EFIMAS simulation module

One of the key outcomes of EFIMAS is development of an operating model within the management evaluation framework that allows testing of plau­sible hypotheses about the dynamics of the stocks and fleets before implementation and which can appra­ise the biological and social and economic effects of different existing fishe­ries management measures in EU.

Overview of the planned EFIMAS simulation module

Simulation module
Diagrammatic example of MEF phases evaluating and comparing two (A & B) alternative management options. Click to see enlarged version

Databases: E.g. research surveys, sampling from commercial vessels and market samples, effort, (including spatial distribution of effort), prices and costs of fishing operation, etc. Data can be obtained by random number generators, or they can be bootstrapped from existing databases. Measurement errors can be imputed. This module allows for simulating increased/reduced sampling intensity, as well as change of stratification. The framework will use existing databases.

Data Processing: Can be used to simulate alternative data post-stratifications and methods of data processing. This can be done by boot-strapping.

Data Evaluation: Variability and uncertainty in data can be calculated, e.g. by using Bayesian methods.

Simulations of output from fisheries/stock evaluations (assessment) will include output from fish stock assessment along the lines of ICES Working Groups supplemented by bio-economic analysis or other descriptive fisheries / stock assessment models and analysis tools. The impact of process errors will be evaluated.

Management advice will be based on a suite of harvest control rules, most of which can be fleet or stock specific. This module will simulate the advisory functions of e.g. ACFM and STCEF. 

Simulation of implementation: This module can simulate or evaluate the reaction of fishers to management regu­la­tions. It consequently can simulate or evaluate the behaviour of the fishing industry. "Implementation errors" imply modelling or evaluating the un-intended effects of regulations, lack of effect (compliance) and control. Behaviour cover "strategic or structural behaviour" and "tactic or trip related behaviour". Structural behaviour accounts for the invest­ment in new vessels and withdrawal from the industry (e.g. decommission). Trip related behaviour accounts for the decisions made by the fishers in relation to fishing operations (e.g. choice of gear and fishing grounds).

Output from the simulation or evaluation: See above diagram.

18 OCTOBER 2021