This project is co-financed by the European Union s DG ENV/MSFD/Action Plans 2014, under the agreement no /2015/712630/SUB/ENVC.

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1 This project is co-financed by the European Union s DG ENV/MSFD/Action Plans 2014, under the agreement no /2015/712630/SUB/ENVC.2 OSPAR Implementation and assessment of a food web indicator (OSPAR FW4) on a subregional scale: first workshop on methodology to be applied Applying an ecosystem approach to (sub) regional habitat assessments (EcApRHA): addressing gaps in biodiversity indicator development for the OSPAR Region from data to ecosystem assessment Paris, 21 & 22 March 2016 Report of the EcApRHA WP3 action 3.1: Implementation and assessment of a food web indicator (OSPAR FW4) on a sub-regional scale: Second workshop on methodology to be applied Content 1. General summary 3 a. Participants... 3 b. Purpose of the workshop / cross reference to the action it responds to in the Grant Agreement 3 c. Have workshop objectives been achieved?... 3 d. Workshop products/outcomes and key messages for the interim report... 3 e. Any bottlenecks/additional challenges? Key discussion points and Conclusions 4 a. Agenda Item 1 Assessing the MTL indicator on Bay of Biscay Northern part using EVHOE data: case study for finalising the methodology to be applied... 4 b. Agenda Item 2 Investigating landings data to assess the indicator on Bay of Biscay Northern part 4 c. Agenda Item 3 How can we optimise the trophic level estimation of species?... 4 d. Agenda Item 4 EMODNET Applying MTL in a gridded map: appropriateness of the approach 5 e. Agenda Item 5 Using MTL indicators in NEAT (Nested Environmental Assessment Tool) 6 3. What are the next steps/actions? 6 4. Any other Business 7 1 of 10

2 5. Annex 8 a. Annex 1 - Agenda... 8 b. Annex 2 Actions list c. Annex 3 - Participant list sign up of 10

3 1. General summary a. Participants Institutions: Institut de Recherche et Développement (IRD) and Centre National de la Recherche Scientifique (CNRS) Experts: Francois Le Loc h (FR), Pauline Vouriot (FR) and Georges Safi (FR) b. Purpose of the workshop / cross reference to the action it responds to in the Grant Agreement Further develop and refine methodologies to facilitate the contribution of this indicator to the OSPAR intermediate assessment c. Have workshop objectives been achieved? Workshop objectives were achieved since: The final methodology to be applied for the MTL indicators was confirmed by all partners and this will lead to a publication as a first step for MTL application This workshop has helped defining milestones to finish writing and submitting a publication on the ongoing tests for MTL methodology to be applied MTL using the NEAT tool was tested and this could be useful for WP4 work within the EcAPRHA project (aggregating indicators to evaluate environmental status) A report on using MTL indicator in gridded map is also given below d. Workshop products/outcomes and key messages for the interim report The workshop was based on discussions to progress in work on MTL methodology and publication of this work proposing a way to run MTL indicators from a food web perspective. Some of the main key messages of the workshop are: MTL indicators show a good sensitivity to changes in the ecosystem in agreement with the descriptions made (e.g. existing literature) regarding changes in food webs. It is important to make a regional testing of the indicator before its application. Species structure (abundance/ biomass ratios) within data sets and their representation in the indicators need to be understood before assessing the environmental status of the concerned food web/ecosystem. The MTL indicator can be used in the NEAT tool (see section 2e) as part of a set of indicators aggregated to evaluate the status of an ecosystem The application of MTL in a gridded map needs to be further discussed with experts. Some concerns regarding the appropriateness of this approach are developed below (see section 2d). e. Any bottlenecks/additional challenges? No major challenges have been found during this workshop. 3 of 10

4 2. Key discussion points and Conclusions a. Agenda Item 1 Assessing the MTL indicator on Bay of Biscay Northern part using EVHOE data: case study for finalising the methodology to be applied Item 1.1 This agenda item was already discussed with the IEO colleagues during the February workshop. However, it was important to discuss the results with the French co-leader of this indicator who was not available during the February workshop. Item MTL indicator was assessed on EVHOE data for the Northern Bay of Biscay (ICES VIIIa&b zone). A discussion was undertaken considering the appropriateness of the various cut-offs on the indicator (i.e. cut-offs of different trophic level) for the description of the food web structure. The indicator is expected to reflect changes occurring in the food web structure as a response to either an increase in fishing pressure or a recovery after a decrease in fishing pressure. An interpretation of the various signals (i.e. trends in the MTL with cut-offs) was made. Item 1.3 A general discussion was undertaken at the end of the presentation regarding the indicator trends and the species that are playing a major role in the observed trends. Survey data are useful in evaluating the state of an ecosystem as the species representation is not biased by fishing strategy. The observed trends show a slight recovery of the ecosystem, which was subjected to a higher fishing pressure in the past (80-90) decades. These results are in agreement with the latest observations and descriptions made in the Bay of Biscay. The current methodology that is being tested seems appropriate to be used in the evaluation of the Good Environmental Status when using survey data. Item 1.4 The work on the MTL methodology using the Bay of Biscay s case study needs to be published to be used afterwards in other case studies. An action list with milestones was defined for that purpose (Annex 2). Item 1.5 This first study needs to be complemented with the Southern Bay of Biscay case study. The idea would be to investigate the evolution of the food web structure of the Bay of Biscay using the DEMERSALES data (northern Iberian continental shelf). This could inform us about the complementarity of the surveys in both (sub) regions and will add information to help in testing the indicator b. Agenda Item 2 Investigating landings data to assess the indicator on Bay of Biscay Northern part Item MTL was assessed on Landings data of the Northern Bay of Biscay (ICES VIIIa&b zone). A discussion was undertaken considering the appropriateness of the data set to calculate the indicator in the description of the food web structure of the area. Item 2.2 Landings data have many shortcomings, e.g. fishing strategies, market values, lack of georeferencing data etc...however, the long-time series available may be useful to help interpreting some trends. Item 2.3 The use of landings data needs to be correlated to local fishing mortality indices and a certain number of information such as the fishing effort, the quota evolution on species etc. This work will need time in order to be complete. It was discussed the possibility to split the work on landings and survey in order to have all the required information to interpret the landings based MTL indicator. c. Agenda Item 3 How can we optimise the trophic level estimation of species? Item 3.1 Three levels of optimisation were discussed in order to have more accurate values of trophic level (TL) estimations. 4 of 10

5 1- Spatial and temporal variability in TL values. This needs to be optimised by including isotope analysis and stomach content analysis on species collected during survey campaigns. This can be implemented on species representing 95% of total biomass (representing 10 to 20 species) and when possible on the other species. 2- Uncertainty related to various methods of TL estimation: intercomparability between methods (i.e. isotope analysis, stomach content and models). Some of the examples in problems with intercomparability of methods: over/underestimation of TL values between isotope analysis and models. A similar problem can be found between isotope analysis and stomach content analysis in TL estimation. 3- Uncertainty related to each estimation method. Example stomach contents: Stomach content analysis is only a snapshot of a pool of preys recently consumed by an individual. It thus have a low temporal resolution, and does not capture the frequent changes of a diet. Additionally, preys can often be absent or in minimal amount in fish stomachs. Therefore, a large number of samples is required to provide a representative view of a diet. Isotope analysis: Uncertainty intervals around the TL of consumer is related to different components (details in Jennings and van der Molen 2015): 1) First of all, the choice of an appropriate isotopic baseline (d15nbase) to estimate the trophic position of consumers 2) TL estimations are potentially biased by lack of empirical knowledge on 15N fractioning (Layman et al. 2012). Indeed, if the nitrogen trophic enrichment factor is globally accepted and checked for carnivorous organisms (3 3.4 ), it is controversial for lower trophic levels (average of 2.5 for primary consumers). A scaled 15N framework would greatly improve the accuracy of trophic estimates as described by Hussey et al. (2014). d. Agenda Item 4 EMODNET Applying MTL in a gridded map: appropriateness of the approach Item 4.1 The European Marine Observation and Data Network (EMODnet) consists of more than 100 organisations assembling marine data, products and metadata to make these fragmented resources more available to public users. Item EMODnet Biology provides three keys services and products to users: Data Portal [search for datasets by theme (e.g. benthos, fish, algae, pigments)], data catalogue (easiest way to access nearly 1000 datasets available) and data products (produces dynamic gridded maps of selected species abundance). Item 4.3 The possibility of using MTL indicator in gridded maps based on the ICES statistical rectangles was discussed. Two main concerns were identified: 1- The number of hauls per statistical rectangle. Indeed, the number of hauls per statistical rectangle was investigated in the Bay of Biscay continental shelf case study (ICES VIIIa and VIIIb). One to two hauls were found per statistical rectangle which seems very limited to describe the ecosystem state on this spatial resolution. When considering all the hauls in the continental shelf ecosystem, we have a better picture of populations structure evolution. If we want to down scale the indicator, it would be more appropriate to be on community level according to predefined communities in the ecosystem (e.g. Souissi et al. 2001). Sami Souissi, Frédéric Ibanez, Radhouan Ben Hamadou, Jean Boucher, Anne Claire Cathelineau, Fabian Blanchard & Jean-Charles Poulard (2001) A new multivariate mapping method for studying 5 of 10

6 species assemblages and their habitats: example using bottom trawl surveys in the Bay of Biscay (France). Sarsia 86: The appropriateness of downscaling trophic level (TL) values to this level of spatial coverage. In the current state of available information on TL values, reducing spatial scale would increase the uncertainty around the estimated MTL indicator. Indeed, spatial variability in TL values exists with an inshore-offshore gradient and sensitivity to diet change. However, this level of information is not yet available in order to allow MTL assessment at this spatial scale (i.e. ICES statistical rectangle). To reduce this uncertainty, we applied a local mean TL value on the whole ecosystem (ICES subdivisions VIIIa and VIIIb) which would not be appropriate on lower spatial resolution. e. Agenda Item 5 Using MTL indicators in NEAT (Nested Environmental Assessment Tool) Item 5.1 The NEAT tool is being developed by the DEVOTES project and its original version was initially tested as a HELCOM biodiversity status assessment tool (BEAT 1.0 version). A certain amount of information is required from each indicator in order to incorporate it to the NEAT tool. Once information from all indicators is included, this aggregating tool is capable of giving a final environmental status of a given ecosystem with an associated confidence estimation (see details in Anderson et al. 2014: Item 5.2 In order to see the applicability of this tool using MTL indicators, an exercise was undertaken using the Bay of Biscay case studies (i.e. EVHOE survey). Item 5.3 The exercise has shown that the synoptic information (i.e. Reference condition, acceptable deviation from reference conditions, observations of present state and the type of the indicator used) required for the NEAT tool can be defined for the MTL indicators. However, this information is not standard for all regions and ecosystems. These values need to be defined at (sub) regional scale and are dependent on the data source (e.g. EVHOE vs DEMERSALES). Indeed, data sources can be different regarding time series length, targeted species, etc. Item 5.4 EVHOE survey: based on this case study, it was suggested during the workshop to use the current situation (ie current values of MTL in the latest years) as reference condition. The MTL shows that the current ecosystem state in the Bay of Biscay continental shelf is better than in the beginning of the time series (ie 1997). By defining the current state as a reference value, we increase the confidence around defining a good limit for this indicator in this sub-region. The reference value can have with it an acceptable deviation (which is a percentage of the reference value). We can have thus a reference value with an acceptable deviation that represents the lower limit for the MTL indicator in the assessment of the ecosystem state in the Bay of Biscay continental shelf. Knowing that the target of this indicator is to avoid having a significant decrease of the mean trophic level with a lower limit set at the reference value with the acceptable deviation. Item 5.5 Concern about this tool: Indicators are weighted in order to balance between different level of information (e.g. Balance between fish and plankton indicators). How is this balance made? How is the expert group formed and on which basis (e.g. scientific basis)? 3. What are the next steps/actions? The next steps were defined during the workshop and can be found in the action list (Annex 2) at the end of this report. 6 of 10

7 4. Any other Business WP3 workshop in May (Monday 23 and Tuesday 24): A final workshop for action 3.1 in WP3 is programmed in May. This workshop will gather all collegues working on the MTL indicator: IRD (Francois Le Loc h), IEO (Izaskun Preciado and Nina Larissa Arroyo), CEFAS (Christopher Lynam) and CNRS (Nathalie Niquil, Pauline Vouriot and Georges Safi). The possibility of including modelling into this indicator assessment needs to be discussed with the CEFAS colleague. Furthermore, IEO and the CNRS will present the progress of their work before the first deliverable to be submitted (due date 15 June 2016 for interim report). Symposium: CNRS and IEO have the intention to present their first EcApRHA results during the ISOBAY 2016 symposium ( from the 22nd until the 24th of June in Bilbao. The abstract submission deadline was on the 14 th of April and was extended to the 22 of April. CNRS submission date was set to the 15 th of April (see action list). 7 of 10

8 5. Annex a. Annex 1 - Agenda Implementation and assessment of a food web indicator (OSPAR FW4) on a subregional scale: first workshop on methodology to be applied EcApRHA 15/00/01-E Applying an ecosystem approach to (sub) regional habitat assessments (EcApRHA): addressing gaps in biodiversity indicator development for the OSPAR Region from data to ecosystem assessment Paris, 21 & 22 March 2016 WP3 action 3.1: Implementation and assessment of a food web indicator (OSPAR FW4) on a sub-regional scale: Second workshop on methodology to be applied Start of meeting: 9:15 Monday, 21 March Close of meeting: 17:00 Tuesday, 22 March Venue : Muséum National d Histoire Naturelle (MNHN), Paris, France Monday, 21 March 09:15 Open Agenda item 1 Assessing the MTL indicator on Bay of Biscay Northern part using EVHOE data: case study for finalising the methodology to be applied 12:00 13:00 Lunch a. General information on Bay of Biscay and EVHOE survey b. Assessing a set of Mean Trophic Level (MTL) indicators to describe the food web structure of the Northern Bay of Biscay Agenda item 1 Assessing the MTL indicator on Bay of Biscay Northern part using EVHOE data: case study for finalising the methodology to be applied b. Assessing a set of Mean Trophic Level (MTL) indicators to describe the food web structure of the Northern Bay of Biscay c. General discussion about the indicators and the food web structure Agenda Item 2 Investigating landings data to assess the indicator on Bay of Biscay Northern part a. Assessing MTL indicators using landings data to describe the food web structure of the Northern Bay of Biscay b. General discussion about the indicators and the food web structure 18:00 Close Tuesday, 22 March 8 of 10

9 09:15 Open Agenda Item 3 How can we optimise the trophic level estimation of species? 12:30 14:00 Lunch Agenda item 4 EMODNET - Applying MTL in a gridded map: appropriateness of the approach Agenda item 5 Using MTL indicators in NEAT (Nested Environmental Assessment Tool) Agenda Item 6 Questions and AoB 17:00 Close 9 of 10

10 b. Annex 2 Actions list Implementation and assessment of a food web indicator (OSPAR FW4) on a sub-regional scale: first workshop on methodology to be applied ANNEX 02 Nr. What (task/action) Agenda ref. 1 Finish testing and circulate results for end of March 2 Finish Materials and methods of the paper for mid-april 3 Submit an abstract to ISOBAY 2016 conference in Biblao 4 Finish first draft of papers discussion for mid- May 5 Circulate first completed draft of the publication in prep for all co-authors 6 First finalised version of the paper for end of June Who? (name) CNRS CNRS CNRS CNRS Due Date? 31 March April April May 2016 IEO and CNRS 15 May 15 June June Submit the publication to international journal (e.g. ecological indicators) CNRS June 2016 c. Annex 3 - Participant list sign up 10 of 10

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