Search Results (4)

This review addresses the critical conservation challenges faced by Pinna nobilis, the noble pen shell, a keystone umbrella species in Mediterranean marine ecosystems. Since 2016, the species has experienced catastrophic population declines due to mass mortality events likely driven by protozoan, bacterial, and viral infections. Despite these severe circumstances, small resilient populations persist in select estuaries and coastal lagoons across the Mediterranean, offering potential for recovery. We provide a comprehensive overview on research dedicated to Pinna nobilis’ biology, genetic variation, disease dynamics, and environmental factors influencing its survival, with a focus on refugia where populations still endure. Remarkably, recent studies have revealed signs of resistance in certain individuals and the potential for hybridisation with Pinna rudis. In this context, the possible impact of the increasing occurrence of hybridisation between Pinna nobilis and Pinna rudis on the conservation of their genetic diversity should be carefully considered. This review highlights the importance of ongoing conservation efforts including habitat restoration, protection of remaining populations, assessment of past and present genetic variability, and the development of captive breeding programmes. We aim to elucidate the need for continued studies on Pinna nobilis’ biodiversity, particularly its evolutionary dynamics, genetic makeup, and the interplay of environmental variables influencing its survival and persistence. Full article

The present study aimed to address the issue of pressure on the remaining populations of the critical endangered species, fan mussel, Pinna nobilis, in the Eastern Mediterranean. Marine professional (shell/fish farmers, divers, fishers, administrators, etc.) stakeholders’ knowledge (n = 151) in Greece reports that there was a reduction (81.6%) of the P. nobilis individuals during the last 15 years, especially in the years 2010–2012 and 2017–2018. Species’ abundance decline is significantly (ρ = 0.293, p < 0.05) correlated over the last 5 years with the observed natural ecosystem degradation. Participants also stated that the main cause was pathogens alone (28.8%) or in combination with (illegal) fishing (17.1%) or pollution (14.4%). Additionally, 88% of them supported a total prohibition on the use of fan mussels for commercial purposes in order to restore stock levels.; 72.4% stated claimed that no appropriate control was in place and that they (>59.4%) were unsure if this monitoring control is carried out by the competent authorities. Marine stakeholders consider the importance of the species for biodiversity preservation (56.1%), environmental education (35.1%), and diving parks (29.7%). They declared that it is important to record-observe P. nobilis conservation reserves regions (42.6%), monitor areas of responsibility (39.9%), participate in the information society/use of social networks (38.5%), and participate in informational meetings (37.9%). The lack of interest among shell/fish farmers to contribute to P. nobilis on-growing farming indicates the ignorance to the potential benefits of the valuable ecosystem services provided by aquaculture through biodiversity conservation. Nevertheless, there is a demand for promoting the “conservation aquaculture” concept through its incorporation into marine farming activities supplementary to their core business in “production”. Full article

In this study, we present the relationships between total length, unburied length, and shell width and between total length and net weight for the critically endangered Pinna nobilis. This is the first transplantation study in which live specimens of P. nobilis have been used for estimating the length–weight relationship by deploying the unburied length. Length–length relationships were all linear for all cases (r² > 0.900), whereas the length–weight relationship was negative allometric with the values of the exponent b ranging from 2.159 to 2.828. These relationships are important because they offer a restorative monitoring tool without damaging or sacrificing this endangered species, as total length can be computed using unburied length. By examining the relationships between different size dimensions in this re-allocated population, the present study also provided valuable insights for comparative growth studies, stock assessment models, and conservation purposes. Full article

A non-invasive laser fiber-optic method based on infrared sensors for heart rate (Hr) recording was applied to assess the physiological condition of Pinna nobilis. During 2017, the specimens of P. nobilis were sampled at three sites within the Boka Kotorska Bay, Montenegro and used for ex situ experiments with short-term reduction/restoration of ambient salinity to evaluate their physiological adaptive capacity based on heart rate recovery time (T_rec). Mean T_rec for specimens from Sv. Nedjelja (reference site), Dobrota and Sv. Stasije were 72 ± 3, 91 ± 7 and 117 ± 15 min, while the coefficients of variation (CV) were 0.12, 0.13 and 0.17, respectively. Resting heart rate (Hr_rest) and T_rec showed statistically significant differences between the groups of mussels from Dobrota and Sv. Stasije in comparison to the reference site. Statistically significant correlations were observed between T_rec and shell length/width, which was not the case in comparison between Hr_rest and shell length/width. The lower adaptive capacity within the P. nobilis specimens from Dobrota and Sv. Stasije in comparison to the reference site could occur due to stress induced by deterioration of environmental conditions, which could have led to impairment of the physiological state of the mussels evaluated by Hr. All the specimens of P. nobilis survived the experimental treatments; afterwards, they were successfully transplanted at the Dobrota site. The experimental unit with sensor technology applied in this study can provide Hr recording in real time and could have an application in monitoring the physiological/health state of P. nobilis individuals maintained in aquaria. Full article