Summary 1. The development of ecosystem approaches to environmental management implies the need to account for multiple pressures on ecosystems. Trends in multiple metrics that respond differently to changes in major environmental pressures need to be combined to evaluate the impacts of fishing and environmental changes on fish communities. 2. An exploited fish community is viewed as a three‐level food chain in which the two upper levels, or functional groups, are targeted by fishing fleets, while the lowest level is subject to environmental variation. Qualitative modelling is used to predict changes at the two upper levels, that is, top‐down vs. bottom‐up perturbations. Abundance and length metrics are calculated from survey data for 14 Mediterranean and East‐Atlantic groundfish shelf communities at both population and functional group levels. The joint likelihood of time trends in metrics is used to evaluate the evidence for different causes of changes. 3. A wide diversity of impacts is found to have equal evidence at the population level within each community. Consistency between the impacts identified and changes in pressures known from independent information is found at the functional group and community level. The results suggest that there is some compensation between species within functional groups. 4. Synthesis and applications. The method can be used to conduct an integrated assessment of community dynamics subject to multiple pressures. Joint trends in metrics provide evidence of which known pressures are having an impact on the community, and thus, which management actions should be taken to mitigate these changes.

The composition of the catch of the deep sea trawl fleet of Porto Santo Stefano (northern Tyrrhenian Sea, western Mediterranean) was analysed. In the period 199599 observations were carried out on board commercial vessels, collecting data for about 500 trawling hours. Nephrops norvegicus, Parapenaeus longirostris and large specimens of Merluccius merluccius were the targets on the fishing grounds from 300 to 450 m, while Aristaemorpha foliacea, Aristeus antennatus and N. norvegicus were targeted from 450 to 650 m depth.By-catch dominated the biomass caught and it was characterized by a high degree of species richness, as a consequence of the reduced selectivity of the bottom trawl gear. An important fraction of the by-catch was made up of non-target commercial species, these providing an important added value to the landings. There was almost no discarding of target species. Annual average discards were about 20% of the total catch. Discarding of commercial species was mostly due to specimens under commercial size, while discarded non-commercial species included large numbers of small sized species of fishes and crustaceans. The results seem to indicate that this kind of fishery achieves a reasonable compromise between efficiency of resource utilisation and impact on the demersal communities.

Maiorano, L., Bartolino, V., Colloca, F., Abella, A., Belluscio, A., Carpentieri, P., Criscoli, A., Jona Lasinio, G., Mannini, A., Pranovi, F., Reale, B., Relini, G., Viva, C., and Ardizzone, G. D. 2009. Systematic conservation planning in the Mediterranean: a flexible tool for the identification of no-take marine protected areas. – ICES Journal of Marine Science, 66: 137–146. We propose the use of systematic conservation planning in the Mediterranean context for the identification of no-take marine protected areas (NTMPAs). We suggest a logical framework that should be used for the identification of areas to be targeted for multispecies, spatially explicit conservation actions. Specifically, we propose seven steps: (i) definition of the study area; (ii) selection of the species or habitats to be considered; (iii) definition of the planning units; (iv) measurement of the fishing effort; (v) definition of the conservation targets; (vi) review of the existing conservation areas; (vii) selection of additional NTMPAs. Moreover, we consider the potential impact of different conservation plans on existing fishing vessels. A working example is presented, focusing on a limited number of species and on a limited study area. This framework can be easily expanded to include datasets of different origin and to accommodate larger spatial scales. Such a process involves major data-collection and capacity-building elements, and conservation of productive commercial fisheries must be a priority.

No abstract