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The Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) develops methods and performs assessments to evaluate benthic impact from fisheries at regional scale, while con- sidering fisheries and seabed impact trade-offs. In this report, new fishery benthic impact assessments (ToR A) are shown out for several sub- regions in (French Mediterranean, Celtic Seas). For other regions, updates of the whole assess- ment or specific steps only were presented. To further standardise the different components of the WGFBIT approach across all (sub-)re- gional assessments, a more detail overview of those components was compiled. These compo- nents were slightly different among those regions, related to variation in data availability, envi- ronmental characteristics and implementation possibilities among the (sub-)regions. In WGFBIT, assessments are sometimes based on trawl or grab data, which are sampling differ- ent components of the seafloor ecosystem and can have consequences on the created sensitivity layer. Therefore, there is looked in more detail how the sensitivity outcome (and layers) can dif- fer due to the use of benthic data gathered with different gears (grab/core, trawl or video). The preliminary comparability analyses are performed on different levels: (1) based on co-located sampling; (2) comparing sensitivity maps of the (sub-) area, based on different gears. There were differences observed in longevity distribution at locations sampled with different gears and dif- ferences in data and models lead also to differences in the sensitivity layers. The WGFBIT seafloor assessment framework is not the only way to assess benthic impacts from physical disturbance. A discussion session was held on how the future workflow on advice that ICES WGFBIT assessment contribute to, will be organized. Marine sediments harbour significant levels of biodiversity that play a key role in ecosystem functions and services such as biogeochemical cycling, carbon storage and the regulation of cli- mate. Through the removal of fauna, changes in physico-chemical nature and resuspension of sediment, bottom trawling may result in significant changes in the ecosystem functioning of shelf seas. An assumption of the current PD model is that high community biomass implies higher ecosystem functioning. However, total community biomass does not necessarily reflect changes in species and functional trait composition which play a key role in regulating ecosystem func- tions. ToR D is working on an improved understanding of the link between species functional effect traits and proxies and processes for specific ecosystem functions to improve our ability to predict the impact of fishing disturbance on benthic ecosystem functioning more accurately. Links between species traits and biogeochemical parameters and the impact of trawling on these links are being explored using multivariate ordination analyses using different fauna and bioge- ochemical datasets collected in the North Sea, Celtic Sea, Kattegat, Baltic Sea and the eastern Mediterranean. Changes due to trawling in the trajectories of species densities over time and the concurrent changes in the bioturbation and bioirrigation potential of communities are being modelled using a combination of data-driven mechanistic model and a biogeochemical model. We report on the different data analysis methods that ToR D members have developed over the last year. ICES Published Refereed

The International Bottom Trawl Survey Working Group (IBTSWG) coordinates fishery-independent bottom trawl surveys in the ICES area in the Northeast Atlantic and the North Sea. These long-term monitoring surveys provide data for stock assessments and facilitate examination of changes in fish distribution and relative abundance. The group also promotes the standardization of fishing gears and methods as well as survey coordination. This report summarizes the national contributions in 2021–2022 and plans for the 2022–2023 surveys coordinated by IBTSWG.In the North Sea, the surveys are performed in quarters (Q) Q1 and Q3, while in the Northeast Atlantic the surveys are conducted in Q1, Q3, and Q4 with a suite of 14 national surveys covering a large area of continental shelf that extends from the north of Scotland to the Gulf of Cádiz. North Sea surveys in 2022-Q1 were affected severely by mechanical and COVID-related issues, as well as the number of storms experienced during the survey period. Some of the ICES rectangles in the survey area could not be sampled and a larger number of the rectangles were only sampled with a single tow.North Sea surveys in 2021-Q3 were broadly complete, with the wider area surveyed and comparable number of hauls. However, some rectangles close to shore or with obstructions may not have had full coverage.Most of the surveys in the Northeast Atlantic were completed successfully. However, the two Spanish groundfish surveys in the Gulf of Cádiz could not be undertaken in 2021. Vessel-related problems also affected the Spanish survey of the Cantabrian Sea, although this survey was completed using two vessels over a more protracted survey window. The IBTSWG welcomed the return of the Portuguese groundfish survey (Q4) after a two-year absence, with the survey being undertaken by the new research vessel, the “Mario Ruivo”.IBTSWG discussed the roadmap for the new survey trawl, following on from the Workshop on the Further Development of the New IBTS Gear (WKFDN). IBTSWG agreed the main aspects of the new trawl, and will meet intersessionally to discuss and agree the final net plans. Trials are planned to start in late 2022 with the subsequent introduction of the trawl in the North Sea over the next few years.IBTSWG met with members of various assessment groups, including the Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) and the Working Group for the Bay of Biscay and the Iberian Waters Ecoregion (WGBIE) to discuss how closer cooperation could enhance the use of data outcomes. IBTSWG members subsequently gave presentations to some of the assessment working groups using the data collected under the auspices of IBTSWG and intends to incorporate feedback into the its work.The trawl surveys coordinated by IBTSWG also provide an important platform for the collection of additional data, including the sampling of sprat larvae, fish stomachs and fish parasites.

The Marine Strategy Framework Directive (MSFD) requires EU Member States to achieve and maintain good environmental status (GES) across their marine waters. WKBENTH3 convened as a hybrid meeting to evaluate benthic assessment methods and indicators for their potential to meet the criteria described under the MSFD Descriptor 6 (seabed integrity). They evaluated a suite of indicator methods, proposed by participants. Those included five indicator methods de-scribing the ‘Condition of the Benthic Habitat’, primarily linked to D6C5, and six indicator meth-ods for ‘Physical Disturbance on Benthic Habitats’, primarily linked to D6C3. Variants of some of the indicators as well as some other commonly used diversity indices were also assessed. A common dataset with broad regional representation was used to compare and contrast indi-cator performance with 17 benthic invertebrate datasets drawn from a range of pressure gradi-ents (14 over gradients of commercial bottom trawling intensity, 2 over gradients of eutrophica-tion and 1 over a pollution gradient). A meta-analysis of the mean response to trawling across all locations showed that most indicators had, on average, declined at the high trawl impact rel-ative to the baseline and a significant effect of trawling was detected for the indicators Commu-nity Biomass, Species Richness, Fraction of long-lived species, Median longevity, Fraction of sen-tinel species - SoS, Relative Margalef diversity index DM’, Shannon Index and Inverse Simpson. The complementarity of the different indices was computed using Spearman correlation coeffi-cients between each of the indices for all gradients, ordering indicators with Ward’s hierarchical clustering. One of the key findings was the identification of four groups of indices that showed clear patterns of association. Considering the link of indicators to different benthic community properties, WKBENTH3 proposed that the assessment of D6 should be carried out selecting a number of indicators drawn from different cluster groups to ensure that components of diver-sity, species sensitivity and abundance (density and/or biomass – or other proxy linked to benthic habitat functioning) are addressed. WKBENTH3 further ranked model-based benthic sensitivity and impact outputs across broad habitat types (BHTs) in eight different subdivisions in order to contrast indicator responses. The ranking showed a broad congruence, however, every subdivision had variation in ranking of BHTs among indicator methods. Further work is needed to determine the cause of those discrep-ancies and to look more closely at the values and the response curves generated. WKBENTH3 developed a worked example of how to estimate thresholds for GES based on the approach of ‘detectable change’. The approach was applied to each of the different pressure gra-dients and to muddy sand habitats. It was not able to estimate thresholds for all gradients da-tasets as the confidence intervals around some relationships were very wide. Experts highlighted that the assessment of seabed integrity needs to ensure that cross-regional, regional, national and local scale assessments can “talk” to each other and that they are complementarity in terms of what aspects of the ecosystem the respective indicators are capturing and what pressure they are tracking (linked to manageable human activity). Cross-regional assessments will inform whether assessments are measuring the same or similar things, allowing for such crosschecking. ICES Published Refereed

The Marine Strategy Framework Directive (MSFD) requires Member States to achieve good environmental status (GES) across their marine waters. The EU have requested ICES to advise on methods for assessing adverse effects on seabed habitats, through selection of relevant indicators for the assessment of benthic habitats and seafloor integrity and associated threshold values for GES in relation to Descriptor 6 – Seabed integrity under the MFSD. Two sets of criteria were developed to evaluate indicators and thresholds respectively for evaluation of suitability for assessing GES. 16 indicator and 12 threshold criteria were compiled and weighted by importance. The criteria were designed for evaluation at a subregional or regional level. The scoring for these criteria is meant as a guidance when choosing indicators and thresholds, so failure to meet one criterion will not necessarily prevent the use of the indicator or thresh-old in an assessment. The framework was evaluated for 6 indicators and for 11 methods for setting thresholds. The criteria were found to be useful for evaluation both indicators and thresholds. The process works most consistently when there are experts in the group on both the criteria themselves and on the indicators and thresholds. The MFSD Descriptor 6 determination of GES needs both a quality threshold (when are seabed habitats in a good state in a specific location) and an extent threshold (proportion of the assessment area that needs to have seabed habitats in good state). Eleven different methods for setting thresholds were identified, of which more are suitable for setting quality than for extent thresholds. Preferred methods identified an ecologically-motivated difference between a good and de-graded state, rather than another transition. Quality thresholds based on the lower boundary of the range of natural variation were considered most promising. This approach can be used for most, but not all, indicators. The WK collated a standardized dataset to test the specificity, sensitivity and/or responsiveness of sampling-based benthic indicators to pressure gradients for evaluation by WKBENTH3. Risk-based methods will be evaluated as maps and by scored sensitivity and impact score per MSFD habitat type and subdivision. Participants provided input into the selection of indicators for the compilation of indicators. A template was developed for documenting the characteristics of each indicator to facilitate the evaluation of the indicators. ICES Published Non Refereed

The Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) develops methods and performs assessments to evaluate benthic impact from fisheries at regional scale, while con-sidering fisheries and seabed impact trade-offs. In this report, new fishery benthic impact assessments are carried out for several sub-regions in the Mediterranean (Greek waters, South Adriatic Sea, Sicily waters). For other regions, updates of the whole assessment or specific steps only were presented. A standard advice sheet for the regional benthic assessments, intended as input to the next generation of the ICES Ecosystem and Fisheries Overviews, was finalised and compiled for some regions as example (Greek wa-ters, Baltic Sea). A validation of the longevity relationships using new data was executed for the Kattegat area and the Southern North Sea. In relation to the methodology, some recommenda-tions were formulated concerning the update on depletion rates, the use of epifauna- or infauna-based data, guidance on which set of epibenthic species to include and the time scale for setting the average swept-area-ratio (SAR) used in model fitting and assessment. A benchmarking pro-cess comparing available benthic impact assessment approaches for MSFD descriptor 6 “Seafloor integrity” is needed, as the WGFBIT approach (relative benthic state) is not the only way to assess benthic impacts from physical disturbances. A start was made to explore how to incorporate more explicitly ecosystem functioning in to the WGFBIT seafloor assessment methodology. An improved understanding of the relationships between total community biomass and ecosystem functioning may assist in setting acceptable thresholds for ecosystem impacts from trawling. Furthermore, an improved understanding of the link between species functional effect traits and proxies and processes for specific ecosystem functions could help increase our ability to predict the impact of fishing disturbance on benthic ecosystem functioning more accurately. The ecosys-tem function we focus on is the biogeochemical cycling of organic matter. Two approaches were discussed (i) Biological traits approach focusing on the linkage between biological traits and eco-system functions and (ii) biogeochemical modelling approach using the established the OMEXDIA model. FBIT Published Non Refereed

The International Bottom Trawl Survey Working Group (IBTSWG) coordinates fishery-independent multispecies bottom-trawl surveys within the ICES area. These long-term monitoring surveys provide data for stock assessments and facilitate examination of changes in fish distribution and abundance. The group also promotes the standardization of fishing gears and methods and survey coordination. This report summarizes the national contributions in 2020–2021 and plans for the 2021–2022 surveys coordinated by IBTSWG. In the North Sea, the surveys are performed in quarters (Q) Q1 and Q3 while in the Northeast Atlantic the surveys are conducted in Q1, Q3, and Q4 with a suite of 14 national surveys covering a large area of continental shelf that ranges from North of Scotland to the Gulf of Cádiz. Despite the COVID-measures and bad weather, most surveys were able to complete the majority of the planned hauls. The Portuguese survey (PT-GFS-Q4) was cancelled in 2020 due to issues associated with the new vessel and a COVID-outbreak. A COVID-related delay in submitting the cruise application form for the French CGFS20 survey resulted in no authorisation to trawl in UK waters and only 70% of the core stations were completed. Issues with the UK permits, were also experienced in the North Sea surveys, only being resolved at the last moment, expected to be a returning issue. Therefore, IBTSWG addressed the permit issue in further detail in order to better evaluate the impact and propose possible solutions.All surveys, except for the Spanish GCGF-Q1 21 which is cancelled due to a vessel refit, are planned to take place according to the manuals in the next year.The SCOROC Q3 20 survey recorded second highest recruitment of zero group haddock on the Rockall Bank since the start of the new survey series in 2011. The North Sea Q1 21 survey recorded good recruitment of haddock as well, and high recruitment of mackerel, while overall herring recruitment seemed low except for three exceptionally large catches in the Skagerrak/Kattegat bringing the index above average. Both North Sea surveys reported large amounts of target species outside their index areas, which may warrant a revision of the species-specific areas on which the standard abundance indices are calculated.IBTSWG will continue a number of collaborative activities later this year. The Workshop on the Further Development of the New IBTS Gear (WKFDN) will focus on updating results of gear trails with the potential new gears. The Workshop on the production of swept area estimates for all hauls in DATRAS for biodiversity assessments (WKSAE) will continue work on the Northeastern Atlantic Flexfile available via DATRAS, for which country specific algorithms are used to fill data gaps relevant for the calculation of the swept area. This and the already available North Sea Flexfile can be used to produces swept area indices. IBTSWG also met with members of the assessment groups, Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) and Working Group on Elasmobranch Fishes (WGEF), to improve communication on for example circumstances affecting the execution of the surveys but also changes in survey design potentially impacting the indices.

The Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT) develops methods and performs assessments to evaluate benthic impact from fisheries at regional scale, while considering fisheries and seabed impact trade-offs. WGFBIT has attempted to per-form these assessments for as many regions as possible, and for each region indicate, prioritize and execute (if feasible) potential improvements. In order to broadly anchor the assessment methodology, demonstrate its utility and flexibility and identify relevant data gaps and appropriate improvement potentials it was key that each assessment was per-formed and discussed by the regional experts at the meeting. The FBIT assessment framework was successfully applied in 5 ecoregions; the Arctic Sea, the Baltic Sea, the North Sea, the Celtic Sea and the Mediterranean Sea, with variable level of completeness and robustness. Standard structured regional outputs from the WGFBIT assessment workflow, in terms of pressure, sensitivity and impact estimates, were produced and presented for each region. This is a significant step towards the WGFBIT term of reference ‘to produce a framework for MSFD D6/D1 assessment related to bottom abrasion of fishing activity at the regional scale’. An additional outcome from the assessments was an increased consensus and appreciation of the utility of the FBIT assessment framework. Each regional group identified where and how the assessment and methodology could be further improved; e.g. the need for updated and regionwide fishing pressure data and the inclusion of additional region-specific environmental variables in the estimation of habitat sensitivity. Moreover, a strategy was agreed on to further operationalize the current ecoregion assessments as well as bring in additional ecoregions. Four intersessional subgroups (trade-off, deep sea, data-script management, communication and advice) were established to facilitate future advances in the work of WGFBIT. These groups will be seeking to update and increase coverage of fishing pressure data (mainly for the Mediterranean), develop longevity estimation methods for deep-sea species and habitats, refine assessment approaches, integrate additional physical disturbance pressures, in addition to fishing, in the assessment and further develop communication material addressing dissemination of the methodological details, the actual assessment procedures and standardized workflow.

BENTHIS developed the scientific basis to quantify the impact of bottom trawling on the seafloor and the benthic ecosystem. Based on insight in how fishing gear affects the seafloor, an assessment framework was developed that provide indicators of impact and seafloor status on a continuous scale that can be applied in the context of the MSFD. The mechanistic approach allows us to set reference values of impact (status) to estimate the proportion of a region or habitat where the impact is below (status is above) the threshold. The methodology combines estimates of trawling intensity with the depth to which the fishing gear penetrates into the sea bed (penetration profile) and the sensitivity of the habitat. Habitat sensitivity is estimated from the longevity composition of the benthic community that is related to the recovery rate. The mortality imposed by trawling was shown to be related to penetration depth of the fishing gear. The framework was applied to explore which fisheries had the greatest impact and which habitats were impacted the most. Fishers concentrate their activities in only a part of their total fishing area. These core fishing grounds are characterised by a relative low status (high impact). Additional fishing in these core grounds have only a small impact. In the peripheral areas where fishing intensity is low, additional fishing will have a much larger impact. Hence, shifting trawling activities from the core fishing grounds to the peripheral areas will increase the overall impact. Shifting activities from the peripheral grounds to the core will reduce the overall impact. This asymmetry provides the possibility to reduce the impact at a minimal cost. It was shown that implementing a habitat credit management system can provide incentives to reduce fishing in peripheral areas at minimal cost. In collaboration with the fishing industry and gear manufacturers, technological innovations were studied to reduce the impact of trawling. Promising results were obtained showing that (semi-) pelagic otter doors can be applied to reduce bottom impact and at the same time reduce the fuel cost without affecting the catch rate of the target species. Replacing mechanical stimulation by tickler chains with electrical stimulation In the beam trawl fishery for sole, reduced footprint and penetration depth as well as the fuel cost. Electrical stimulation is also a promising innovation to reduce the bycatch and bottom contact in the beam trawl fishery for brown shrimps. Sea trials to replace bottom trawls with pots were inconclusive. Results suggest that creels may offer an alternative for small Nephrops fishers in the Kattegat. In waters off Greece, the catch rates were very low. Sea trials with the blue mussel fishery showed that fishers could reduce their footprint by deploying acoustic equipment to detect mussel concentrations that allow the fishers to more precisely target the mussel beds and hence reduce fishing in areas with low mussel density. A review of the various case studies carried out in BENTHIS revealed the critical success factors for implementing technological innovations to mitigate trawling impact. While economic investment theory predict that economic profitability should lead to investment in innovative gears, it appeared that many other factors play a role in the successful uptake of new technology such as social, regulatory, technological and environmental factors. For the successful development and implementation of gear innovations, collaboration between fishers, gear manufacturers, policy makers, scientist and society is important

Many specimens of Kaloplocamus ramosus (Cantraine, 1835) were collected in the Bay of Biscay during Ifremer’s EVHOE scientific cruises in 2009 and 2010 (October – November). This species is new to the French Atlantic coast, which is its most northern known occurrence, and a map of its distribution in the Bay of Biscay is provided. Two preyspecies (Bryozoa) were observed from gut contents. One of these, Cellaria salicornioides, is an addition to the known food-list of K. ramosus. Data on the taxonomy are given and Doris fimbriata delle Chiaje, 1841 is added to the synonymy of K. ramosus.

Poster presentation at ATLAS 3rd General Assembly. Deep-water coral reefs or sponge aggregations are unique ecosystems, but they are poorly known. They are also extremely vulnerable to anthropogenic disturbance. Damage to these so-called vulnerable marine ecosystems (VMEs) has already been described. They may take decades or even centuries to recover. It is recognised that fisheries are the biggest threat to VMEs. Ensuring the conservation or the protection of VMEs is a challenge that requires an accurate knowledge of fisheries spatial footprint. Here, we aimed at identifying the interaction of fisheries with VMEs in the Bay of Biscay and their potential dependencies over those vulnerable ecosystems. At the regional scale, maps of fishing effort and abrasion are produced from vessel monitoring system (VMS) data in the main VMEs area of the Bay of Biscay, and statistics are derived for depth classes ranging from 200m to 1000m. Proxy distributions of fish species of commercial interest though to be present in the CWC habitat are also produced from the commercial landings to illustrate fishing dependencies to those areas. At the fine scale, an analysis is performed computing the swept area from fishing vessels occurring in the vicinity of known VME areas of the Bay of Biscay. Areas impacted by fishing vessels are also compared to potential VME habitats derived from a modeling approach. Our results suggest that locations where VMEs have not been directly impacted by bottom trawling should exist in the Bay of Biscay. It provides an evidence base through which managers can explore the opportunity of protecting those preserved VMEs from human impacts. &nbsp

Poster presentation at ATLAS 3rd General Assembly. Deep-water coral reefs or sponge aggregations are unique ecosystems, but they are poorly known. They are also extremely vulnerable to anthropogenic disturbance. Damage to these so-called vulnerable marine ecosystems (VMEs) has already been described. They may take decades or even centuries to recover. It is recognised that fisheries are the biggest threat to VMEs. Ensuring the conservation or the protection of VMEs is a challenge that requires an accurate knowledge of fisheries spatial footprint. Here, we aimed at identifying the interaction of fisheries with VMEs in the Bay of Biscay and their potential dependencies over those vulnerable ecosystems. At the regional scale, maps of fishing effort and abrasion are produced from vessel monitoring system (VMS) data in the main VMEs area of the Bay of Biscay, and statistics are derived for depth classes ranging from 200m to 1000m. Proxy distributions of fish species of commercial interest though to be present in the CWC habitat are also produced from the commercial landings to illustrate fishing dependencies to those areas. At the fine scale, an analysis is performed computing the swept area from fishing vessels occurring in the vicinity of known VME areas of the Bay of Biscay. Areas impacted by fishing vessels are also compared to potential VME habitats derived from a modeling approach. Our results suggest that locations where VMEs have not been directly impacted by bottom trawling should exist in the Bay of Biscay. It provides an evidence base through which managers can explore the opportunity of protecting those preserved VMEs from human impacts.