A mass mortality event is devastating the populations of the endemic bivalve Pinna nobilis in the Mediterranean Sea from early autumn 2016. A newly described Haplosporidian endoparasite (Haplosporidium pinnae) is the most probable cause of this ecological catastrophe placing one of the largest bivalves of the world on the brink of extinction. As a pivotal step towards Pinna nobilis conservation, this contribution combines scientists and citizens’ data to address the fast- and vast-dispersion and prevalence outbreaks of the pathogen. Therefore, the potential role of currents on parasite expansion was addressed by means of drift simulations of virtual particles in a high-resolution regional currents model. A generalized additive model was implemented to test if environmental factors could modulate the infection of Pinna nobilis populations. The results strongly suggest that the parasite has probably dispersed regionally by surface currents, and that the disease expression seems to be closely related to temperatures above 13.5 °C and to a salinity range between 36.5–39.7 psu. The most likely spread of the disease along the Mediterranean basin associated with scattered survival spots and very few survivors (potentially resistant individuals), point to a challenging scenario for conservation of the emblematic Pinna nobilis, which will require fast and strategic management measures and should make use of the essential role citizen science projects can play.

No abstract

The endemic limpet Patella ferruginea is the most endangered invertebrate in the Mediterranean Sea. Our study examined a population of P. ferruginea in the Marine Protected Area of "Penisola del Sinis -Isola di Mal di Ventre" (western Sardinia, Italy). During the summer 2009, we carried out a systematic census of P. ferruginea along a 8114 m georeferenced perimeter of coast in the "no take-no entry area" to assess its density, spatial distribution, and morphometric characteristics. Our aim was to provide a detailed map of the distribution of P. ferruginea and to investigate the effects of accessibility, wave exposure and slope of the coast on its occurrence. Patella ferruginea showed the lowest mean density ever reported (0.02 ind/m) and a unimodal population structure characterised by fewer females and juveniles. Accessibility had a major negative effect on the occurrence of P. ferruginea. Exposure was also an important factor in influencing its density, size composition and specimen position within the mesolittoral, while the slope had little influence. Morphometric analysis showed the dominance of the Rouxi form, while the Lamarcki form was confined to exposed sites. Our results demonstrate a highly endangered population of P. ferruginea and suggest that human pressure represents the main risk factor.

No abstract

ABSTRACT1. Many marine protected areas (MPAs) around the world are 'paper parks'. A key factor contributing to their ineffectiveness is non-compliance with the rules in place.2. This paper contributes to the existing academic discussion on 'paper parks' by drawing on critical regulation scholarship to develop a theoretical framework to assess and address compliance gaps in MPAs.3. The theoretical insights are then explored using a case study of the second largest Italian MPA (the 'Penisola del Sinis-Isola di Mal di Ventre'), employing a multidisciplinary perspective built on both biological and socio-legal expertise.4. The biological study consists of a review including existing unpublished data on biological resources in the MPA coupled with new analyses on the effects of sea urchin harvesting restrictions. The socio-legal research consists of the analysis of primary qualitative research in the form of semi-structured interviews conducted with key stakeholders at the local and regional level in 2014, followed by two workshops (one with stakeholders and one with the general public) in 2015 to discuss the research findings collectively.5. The results show that the Sinis MPA is not achieving its conservation goals, primarily because of actors' noncompliance with the rules. The interviews with key stakeholders reveal a number of interlinked social, normative and calculative motivations at the basis of non-compliance. Policy solutions are then offered.6. This study offers a novel analysis on 'paper parks' that may be applicable to other MPAs experiencing similar compliance issues.

The giant limpet Patella ferruginea is the most endangered endemic species in the Mediterranean Sea. It is at serious risk of extinction, especially along the coast of Corsica and Italy. The small population of P. ferruginea in the marine protected area (MPA) Penisola del Sinis ‐ Isola di Mal di Ventre (W Sardinia, Italy) is an isolated unit whose preservation is critical also from the perspective of conservation genetics. This study considered the impact of illegal harvesting on the conservation status of P. ferruginea in the MPA. Site accessibility (semi‐accessible and hardly accessible) and legal protection (Zone A, B, C) were considered in two field surveys conducted in the Mal di Ventre Island in 2011 and 2013. Furthermore, Zone A was monitored annually from 2009 to 2013 to assess population dynamics and extinction risk. In summer 2013 the total population size was estimated at 310 specimens (0.016±0.005 ind m‐1) with a significant decrease compared with 2011 (–52%), mainly due to poaching. Significantly higher density was found in the hardly accessible sites (0.039±0.007 ind m‐1 in 2013) and generally in Zone A (0.042±0.009 ind m‐1 in 2013). The size distribution showed a similar pattern, with larger sized individuals in those sites with maximum legal protection and a lower degree of accessibility. Juveniles (<25 mm) were almost absent and the mean individual growth rate (2.6±0.5 mm yr‐1) was lower in comparison with other Mediterranean populations. The population viability analysis predicted that, with current rates of harvesting, P. ferruginea may face local extinction within the next 10 years. Without a joint effort towards the protection of intertidal habitats by enforcement bodies, regulators, researchers and sea users, the MPA will not achieve its conservation objectives and P. ferruginea will disappear from Mal di Ventre Island. Copyright © 2015 John Wiley & Sons, Ltd.

No abstract

Pinna nobilis is an endemic bivalve of the Mediterranean Sea. In the last decades P. nobilis populations have declined drastically due to increasing anthropogenic pressure and it has been declared a protected species since 1992. Despite the need for conservation, knowledge of the ecology and monitoring of the main populations of P. nobilis are limited. This study considered a population living within a Posidonia oceanica meadow in the Gulf of Oristano (western Mediterranean, Italy). The study area, about 150 hectares, part of which is included within a Marine Protected Area and a Site of Community Importance, was subdivided in 3 sub-areas. The percentage cover of different habitat types (P. oceanica, dead matte and sand) in each sub-area was measured and meadow features (substrate coverage, matte compactness and shoot density) characterized. The hypotheses of differences in density, percentage of dead individuals, population structure, shell burial level and orientation of P. nobilis, were investigated according to sub-areas and to habitat type. The spatial distribution was patchy, and the habitat type resulted a key factor in determining both density and distribution. A strong edge effect was demonstrated: more than half of the observed individuals colonized the P. oceanica border. Matte compactness and shoot density were found to affect the density and distribution of P. nobilis. Shell burial level and percentage of dead individuals varied with sub-areas and habitat types. Size distribution was bimodal and common shell orientation was observed in two sub-areas. These results contribute to increase the knowledge of population ecology of this species and to provide useful information for implementing conservation policies.