Development of a Management Strategy Evaluation process for IOTC - Working paper in support to the Scientific Committee of the Indian Ocean Tuna Commission

This report contains the working report ‘Development of a Management Strategy Evaluation process for IOTC’ in support to the 14th Session of the Scientific Committee of the Indian Ocean Tuna Commission, Victoria, Mahé, Seychelles, 12-17 December 2011. The paper serves as basis for initial discussions on the implementation of an Management Strategy Evaluation (MSE) approach within the IOTC.JRC.G.4-Maritime affair

Bioeconomic Modelling for Fisheries

Current fisheries advice requires an increased consideration of bioeconomics and the interactions of fishing fleets with the biological stocks. This is particularly important when evaluating proposed multi-annual management plans. To achieve this, modelling tools need to be able to consider the dynamics of individual fisheries. This becomes more challenging with mixed fisheries when multiple species are caught by multiple fleets. A suitable balance needs to be found between replicating the details of the complex fishery system and simplifying a model to the level that makes it tractable but still useful. Much of the bioeconomic fisheries modelling work performed at the JRC uses the FLR software framework. The JRC has developed a new FLR package, FLasher, for performing projections and forecasts with multiple individual fisheries and multiple species. This allows the dynamics of mixed fisheries to be more accurately modelled and allows the evaluation of the economic performance of alternative management decisions. This document presents some of the features and capabilites of FLasher using a case study based on a semi-realistic flatfish fishery: two fleets with different selectiviuty patterns, bottom trawl and gillnet, catching two species with different life histories and maximum sizes, European plaice (Pleuronectes platessa) and common sole (Solea solea). FLasher expands the current modelling capabilities of FLR, allowing the impacts of proposed management plans to be evaluated in greater detail by (1) explicitly modelling the dynamics of each individual fleets, which could be affected in different ways by management, (2) forecasting in parallel the full species and fleet assemblage found in mixed fisheries, and (3) employing the latest iteration of the C++ language and a new library for automatic differentation.JRC.D.2-Water and Marine Resource

AN EVALUATION OF THE PERFORMANCE OF THE KOBE STRATEGY MATRIX: AN EXAMPLE BASED UPON A BIOMASS DYNAMIC ASSESSMENT MODEL

The main management objective of ICCAT is to maintain the populations of tuna and tuna-like fishes at levels which will permit the maximum sustainable catch. Scientific advice designed to meet this objective, in common with other tuna Regional Fisheries Management Organisations' (tRFMO) scientific committees is presented in the form of the Kobe II Strategy Matrix (K2SM). This is essentially a decision table showing the time taken to achieve management objectives (e.g., stock recovery) for different levels of TAC or effort. The role of the K2SM as an important tool to communicate efficiently among all stakeholders and to assist in the decision-making process according to different levels of risk has been recognised.JRC.G.4-Maritime affair

P491-BioMod Deliverable 4913 Management Strategy Evaluation Error Model

In terms of analysing and simulating fisheries management systems, implementation error can be considered to be the difference between management decisions (for example, the TAC or effort limits set for the following year) and what the fishing fleets actually do (for example, the actual catch taken or fishing effort applied that year). It is thought that implementation error can have a strong impact on the potential success of a management plan, but the precise level of impact and the effect of implementation error combined with other sources of uncertainty requires further study. This document describes the application of a simple Management Strategy Evaluation simulation to investigate the potential impacts of management plan implementation error on the sustainability of a stock. The simulation is based on the cod stock in the Eastern English Channel and Southern Celtic Seas. The results are illustrative only and are not meant to provide advice for the stock. It was found that including implementation error in the projections (i.e. the realised catch being greater than the desired TAC) not only led to the stock being more exploited (lower SSB, higher fishing mortality) but also increased the uncertainty in the stock status. This will be of particular interest when a risk-based approach to fisheries management is being considered. The implementation of a management plan is strongly in influenced by a range of economic factors that drive the dynamics of the fishing fleet. The simulations here do not make a full economic analysis and focus on the sustainabilty of the stock rather than the economic viability of the fishing fleet. Future work will include more economic modelling to improve the implementation error model. Note that this report was not prepared using MS Word. It was prepared using Latex / KnitR and R. This allows the computer code that was used to generate the results to be embedded in the report and executed during the report compilation, including the plotting of figures. This is preferable for scientific report writing as it ensures that the results presented here are ‘live’. Consequently, the following report may not strictly adhere to the JRC template.JRC.G.3-Maritime affair

A KOBE STRATEGY MAATRIX BASED UPON PROBABILISTIC REFERENCE POINTS: AN EXAMPLE USING A BIOMASS DYNAMIC ASSESSMENT MODEL

The main management objective of ICCAT is to maintain the populations of tuna and tuna-like fishes at levels which will permit the maximum sustainable catch. Scientific advice designed to meet this objective, in common with other tuna Regional Fisheries Management Organisations (tRFMO) scientific committees, is presented in the form of the Kobe II Strategy Matrix (K2SM). A decision table is given showing the time taken to achieve management objectives (e.g., stock recovery) for different levels of TAC or effort. However, substantial uncertainties still remain in assessments and therefore a key area of research is to show how uncertainty and improvements in information, consistent with the principles of the precautionary approach, can be incorporated into advice, so that for any level of uncertainty there is the same risk of depletion.JRC.G.4-Maritime affair

The Conservation and Management of Tunas and Their Relatives: Setting Life History Research Priorities

Scombrids (tunas, bonitos, Spanish mackerels and mackerels) support important fisheries in tropical, subtropical and temperate waters around the world, being one of the most economically- and socially-important marine species globally. Their sustainable exploitation, management and conservation depend on accurate life history information for the development of quantitative fisheries stock assessments, and in the fishery data-poor situations for the identification of vulnerable species. Here, we assemble life history traits (maximum size, growth, longevity, maturity, fecundity, spawning duration and spawning interval) for the 51 species of scombrids globally. WJRC.G.4-Maritime affair

Common Fisheries Policy Monitoring - Protocol for computing indicators

Common Fisheries Policy Monitoring - Protocol for computing indicators This document presents the protocol to compute indicators for monitoring the Common Fisheries Policy. A set of indicators both design-based and model-based are described mathematically. The list of stocks that should form the dataset on which the indicators are computed is also described as well as a set of rules to update the stocks' lists when needed. The protocol was presented and approved by the STECF's 2015 winter plenary (STECF-PLEN-15-03).JRC.G.3-Maritime affair

The a4a Assessment Model - Model description and testing

The a4a initiative aims to provide timely and cost effective advice for the circa. 250 fish stocks that, through the EU Data Collection Framework, will have at least 10 years of data by the year 2020. Current processes for assessing the state of and managing fish stocks are intensive processes, each stock requiring the attention of one or more stock assessment scientist to produce preliminary catch advice, which is subsequently reviewed by one or two committees before the final catch advice is published. Ingrained in the development of these processes has been the development of more and more complex stock assessment models which typically require highly skilled personnel to set up and run.JRC.G.4-Maritime affair

Testing the robustness of HCRs applied to Baltic pelagic stocks - Working Document in support to the STECF Expert Working Group 12-02 Management Plans - part 1

This work replies to a request from STECF EWG 11 15 to JRC to provide tests on the robustness of the target shing mortality (Ftrgt) and biomass trigger (Btrg) used on the harvest control rule (HCR) of the Baltic pelagic stocks. The main conclusion is that the successful candidates must assure Btrg is above the S/R break point and an exploitation level that is consistent with Btrg considering the stock dynamics.JRC.G.4-Maritime affair

a4a assessment model simulation testing

The a4a initiative seeks to overcome these issues by developing a flexible, robust and easy to use stock assessment model, thus making stock assessment accessible to a wide range of scientists that do not have the high skilled quantitative background required to run very complex models. Forthcoming research will describe how to overcome the burden of producing catch advice for such a large number of stocks. This technical report presents assessment model simulation testing undertaken under the a4a Initiative.JRC.G.4-Maritime affair