Allowable Zones of Effect for Mediterranean marine Aquaculture (AZE)

Sustainability of Mediterranean aquaculture will be focus regarding to the environmental dimension of minimize the local impact on environmental conditions and biodiversity and respect the ecological services of the ecosystem. The development of floating cages on coastal systems needs to develop a regulatory framework for offshore aquaculture, considering important aspect such as permitting and site selection because the potential harmful effects on marine environment. For management purposes, the concept of AZE, area of sea-bed in which competent authority will allow to aquaculture some figures exceeding the relevant environmental quality standard (EQS), producing some non-permanent damage to the environment, can provide a degree of flexibility in the regulation of farms effects and recognises that it is quite impossible to cause no environmental effects from intensive fish production in the immediate surrounding area. Monitoring the environmental affection should be necessary for ensure sustainable aquaculture production, and three spatial scales may be considered: immediate vicinity of farm (AZE), to monitor that EQSs sampled around the AZE comply with the EQSs set for the medium field and to evaluate how much EQS at the regional scale differ from the reference sites

The role of the seagrass Posidonia oceanica in the cycling of trace elements

The aim of this study was to investigate the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in different compartments of P. oceanica (leaves, rhizomes, roots and epiphytes) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epiphytes were the compartment, which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica. Trace element translocation in P. oceanica seemed to be low and acropetal in most cases. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi showed the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.This study was funded by the General Secretariat for Research and Technology (IBIS Project) and facilitated by the COST Action ES0906 “Seagrass Productivity: from genes to ecosystem management”. CS was supported by the Ministerio de Educación y Ciencia of Spain

Long-term (1998–2010) large-scale comparison of the ecological quality status of gulf of lions (NW Mediterranean) benthic habitats

12 páginas, 4 tablas, 8 figuras.A comprehensive Mediterranean data set has been used to address 3 questions associated with the use of sensitivity/tolerance based biotic indices to infer the Ecological Quality status (EcoQs) of benthic habitats. Our results showed: (1) a significant effect of the reference database on derived sensitivity/tolerance measure (ES500.05) as well as associated Benthic Quality Index values and derived EcoQs; (2) a lack of correlation neither between BQI and AZTI Marine Biotic Index values nor between BQI and Multivariate-AZTI Marine Biotic Index values; (3) a lack of correlation between the values of the Benthic Habitat Quality Index (index derived from Sediment Profile Imagery) and those of either of the 3 tested biotic indices; and (4) a general agreement between the 3 tested biotic indices in describing the lack of global trend for the EcoQs of the Gulf of Lions despite the occurrence of significant changes in benthic macrofauna composition between 1998 and 2010.This study has been carried out with financial support from the French National Research Agency (ANR) in the frame of the Investments for the future Programme, within the Cluster of Excellence COTE (ANR-10-LABX-45).Peer reviewe

Aquaculture’s struggle for space: the need for coastal spatial planning and the potential benefits of Allocated Zones for Aquaculture (AZAs) to avoid conflict and promote sustainability

Aquaculture is an increasingly important food-producing sector, providing protein for human consumption. However, marine aquaculture often struggles for space due to the crowded nature of human activities in many marine coastal areas, and because of limited attention from spatial planning managers. Here, we assess the need for coastal spatial planning, emphasising the establishment of suitable areas for the development of marine aquaculture, termed Allocated Zones for Aquaculture (AZAs), in which aquaculture has secured use and priority over other activities, and where potential adverse environmental impacts and negative interactions with other users are minimised or avoided. We review existing examples of marine aquaculture spatial development worldwide and discuss the proper use of site selection in relation to different legal and regulatory requirements. National or regional authorities in charge of coastal zone management should carry out spatial planning defining optimal sites for aquaculture to promote development of sustainable marine aquaculture and avoid conflict with other users, following a participatory approach and adhering to the principles of ecosystem-based management

Allocated zones for aquaculture : a guide for the establishment of coastal zones dedicated to aquaculture in the Mediterranean and the Black Sea

This publication is based on the findings of the project Developing site selection and carrying capacity guidelines for Mediterranean aquaculture within aquaculture appropriate areas (SHoCMed), implemented by the Scientific Advisory Committee on Aquaculture (CAQ) of the General Fisheries Commission for the Mediterranean (GFCM) of the Food and Agriculture Organization of the United Nations (FAO) with the support of the European Union (Directorate-General for Maritime Affairs and Fisheries of the European Commission). Concluded in 2016, SHoCMed aimed at developing criteria, standards and guidelines for GFCM contracting parties and cooperating non-contracting parties to improve site selection criteria and set capacity benchmarks and references for aquaculture activities in the Mediterranean.peer-reviewe

Nutrients and fine particulate matter released from sea bass (

Mass budget of the sea bass (Dicentrarchus labrax) farming losses was examined. Experiments were carried out in April, September and November 2001 in tanks of 8.5 m3 containing sea bass of 1, 31 and 53 g, respectively. Samples were taken at the input and discharge points of the tank at hourly intervals over 24 h. They were later analysed for nutrient concentration, as well as particulate organic carbon and nitrogen, chlorophyll a (Chl a) and total bacterial abundance. Despite the high water supply (exchange rate: 50% h−1), NH4 concentration was significantly higher in discharge water than in input water in all three experiments independent of fish size. The same was found to hold true for PO4 for part of the day (April, November) or for the entire day (September). NO3 and SiO2 ions did not show any differences during April. Particulate organic carbon (POC) and nitrogen (PON) were higher in the discharge water in all seasons. Chl a concentration was higher in the discharge water during the entire day in September whereas bacteria presented higher counts in the output water only during part of the day in April. It was found that 5−7% of the nitrogen supplied is released into the water column as fine particulate material in the form of PON and 21−29% as NH4. A small proportion (13−16%) of supplied phosphorus (P) was released as PO4. The results provided in the present paper are useful in assessing environmental changes in water quality in the vicinity of fish farms in the Mediterranean

Contribución de las granjas de peces a la carga de nutrientes del Mediterráneo

Mediterranean fish farming has grown exponentially during the last 20 years. Although there is little evidence of the impact on the trophy status around fish farms, there are concerns that the release of solute wastes from aquaculture might affect larger scales in the ecosystem by changing the nutrient load. After combining information from various sources on waste production and on nutrient loads, it was concluded that the overall N and P waste from fish farms in the Mediterranean represents less than 5% of the total annual anthropogenic discharge, and the overall annual increase in P and N pools in the Mediterranean, under a production rate of 150000 tons, is less than 0.01%. The proportion of fish farming discharged nutrients was slightly higher in the eastern Mediterranean. A simple model was used to assess the long-term effects of nutrients released from various sources taking into account the water renewal rate in the Mediterranean. We conclude that, in the long term, fish farm waste could cause a 1% increase in nutrient concentrations in contrast to other anthropogenic activities which might double the Mediterranean nutrient pool.La piscicultura en el Mediterráneo ha crecido exponencialmente durante los ultimos 20 años. Aunque hay pocas evidencias del impacto sobre el estado trófico alrededor de las granjas de peces, existe la preocupación de que la liberación de residuos solubles procedentes de la acuicultura pueda afectar al ecosistema, de manera notable, a través de cambios en la carga de nutrientes. Después de combinar información de varias fuentes sobre la producción de residuos cargados de nutrientes, se concluyó que el N y el P totales liberados en las granjas de peces en el Mediterráneo, representan menos del 5% de la descarga anthropogénica anual total y el aumento anual del contenido en P y de N en el mediterráneo, bajo una tasa de producción de 150000 toneladas, es menor de 0.01%. La proporción de la descarga de nutrientes procedentes de la piscicultura fue ligeramente mayor en el Mediterráneo Oriental. Se utilizó un modelo sencillo para determinar los efectos, a largo plazo, de la liberación de nutrientes desde varias fuentes considerando la tasa de renovación del agua en el Mediterráneo. Se concluyó que, a largo plazo, las granjas de peces podrían dar lugar a un aumento del 1% de las concentraciones de nutrientes, en contraste con otras actividades antropogénicas que podrían doblar el contenido de nutrientes del Mediterráneo

Response of Benthic Macrofauna to Eutrophication in a Mesocosm Experiment: Ecosystem Resilience Prevents Hypoxic Conditions

A benthic-pelagic mesocosm experiment was performed to study how the benthic macrofaunal community responds to a eutrophication gradient. The novel experimental setup allowed the induction of an eutrophication gradient in the water column and the detailed documentation of the response of the benthos in terms of biodiversity and ecosystem processes. Nine mesocosms were deployed in the facilities of the Hellenic Center for Marine Research in Crete in the eastern Mediterranean. The mesocosms were 4 m deep, contained 1.5 m3 coastal water, and included 85 liters of undisturbed sediment at the bottom. No water or sediment exchange was allowed. The experimental design included a Control and two eutrophication levels (Low and High) for the 58-day duration of the experiment. Macrofaunal samples were collected at the end of the experiment from each mesocosm and compared to the ones collected at the beginning of the experiment from the sediment collection area. Results show that the High eutrophication treatment differed significantly from the Control and Low treatments in terms of macrofaunal species composition, diversity, ecological status and ecosystem processes. The increased availability of organic matter in the sediment caused differences in macrofaunal community structure by favoring deposit-feeding species with high bioturbation ability, which significantly increased their abundance. The increased bioturbation potential of the new community combined with the high organic matter consumption contributed to the oxygenation of the sediment within the mesocosm, preventing the creation of hypoxic conditions in the sediment and maintaining ecosystem health despite the highly eutrophic conditions and significant changes in sediment geochemical variables. In the oligotrophic eastern Mediterranean, healthy benthic ecosystems may use existing ecosystem processes to “buffer” the negative effects caused by eutrophication

Estimating species richness, abundance and diversity with 70 macrobenthic replicates in the Western Baltic Sea

An unusually large number of replicated macrofaunal samples (70) was taken from the Western Baltic in May 1995 for a ringtest in an ICES/HELCOM intercalibration exercise. This data set was employed in this study in order to investigate the performance of numerical methods used for predicting species richness and to assess the accuracy of the estimates of abundance and diversity currently used in benthic ecology. The results of this study indicate that: (1) more than 10 replicates are required in order to include in the data set more than two-thirds of the species found in 70 replicates, and more than 53 replicates are required in order to include 95% of the species; (2) estimates of average abundance and of average Shannon-Wiener diversity index using 5 replicates could result in less than 40% error; this could be less than 30% for 10 replicates and less than 5% for 70 replicates; (3) both types of species-richness predictions (jackknife estimate and S 0) increased with increasing number of samples used in the calculations, indicating that their ability to assess overall species richness in the community is rather limited; in particular, it is shown that jackknife overestimates and S0 slightly underestimates species richness. Different configurations of the S0 method were tested in order to optimize its performance, and it was found that both truncation and increasing sampling lag result in increased and stabilized estimates of species richness