The recent discovery of three young specimens of the critically endangered noble pen shell in the Debeli Rtič Landscape Park has sparked a wave of enthusiasm among both experts and the general public. However, this success story carries a deeper message that touches the very core and mission of the RISTANC project – the importance of comprehensive integration and shared responsibility for our nature.
An Extraordinary Discovery in the Debeli Rtič Landscape Park
Over the past few months, researchers from the Marine Biology Station Piran (National Institute of Biology) spotted three live young specimens of the noble pen shell (Pinna nobilis) within the Debeli Rtič Landscape Park. This news is of paramount importance, as this species, endemic to the Mediterranean Sea, has become one of the most endangered bivalves in the entire Mediterranean due to mass die-offs in recent years. Despite extremely difficult conditions and the near-total extinction of adult specimens in our sea, new young individuals still occasionally appear.
Their reappearance specifically within the Debeli Rtič Landscape Park is no coincidence. With its well-preserved marine habitats and underwater meadows, the area represents a key sanctuary and one of the last safe zones for the conservation of this critically endangered species in the Slovenian sea.
What is the Noble Pen Shell and Why is it Fighting for Survival?
The noble pen shell is the largest bivalve in the Mediterranean Sea, capable of growing up to 1.5 meters in length and living for several decades. As a filter feeder, it plays an invaluable role in cleaning the marine environment, while its hard shells provide a home and habitat for numerous other organisms, ranging from tiny algae to sponges and bryozoans. One could say the pen shell acts as a sort of underwater "builder" or ecosystem engineer of the marine environment.
Years ago, however, the population was struck by a catastrophic epidemic caused by a parasite combined with certain bacteria. The mass mortality destroyed nearly 99% of all noble pen shells in the Mediterranean, making every newly discovered live individual a new beacon of hope for the species.
Connecting Science, the Local Community, and the Public
When the Municipality of Ankaran (a partner in the RISTANC project) published this wonderful news, we in the team were particularly inspired by the wave of positive reactions and comments under the post. People expressed concern, support, and a readiness to help. These comments serve as proof that residents and visitors feel a sense of belonging to our sea and genuinely care.
And this is the common thread of the RISTANC project! Long-term and successful nature conservation can never happen in isolation or merely through prohibitions on paper. Success is only achieved through the synergy of three key pillars:
Science and Profession: Researchers who monitor the situation in the field, look for solutions, and provide precise data (such as the discovery of these three pen shells).
Local Community and Managers: Partners, such as all four coastal municipalities, who take care of systemic spatial planning and monitor compliance with the rules.
The General Public and Visitors: Every individual who receives the information, internalizes it, and acts responsibly in their daily lives.
When these three worlds connect, theory becomes practice, and protected areas truly begin to come alive and show tangible results.
A Summer Reminder: Anchoring as a Direct Threat
During the summer months, the area of the Debeli Rtič Landscape Park (and the Northern Adriatic in general) is under great pressure from visitors and vessels. The nature conservation status of the park and the efforts of researchers cannot protect young bivalves from heavy anchors and boat chains if vessel users are not careful.
Anchoring represents one of the major direct threats to the noble pen shell (as well as to other organisms, such as seagrass meadows and stony corals), as it can physically damage or completely uproot specimens attached to the seabed. Therefore, we take this opportunity to call once again for strict compliance with marine protection regimes:
| Threat | Responsible Behavior |
| Anchoring on underwater meadows and damaging the seabed | Be careful not to anchor in areas where seagrass meadows are present, and never anchor within the zones of Landscape Parks where it is prohibited. |
| Physical contact and disturbing organisms | If you spot a pen shell or other organisms while diving or swimming, do not touch them. Admire them from a distance and do not interfere with their surroundings. |
| Noise and pollution | Reduce vessel speed near the shore, respect marine peace, and do not discard any waste into the sea. |
Only through responsible behavior, mutual cooperation, and consistent respect for nature will we be able to preserve the Slovenian sea as a safe haven for rare and endangered species. The three young pen shells at Debeli Rtič have given us an opportunity and hope – now it is up to us, through our joint efforts, to ensure them a safe future.