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This paper provides an overview of the progress Ifremer has made recently in fisheries acoustics and the study of small pelagic fish by: i) pushing observation frontiers using a range of platforms including an autonomous underwater vehicle, AUV, ii) developing measuring instruments and methods and iii) studying fish distributions. Presently, information from several frequencies of single-beam echosounders is routinely collected together with data from the ME70 multibeam echosounder. For onboard data acquisition control the HERMES software was developed. The new MOVIES 3D software includes modules for simultaneous realistic 3D visualisation and post-processing such as bottom detection, school extraction and calculation of descriptors and integration of all acoustic data. Several data analysis methods are being developed and some initial results are presented. Finally, results on the spatial distribution of small pelagic fish schools in the Bay of Biscay illustrate the role that acoustics can play, and are already playing, in the implementation of an ecosystem approach to fisheries. [ABSTRACT FROM AUTHOR]

Peck, M. A., Neuenfeldt, S., Essington, T. E., Trenkel, V. M., Takasuka, A., Gislason, H., Dickey-Collas, M., Andersen, K. H., Ravn-Jonsen, L., Vestergaard, N., Kvamsdal, S., Gårdmark, A., Link, J., and Rice, J. Forage Fish Interactions: a symposium on “Creating the tools for ecosystem-based management of marine resources”. – ICES Journal of Marine Science, 71: .Forage fish (FF) have a unique position within marine foodwebs and the development of sustainable harvest strategies for FF will be a critical step in advancing and implementing the broader, ecosystem-based management of marine systems. In all, 70 scientists from 16 nations gathered for a symposium on 12–14 November 2012 that was designed to address three key questions regarding the effective management of FF and their ecosystems: (i) how do environmental factors and predator–prey interactions drive the productivity and distribution of FF stocks across ecosystems worldwide, (ii) what are the economic and ecological costs and benefits of different FF management strategies, and (iii) do commonalities exist across ecosystems in terms of the effective management of FF exploitation? [ABSTRACT FROM PUBLISHER]

Lassalle, G., Nelva Pasqual, J-S., Boët, P., Rochet, M-J., Trenkel, V. M., and Niquil, N. Combining quantitative and qualitative models to identify functional groups for monitoring changes in the Bay of Biscay continental shelf exploited foodweb. – ICES Journal of Marine Science, 71: .To develop and implement ecosystem-based management, it is critical to monitor foodweb components or functional groups which are robust to uncertainty in ecosystem structure and functioning yet sensitive to changes. To select such functional groups for the Bay of Biscay continental shelf, both quantitative and qualitative foodweb models were developed. First, functional groups for which predictions of directions of change following an increase in primary productivity, prey or predators, or in fishing activities were identical across alternative qualitative model structures were identified. Second, the robustness to model type was assessed by comparing qualitative predictions with quantitative Ecopath model results. The demersal fish community was identified as a sensitive and robust indicator for monitoring foodweb ecological status in the Bay of Biscay. The present study also suggested the potential antagonistic effects of alternative management measures on small pelagic fish and highlighted the need for the joint management of all pressures. [ABSTRACT FROM PUBLISHER]

Greenstreet, S. P. R., Fraser, H. M., Rogers, S. I., Trenkel, V. M., Simpson, S. D., and Pinnegar, J. K. 2012. Redundancy in metrics describing the composition, structure, and functioning of the North Sea demersal fish community. – ICES Journal of Marine Science, 69: 8–22.Broader ecosystem management objectives for North Sea demersal fish currently focus on restoring community size structure. However, most policy drivers explicitly concentrate on restoring and conserving biodiversity, and it has not yet been established that simply restoring demersal fish size composition will be sufficient to reverse declines in biodiversity and ensure a generally healthy community. If different aspects of community composition, structure, and function vary independently, then to monitor all aspects of community general health will require application of a suite of metrics. This assumes low redundancy among the metrics used in any such suite and implies that addressing biodiversity issues specifically will require explicit management objectives for particular biodiversity metrics. This issue of metric redundancy is addressed, and 15 metrics covering five main attributes of community composition, structure, and function are applied to groundfish survey data. Factor analysis suggested a new interpretation of the metric information and indicated that a minimum suite of seven metrics was necessary to ensure that all changes in the general health of the North Sea demersal fish community were monitored properly. Covariance among size-based and species-diversity metrics was low, implying that restoration of community size structure would not necessarily reverse declines in species diversity. [ABSTRACT FROM PUBLISHER]

Thirty French fleets fishing primarily in the Bay of Biscay were defined based on techno-economic input criteria: i) 18 fishing gear or gear combinations ii) the location of fishing grounds visited during a year (<12 nautical miles from coast, beyond 12 nm or both) and iii) total vessel length (<20 m for trawlers and other gears <24 m). The fleets were then characterised in terms of horse power, economic dependence on a list of nine dominant commercial species (sole, Nephrops, sea bass, hake, monkfish, anchovy, cuttlefish, sardine and squid) and their contribution to the landings of these species from the Bay of Biscay. Most fleets derived the majority of their income from one or two among the nine species. Species dependencies changed little during the study period, except for those vessels targeting anchovy before the fishery restrictions starting in 2005. Fish community impacts were compared based on fleet landings' profiles. Twelve landings profiles were determined using hierarchical cluster analysis. Fleets using similar gears had the same landings' profiles and therefore exercised similar pressures on the ecosystem, though not always in the same areas. The depletion of anchovy and the closure of the fishery lead to a change in landings profile for offshore pelagic trawlers from anchovy dominance to one with a larger proportion of albacore and sea bass. During the study period, the overall vessel number decreased from 2163 to 1845. Few vessels changed fleets, but if they did, they primarily started to fish closer to the coast, which might be a result of increasing fuel prices. [ABSTRACT FROM AUTHOR]

The ecosystem-based approach to fisheries management and, more specifically, the European Marine Strategy Framework Directive require the assessment of the state and dynamics of an ecosystem in order to determine suitable management strategies. This paper takes an analytical approach to assess the state of the Bay of Biscay ecosystem in the early 1990s, chosen as a period of reference because key monitoring data series have been collected since then. To assess the state of the ecosystem, the pressures exerted by six broad categories of human activities were examined. A literature review of the ecosystem components was made and a component tree was tailored according to data availability. Data rich components were subdivided into subcomponents for their assessment while data poor components were assessed at an aggregated level. The component tree of the ecosystem comprised six main branches, four of which further divided into sub-components. In total, assessments were carried out at the level of 19 components. For four of these (fished species, sensitive fish species, marine mammals and turtles) the overall assessments were made combining the status of individual species. Impact from human activities were categorised as (i) "widespread" over the whole Bay of Biscay or "local" and (ii) "possible" when they could be logically expected or "documented" when they were reported in the literature. Fishing appeared to be the only activity exerting widespread documented impacts on several ecosystem components. Terrestrial activities had some possible and documented widespread impacts. With the exception of marine transport impacting seabirds at the regional scale through oil pollution, other activities had only local impacts, mostly nearshore. The reference state in the early 1990s, suggests that continuation of monitoring of vertebrates as well as estuarine and coastal habitats must be central to the monitoring programme and management strategies to be set in the context of the Marine Strategy Framework Directive. Additional monitoring is also required for benthos, substrate and micro-organisms. [ABSTRACT FROM AUTHOR]