Are biochemical biomarker responses related to physiological performance of juvenile sea bass (Dicentrarchus labrax) and turbot (Scophthalmus maximus) caged in a polluted harbour ?

International audienceBiomarker responses to toxic exposure have been used for decades to indicate stress in aquatic organisms, or the magnitude of environmental pollution. However, little has been done to compare the simultaneous responses of both biochemical and physiological biomarkers. The purpose of this study was twofold. Firstly to analyse the responses of several biochemical biomarkers measured on juvenile sea bass and turbot caged in a northern France harbour at a reference and contaminated stations. Several biotransformation parameters (Ethoxyresorufin-O-deethylase - EROD - and Glutathione S-transferase -GST) and an antioxidant enzyme (Catalase -CAT) were analysed. Secondly, to compare their responses to several growth and condition indices, measured on the same fish. In the contaminated station, EROD and GST activities were found to be significantly higher, and a decrease of CAT activity was observed for both species. For individual sea bass, biochemical biomarkers showed numerous significant correlations with growth and condition indices, such as the Fulton's K condition index, the RNA:DNA ratio and the lipid storage index. On the contrary, there were only a few significant correlations for turbot, suggesting a species-specific response. Our study indicates that the analysis of the simultaneous responses of both biochemical and physiological biomarkers can be useful for monitoring complex exposure and to assess habitat quality

Structure and spatio-temporal dynamics of the artisanal small-scale fisheries at the future MPA of "Taza" (Algerian coast, SW Mediterranean)

Artisanal Small-Scale Fisheries (SSFs) are a primordial and very diverse activity in the Mediterranean, also within Marine Protected Areas (MPAs). This diversity is explained in terms of target species, gears, and fishing strategies. The main objective of this work was to investigate the spatio-temporal dynamics of artisanal SSFs of the future MPA of "Taza" (Algeria, SW Mediterranean). Data were collected through direct assessment of daily landings and using questionnaires. They were the subject of multivariate analyses that allowed us to identify the métiers practiced by artisanal fishers. During the one year (May 2013 to April 2014) field work period, 1330 fishing trips and 1613 fishing operations in 16 fishing grounds were recorded in the Ziama fishing harbor, where 15.2 tons of total catch was assessed. Our results show that, in the study area, the boats are predominantly gillnetters and that among the five métiers characterized by target species, gear type, fishing grounds, and fishing seasons, two métiers ("Mullus surmuletus trammel net" and "Sparids monofilament gillnet") are practiced throughout the year, while the remaining three ("Sarda sarda driftnet", "Merluccius merluccius set gillnet", and "Pagellus set gillnet") are specific to a determined period of the year. The 'Mullus surmuletus trammel net' métier represents 40% of the total fishing operations, of which 57.5% are carried out in the coastal sector at - 25 m. This study could contribute to defining the appropriate management approaches for SSFs in the future MPA of "Taza" by providing baseline information to build a sound management plan. In Algeria, it will certainly serve as a scientific reference in terms of zoning, protection of biodiversity, and specific monitoring at particular locations and periods of the year for the sustainable management of MPAs

Crecimiento y condición de juveniles de lenguado (Solea solea L.) como indicadores de calidad de hábitat en áreas de cría costeras y estuáricas del Golfo de Vizcaya con énfasis en zonas expuestas al vertido del Erika

Indicators of growth and condition were used to compare the habitat quality of nurseries of juvenile sole (Solea solea L.) in the Bay of Biscay, based on one survey in 2000. The four biological indicators are poorly correlated with each other, suggesting that no single measure may give an adequate description of fish health and of its habitat’s quality. Growth indicators showed significant differences between northern and southern areas. Juveniles from the two southernmost nurseries, the Gironde estuary and the Pertuis Antioche, displayed significant lower otolith increment widths and mean sizes. These differences were inversely related to water temperature and unrelated to genetic or age differences, and are unlikely to be due to limiting trophic conditions in the nurseries. Hence, they may be considered in terms of differences in habitat quality and potential anthropogenic impacts. Condition indices do not show this north-south pattern but highlight low condition values in the Pertuis Antioche. Short-term and fluctuating biochemical indicators such as RNA/DNA ratios appeared to be unreliable over a long-term study, while morphometric indices seemed to be relevant, complementary indicators as they integrate the whole juvenile life-history of sole in the nurseries. The growth and condition indices of juveniles in September 2000 from nursery grounds exposed to the Erika oil spill in December 1999 were relatively high. These results lead us to suggest that there was no obvious impact of this event on the health of juvenile sole and on the quality of the exposed nursery grounds a few months after the event.Se usaron indicadores de crecimiento y condición de lenguados juveniles (Solea solea L.) para comparar la calidad del hábitat de áreas de cría en el Golfo de Vizcaya basados en un muestreo de 2000. Los cuatro indicadores biológicos mostraron bajas correlaciones entre sí, lo que sugiere que no existe una medida única para describir adecuadamente el estado de los peces y la calidad de su hábitat. Los indicadores de crecimiento mostraron diferencias significativas entre las áreas septentrionales y meridionales. Los juveniles de las áreas situadas más al sur: el estuario del Garona y Pertuis Antioche mostraron incrementos de otolitos y tamaños medios significativamente inferiores. Estas diferencias están inversamente relacionadas con la temperatura del agua, pero no con diferencias genéticas o de edad, y no es probable que se deba a una condición trófica limitante en las áreas de cría. Por tanto, pueden considerarse en términos de calidad del hábitat y el potencial impacto antropogénico. Los índices de condición no muestras este patrón norte-sur sino que destacan los bajos valores de condición en Pertuis Antioche. Los indicadores bioquímicos variables de corto término como las relaciones RNA/DNA no parecieron fiables para estudios de mayor escala, mientras que los índices morfométricos parecen ser relevantes y complementarios ya que integran toda el período juvenil de la vida de los lenguados en sus áreas de cría. Los valores de crecimiento y condición de juveniles en septiembre de 2000 en áreas de cría expuestas al vertido de crudo del Erika en diciembre de 1999 fueron relativamente elevadas. Estos resultados sugieren que no hubo un impacto obvio de este evento sobre la salud de los juveniles de lenguado ni en la calidad de las áreas de cría expuestas transcurridos unos pocos meses después del vertido

Impact de la pollution sur les écosystèmes côtiers : exemple de la Manche orientale

Les estuaires et les zones côtières constituent des territoires à forts enjeux stratégiques pour les économies et pour l’environnement. Ils assurent de nombreuses fonctions biologiques et écologiques, dont celle de nourricerie de poisson. Le bon fonctionnement écologique de ces nourriceries est indispensable pour permettre le déroulement normal du cycle biologique de nombreuses espèces marines d’intérêts économiques majeurs. En Manche orientale, la majorité des espèces halieutiques transitent par ces écosystèmes au cours de leur cycle biologique. Pourtant, il existe un recouvrement entre les principales zones de nourriceries d’intérêt halieutique et les zones soumises à des pressions anthropiques. L’analyse comparée de la qualité des zones de nourriceries a été abordée à partir d’un ensemble d’indicateurs de performances biologiques (croissance et indice de condition des poissons) et chimiques (contaminants métalliques dans les tissus des poissons et dans les sédiments). Les zones côtières fortement anthropisées (estuaire de la Seine, littoral entre Calais et Dunkerque) offrent des habitats de moins bonne qualité pour le développement et la survie des poissons. Beaucoup des espèces fréquentant les écosystèmes côtiers sont indispensables au bien-être des humains, soit directement comme ressources renouvelables à valeur marchande, soit indirectement, pour maintenir le fonctionnement et la viabilité des écosystèmes marins. La nécessité de protéger ces habitats de la pollution et de la destruction est urgente.Estuaries and coastal areas are high strategic areas for economies and environment. They perform many biological and ecological functions such as fish nursery grounds. The ecological functioning of these nurseries is vital to allow the normal life cycle of many marine species of major economic interests. In the Eastern English Channel the majority of fish species pass through these ecosystems during their life cycle. Yet there is an overlap between the main nursery areas and those subject to anthropogenic pressures. Comparative analysis of the quality of nursery areas has been addressed from a set of indicators of biological performance (fish growth and condition index) and chemical contamination (metal contaminants in fish tissue and sediment). Coastal areas strongly exposed to anthropogenic stressors (Seine estuary, coast between Calais and Dunkerque) provide lower quality habitat for fish development and survival. Many of the species that use coastal ecosystems are vital to the well-being of humans, either directly as a renewable resource value, or indirectly to maintain the functioning and sustainability of marine ecosystems. The need to protect these habitats from pollution and destruction is urgent

Impact de la pollution sur les écosystèmes côtiers : exemple de la Manche orientale

Estuaries and coastal areas are high strategic areas for economies and environment. They perform many biological and ecological functions such as fish nursery grounds. The ecological functioning of these nurseries is vital to allow the normal life cycle of many marine species of major economic interests. In the Eastern English Channel the majority of fish species pass through these ecosystems during their life cycle. Yet there is an overlap between the main nursery areas and those subject to anthropogenic pressures. Comparative analysis of the quality of nursery areas has been addressed from a set of indicators of biological performance (fish growth and condition index) and chemical contamination (metal contaminants in fish tissue and sediment). Coastal areas strongly exposed to anthropogenic stressors (Seine estuary, coast between Calais and Dunkerque) provide lower quality habitat for fish development and survival. Many of the species that use coastal ecosystems are vital to the well-being of humans, either directly as a renewable resource value, or indirectly to maintain the functioning and sustainability of marine ecosystems. The need to protect these habitats from pollution and destruction is urgent

Impact de l'anthropisation sur la biodiversité et le fonctionnement des écosystèmes marins.

International audienceLa biodiversité marine est fragilisée par les activités humaines. L'Organisation des Nations Unies a proclamé 2010, année internationale de la biodiversité pour alerter l'opinion publique sur l'état et les conséquences du déclin de la biodiversité dans le monde. En Europe, comme partout dans le monde, les densités de populations humaines ne cessent d'augmenter sur la frange littorale. Cela se traduit par une accélération continue et rapide de l'utilisation de l'espace littoral et un accroissement des pressions sur les écosystèmes et les espèces qu'ils renferment. La pollution de la mer, dont 80 % provient des activités humaines d'origine tellurique, la navigation, l'introduction d'espèces invasives, la surexploitation des ressources halieutiques, la dégradation, la fragmentation et les pertes d'habitats sont autant de facteurs responsables de l'érosion de la biodiversité marine. Exacerbée par le changement climatique, cette anthropisation menace de détruire l'équilibre fragile des écosystèmes marins et de la biodiversité qu'ils renferment. La Manche et la mer du Nord sont un carrefour biogéographique avec une grande diversité d'habitats et une biodiversité importante. D'un point de vue halieutique, c'est l'une des zones les plus productives au monde avec 5 % des prises totales à l'échelle mondiale. Malgré cette richesse, c'est un espace maritime où les conflits d'intérêts sont exacerbés et où les pressions anthropiques sont fortes notamment du fait d'une activité industrielle littorale développée. À travers différents exemples de la littérature récente, nous examinerons les principales causes ayant une incidence sur la biodiversité marine en prenant autant que possible des exemples concernant la Manche et la mer du Nord. Nous discuterons du grave danger que représente la perte de biodiversité pour l'équilibre écologique du milieu marin et le bien-être de l'humanité et sur la nécessité de prendre en compte la biodiversité dans la conduite des activités humaines, quelles soient économiques ou autres

Impact de l’anthropisation sur la biodiversité et le fonctionnement des écosystèmes marins. Exemple de la Manche-mer du nord

Marine biodiversity is affected by human activities. The United Nations have declared 2010 International Year of Biodiversity to alert the public on the status and consequences of declining biodiversity in the world. In Europe, as everywhere in the world, human population densities are increasing along the coastal areas. This result in a continuous and rapid acceleration of the use of coastal areas and increased pressure on ecosystems and species they contain. The pollution of the sea, of which 80 % comes from human activities from the land, navigation, introduction of invasive species, overfishing, degradation, fragmentation and habitat loss are the factors responsible for the erosion of marine biodiversity. Exacerbated by climate change, human impacts threaten to destroy the delicate balance of marine ecosystems and the biodiversity they contain. The English Channel and the North Sea are a biogeographical crossroads with a great diversity of habitats and high biodiversity. From a fisheries perspective, it is one of the most productive in the world with 5 % of the total catch in the world. Despite this richness, it is a maritime area where conflicts of interests are exacerbated and where human pressures are high mainly because of an industrial coastal developement. Through various examples of recent literature, we will examine the main causes affecting marine biodiversity taking as many possible examples for the English Channel and the North Sea. We will discuss the serious danger of the loss of biodiversity for the ecological balance of the marine environment and the well-being of humanity as well as the necessity to take account of biodiversity in the conduct of human activities, be they economic or other

Environmental factors structuring fish composition and assemblages in a small macrotidal estuary (eastern English Channel).

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To what extent is blue mussels caging representative of microplastics in the natural environment?

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