COLLECTORS FOR NOBLE PEN SHELLS INSTALLED
Collectors for noble pen shells were installed in the waters of Lokrum Island on Saturday, 3 July 2021, as part of the “Preservation of the Noble Pen Shell in the Southern Part of the Adriatic Sea” project, co-financed by the Environmental Protection and Energy Efficiency Fund. The collectors were installed by members of “Dubrovnik“ Diving Club in cooperation with the staff of PI Lokrum Reserve at three locations – two lines in Portoč and one on the west coast – in “Pod Bor” Bay, and will remain in the sea until November, serving as a substrate to which noble pen shell larvae can attach.
The Public Institution Lokrum Reserve signed a partnership agreement to implement the “Preservation of the Noble Pen Shell (𝘗𝘪𝘯𝘯𝘢 𝘯𝘰𝘣𝘪𝘭𝘪𝘴) in the Southern Part of the Adriatic Sea” project, as part of the national program for the preservation of the noble pen shell in the Adriatic Sea.
Activities, which constitute part of the project for preservation of the noble pen shell in the Republic of Croatia, are coordinated by the Ministry of Economy and Sustainable Development, and implemented by public institutions for the management of national parks and nature parks, county public institutions for the management of protected natural values, and the scientific community.
According to currently available data, the state of the noble pen shell (Pinna nobilis) population in the Adriatic as well as in the rest of the Mediterranean is alarming, and the survival of this Mediterranean endemic bivalve is uncertain. The data show that the phenomenon of mass mortality has affected the entire Croatian part of the Adriatic Sea. Given the experiences of other Mediterranean countries, it is necessary to implement preservation measures to prevent the extinction of the noble pen shell. Furthermore, considering the declining number of living individuals in the sea, it is crucial for the survival of the species to find potentially resistant individuals that could further reproduce and create natural “immunity”.
In addition to the protection of surviving adults, the measure implemented throughout the Mediterranean, including Croatia, is the installation of larval collectors and the physical protection of collected individuals from anthropogenic activity or natural predators, which increases the survival rate of the species. The Pula Aquarium currently houses about a hundred live adult noble pen shells in quarantine pools, to keep them alive and try to encourage ex situ reproduction.
The Haplosporidium pinnae parasite is considered to be the main cause of mass mortality, but it has not yet been confirmed whether it is its only cause. What is known is that elevated sea temperatures contribute to the spread of pathogens and accelerate the disease process. Taking into account the level of endangerment and the synergistic effect of threats, including global climate change and the sea temperature rise that contributes to the spread of pathogens and high mortality, it is urgent to implement preservation and adaptation measures to try to prevent the extinction of this species.
Activities that the Public Institution Lokrum Reserve will carry out in order to preserve the noble pen shell are the installation of collectors in the waters of the Island of Lokrum, transport of collected juveniles to the Pula Aquarium, and education on the importance and significance of this endemic species in marine systems.
