The last fortress fell: mass mortality of Pinna nobilis in the Sea of Marmara

A spring 2021 cruise to the south Marmara Islands revealed a mass mortality event of Pinna nobilis, which were reported to be healthy just seven months ago. The cause of death might be associated with the epidemic infection or a catastrophic mucilage event seen after November 2020 in the Sea of Marmara. A total of 191 Pinna nobilis individuals were found at seven stations out of 10, of which 88% were dead. In the present study, the population density (dead and alive individuals) of P. nobilis was found to be between 0.3 ind.100 m-2 and 12 ind.100 m-2 in the area. A total of three live and four dead juvenile individuals were observed in the area, indicating low recent recruitment. The highest number of dead Pinna nobilis individuals (92 specimens) was encountered in shallow-waters (0-4 m depth). A total of 34 species belonging to six taxonomic groups (Sipuncula, Oligochaeta, Polychaeta, Crustacea, Mollusca, and Pisces) were found within the dead shells of four P. nobilis individuals. The mass mortality of Pinna nobilis in the Sea of Marmara, the last remaining disease-free sea, indicates the necessity of establishing and implementing emergency action plans for this species, including ex-situ conservation.

Download Full-text

Tracking a mass mortality outbreak of pen shell Pinna nobilis populations: A collaborative effort of scientists and citizens

Scientific Reports ◽

10.1038/s41598-019-49808-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 24

Author(s):

Miguel Cabanellas-Reboredo ◽

Maite Vázquez-Luis ◽

Baptiste Mourre ◽

Elvira Álvarez ◽

Salud Deudero ◽

...

Keyword(s):

Additive Model ◽

Mass Mortality ◽

Salinity Range ◽

Pinna Nobilis ◽

Mass Mortality Event ◽

Virtual Particles ◽

Management Measures ◽

Pen Shell ◽

The Mediterranean

Abstract 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.

Download Full-text

Recruitment Disruption and the Role of Unaffected Populations for Potential Recovery After the Pinna nobilis Mass Mortality Event

Frontiers in Marine Science ◽

10.3389/fmars.2020.594378 ◽

2020 ◽

Vol 7 ◽

Author(s):

Diego K. Kersting ◽

Maite Vázquez-Luis ◽

Baptiste Mourre ◽

Fatima Z. Belkhamssa ◽

Elvira Álvarez ◽

...

Keyword(s):

Mass Mortality ◽

Mortality Event ◽

Pinna Nobilis ◽

Mass Mortality Event

Download Full-text

S.O.S. Pinna nobilis: A Mass Mortality Event in Western Mediterranean Sea

Frontiers in Marine Science ◽

10.3389/fmars.2017.00220 ◽

2017 ◽

Vol 4 ◽

Cited By ~ 42

Author(s):

Maite Vázquez-Luis ◽

Elvira Álvarez ◽

Agustín Barrajón ◽

José R. García-March ◽

Amalia Grau ◽

...

Keyword(s):

Mediterranean Sea ◽

Western Mediterranean ◽

Mass Mortality ◽

Mortality Event ◽

Pinna Nobilis ◽

Mass Mortality Event ◽

Western Mediterranean Sea

Download Full-text

Multiple Non-Species-Specific Pathogens Possibly Triggered the Mass Mortality in Pinna nobilis

Life ◽

10.3390/life10100238 ◽

2020 ◽

Vol 10 (10) ◽

pp. 238 ◽

Cited By ~ 2

Author(s):

Fabio Scarpa ◽

Daria Sanna ◽

Ilenia Azzena ◽

Davide Mugetti ◽

Francesco Cerruti ◽

...

Keyword(s):

Rhodococcus Erythropolis ◽

Mass Mortality ◽

Molecular Diagnostic ◽

Multifactorial Disease ◽

Heterologous Host ◽

Pinna Nobilis ◽

Mass Mortality Event ◽

Species Specific ◽

Vibrio Spp ◽

Mycobacterium Spp

The fan mussel, Pinna nobilis, represents the largest bivalve endemic to the Mediterranean Sea. Since 2016, dramatic mass mortality of this species has been observed in several areas. The first surveys suggested that Haplosporidium pinnae (currently considered species-specific) was the main etiological agent, but recent studies have indicated that a multifactorial disease may be responsible for this phenomenon. In this study, we performed molecular diagnostic analyses on P. nobilis, P. rudis, and bivalve heterologous host species from the island of Sardinia to shed further light on the pathogens involved in the mass mortality. The results support the occurrence of a multifactorial disease and that Mycobacterium spp. and H. pinnae are not necessarily associated with the illness. Indeed, our analyses revealed that H. pinnae is not species-specific for P. nobilis, as it was present in other bivalves at least three years before the mass mortality began, and species of Mycobacterium were also found in healthy individuals of P. nobilis and P. rudis. We also detected the species Rhodococcus erythropolis, representing the first report in fan mussels of a bacterium other than Mycobacterium spp. and Vibrio spp. These results depict a complicated scenario, further demonstrating how the P. nobilis mass mortality event is far from being fully understood.

Download Full-text