Subtask 3d

Subtask 3d

Evaluation of biological and economic impact of upgrading less fuel intensity towed gears in the short-medium-long term

SubTask leader

Partners involved

This Subtask is aimed at investigating the consequences of the implementation of upgrading less fuel intensity towed gears in the trawl fisheries, using biological, impact and economic indicators. The approach will be based on simulations and scenarios’ modelling to predict short-, medium- and long-term changes, using BEMTOOL bio-economic model in GSAs 9, 10, 11 (G SA8 will be included in case of socio-economic data availability) and Ecopath, with Ecosym and Ecospace in GSA6. 

 BEMTOOL model provides a list of socio-economic indicators that are in line with the Annual Economic Report (AER). While Ecopath with Ecosim and Ecospace provide several economic indicators mainly based on revenues and energy costs (the latter relatively to the revenues). Although a complete overlap of the models’ outcomes cannot be done, due to the models’ specificities, BEMTOOL indicators could be put also in relative terms (concerning the fuel costs respect to revenues) to provide a comparison among the two areas in terms of fuel cost impact on the revenues. 

The simulations will assume the adoption of the technical innovation by a group of vessels (a fleet segment) large enough to have an impact on the biomass (in case the innovation can modify the catch rates). Simulations would be carried out with the BEMTOOL model (Rossetto et al., 2015) by case study, where inputs to the model would come from the pilot studies and the official data collected in the previous points. The model would also simulate the indirect effects on fleet segments involved in the same fisheries, different than those adopting the technical innovation (including other gears than trawlers). 

In GSA6 a similar approach will be developed using Ecopath, with Ecosym and Ecospace, coupled with an economic impact model. 

Building on the experience gained in the IMPLEMED project (Sbrana, 2022), the results of the pilot studies will be incorporated in the model in terms of initial investment, change in energy consumption and costs, changes of the selectivity, discard volume of target species, revenues, species composition to closely assess the time needed to absorb the initial economic investment differentiating by fleet segment and by area, depending on the cost structure of each of them. 

The impact on the economic performance of the fleet and on the biological status of the target stocks will be evaluated in the short and medium term through simulation scenarios corresponding to the tested net configurations in the pilot studies, including uncertainty. A set of indicators will be produced to be shared/discussed in cooperation with stakeholders.