Rare limpets found thriving on Westview Park revetment, including species record 

A scientific report commissioned by the Gibraltar government ahead of a proposed reclamation project in the harbour basin has identified over 2000 strictly-protected Mediterranean ridged limpets on the Westview Park revetment, including what is believed to be the largest recorded individual specimen of the rare species. 

The report by Aquareef Tech in February this year recorded 2181 specimens of patella ferruginea on the site’s intertidal zone, with each individual specimen measured and geolocated using GPS. 

The results showed a healthy population dominated by larger individual limpets and reproductive females. 

“This site has also yielded a total of 12 individuals over 12cm in size, and one greater than 13cm, these being amongst the largest reported sizes anywhere within its recorded range, with the latter probably being a new species record,” the report noted. 

The report was published earlier this year as part of the extensive documentation provided in the planning application for the project but its findings have not been previously reported. 

It was flagged to this newspaper by a resident in the area concerned about the proposed scheme, which is set to be debated by the Development and Planning Commission today. 

The reclamation proposal is a Government application and seeks permission to reclaim land from the sea at the western sea front of Westview Park, to create land including for an affordable housing scheme.  

But the project has caused grave unease among many residents in the area worried about its physical and environmental impact, not just on their homes and the waterfront but on port operations too. 

The DPC has received numerous objections to the application, some representing the views of hundreds of residents, raising concerns ranging from the loss of sea views and the Westview Park promenade to potential conflicts with prior contractual and proprietary protections, overpopulation in a small area, the impact of increased traffic and demands on existing infrastructure including utilities and schools. 

‘OPTIMUM ENVIRONMENT’ 

The presence of a large population of rare limpets on the Westview Park revetment will add to the challenge of developing the site, though Gibraltar has in recent years helped pioneer techniques to relocate limpets when needed with significant success. 

Mediterranean ridged limpets are protected under Gibraltar’s nature protection legislation, which mirrors similar EU law.  

The species was once common around the western Mediterranean in Europe and North Africa but started disappearing at the beginning of the 20th century to the point it has almost completely vanished from many European shorelines. 

The Alboran Sea is where it is most firmly established, both on European and North African shores, with Gibraltar one of the places where limpet populations are growing. 

But the species is often found on rock revetments where construction or maintenance often places it under massive pressure. 

Some countries resist moving them as a viable conservation tool but a study in Gibraltar showed that the careful movement of boulders with limpets attached reported survival rates of over 85%, “which opened the doors to further work on the active conservation management of this species via translocation”, the report by Aquareef Tech noted. 

“Most recently, work undertaken by a team of Gibraltar and Spanish scientists that have been working on this species over many years have established a methodology that has generated survival rates of up to 100%, based on careful extraction and relocation techniques following strict parameters and which does not require the moving of any rocks,” it added. 

A spokesperson for the Gibraltar Government told the Chronicle that the plan is to transfer the Westview Park limpets to “other suitable locations” using “established methodology”, adding further announcements on the reclamation project will be made once the DPC has considered the application and any subsequent contractual arrangements are finalised. 

Studies have shown a significant rise in limpet numbers not just in Gibraltar – including along the Westview Park revetment – but in Ceuta too, suggesting a regional phenomenon likely due to ongoing conservation efforts. 

The size of the limpets in the Westview Park revetment suggests “an optimum environment for growth”, particularly given the site was reconstructed following storm damage some 16 years ago. 

The Government said the findings in the Aquareef Tech report were an endorsement of its handling of the protected species in areas under development. 

“These findings are very positive indeed and highlight the successful protection and surveillance measures in place locally to safeguard the species,” the spokesperson for No.6 Convent Place said.  

“The large sized specimens indicate that the sub-population is well established and has an elevated reproductive capacity further justifying the proposed translocation exercise.” 

Separate underwater surveys of the waters off the revetment and the seabed around the extension jetty found no other protected species but noted environmental degradation and “blanket coverage” of invasive seaweed that has plagued the Strait of Gibraltar region in received years. 

Today’s DPC meeting is also due to discuss plans for a new urban wastewater treatment plant at the former Brewery Crusher site, including a new pumping station at Little Bay car park and a transfer pipeline towards and through Keightley Way Tunnel linked to the project.