Marine Protected Areas effectively maintain endemic Pinna nobilis populations

Coastal habitat degradation compromise sessile marine species. Populations of the endemic species, fan shell bivalve Pinna nobilis are declining in spite of species protection. Models analyzed environmental versus human-derived stressors as explanatory variables depicting populations at mesoscale level. Human stressors explained most variability in density spatial distribution significantly disturbing benthic communities, while habitat protection affected P. nobilis structure and physical aggression by anchoring highly impact on densities. Environmental variables played a secondary role, indicating that global change processes are not so relevant in coastal benthic communities as human-derived impacts

Isotopic tissue fractionation at bivalve Pinna nobilis, a non-invasive approach

Carbon and nitrogen isotopic values of muscle and mantle in Mediterranean endemic bivalve Pinna nobilis individuals have been analyzed to study tissue fractionation. Muscle tissue is enriched in both δ13C and δ15N compared to mantle on average 1.11 ‰ and 0.71 ‰, respectively. Analyses of mantle tissue do not involve sacrifice of individuals and are therefore proposed as a conservation tool in the study of P. nobilis

Intertidal and subtidal rocky shore sampling methods: a review. Addressing the needs of WFD and MSFD

With European legislations compelling Member States to evaluate their seas, the need of comparable data and methodologies grows. In the intertidal and the subtidal rocky shores, benthic communities (flora and fauna) and macroalgal communities are the most assessed. Strategies and methodologies applied are diverse. Visual censuses are the most used strategy, while quadrats are the most applied methodology. A review of different methods is presented

Pinctada imbricata radiata in the Balearic Archipelago

The presence of Pinctada imbricata radiata (rayed pearl oyster) was explored in the Bay of Palma (Balearic Archipelago, NW Mediterranean Sea) by means of Rapid Assessment Surveys (RAS). Forty-three specimens were found in rocky substrates from recreational marinas and neighbouring natural habitats, including Cabrera National Park. Average hinge length was 26.8 ± 13.3 mm and average shell height was 28.6 ± 16.2 mm; a maximum size of 55.6 × 55.9 mm was measured. The main occurrence of the exotic oyster in marinas, and also far away in Cabrera, points to maritime transport as the primary introduction vector; whereas records in the adjacent natural habitats suggest secondary spread by natural dispersal has occurred. Considering the populations of P. imbricata radiata documented in the Balearic Archipelago, the bivalve seems to be well established in the area. The study explores the potential of RAS as early detection tools for invasive species along the coastline, and recommends further assessment on the ecological impact of P. imbricata radiata in marine protected areas.En prens

Estado de conservación del bivalvo amenazado Pinna nobilis en el Parque Nacional de Cabrera.

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Population Structure and Growth of the Threatened Pen Shell, Pinna rudis (Linnaeus, 1758) in a Western Mediterranean Marine Protected Area

Coastal ecosystems are being extensively degraded by human activities. Benthic, slow-growing and long-lived species are highly vulnerable to these impacts. Marine protected areas may avoid biodiversity losses through habitat protection. The pen shell Pinna rudis is a protected species, but scarce data are available on its ecology and biology. The present study is a comprehensive ecological study encompassing several unknown aspects of the growth and inner record in relation to habitat types, density and size distribu¬tion. During the summers of 2011, 2012 and 2013, a total of 418 strip transects were conducted by scuba diving in the Marine Pro¬tected Area of Cabrera National Park (39.14° N, 2.96° E). Samples were conducted across different habitats and depths, exploring 152,146.35 m2 in total. A large range of sizes and ages were recorded within the park with densities ranging from 0 to 6.89 ind./100 m2. Most pen shells were patchily distributed and concentrated mainly in caves. Two hotspots represented the highest densities ever recorded worldwide, showing a potential link to high larval accumulation and settlement. The population size structure showed a unimodal distribution with shell width ranging from 6.2 to 25.0 cm, with an average shell width of 16.0 ± 3.4 cm. The absolute growth was asymptotic, with a maximum age of 28-31 years and length of 45 cm. This study on the biology and ecology of a well-established population of Pinna rudis in the Western Mediterranean could set a baseline for the conservation of this species in other areasVersión del editor0,56