SEAwise report on the impact of socio-economic effects of fisheries management

The SEAwise project works to deliver a fully operational tool that will allow fishers, managers, and policy makers to easily apply Ecosystem Based Fisheries Management. Assessing socio-economic impacts of fisheries management is crucial to a full implementation of ecosystem-based fisheries management. This SEAwise report demonstrates evaluations of predicted effects of management measures under future climate change, using the bio-economic models already used in Deliverable 6.4 to explore a variety of management measures based on the Management Plans in force in Mediterranean Sea, North Sea, Bay of Biscay and Celtic Sea. The models included enhanced stock productivity models developed in WP3, in response to varying climate change scenarios, to assess the robustness of management measures across different productivity regimes from a socio-economic perspective. The socio-economic components of the bio-economic models applied for this purpose have been improved relative to previous deliverables by incorporating enhanced sub-models developed in Deliverable 2.2. The impact on the fleets considered was assessed using key indicators established in the CFP and identified during the WP2 synthesis workshop in July 2023.

Five scenarios were used to simulate the management and the fleet dynamics:

• Status-quo scenario: current fishing mortality was maintained following the catch advice (North Sea and Western Waters) or the effort quotas (Mediterranean Sea) in the Management Plans in place in the different regions.
• FMSY (or, where Landing obligation are in force, FMSY_Landing_Obligation scenario) scenario: catch/effort advice was produced using the MSY approach of all the stocks. This scenario is driven by the most endangered stock(s) and, where in force, mimicked the full implementation of the landing obligation.
• PGY (pretty good yield) or FMSY range scenario: catch/effort advice was produced using the fishing mortality ranges within the MSY approach to relax choking/underutilization effects of the FMSY scenario implementation.
• (FMSY combined) scenario: the effort reduction is set to achieve a combined FMSY on all main stocks, with the same objective of the PGY scenario.
• Case-specific scenario: the MSY approach was used to generate the catch advice and the fleet dynamics were tailored to the best knowledge of the system.

For the Bay of Biscay demersal fishery and the Basque pelagic fishery (Western Waters case study), management scenarios had a larger impact than climate change scenarios. In economic terms, the different management scenarios performed differently depending on the scale of the fleet, while the climate change scenarios had a minor impact. The large-scale fishery (LSF) achieved the best economic value in the Case-specific scenario, followed by the Status-quo scenario. These scenarios produced more stable gross surplus throughout the entire projected period. The Status-quo resulted in higher CO₂ emissions per fish kg. The profitability of the small scale fleet (SSF) was lower than that of the large scale fleet, and achieved the highest levels in the Case-specific and FMSY_Landing_Obligation scenarios whereas the greatest stability in gross surplus was achieved in the Case-specific and StatusQuo scenarios. Regarding the energy performance, the FMSY_Landing_Obligation scenario provided the best value.

In the Celtic Sea case study (Western Waters) the productivity of cod and whiting was predicted to decline due to warming, though there was some variation around this result. Hake and megrim exhibited increased productivity under climate change. The economic indicators showed no clear trends. Overall, climate change mainly led to improved gross profit for the large scale fleet segments as the total value of their landings would increase compared to the small scale fleet. Further, climate change resulted in a more variable income for fleets, with a higher chance of experiencing an income loss of 20% or more from one year to another.

In the North Sea case study the revenues were higher for the scenarios with a stronger relaxation of the constraints imposed by the landing obligation. Though stocks were expected to recover due to lower fishing mortalities, the effects of climate change on the productivity of cod and saithe had negative consequences on economic performance of both small- and large-scale fleets. As stock productivity declined, revenues from the fishery decreased under stronger warming scenarios, leading to lower employment and higher chances to suffer an income loss. Management measures relaxing the landing-obligation between the two extremes of Status-quo and FMSY_Landing_Obligation were able to buffer some of negative climate change effects on the fishery.

In the Eastern Mediterranean Sea, total landings were highest in the Fcomb and Status Quo scenarios for the SSF and the PGY scenario for the LSF. The effect of the climate change on landings was minor, and solely due to the effect of the environment on recruitment of hake. Despite the high uncertainty, the effect of climate was more evident in the economic indicators. These declined towards 2060, and this decline was not observed if current climatic conditions were retained. The current SSF contribution of ~75% of the landings value percentage was unchanged under F01 (used as proxy of FMSY) scenario, while it increase to 85% under the Fcomb scenario and reduced to 50% under the PGY. The chance of the SSF suffering a 20% income loss in a year (currently at ~20%) increased under future climatic conditions, reaching up to 30% under Status-quo and Fcomb management in 2045-2050. As SSF had the greatest contribution to landings and value, they were the most vulnerable to climate change.

In the Adriatic and Western Ionian Sea, the PGY scenario returned the highest GVA for LSF, whereas the FMSY scenario performed better for SSF due to the greater effort reduction impacting trawlers (part of LSF). The PGP fleet was adversely affected by rising temperatures, as this fleet targeted the negatively impacted hake and red mullet stocks. In contrast, trawlers would benefit from a moderate temperature increase (RCP4.5) due to its positive effect on shrimp stocks. In both FMSY (returning the lowest values) and PGY scenarios, CO₂ emissions per kilogram of fish landed decreased over time, in contrast to the status quo scenario, which remained more stable. The ratio between SSF and LSF landing value remained relatively stable for Adriatic fleets across all scenarios. For the Italian fleet operating in GSA 19, however, climate change led to a significant increase in shrimp landings, which benefited the LSF and hence reduced the SSF to LSF ratio. All indicators showed that the FMSY scenario performed best closely followed by the PGY scenario that would lead to less severe effort and, subsequently, overall GVA reduction.

Across cases, the simulations showed that continued fishing in status-quo scenarios is suboptimal in socio-economic terms compared to the alternative scenarios explored. Depending on the specific fleet and country, the results indicated that management measures positioned between the extremes of status quo and FMSY with a strict enforcement of the landing obligation can potentially mitigate some of the negative socioeconomic impacts of climate change on the fishery and decrease CO₂ emissions per kg of fish landed. In economic terms, the different management scenarios perform differently depending on the scale of the fleet. The climate change impact favoured small or large scale fleet segments depending on the region and the impact of environment on the stocks targeted by the two segments.

Read more about the SEAwise project at https://seawiseproject.org/