Golfe de Porto : calanche de Piana, golfe de Girolata, réserve de Scandola

The land part of the property represents 8130 ha or 70% of the area. Of this portion 0.61% is urbanized and 50 km of roads are present. The rest of the land area is inaccessible to the public and hiking trails are rare (74 km). On the marine part, three sectors are mainly frequented: Scandola, Girolata, Capu Rossu, representing less than 35% of the coastal linear of the property. However, in these sectors, the rapid increase in visitation by motorboats has resulted in a general decline of marine biodiversity (Préfecture de Corse, 2025). Not only is wildlife threatened by this excessive boat traffic, but the entire landscape values of the property are compromised, given the steady stream of tourist boat traffic going back and forth and queuing to enter the grottos, often using loudspeakers and light shows. Ultimately, there is extreme pressure on the fauna and landscape values due to tourism.

The problem started because the terrestrial part of the property had comprehensive legal protection but there was no corresponding legislation for the marine part and motorboat activity to view the remarkable landscape and marine biodiversity increased exponentially, leading the property to lose its European Diploma in 2020 (Biber, 2019; Siblet, 2019; e.g. GEO, 2020). As tourism is of high economic importance, the “acquired right” of boats to navigate in the property has led to severe conflict. The government recognizes that the various pressures including “anchoring, wildlife disturbance, underwater noise, ship damage to habitats or the introduction of invasive alien species” are “incompatible with the long-term objectives of preserving the natural heritage carried out by the protected area” (Préfecture de Corse, 2025). It is estimated that around 11,000 boats navigate in the reserve from April to October, with a mean of 50 boats/day with 159,000 visitors, which is an increase of 6% in 12 years (Figaro, 2025). The boat counts carried out by the PNRC staff in the Scandola reserve however show a decline in nautical attendance in recent years, going from an average of 56 boats in instantaneous count at midday in summer 2020 to 17 boats in 2023 (PNRC 2023). An update of this study was commissioned in 2024 by the OEC and the results are expected in 2025 (IUCN Consultation, 2024).

Various provisions have targeted the problem posed by tourism. Contractual measures (Natura 2000 charter) and regulatory measures have prohibited navigation near osprey nests when they are breeding and a number of decrees to improve the situation have been made e.g. prohibiting anchoring of vessels > 24 m in the entire Posidonia meadow; prohibiting navigation around all breeding nests, from the beginning of May to the end of July; speed limit of 5 knots within 300 m of the coast; prohibiting navigation around the UNESCO World Heritage Site "Gulf of Porto" for vessels with a tonnage of ≥ 500 UMS.

Resolution 25/023 AC of the Corsican Assembly on the draft decree establishing the Scandola Nature Reserve calls for the establishment, within the perimeter of the Scandola Nature Reserve's fully protected area, of a professional and recreational boating licensing system authorizing navigation, both quantitatively and qualitatively, based on the obligation, for all beneficiaries, of training and compliance with good environmental practices. The proposed decree of 2025 still under debate. The public consultation ended in February 2025 with a large majority in favour of stronger rules in order to protect the marine reserve, but no consensus has been reached (Francetvinfo, 2025). Nevertheless, since 2020, the Corsican Environment Office has implemented several important actions to contribute, in coordination with the SMPNRC, to achieving the objectives of the proposed decree: 1) Long-term monitoring of osprey nests, not only across the RNS, but also along the entire island coastline; 2) The intensification of the animation of the “Natura 2000” network, allowing fruitful exchanges with socio-professionals, in a logic of collective preservation of the natural heritage, in particular, of the osprey, from Calvi to Carghjese. In this perspective, the principles of non-disturbance of all nests, in the breeding phase, over a time period, as long as possible but corresponding to the ecological reality of the species, then the tranquilization of occupied nests were recorded and concretized. Discussions were initiated with the Maritime Prefecture, to determine the feasibility of setting up a system of licenses, intended for socio-professionals and pleasure boaters, limiting, quantitatively and qualitatively, nautical attendance during the summer season; 4) The prefiguration of the Corsican Nature Reserve project, on the North-West maritime coast, during the first technical consultation meetings with the territory’s stakeholders; 5) And finally, the request for the modernization process of the decree creating the Scandola Nature Reserve to introduce, in particular, the possibility of regulating anchoring and overflight of drones.

Osprey breeding monitoring results suggest that the population is stable and that the breeding success rate, which fell sharply in the early 2010s, now appears to be holding steady. Therefore, there was no downward trend between 2020 and 2025.
Between 1999 and 2012, the main breeding monitoring indicators experienced significant interannual variations, particularly with regard to the number of fledglings. However, the number of pairs with eggs remained stable over time between 1998 and 2024, with an average of 21 pairs (Faggio et al., submitted). Furthermore, statistical analyses indicate that there is no "nest effect" or "year effect" between 2020 and 2024 (Lathuile, 2024). Concretely, this indicates that there is no difference in reproductive success over the last four years, including the two years with minimal boating activity due to travel restrictions during the COVID periods and that nests known to be popular with boaters do not perform worse, nor better, than nests where there is little tourism.

Regarding marine biodiversity, between 2015 and 2023, assessments of the EBQI reef index were conducted at 96 sites along the French and Monegasque Mediterranean coasts (Jacob et al. 2024). The objectives of this article were to establish a framework for assessing the IRR of the French Mediterranean using the EBQI reef index and to analyse the influence of local specificities, management practices, geomorphology, and anthropogenic pressures on the ecological status. The 4 areas of the Scandola Nature Reserve are all ranked with an EBQI score allowing 3 of them (Gargalu, Palazzu, Solana) to be considered as being in high i.e. good condition (13 sites out of 93) with a score above 7.5 (max 8.92). Another area (le site des orgues) is considered to be in good condition with a score of 7.38 (15th out of 96 sites on the French Mediterranean coast) (OEC-APMIL, 2025). These results show a good quality of the rocky environments of the RN of Scandola, even though they are subject to the highest tourist traffic within the perimeter of the property.

Fishing is allowed in some parts of the property and seasonal professional fishing activities (trammel nets, longlines and traps) are carried out from March to October, with at most six small boats fishing at the same time. Recreational and spear-fishing is not allowed, but does occur illegally (Tavernier, 2014; CdeC et al., 2015). Trammel nets are of concern as selectivity is lower with catches of small organisms and non-target species, and if lost they become ghost nets. However, fishing in the property is considered to be sustainable (Le Diréach et al., 2018).

A recent mission of the WWF (Estaque et al. 2023), attests to a high biomass and abundance of species sought after for fishing in the perimeter of the nature reserve, including the sector where professional fishing is practiced (no recreational fishing). These values rank the reserve among the 3 richest in the Mediterranean. In contrast, the rest of the maritime sector reaches low values, suggesting that recreational fishing has a strong impact on resources. There were 15 fishing boats in the ports of the sector in 2015 (Santelli and Cannac , 2015) and 10 in 2024 (OEC observations).

In Corsica, the partnership enabling the collection of fisheries data between scientists, managers of protected areas and artisanal fishermen is long-standing. Initiated in the island protected areas, it began in the former Lavezzi Islands nature reserve in 1992 (Culioli, 1994) and was then extended to the entire Bucchi di Bunifaziu nature reserve between 2000 and 2024 (Culioli et al. 2023). At the regional level, a series of sea sampling campaigns was financed by the Corsican Environment Office (OEC) between 2004 and 2012 on all island fisheries in collaboration with Stareso and then at the initiative of the DGAMPA. From 2017, these different fishing campaigns were homogenized within the framework of the DACOR project (2017-2020 Measure 28 of the EMFF). The marked poly-activity of small-scale coastal island fishing, associated with multi-specific catches and exclusively passive fishing gear is also recognised for its good practices and moderate fishing effort (Santoni et al., 2024). According to an analysis of OEC fisheries data from the Porto-Galeria sector between 2018 and 2023, the average profitability of a fishing net is equivalent to the average CPUE recorded across Corsica (OEC, 2025).

In its marine part of the reserve, two invasive algae and potentially other species have been recorded as problematic in areas which have previously been damaged. In the terrestrial part of the property, invasive alien species are less of an issue although certain introduced species such as Opuntia need to be monitored (Tavernier, 2014). Black rats are a problem on Ile Gargalu where Scolopi's Shearwater breed, and efforts to control the rat population (as well as the invasive plant Carpobrotus spp. which has been associated with black rats) have been undertaken since 2021 (CREEE, 2024). An action plan to limit the presence of rats on the island in the Scandola nature reserve housing a colony of Scopoli's Shearwater began in autumn 2023 (Braschi et al, 2023).

Invasive alien species monitoring networks are in place at the regional or Mediterranean scale for both the terrestrial environment and the marine environment. For terrestrial plant species, a strategy is defined at the regional scale by the National Botanical Conservatory of Corsica (Petit & Hugot , 2019). Within the perimeter of the property, 30 proven or potential IAS are present, including 22 terrestrial plant species. For the marine environment, 3 plant species (6 locations) and 3 animal species (3 locations) have been identified.

In 2013, the World Heritage Committee requested the State Party to provide further details on the project to widen the D424 and D81 roads (WHC, 2013) to make traffic safer. The D424 has been widened over a 2.5 km section, and the impact study has taken into account the OUV of the property. The D81 road is narrow and doesn't allow vehicles to pass each other everywhere. Alternating traffic for large vehicles is the only solution to avoid damaging this section with widening work that would be detrimental to the geological and landscape quality. The situation has improved thanks to the introduction of alternating traffic during peak periods.

However, the current situation of road traffic, even alternating, through the Calanche de Piana presents a threat to visitor appreciation of the exceptional landscape and geological features in this part of the property.

Climate change in Corsica is characterized by three essential factors: rising temperatures, changes in water regimes and rising sea levels. Based on historical data by Météo France at Ajaccio and Bastia, between the 1950s and today there has been a 1°C increase in global temperature. (Cerema, 2021). The coastline appears particularly vulnerable to induced changes, directly or indirectly, through climate change. The marine environment will also be particularly impacted, in terms of seawater quality or conservation of ecosystems and their species (Laffoley et al., 2018; Montero‐Serra et al., 2019). There has been a demonstrated negative impact of climate change (rising sea level) on Lithophyllum algae (Blanfuné et al., 2023) and a 70% reduction in red coral since 2003, with an estimated coral loss of 70% in the Scandola reserve (Cerema, 2021).

The origins of climate change are global and difficult to resolve at the local scale apart from the implementation of good practices and the preservation of natural habitats. In the municipality of Piana, the annual average air temperature increased by 2°C between 1979 and 2023 (source meteoblue ). The phenomenon is also marked on the surface marine environment causing variations in zooplankton blooms which have an impact on the food chain. Climate change mainly leads to the development of extreme phenomena such as the storm of August 18, 2022 which caused numerous boat sinkings or the heavy rains of November 3, 2023 causing gullies of waterways, landslides and filling of the port of Porto. The direct impact of climatic events on wildlife remains to be researched, particularly on the osprey during the most delicate periods of reproduction (heavy rains, stormy winds, significant swell, etc.) (IUCN Consultation, 2024).

Currently, marine pollution seems to mainly concern the presence of micro and macro plastic waste at sea or washed up on certain sections of the shore. However, the beaches are less polluted than other sites in Corsica, but the problem is recurrent in the Mediterranean. On the other hand, the presence of biomedia from wastewater treatment plants is very low compared to the east coast of Corsica. The study of intertidal algal biocenoses indicates a very good ecological state (Thibaut et al 2011). The work to develop the management plan highlights the need to have a POLMAR sea unit on site in the event of accidental pollution caused by a ship. The high number of boats in the property increases the risk of marine pollution from engine discharges (even if there are also an increasing number of electric boats). More significant oil pollution could occur in the event of an accident (shipwreck, natural disaster) and cause significant damage to the property (Tavernier, 2014).

The POLMAR system is operational with a first intervention unit located in Ajaccio (French Navy) and intervention exercises are conducted with the various managers on the marine and land parts.