Detection of Haplosporidium pinnae from Pinna nobilis Faeces

Pinna nobilis (Linnaeus, 1758) is the largest bivalve endemic to the Mediterranean. It is distributed in a wide range of coastal environments, including estuaries. Pinna nobilis has recently become a critically endangered species (with almost 100% mortality) along the entire Spanish Mediterranean coast. This may be due to coinfections caused by Haplosporidium pinnae and bacterial pathogens such as Mycobacterium spp. We extensively sampled P. nobilis from Mar Menor lagoon (SE Spain), a site where individuals still survive. Using conventional PCR, we found Haplosporidium spp. in 7.1% of mantle and faecal DNA samples in different individuals of P. nobilis. We identified and quantified Haplosporidium pinnae in P. nobilis using Sanger sequencing and qPCR. Faecal H. pinnae detection is non-invasive, unlike biopsies. Therefore, this non-lethal and non-invasive sampling method could contribute to the welfare of living populations, particularly in eutrophic environments, where they are prone to septicaemia. The use of faecal DNA analysis could be a major advance in epidemiology and recovery assessment studies of P. nobilis.info:eu-repo/semantics/publishedVersio

The relict population of Pinna nobilis in the Mar Menor is facing an uncertain future

Pinna nobilis is undergoing one of the most dramatic events suffered by an endangered species. An emerging disease has relegated its populations to coastal lagoons or estuaries with salinities beyond the 36.5–39.7 psu range. The Mar Menor is one of two such locations on the Spanish coastline. Poor environmental conditions and eutrophication and anoxia events, that became critical in 2016, 2019 and 2021, have reduced its population in >99 %. In this work, the spatial distribution of the species within the lagoon and the factors determining its survival along the successive crises of eutrophication are studied using a two-stage (presence/absence estimation and density modelling) Species Distribution Model. A potential area of 200.97 ha and an average density of 1.05 ind.100 m2 is estimated for 2020. The viability of the Mar Menor population depends on management actions designed both for the species and to improve the lagoon environmental state.This research was supported by the EU LIFE Programme Project “Protection and restoration of Pinna nobilis populations as a response to the catastrophic pandemic started in 2016” (LIFE PINNARCA) [grant number LIFE20 NAT/ES/001265] and the Biodiversity Foundation of the Ministry for Ecological Transition and the Demographic Challenge Project RECUPERA PINNA [grant number IRTA1-21T]. This research was supported by the Dirección General del Mar Menor, Consejería de Agua, Agricultura, Ganadería, Pesca y Medio Ambiente (CARM), Project “Proyecto para la cría ex situ de Pinna nobilis y creación del Banco de Especies protegidas y singulares del Mar Menor”

Bathyal megabenthic assemblages in the south-eastern Iberian Peninsula (Western Mediterranean)

The SE Iberian sector represents an interesting transition and connectivity zone between the Alboran Sea and the Algerian Balearic basin, and the area comprises a system of tectonic canyons (Mazarron Escarpment), seamounts and pockmarks fields. Despite this, relatively few studies have been conducted on the bathyal zone. During the LIFE IP Intemares A2.2-Mu0820 survey, the continental slope was observed by ROV Liropus-2000, between 183 and 1735m depth following bathymetric mapping using a multibeam echosounder. A combination of multivariate analysis of still imagery and video groundtruthing have been able to discriminate some megabenthic assemblages. On hard bottoms of the upper bathyal horizon: i) Neopycnodonte cochear-Mergelia truncata facies, 193-244m depth; ii) Ellisella flagellum facies, 2441-320m; iii) Antipathes dichotoma facies, 259-270m. Middle horizon: i) Demospongiae facies (Pachastrella, Phakellia, Aaptos…), 241-494m; ii) gorgonian assemblage (Callogorgia, Paramuricea, Placogorgia), 294-624m; iii) Leptometra phalangium facies 293-611m; iv) cold-water corals (Desmophyllum, Madrepora), 516-607m; Antipatharia facies (Antipathella, Leiopathes, Parantipathes), 519-624m. Lower bathyal horizon:; Dicopia antirrhinum facies, 645-1167m. On soft bottoms (mud, sandy-mud) of the upper bathyal horizon: i) Ceriantharia facies, 213-219m depth. Middle horizon: i) Pennatulacea facies (Funiculina, Kophobelemnon, Pteroeides…), 219-541m; ii) Thenea muricata facies, 418-814m; iii) Isidella elongata facies, 462-681m. Lower horizon: i) Pelosina fields, 235-1321m. The results reveals that the bathyal zone of the SE Iberian Peninsula is topographically complex and harbours diverse benthic assemblages, some of which fall within the category of Vulnerable Marine Ecosystems; and some species are listed in annex II of the RAC/SPA list of endangered or threatened species

Vulnerable Marine Ecosystems found in a bathyal zone off the SE Iberian Peninsula (Western Mediterranean)

The Spanish Intemares LIFE IP project contemplates the creation of Special Areas of Conservation within the Natura 2000 Network. During its August 2019 cruise, a series of towed sledge transects were conducted on two seamounts (“Planazo” and “Plis Plas”) and a muddy field of pockmarks, both located in areas off the SE Iberian Peninsula (Western Mediterranean), between 220 and 694m depth. The prospected area has a significant pressure from bottom trawl (directed towards Aristeus antennatus, Nephrops norvegicus, Plesionika spp.) and, to a smaller extent, of bottom longline fisheries (focused on Merluccius merluccius and Pagellus bogaraveo). Some of the observed bathyal habitats fall into the category of Vulnerable Marine Ecosystems (VME), according to FAO (2009, 2016), since they present at least one of the following characteristics: i) uniqueness or rarity; ii) functional significance of habitat; iii) fragility; iv) life history traits of component species that make recovery difficult; and/or v) structural complexity. Among them, “gorgonian gardens” (of Paramuricea hirsuta, Callogorgia verticillata, Bebryce mollis, Swiftia pallida, and Ellisella flagellum) and the yellow tree coral (Dendrophyllia cornigera) highlight rocky bottoms; while on muddy substrates, sea-pen fields (Funiculina quadrangularis and Kophobelemnon stelliferum) and “bamboo coral gardens” (Isidella elongata) do so. These habitats, along with fields of the crinoid Leptometra phalangium, are also considered Essential Habitats for target species of fishing interest. The location, mapping and characterization of these habitats are necessary to establish “no-take” zones within the future management plan for the area studied

Factors structuring microbial communities in highly impacted coastal marine sediments (Mar Menor lagoon, SE Spain)

Coastal marine lagoons are environments highly vulnerable to anthropogenic pressures such as agriculture nutrient loading or runoff from metalliferous mining. Sediment microorganisms, which are key components in the biogeochemical cycles, can help attenuate these impacts by accumulating nutrients and pollutants. The Mar Menor, located in the southeast of Spain, is an example of a coastal lagoon strongly altered by anthropic pressures, but the microbial community inhabiting its sediments remains unknown. Here, we describe the sediment prokaryotic communities along a wide range of environmental conditions in the lagoon, revealing that microbial communities were highly heterogeneous among stations, although a core microbiome was detected. The microbiota was dominated by Delta- and Gammaproteobacteria and members of the Bacteroidia class. Additionally, several uncultured groups such as Asgardarchaeota were detected in relatively high proportions. Sediment texture, the presence of Caulerpa or Cymodocea, depth, and geographic location were among the most important factors structuring microbial assemblages. Furthermore, microbial communities in the stations with the highest concentrations of potentially toxic elements (Fe, Pb, As, Zn, and Cd) were less stable than those in the non-contaminated stations. This finding suggests that bacteria colonizing heavily contaminated stations are specialists sensitive to change

A widespread picornavirus affects the hemocytes of the noble pen shell (Pinna nobilis), leading to its immunosuppression

IntroductionThe widespread mass mortality of the noble pen shell (Pinna nobilis) has occurred in several Mediterranean countries in the past 7 years. Single-stranded RNA viruses affecting immune cells and leading to immune dysfunction have been widely reported in human and animal species. Here, we present data linking P. nobilis mass mortality events (MMEs) to hemocyte picornavirus (PV) infection. This study was performed on specimens from wild and captive populations.MethodsWe sampled P. nobilis from two regions of Spain [Catalonia (24 animals) and Murcia (four animals)] and one region in Italy [Venice (6 animals)]. Each of them were analyzed using transmission electron microscopy (TEM) to describe the morphology and self-assembly of virions. Illumina sequencing coupled to qPCR was performed to describe the identified virus and part of its genome.Results and discussionIn 100% of our samples, ultrastructure revealed the presence of a virus (20 nm diameter) capable of replicating within granulocytes and hyalinocytes, leading to the accumulation of complex vesicles of different dimensions within the cytoplasm. As the PV infection progressed, dead hemocytes, infectious exosomes, and budding of extracellular vesicles were visible, along with endocytic vesicles entering other cells. The THC (total hemocyte count) values observed in both captive (eight animals) (3.5 × 104–1.60 × 105 ml−1 cells) and wild animals (14 samples) (1.90–2.42 × 105 ml−1 cells) were lower than those reported before MMEs. Sequencing of P. nobilis (six animals) hemocyte cDNA libraries revealed the presence of two main sequences of Picornavirales, family Marnaviridae. The highest number of reads belonged to animals that exhibited active replication phases and abundant viral particles from transmission electron microscopy (TEM) observations. These sequences correspond to the genus Sogarnavirus—a picornavirus identified in the marine diatom Chaetoceros tenuissimus (named C. tenuissimus RNA virus type II). Real-time PCR performed on the two most abundant RNA viruses previously identified by in silico analysis revealed positive results only for sequences similar to the C. tenuissimus RNA virus. These results may not conclusively identify picornavirus in noble pen shell hemocytes; therefore, further study is required. Our findings suggest that picornavirus infection likely causes immunosuppression, making individuals prone to opportunistic infections, which is a potential cause for the MMEs observed in the Mediterranean

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

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.info:eu-repo/semantics/publishedVersio

Mar Menor: una laguna singular y sensible. Evaluación científica de su estado.

Este libro recopila las aportaciones que equipos de investigación de la Universidad de Murcia, Universidad Politécnica de Cartagena, Instituto Geológico-Minero de España, Universidad de Alicante, el Instituto Español de Oceanografía y otros organismos hicieron en las Jornadas Científicas del Mar Menor, celebradas en diciembre de 2014.La información recogida en este libro se estructura en dos grandes bloques, uno de Biología y Ecología del Mar Menor (capítulos 1 al 8) y otro de Condiciones fisicoquímicas e impacto de actividades humanas en la laguna (capítulos 9 al 14). El primer bloque resume buena parte de los estudios ecológicos realizados en el Mar Menor, que han servido para mejorar su conocimiento y también para cambiar antiguas asunciones sobre la naturaleza y el funcionamiento de estos ecosistemas lagunares (Capítulo 1). El segundo capítulo muestra que esta laguna alberga en zonas someras de su perímetro hábitats fundamentales para mantener y conservar tanto especies migratorias como residentes, que es necesario conocer para paliar el impacto de las actividades humanas que les afectan. En este sentido la reducción de la carga de nutrientes y contaminantes orgánicos e inorgánicos que fluyen hacia el Mar Menor puede ayudar a preservar la laguna en mejores condiciones, bien sea tratando las escorrentías (plantas de tratamiento, humedales artificiales u otras técnicas) y recuperar este agua para uso agrícola o evitar su descarga en la laguna (Capítulo 3). Estas actuaciones serán clave para la conservación de especies emblemáticas como el caballito de mar (Capítulo 4) y reducir el impacto de las proliferaciones masivas de medusas que se producen en la laguna desde 1993 (Capítulo 5). En este mismo sentido los cambios acaecidos en la laguna han favorecido la incursión de invertebrados marinos alóctonos (Capítulo 6) y han afectado a la respuesta de la dinámica poblacional de las aves acuáticas a distintas escalas (Capítulo 7). Para completar este bloque se ofrece una perspectiva histórica de la importancia que ha tenido la investigación sobre acuicultura realizada en esta laguna, que ha servido de base para su gran desarrollo actual (Capítulo 8). El segundo bloque se inicia con una evaluación del origen y evolución del Mar Menor desde el punto de vista geológico, y evidencia su vulnerabilidad ante el deterioro que puede sufrir la desaparición de la barrera de cierre y/o su colmatación (Capítulo 9). En el Capítulo 10 se describe la relevancia que tiene la interacción de los acuíferos del Campo de Cartagena con la laguna, que se produce no sólo a nivel superficial sino también subterráneo. Esta interacción permite el acceso de nutrientes a la laguna, a pesar de la cierta capacidad de depuración de los humedales que le circundan, y también de metales traza por los aportes de residuos mineros (Capítulo 11). De hecho los metales traza están presentes en los sedimentos de la laguna, y su distribución se ha caracterizado en la columna sedimentaria relacionándola con la granulometría y el contenido de materia orgánica del sedimento (Capítulo 12). Posteriormente se describe la entrada de diversos contaminantes orgánicos, incluyendo pesticidas y fármacos a través de la rambla del Albujón, y su distribución estacional en agua y sedimento de la laguna (Capítulo 13). Este segundo bloque finaliza con el Capítulo 14 en el que se describe la bioacumulación de hidrocarburos aromáticos policíclicos, pesticidas y fármacos en moluscos y peces del Mar Menor, así como los efectos biológicos que la carga contaminante que accede a través de la rambla del Albujón produce en los organismos que allí habitan. El libro concluye con un breve epílogo redactado por los editores de este libro

Point pattern analysis as a tool for assessing disease spread and population features in remaining sanctuaries of the critically endangered bivalve Pinna nobilis

An emergent disease has relegated populations of the Mediterranean pen shell, Pinna nobilis L. critically endangered to sanctuaries featuring salinities outside the 36.5 to 39 range. Point pattern analysis was used in three areas of the Alfacs Bay (Ebro Delta) still hosting pen shells to assess the possible undergoing of disease spread by comparing the spatial distribution of live individuals vs. empty shells across spatial scales. We also evaluated the importance of other ecological aspects of conservation relevance such as the size distribution of individuals, and the possible association to seagrass habitats. The population assessment showed no recent mortality and a clear dominance of large adults among empty shells (97.3%) pointing to no disease spread during the study period. At the low spatial scale Nearest Neighbor (NN) analyses evidenced significant clustering (NN Ratios of 0.4–0.8), but in one of the zones NN distances were closer in empty shells than in live individuals, suggesting a former localized outbreak. At the larger spatial scale, MDSCA confirmed clustering patterns up to distances of 115 to 190 m, with higher aggregation of empty shells at the same study zone. The bay also featured low juvenile availability (3.2%), which risks the continuity of the population. No evidence for habitat or conspecific selection could be observed from abundance patterns and variation in NN across study regions. Our research provides a tool for assessing population condition in paralic environments, where salinity conditions tend to slow down disease spread, thus allowing a time gap for undertaking conservation decisions.info:eu-repo/semantics/acceptedVersio

Bathyal megabenthic assemblages in the south-eastern Iberian Peninsula (Western Mediterranean)

The SE Iberian sector represents an interesting transition and connectivity zone between the Alboran Sea and the Algerian Balearic basin, and the area comprises a system of tectonic canyons (Mazarron Escarpment), seamounts and pockmarks fields. Despite this, relatively few studies have been conducted on the bathyal zone. During the LIFE IP Intemares A2.2-Mu0820 survey, the continental slope was observed by ROV Liropus-2000, between 183 and 1735m depth following bathymetric mapping using a multibeam echosounder. A combination of multivariate analysis of still imagery and video groundtruthing have been able to discriminate some megabenthic assemblages. On hard bottoms of the upper bathyal horizon: i) Neopycnodonte cochear-Mergelia truncata facies, 193-244m depth; ii) Ellisella flagellum facies, 2441-320m; iii) Antipathes dichotoma facies, 259-270m. Middle horizon: i) Demospongiae facies (Pachastrella, Phakellia, Aaptos…), 241-494m; ii) gorgonian assemblage (Callogorgia, Paramuricea, Placogorgia), 294-624m; iii) Leptometra phalangium facies 293-611m; iv) cold-water corals (Desmophyllum, Madrepora), 516-607m; Antipatharia facies (Antipathella, Leiopathes, Parantipathes), 519-624m. Lower bathyal horizon:; Dicopia antirrhinum facies, 645-1167m. On soft bottoms (mud, sandy-mud) of the upper bathyal horizon: i) Ceriantharia facies, 213-219m depth. Middle horizon: i) Pennatulacea facies (Funiculina, Kophobelemnon, Pteroeides…), 219-541m; ii) Thenea muricata facies, 418-814m; iii) Isidella elongata facies, 462-681m. Lower horizon: i) Pelosina fields, 235-1321m. The results reveals that the bathyal zone of the SE Iberian Peninsula is topographically complex and harbours diverse benthic assemblages, some of which fall within the category of Vulnerable Marine Ecosystems; and some species are listed in annex II of the RAC/SPA list of endangered or threatened species.INTEMARES_A_22_MProyecto INTEMARES. Subacción A 22: Mejora del conocimiento para la declaración de nuevos espacios marinos por su importancia para hábitats