• Energy Research

Mean temperature (MTC) and mean trophic level (MTL) spatiotemporal patterns of MEDITS survey catches were examined in 13 geographic statistical areas (GSAs) of the Mediterranean between 1994 and 2016. The study aimed to detect changes in the demersal community structure related to anthropogenic impacts. A generalized additive modelling approach was used to examine the effects of year and GSA on the MTC and MTL indexes and on bottom temperature by haul. For the MTC index, the year was significant only in 4 GSAs, while for MTL it was significant in 5. Higher MTC values were observed in central and eastern areas. Bottom temperature increased after 2010, and also from west to east and from north to south. Our results indicate that the recently observed increase in bottom sea temperature has not resulted in an immediate response by demersal marine communities, but areas with higher warming rates or shallow depths were found to be more susceptible to sea warming. For MTL, decreasing trends were observed in only 2 GSAs, while the temporal trends observed in 5 GSAs may have reflected changes in fishing activity patterns. However, higher MTL values were observed in GSAs with generally higher exploitation rates, indicating that factors other than fishing play an important structuring role in marine communities. The present results indicate differences among Mediterranean subareas in regard to changes in the community structure attributed to environmental conditions and exploitation patterns and have implications for the ecology and dynamics of the stocks.

The new Common Fisheries Policy (CFP) is designed to represent an appropriate response to the uncertainties and challenges facing the fisheries sector. It also adopts a holistic approach to fisheries management, considering all factors driving fishers' behavior, and ultimately, the long-term maintenance of living resources. The most reliable way to pursue these aims could be represented by a change in the exploitation pattern, in order to guarantee the sustainability of fisheries without compromising their socioeconomic viability. In this paper, the demersal fisheries of the Ionian Sea [Geographic Sub-area (GSA) 19] were analyzed with respect to their spatial, temporal, economic, and biological characteristics in terms of four key species for fisheries, namely European hake, red mullet, giant red shrimp, and deep-water rose shrimp. Specifically, (1) a quantitative procedure was applied to break down the whole system (including small-scale fleet components) into a series of fishing grounds using input data about fishing efforts; (2) the different fleet segments were defined as a combination of main gear and fishing grounds; (3) the effort and production by fleet segment were derived according to biological samplings of commercial data (Data Collection Framework for the collection and management of fisheries data, DCF), information on localization of nursery and spawning grounds, and expert knowledge; and (4) all this information was used to feed a bioeconomic modeling tool (BEMTOOL), and to explore alternative exploitation patterns. A series of scenarios including the status quo were defined, starting from the actual management approach based on temporal fishing closure. The results showed that significant improvements in the exploitation pattern could be achieved by setting up spatial and/or temporal gear-specific bans of the fishing activity. More specifically, scenarios based on a 3-month fishing ban for trawlers are expected to provide high rebuilding of the spawning stock biomass (SSB) for all target stocks, and at the same time, result in a remarkable reduction of discards. When combined with a seasonal fishing ban for small-scale fleets equipped with nets and longlines, this approach could lead to a significant improvement in all indicators, but especially the SSB of the exploited species.

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. This SEAwise report explored the impact of alternative future socio-economic scenarios (Global Sustainability, National Enterprise, Local Stewardship, World Markets), integrating climate change and incorporating enhanced economic (Bitetto et al., 2023) and productivity (Melià et al., 2023) sub-models. Deliverable 2.4 is aimed at exploring the full MSEs conducted in WP6, focusing on the management strategies other than FMSY and PGY. In particular, the socio-economic and carbon emission impacts of management measures based on change in selectivity and on the new spatial closures from task 5.5 (Bastardie et al., 2024) are investigated.The socioeconomic scenarios examined differ in climate change impact, fuel and fish price following the categorisation developed in the CERES project (Peck et al., 2020). These scenarios were combined with management scenarios and with a specific focus on small scale (SSF) and large-scale (LSF) fleets in the North Sea, Celtic Sea, Bay of Biscay and Central Mediterranean Sea. In addition to indicators related to socioeconomic aspects such as GVA and wages, carbon emissions were estimated as kg CO2 per kg of fish landed for all cases. Moreover, a specific focus was made in this Deliverable on the organic carbon pool in the stocks, in terms of biomass left in the sea and extracted by the sea (landings) to provide some insights on the carbon cycle.The Bay of Biscay case study reveals that under the Landing Obligation, the Gross Value Added (GVA) increased over time across all scenarios. Although the one-month spatial closure aimed at reducing the bycatch of common dolphins could have negative effects on GVA, these are mitigated by the positive impacts of the socio-economic scenarios. The first sale price under these socio-economic scenarios is higher than in the status quo or baseline scenario, compensating for the increase in fuel prices. The CO2 emissions per kg fish show an increasing trend over the projected period for the Large-Scale Fisheries (LSF), indicating that a dedicated effort is needed to reduce carbon emissions from these fleets. In contrast, the CO2 emissions from the Small-Scale Fisheries (SSF) decreased from the first period (2025 – 2030) to the second period (2035 – 2040) and then remained relatively stable. Regarding organic carbon in the Spawning Stock Biomass (SSB), the simulations show differences between scenarios only in species whose biomass dynamics have been modelled considering climate change (anchovy and northern hake). For anchovy, organic carbon is higher without climate change, while for northern hake, organic carbon is higher in the RCP8.5 scenarios.In the Celtic Sea case study, the effect of an alternative fleet structure was explored. The effort of bottom trawl fleets was reduced with 50%, and the effort of static fleets was increased with a factor of 2, 5 and 10. This explorative analysis showed that such fleet modification would increase catches of several demersal stocks without compromising the biomass. A reduction of bottom trawling combined with a doubling of the static fishing effort is currently identified as the best scenario. It would result in a better uptake of catches of the different stocks, allow rebuilding of the cod stock, and reduce direct CO2 emissions per kg of landed fish below current levels. However, CO2 emissions per kg landed fish still exceeded emissions in the strict implementation of the Landing Obligation (FMSY-min).In the North Sea, applied gear modifications led to lower catches of young roundfish, while utilising higher quotas of flatfish, thus delaying choking for the fleets under the landing obligation scenarios. The effect in the bioeconomic submodel explicitly accounting for price differences with age was stronger, as a larger portion of older age classes of roundfish were targeted. Even though the gear modifications resulted in an effort increase for fleets to fish out their quota, with higher fuel utilisation and costs, the impact of the positive fish price developments under the CERES projections still exceeded higher fuel price effects, resulting in a general positive economic performance of both the large and small scale fleets under the landing obligation. However, due to the decrease in CPUE under the gear modification scenarios, the CO2 emissions per kg fish generally increased over the level of the Status-quo scenario.In the Central Mediterranean case study (Adriatic and Western Ionian) the scenarios on gear modification to improve selectivity led to economic improvement in the medium to long term, with the best scenario for social and economic sustainability (Local Stewardship) emerging from 2035. In general, CO2 emissions per kg of fish decreases over time for large-scale fisheries (LSF), but the most negative climate scenarios (related to RCP8.5, NE and WM) are less efficient and yield lower catches. For small-scale fisheries (SSF), emissions remain stable and lower than those of LSF. Organic carbon stored in fish stocks increases over time due to management measures, especially under moderate climate scenarios. In general, the organic carbon stored in hake and red mullet stocks increase until 2040, followed by a decline, in line with the SSB corresponding trends.The additional management scenarios analysed in this deliverable provided further insights on how the gear modification to improve selectivity, effort reallocation among gears and spatial closures, can impact on carbon emissions and fleet performances under the four socio-economic scenarios across the four case study areas. Finally, further insights on the carbon cycle were provided (e.g. organic carbon in SSB).

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. Evaluating fishing management strategies in relation to stock sustainability and ecosystem health under changing environmental condition requires integration of ecological processes into predictive models. This SEAwise report describes the work aiming at integrating key environmental drivers into enhanced multi-stock multi-fleet models, that will allow evaluating the impacts of management strategies on stock and ecosystem indicators under climate change as conducted in the first 30 months of SEAwise.Different modelling frameworks were used to explore the impacts of abiotic (defined here as environment, climate change and their impacts on e.g. plankton) and biotic factors (predation interactions, density-dependence) on stocks dynamics and management strategy evaluations. The Mediterranean Sea, Westerns Waters and the North Sea were modelled using both multi-stock multi-fleet models (FLBEIA, BEMTOOL) and food web models (StrathE2E, EwE, OSMOSE). Using different types of models proved to be useful to explore environmental effects on stocks dynamics, provide wider ecosystem implication of management strategies and investigate the impact of model structure on predicted effects. First, knowledge from other SEAwise WPs was compiled and integrated in the formulation of some ecological processes within simulation models. Environmentally mediated processes were mainly related to recruitement, but integration of environmental conditions was also performed for growth and consumption rate and attempted for predation mortality. Second, future projections of environmental variables were used to simulate the impact of several management strategies on stocks and ecosystem dynamics. Management scenarios were similar to those already studied within SEAwise, and corresponded to status quo situation, to a perfect implementation of the landing obligation, to a pretty good yield situation and to a case-specific scenario. From some simulations covering the three case studies, results indicated that considering environmental drivers leads to worse projected stock status for the majority of stocks compared to the reference situation with no environmental change. However, the relative ranking of management scenarios in terms of stock biomass did not seem to change.Future work will involve more models, and will integrate biotic and abiotic factors in additional ecological processes. Model coupling and comparison were informative and such approach will be pursued in the future deliverable too. This will allow investigation of the uncertainty linked to model structure, process formulation and environmental projections.Read more about the SEAwise project at https://seawiseproject.org/

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/

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 (EBFM) in their fisheries. This SEAwise report aims to synthesise the results of population dynamic modelling tools used in a single species mode to demonstrate the effect of integrating the impact of environmental drivers on our perception of stock productivity, as well as the effect of different environmental scenarios, all other things being equal. At this stage, the stocks of interest have been parametrised in the different modelling tools (FLBEIA, BEMTOOL, BEE, SMS) and for each of them a baseline scenario, in which the productivity of the stock (weight/length at age, maturity and natural mortality) and the exploitation pattern (selectivity, discards) remain aligned to the stock assessment has been parametrized and run.Overall, the baseline runs presented here are considered to be realistic and consistent with perception of long-term stock productivity under current management and reference points. However, several stocks are currently in a benchmarking process and the baseline simulations conducted under this task will be updated in the future.Read more about the project at www.seawiseproject.org