Sublittoral meiobenthic assemblages from disturbed and non-disturbed sediments in the Balearics

Qualitative and quantitative differences in species composition of meiobenthic communities illustrate the differences among various taxonomic assemblages in the Balearic Islands (Western Mediterranean) analysed by means of multivariate analysis. Average densities ranged between 1000 and 4000 ind.10cm-2, and are in the same range as previously reported from other shallow Mediterranean areas. The dominant meiofaunal taxa were Nematoda (range 40 to 75%), Turbellaria (5-47%) and Copepoda (2-14%), while other meiofaunal groups (Tardigrada and Rotifera) were only represented by approximately 5% of the total abundance. The dominant nematode families were Desmodoridae, Chromadoridae and Xyalidae. The meiofaunal communities showed little variation among locations. Moreover, small-scale heterogeneity does not seem to affect nematode distribution as shown by the high similarity between replicates in the multivariate analysis

Revising interactions of plastics with marine biota: evidence from the Mediterranean

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Benthic indexes applied to intertidal and infralittoral rocky bottoms in relation to the WFD and MSFD: assessing metrics

Currently used benthic indexes for the assessment of Good Ecological Status (GEcS) and Good Environmental Status (GenS) according to European legislations (WFD and MSFD) are reviewed. A total of 16 indexes have been found. The most targeted biocenosis are macroalgal communities. A catalogue of indexes with targeted biocenosis and applied metrics is presented

Are feeding traits and habitat responsible of microplastics ingestion in fish, crustaceans and elasmobranches at the western Mediterranean?

Marine litter loads are increasing worldwide and impacts and effects on marine ecosystems and their inhabitants are still unknown [1,2]. Whereas interaction effects of macrolitter, especially on species as sea turtles and marine mammals has been more investigated, the microscopic fraction has been less addressed. Therefore, several key species of fish, crustaceans and elasmobranches have been studied to assess microplastics ingestion in the Western Mediterranean. Mean ingested microplastics (MPs) ranged up to 2.3 MPs/ind indicating a threat of this man made contaminant on species which are commercialised

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

No habitat preference in mixed meadows and rocky bottoms for Mediterranean Labridae and Sparidae fish species

Fish species composition, abundance, diversity and niche breadth of Mediterranean littoral communities have been assessed for two types of habitat: rocky bottoms and mixed meadows of Posidonia oceanica (L.) Delile, 1813 and rocks. Labridae and Sparidae species have been considered to test differences in abundances between both habitats by means of underwater visual census. Data obtained suggests that these fish assemblages are very similar, and there are no significant differences in the niche breadth of both habitats. Differences in physical structure of the habitats are not enough to produce differences in the fish assemblages observed. A high fishing pressure in the study area may be removing the predator fish species, and consequently determining the species composition and abundance for rocky bottoms.Se ha estudiado la composición específica, la abundancia, la diversidad y la amplitud de nicho de dos comunidades ícticas mediterráneas mediante censos visuales en dos tipos de hábitat: fondos rocosos y fondos mixtos de Posidonia oceanica (L.) Delile, 1813 y roca. Se han observado especies de lábridos y espáridos y no se han encontrado diferencias significativas en las variables analizadas de estas comunidades en ambos hábitats. Las diferencias en la estructura física de los dos tipos de hábitat no son suficientes para justificar la aparición de variaciones significativas en las comunidades ícticas estudiadas. Un factor condicionante puede ser la elevada tasa de presión pesquera, que elimina las especies depredadoras y determinaría la composición específica y la abundancia de peces en los fondos rocosos.Instituto Español de Oceanografí

Anthropogenic effects on digestive gland of Pinna nobilis using oxidative stress biomarkers

The fan mussel Pinna nobilis L. is the largest endemic bivalve in the Mediterranean Sea under strict protection. The aim was to determine the effects of anthropogenic activity on antioxidant and oxidative stress biomarkers in digestive gland of P. nobilis. Antioxidant enzyme activities and protein oxidation were significantly increased in mussels sampled in the impacted area. The anthropogenic activities induced a situation of oxidative stress in P. nobilis, resulting in an antioxidant response and in an increased protein oxidatio