectinata, a shell of the same family, has been used in
Sardinia as a substitute for
Pinna nobilis, to weave
sea silk. == Protection ==