Occurrence and distribution of different bed types of seagrass Posidonia oceanica around the Maltese Islands

The small-scale distribution of Posidonia oceanica bed types were mapped at four locations off the northern coast of the Maltese Islands, using aerial photography supplemented by surveys using SCUBA diving. Results showed a similar pattern of occurrence of the seagrass at all locations surveyed. In shallow waters (2 m – 4 m), P. oceanicaoccurred as patches of variable size on a rocky and/or sandy substratum. In deeper waters (5 m – 10 m), the patches of seagrass were often replaced by reticulate beds consisting of P. oceanicainterspersed with areas of bare sand. Deeper still (11 m – 13 m), a transition from reticulate to continuous beds occurred. Continuous beds extended to depths of around 25 - 30 m and eventually became reticulate or patchy in deeper waters (>25 m). Values of total seagrass percentage cover increased, while the ratio of fragmented:continuous bed cover decreased for the four study locations on moving southwards (Ramla Bay to St Thomas Bay), indicating that P. oceanica habitat was more abundant and less fragmented in the south-eastern parts of the Maltese Islands. However, values calculated using an exposure index did not did indicate a relationship between exposure and the observed decease in fragmentation of seagrass beds on moving northwest to southwest along the north-eastern coast. Data from the four sites surveyed, together with data from other surveys, were used to show the large-scale distribution of P. oceanica beds around the Maltese Islands. The implications of the study findings for the conservation and management of P. oceanica habitat around the Maltese Islands are discussed.peer-reviewe

"Protected" marine shelled molluscs: thriving in Greek seafood restaurants

International agreements as well as European and national legislation prohibit exploitation and trading of a number of edible marine shelled molluscs, due to either significant declines in their populations or destructive fishing practices. However, enforcement of existing legislation in Greece is ineffective and many populations of “protected” species continue to decline, mainly due to poaching. The extent of illegal trading of protected bivalves and gastropods in Greek seafood restaurants was investigated by interviewing owners or managers of 219 such restaurants in 92 localities. Interviews were based on questionnaires regarding the frequency of availability in the menus and the origin of twenty-one species or groups of species, among which eight are protected - illegally exploited. Forty-two percent of the surveyed restaurants were found to serve at least one of the protected ¬- illegally exploited species. Among the illegally traded species, Lithophaga lithophaga, Pecten jacobaeus, and Pinnanobilis were served in a relatively high proportion of the surveyed restaurants (22.8%, 19.2%, and 16.4% respectively), outrunning many commercial species. In many cases these species were always or often available (11.4%, 4.6% and 5.0% respectively). There was substantial spatial variation in the proportion of restaurants that illegally served protected species with differing patterns for each species; very high proportions of illegal trading were observed in some marine regions (e.g., date mussels were served in >65% of the seafood restaurants along the coastline of Evvoikos Gulf). In most cases the illegally traded species were of local origin, while there was no finding of illegally imported molluscs from other countries. The strategy for enforcement of existing legislation should be greatly improved otherwise protection of shelled molluscs will remain ineffective

Fish assemblages associated with Cymodocea nodosa and Caulerpa prolifera meadows in the shallow areas of the Mar Menor coastal lagoon

The present study investigates several biological parameters of the fish assemblages, mainly juvenile fishes and adults of small sized species, associated with the seagrass Cymodocea nodosa and the macroalga Caulerpa prolifera in the shallow littoral areas of the Mar Menor coastal lagoon. Results showed that C nodosa seagrass meadows have a much higher number of fish species and considerably greater fish abundance and biomass than Ca. prolifera meadows. Other community variables (diversity and evenness) did not show significant differences between both meadows.En el presente estudio se investigaron diversos parámetros biológicos de las comunidades de peces, principalmente peces juveniles y adultos de especies de talla pequeña, asociadas a las praderas de la fanerógama acuática Cymodocea nodosa y la macroalga Caulerpa prolifera en las zonas someras litorales de la laguna costera del Mar Menor. Los resultados mostraron que las praderas de C. nodosa presentaron un mayor numero de especies y una mayor abundancia y biomasa de peces que las praderas de Ca. prolifera. Otras variables de la comunidad (diversidad y equitatividad) no mostraron diferencias significativas entre ambos tipos de praderas

Marine macrophytes and the Water Framework Directive: preliminary studies in southern Spain

The Water Framework Directive (WFD) includes angiosperms and macroalgae as biological quality elements (BQE) for coastal and transitional waters. In southern Spain (Andalusia), studies to implement the WFD using angiosperms (seagrasses) started in June 2009. Different approaches have been considered; the first was the variation of this BQE along an environmental gradient; the second consisted on an extensive sampling campaign in the coastal waters from the western province of Huelva to the eastern province of Almeria. The surveys showed marked differences among the sites and species, indicating a broad variation in the ecological quality values for the water bodies. Additionally, these results will be compared with a similar research conducted on Ria Formosa (Portugal) to provide preliminary classifications of the ecological status of coastal and transitional waters of the southern Iberian Peninsula. With respect to the BQE “macroalgae”, two indices; the CFR (quality of rocky shores) and RSL (reduced species list) have been estimated. The ecological differences between coastal zones in the North Atlantic ecoregion where these methods of assessment have been developed (Northern Spain and the United Kingdom, respectively) and the Atlantic coast of Cadiz, suggested the need for an adaptation of both indices in southern Spain. These extensive surveys have allowed the elaboration of a reduced species list for the rocky shores on the southwestern Spanish Atlantic coasts. The present study shows the preliminary efforts and results of the assessment of BQEs based on marine macrophytes in Southern Spain. Some concerns about the need of reassessment of the proposed tools from the North Atlantic ecoregion when applied to Andalusian water bodies are also discussed.La Directiva Marco de Agua (DMA) incluye como elementos de calidad biológica (BQE) de las aguas de transición y costeras a las angiospermas y macroalgas. En el sur de España (Andalucía), los trabajos para implementar la DMA utilizando angiospermas marinas comenzaron en Junio de 2009. Se han considerado distintas aproximaciones; la primera fue el estudio de los cambios de este BQE a lo largo de un gradiente medioambiental; la segunda consistió en una intensa campaña de muestreo en las aguas costeras desde la provincia más occidental (Huelva) hasta la más oriental (Almería). Las campañas mostraron diferencias notables entre los sitios y las especies, lo que implicó una amplia variación en los valores de calidad ecológica de las masas de agua. Adicionalmente, estos resultados se compararán con un trabajo similar desarrollado en Ria Formosa (Portugal) de forma que se pueda proporcionar una clasificación preliminar del estado ecológico de las aguas costeras y de transición del sur de la Península Ibérica. Con respecto al BQE “macroalgas” se han estimado dos índices: el CFR (calidad de los fondos rocosos) y el RSL (lista reducida de especies). Las diferencias ecológicas entre las zonas costeras de la ecoregión Atlántico Norte donde se han desarrollado estos métodos de evaluación (norte de España y Reino Unido respectivamente) y la costa atlántica de Cádiz, sugirieron la necesidad de una adaptación de ambos índices para el sur de España. Los muestreos intensivos han permitido la elaboración de una lista reducida de especies para las costas rocosas sudoccidentales de España. El presente trabajo muestra los esfuerzos y resultados preliminares de la evaluación de BQEs basados en macrófitos marinos en el sur de España. Se discuten también algunos interrogantes sobre la necesidad de una reevaluación de las herramientas propuestas para la ecorregión Atlántico Norte cuando se aplican a las masas de agua de Andalucía.Universidad de Cádiz. Área de Ecología. Facultad de Ciencias del Mar

The spread of Caulerpa cylindracea in Calabria (Italy) and the effects of shipping activities

A survey to state the spread of Caulerpa cylindracea in the Calabrian Tyrrhenian coasts has been undertaken. The research aims to value the role of shipping activities in the ten-year’s study from 1999 to 2009, as a vector in the spreading of the species. The outcome of this study has shown that, during the last ten years, the species has colonized most of the regional coastline, on all kinds of substrata, in areas closed to harbours and subjected to high rate of sedimentation. The main effects of Caulerpa cylindracea colonization have resulted in a gradual decrease of crustose species while the turf ones have increased their abundance, altering the native structure of the macroalgal assemblages. These results confirm the extremely invasive behaviour of this strain in the Calabrian Tyrrhenian coasts and, more generally, in the Mediterranean Sea

A new record of the invasive seaweed Caulerpa cylindracea Sonder in the South Adriatic Sea

The green alga Caulerpa cylindracea Sonder is one of the most infamous and threatening invasive species in the Mediterranean Sea. Since 1985, it started rapidly spreading to all Mediterranean regions causing many ecological changes on natural communities. In the present study, we present an example of this proliferation with the first record in the Marine Protected Area of Tremiti Island (MPATI) in the South Adriatic Sea. Fifteen sites along the coast and 5 different depths have been investigated. Our results provide eveidence of a wide invasion of this pest in three islands, San Domino, San Nicola and Capraia. This study fills a particular data gap in the ongoing biomonitoring of invasive seaweeds in the Mediterranean Sea representing a base line of this invasive species for the MPATI

Indirect effects of climate changes on cadmium bioavailability and biological effects in the Mediterranean mussel Mytilus galloprovincialis

none6noDespite the great interest in the consequences of climate change on the physiological functioning of marine organisms, indirect and interactive effects of rising temperature and pCO2 on bioaccumulation and responsiveness to environmental pollutants are still poorly explored, particularly in terms of cellular mechanisms. According to future projections of temperature and pH/pCO2, this study investigated the main cellular pathways involved in metal detoxification and oxidative homeostasis in Mediterranean mussels, Mytilus galloprovincialis, exposed for 4 weeks to various combinations of two levels of pH/pCO2 (8.2/∼400 μatm and 7.4/∼3000 μatm), temperature (20 and 25 °C), and cadmium addition (0 and 20 μg/L). Bioaccumulation was increased in metal exposed organisms but it was not further modulated by different temperature and pH/pCO2 combinations. However, interactions between temperature, pH and cadmium had significant effects on induction of metallothioneins, responses of the antioxidant system and the onset of oxidative damages, which was tissue dependent. Multiple stressors increased metallothioneins concentrations in the digestive gland revealing different oxidative effects: while temperature and cadmium enhanced glutathione-dependent antioxidant protection and capability to neutralize peroxyl radicals, the metal increased the accumulation of lipid peroxidation products under acidified conditions. Gills did not reveal specific effects for different combinations of factors, but a general stress condition was observed in this tissue after various treatments. Significant variations of immune system were mainly caused by increased temperature and low pH, while co-exposure to acidification and cadmium enhanced metal genotoxicity and the onset of permanent DNA damage in haemocytes. Elaboration of the whole biomarker data in a cellular hazard index, corroborated the synergistic effects of temperature and acidification which increased the toxicological effects of cadmium. The overall results confirmed that climate change could influence ecotoxicological effects of environmental contaminants, highlighting the importance of a better knowledge of cellular mechanisms to understand and predict responsiveness of marine organisms to such multiple stressors.openNardi, Alessandro; Mincarelli, Luana Fiorella; Benedetti, Maura; Fattorini, Daniele; D'Errico, Giuseppe; Regoli, FrancescoNardi, Alessandro; Mincarelli, LUANA FIORELLA; Benedetti, Maura; Fattorini, Daniele; D'Errico, Giuseppe; Regoli, Francesc