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Population studies in support of the conservation of the European sea bass - MF1233

European sea bass are shared between recreational and commercial fishing sectors, both of which depend on healthy stocks and sustainable fishing, but which have contrasting objectives, for example the maximization of commercial fishery yield as opposed to promoting survival to the larger sizes of fish prized by anglers. A range of different approaches are possible, including spatial or seasonal elements, which might achieve the necessary control over fishing mortality whilst achieving a tradeoff between each sector’s objectives. To evaluate such approaches, the project will establish a clear spatial picture of the fishing pressures on bass, and how fishing mortality is generated by the distribution and movements of the fish relative to fishing pressure zones. For example, adult bass migrate annually to offshore waters where international fleets operate, but tend to return to the same coastal location where persistent localized depletion could potentially occur dependent on the fishing effort exerted there. The project will develop models incorporating these aspects of behaviour relative to fishing pressure zones, to provide a tool for exploring a range of conservation measures. We will apply a portfolio of complementary research approaches to build the best available evidence of bass population structure, biology and movements to inform the development of the spatial population models. Throughout the project we will work with stakeholders to collect data, benefit from their knowledge and to help validate model results.

The work programme incorporates five linked work-packages (WPs). WP1 will map spatial fishery pressures and impacts on bass, evaluate the relative benefits of different approaches to keep fishing mortality within sustainable limits, and identify uncertainties and data gaps affecting the ability to predict the benefits of conservation measures. In WP2, a large-scale programme of tagging, involving recreational anglers, will be carried out in parallel with the release of 100 mature bass tagged internally with floated electronic data storage tags (DSTs) to identify patterns of bass movements within and between inshore and offshore fishery pressure zones. WP2 includes a studentship proposal (to be funded externally) to study stock structure based on genetics and isotope analysis, and a data workshop which is planned to promote cooperative interpretation of European bass tagging programmes and help steer future research. Data compiled in WP1 and gathered in WP2 will be applied in WP3, where the spatial, individual-based models will be developed to assess conservation strategies for sea bass.

A desk study will collate current knowledge of several other key species such as grey mullet, black bream and gilthead bream which are of importance for recreational sea-angling (WP4), and consider if they are amenable to the modeling approaches developed for bass. Given the high level of stakeholder engagement in the project, a communication plan including a steering group will be established early in the project (WP5). The steering group will draw from the sea-angling and commercial fishing communities, media, scientists, policy makers and Inshore Fisheries and Conservation Authorities, with continued engagement over the lifetime of the project to maximise feedback and the uptake and dissemination of results.
The overall aim of this project is to build the evidence-base and methods required to successfully manage the Europen sea bass, and understand how these can be applied to other species that are important to both commercial fishers and recreational anglers. This will be done through a process that engages and builds trust with stakeholders.

Reporting will follow an annual cycle (milestones 1, 9, 12, 13 &18), with a final report (milestone 19) at the end of the project. As milestones align primarily with annual reporting, the project breakpoints occur at the end of years 1, 2 and 3 (milestones 9, 12 and 13). The proposed work will be executed in the five following work-packages (WPs):

WP1: Engagement with commercial fishing and recreational angling stakeholders
This workpackage will engage with a range of stakeholders to enhance the quality, utility and understanding of the outputs. This will be achieved through the creation of a website (Milestone 2) and formaton of a steering group (Milestone 3). There are no dependencies.

WP2: Understanding the impact of management measures and identifying key data gaps.
WP1 will identify the commercial and recreational fishing pressures on the bass population in the North Sea, English Channel, Celtic Sea and Irish Sea, and will explore the relative effectiveness of different conservation measures. This will include quantification of spatial fishery impacts on sea bass (Milestone 4), exploration of the relative effectiveness of a range of possible conservation measures (Milestone 5), and identificaton of the uncertainties and data gaps most influencing the predicted benefits of conservation measures (Milestone 6). The majority of this task will be completed during the first year of the project as this work is necessary to inform the scenario modeling in WP4. There are no dependencies.

WP3: Population dynamics of European sea bass
A combined approach to understanding and quantifying population dynamics of bass using both artificial and natural markers will be applied, involving stakeholder participation, and building on existing studies. The overall aim is to achieve a more comprehensive overview of bass stock structure and distribution and gain fundamental understanding of the life-history movements of bass. The objectives are to understand the movements of bass through tagging programmes that include stakeholders (Milestone 10) and better understand bass population dynamics through a data sharing workshop including invited European experts(Milestones 11). No significant depencies, but some output from WP2 may be used to develop tagging programmes and bass movement will be used to inform the scenario modelling in WP4.

WP4: Scenario modelling to assess conservation strategies for European sea bass
This will develop individual-based models (IBMs) of the pelagic (Milestone 7) and adult phases (Milestone 16) and use these models to explore alternative conservation strategies for bass (Milestone 16). This is dependent on the outputs from WP2 (Milestones 4 & 5) for input parameters for the individual-based models (e.g. growth, removals, spawning locations, conservation strategies) and WP3 to provide information on sea bass movements.

WP5: Application to other species
This will collate and evaluate existing knowledge on the biology and processes known to affect the abundance and distribution of several additional recreational fish species of interest to the UK like grey mullet, black bream and gilthead bream (Milestone 8). Where possible, we will identify important gaps in understanding of population biology relevant to fish stock assessment, management and conservation. The potential for methods developed in WP4 to be applied to these other species will also be addressed (Milestone 17).

Project Documents
• TPS - Two Page Summary : MF1233 initial two page summary final   (318k)
Time-Scale and Cost
From: 2013

To: 2020

Cost: £574,127
Contractor / Funded Organisations
Fields of Study
Marine Fisheries