Report of the Joint ICES/NAFO Working Group on Deep-water Ecology (WGDEC)

Transcription

1 ICES WGDEC REPORT 2016 ICES ADVISORY COMMITTEE ICES CM 2016/ACOM:28 REF. WGMHM, ACOM Report of the Joint ICES/NAFO Working Group on Deep-water Ecology (WGDEC) February 2016 Copenhagen, Denmark

2 International Council for the Exploration of the Sea Conseil International pour l Exploration de la Mer H. C. Andersens Boulevard DK-1553 Copenhagen V Denmark Telephone (+45) Telefax (+45) info@ices.dk Recommended format for purposes of citation: ICES Report of the Joint ICES/NAFO Working Group on Deep-water Ecology (WGDEC), February 2016, Copenhagen, Denmark. ICES CM 2016/ACOM: pp. For permission to reproduce material from this publication, please apply to the General Secretary. The document is a report of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council International Council for the Exploration of the Sea

3 ICES WGDEC REPORT 2016 i Contents Executive Summary... 1 Opening of the meeting Adoption of the agenda Provide all available new information on distribution of VMEs in the North Atlantic with a view to advising on any new closures to bottom fisheries or revision of existing closures to bottom fisheries (NEAFC standing request). In addition, provide new information on location of habitats sensitive to particular fishing activities (i.e. Vulnerable Marine Ecosystems, VMEs) within EU waters (EC request) Introduction Areas within the NEAFC regulatory area Rockall Bank and Hatton-Rockall Basin Areas considered within the EEZs of various countries Rockall Bank and the adjacent continental slope Greenland Bill Baileys Bank Areas within the NAFO regulatory area Flemish Cap Bank, Grand Banks and Flemish Pass Basin References Refinement of the VME Indicator Weighting System Background How expert judgement was used to score each VME indicator against the FAO criteria Choice of descriptive statistic for 'c-square' Method of classifying low, medium and high categories for a c- square Method of calculation of the uncertainty index Deciding on spatial resolution of the c-square Implementation of the revised weighting system Illustrative case study of implementation (Hatton-Rockall area) Summary of the main changes implemented on the weighting system References Development of a consolidated approach for the delineation of bottom fishing closures in light of recent work undertaken by WGDEC Background... 24

4 ii ICES WGDEC REPORT Buffer zones Minimum distance spacing criterion for VME Indicator records Bona fide VME Habitat records Conclusions References Development of the ICES VME Database and ICES VME Data Portal Introduction Workshop on the Vulnerable Marine Ecosystem Database (WKVME) Controlled vocabularies Other modifications to the database Data availability through the ICES VME Data Portal References Recommending options for sensitivity assessments of deep-sea habitats (contribution to WKFBI) Introduction Habitat mapping Sensitivity mapping Sensitivity assessment methods Deep-sea habitat sensitivity Conclusion References Annex I: ICES VME Data Agreement Annex 2: Submitted and (where required) corrected scientific nomenclature within the GeneralTaxonDescriptor field Annex 3: VME Database Schema Annex 4: Evidence collated from peer-reviewed literature, grey literature and expert judgement on the resistance and resilience of communities at Level 4 of the UK deep-sea habitat classification Annex 5: List of participants Annex 6: Draft WGDEC terms of reference for the next meeting Annex 7: Recommendations Annex 8: Technical minutes from the Vulnerable Marine Ecosystems Review Group... 70

5 ICES WGDEC REPORT Executive Summary On 15th February 2016, the joint ICES/NAFO Working Group on Deep-water Ecology (WGDEC), chaired by Neil Golding (UK) and attended by eleven members, met at ICES HQ, Copenhagen, Denmark, to consider the terms of reference (ToR) listed in Section 1. WGDEC was requested to provide all new information on the distribution of vulnerable marine ecosystems (VMEs) in the North Atlantic. A total of 487 new records, from within the NEAFC and NAFO Regulatory Areas (RA) and areas within the EEZs of member states, were submitted and appended to the ICES VME database. The new data were from a range of sources including fisheries and scientific visual seabed surveys. No recommendations were made for the modification of existing, or creation of new bottom fishing closures. WGDEC sought to refine the VME indicator weighting system developed through 2014 and In addition, WGDEC consolidated a number of approaches for the delineation of bottom fishing closures, providing some guiding principles in order to help standardise the delineation of closures when considering a range of different data types. The new ICES VME Data Portal was launched. For the first time, users can view and download data on VME indicators and habitats used by WGDEC. Finally WGDEC contributed to a request from the European Commission s Environment Directorate-General (DGENV) to ICES, to provide guidance on the interpretation of bottom fishing pressure maps in relation to impacts on benthic habitats and the related indicators across an EU regional scale. Specifically, WGDEC collated habitat sensitivity information for each deep-sea benthic habitat to fishing pressure, for presentation at WKFBI (ICES Workshop on Fisheries Benthic Impacts).

6 2 ICES WGDEC REPORT 2016 Opening of the meeting WGDEC began discussions at 13:00 on February 15th 2016 at ICES Headquarters, Copenhagen. Following introductions, the opening discussion focused on assigning leads to each Terms of Reference; these were assigned as follows: ToR (a) lead: Helle Jorgensbye; ToR (b) leads: Francis Neat and Telmo Morato; ToR (c) lead: Carlos Pinto; ToR (d and e) lead: Laura Robson. Following a review of the agenda and identification of key issues, the group commenced working through the terms of reference. Plenary sessions were held each morning with video conferencing, when remote participants of the working group could participate. During these plenary sessions, ToR leads updated the group with progress, while remote participant could comment on working documents circulated previously.

7 ICES WGDEC REPORT Adoption of the agenda 2015/2/ACOM29 The Working Group on Deep-water Ecology (WGDEC), chaired by Neil Golding, UK, will meet at ICES HQ in Copenhagen, Denmark, February 2016 to: a ) Provide all available new information on distribution of VMEs in the North Atlantic with a view to advising on any new closures to bottom fisheries or revision of existing closures to bottom fisheries. In addition, provide new information on location of habitats sensitive to particular fishing activities (i.e. vulnerable marine ecosystems, VMEs) within EU waters; b ) Review the process by which boundaries for bottom fishing closures are considered and develop a consolidated approach in light of recent work undertaken by WGDEC; c ) Continue development of the ICES VME Database and ICES VME Data Portal; d ) Recommend a scoring process (or relevant options for processes) for sensitivity of habitats, which should also include rules on: i ) How to scale-up sensitivity to a c-square resolution of 0.05 o x 0.05 o ii ) How to treat variation in habitat type when evaluating sensitivity within c-square resolution of 0.05 o x 0.05 o iii ) How to interpolate and/or extrapolate information on sensitivity when habitat data are missing. e ) Based on TOR d, provide input to WGMHM. Work on ToR d e should be done both intersessionally (January May 2016) and during the WGDEC meeting. WGDEC will report on TOR d e as soon as possible but at the latest by 2 May 2016 for the attention WGMHM (and of ACOM). WGDEC will report by 25 March 2016 to the attention of the ACOM Committee.

8 4 ICES WGDEC REPORT 2016 Supporting Information Priority: Scientific justification and relation to action plan: Resource requirements: Participants: Secretariat facilities: Financial: Linkages to ACOM and its expert groups High as a Joint group with NAFO and is essential to providing information to help answer external requests a) This information and maps are required to meet part of the European Commission MoU request to provide any new information regarding the impact of fisheries on... sensitive habitats and the NEAFC request to continue to provide all available new information on distribution of vulnerable habitats in the NEAFC Convention Area and fisheries activities in and in the vicinity of such habitats. The location of newly discovered/mapped sensitive habitats is critical to these requests. It is essential that ICES/WG chair asks its Member Countries etc. to supply as much relevant information as they may have by one month in advance of the WGDEC meeting; b) This is an important development of the VME database. Records within the VME database originate from a number of different sources; from specific targeted habitat mapping surveys with a high degree of spatial accuracy through to bycatch records from towed gear/longlining. Through developing a weighting system for these records, the information underpinning any new recommendations on closures, or modifications to existing closures, can be assessed and weighted based on reliability and significance. A clear method of setting boundaries around groups of records would be of considerable help in providing justification for such boundaries; c) There is a requirement to update the ICES VME database to include new information on the distribution of VMEs (including VME indicator species) submitted under ToR (a); d) TOR d e. ICES has been asked by the EU (DGENV) to provide guidance in the interpretation of fishing pressure maps in relation to impacts on benthic habitats and the related indicators. WGDEC and BEWG will provide recommendations for scoring the sensitivity of habitats; these recommendations should preferably be compatible with each other. WGMHM will incorporate information on sensitivity of the benthic community of the various seabed habitats, and will produce habitat sensitivity maps for at least one demonstration area of NW European waters (MSFD region/subregion). WGSFD will produce impact maps by combining and evaluating the benthic information on sensitivity and fishing pressure maps (fishing abrasion, weight and value of landed catch), taking into account differences in benthic impact of the various fishing gears / métiers. Following this, an ICES Workshop on guidance on how pressure maps of fishing intensity contribute to an assessment of the state of seabed habitats (WKFBI) on 31 May 1 June 2016 will develop indicator principles and good practices for use regionally when assessing the impact of fishing on the seabed. The workshop outputs will then be used in the ICES advisory process. The usual helpful support from the Secretariat will be appreciated. The Group is normally attended by some members and guests. None, apart from the SharePoint site No financial implications. ACOM is parent group. WGDEEP is related, but no explicit overlap in work this year.

9 ICES WGDEC REPORT Linkages to SCICOM and its expert groups Linkages to other organisations: No direct linkages, though the work of BEWG is related OSPAR, NEAFC

10 6 ICES WGDEC REPORT Provide all available new information on distribution of VMEs in the North Atlantic with a view to advising on any new closures to bottom fisheries or revision of existing closures to bottom fisheries (NEAFC standing request). In addition, provide new information on location of habitats sensitive to particular fishing activities (i.e. Vulnerable Marine Ecosystems, VMEs) within EU waters (EC request) 2.1 Introduction New data on VME indicator organisms were submitted to ICES WGDEC in 2016 and these were incorporated into the ICES VME database. A total of 487 new records were added within the NEAFC and NAFO Regulatory Areas (RA) and areas within the EEZs of member states. As the ICES VME database has expanded considerably over the last few years, it is no longer considered feasible to present existing VME data alongside new VME data on the maps within this section, primarily from a clarity perspective. Therefore, as a general rule, only newly submitted data will be mapped. However, whenever existing bottom fishing closures are revised or new closures proposed, all supporting data will be shown. This chapter is split according to areas within the NEAFC RA, those areas within the EEZs of the EU or other countries and those within the NAFO RA. Areas considered within the NEAFC RA: Rockall Bank and Hatton-Rockall basin Areas considered within the EEZs of various countries: Rockall Bank and the adjacent continental slope Greenland Bill Baileys Bank Areas considered within the NAFO RA: Flemish Cap Bank, Grand Banks and Flemish Pass Basin 2.2 Areas within the NEAFC regulatory area Rockall Bank and Hatton-Rockall Basin Rockall Bank is a large plateau that lies some 250 km to the west of the UK and Ireland surrounded on all sides by deep water. It lies partly in the EU EEZ and partly in international waters where bottom fisheries are regulated by NEAFC Fish stock assessment cruises Two fish stock assessment cruises (survey 0415S and 1115S) were undertaken in 2015 by Marine Scotland Science over Rockall Bank. Bycatch of benthic species was recorded, with only those species/groups classed as VME indicators being considered

11 ICES WGDEC REPORT further. Within the NEAFC Regulatory Area (RA), VME indicators included small fragments of stony corals, sponges, seapens and the occasional black coral. In all cases amounts were below NEAFC catch thresholds (below 1 kg) and thus insufficient to confirm the area as a VME Ecological research survey A Marine Scotland ecological research survey (survey 0915S) to the eastern edge of the Hatton-Rockall basin in 2015 (see Figure 2.1) collected records of VME indicators. The aim of the survey was to confirm the presence of the cold seep community, first proposed in 2012 (from records of chemosynthetic bivalves), in an area at the margin of Rockall bank. Towed camera transects confirmed the presence of the cold seep habitat (bacterial mats, fluid vents) as well as coral gardens on steeper sloped areas (Figures 2.2, 2.3 and 2.4). The video footage is still in the process of being analysed; the data are anticipated to be available for WGDEC The entire area surveyed lies within the area closed by NEAFC in No amendments to boundary closures are recommended at this time. Figure 2.1. The eastern edge of the Hatton-Rockall basin (see inset map with white box indicating location) showing records of VME indicators sampled in the trench area where the cold seep ecosystem was found. The cold seep is located at the bottom of the trench; the VME indicators are from surrounding areas, notably on the steeper sides of the trench. Depth contours shown are derived from a ship-board Olex seabed mapping system and should only be used as an approximation of the seabed topography. Deepest depth contour is 1210 m, shallowest is 1100 m.

12 8 ICES WGDEC REPORT 2016 Figure 2.2. The eastern edge of the Hatton-Rockall basin. Bacterial mats on the seabed at the bottom of the trench in 1200 m water depth indicating a cold-seep ecosystem, west of Rockall Bank. Figure 2.3. The eastern edge of the Hatton-Rockall basin. Active emission of fluid rich in sediment. Picture taken from the bottom of the trench at 1200 m, west of Rockall Bank.

13 ICES WGDEC REPORT Figure 2.4. The eastern edge of the Hatton-Rockall basin. Coral gardens (gorgonians, sponges and stony coral) on the steep eastern side of trench where the cold seep ecosystem is found. West of Rockall Bank, depth = 1100 m. The same survey (0915S) also covered an area in the centre of the Hatton-Rockall basin. It was previously known to contain deep-sea sponge aggregations and unusual geological seabed formations known as polygonal faults. Following ICES Advice (ICES, 2013), NEAFC closed an area to bottom fishing in 2014, to protect the sponge community. A Scottish MPA was also designated in this area in This new survey was focused on an area further south of the NEAFC closure (Figure 2.5) where benthic Agassiz trawl sampling yielded specimens of sponges and soft corals. This area is not currently closed to bottom fishing by NEAFC, although as it isn t currently a NEAFC fishing area, it is highly unlikely to have been fished. Video footage is still to be analysed and these data are anticipated to be available for WGDEC Following review of these data, a bottom fishing closure may then be recommended.

14 10 ICES WGDEC REPORT 2016 Figure 2.5. New VME indicator records for central Hatton-Rockall Basin (see white box in inset map) located to the southeast of the current NEAFC bottom fishing closure. Figure 2.6. Southwest Rockall Bank (see white box in inset map). A new Russian VME indicator record.

15 ICES WGDEC REPORT A Russian fishery with observer on board was conducted on southwest Rockall Bank at 56 26' 57 04'N, 15 20' 14 52'W at a depth between m (Figure 2.6). The only VME indicator, the sponge Phakellia sp., was found at 56 37'N, 15 07'W at the depth of 270 m and had a weight of kg. 2.3 Areas considered within the EEZs of various countries Rockall Bank and the adjacent continental slope The two fish stock assessment cruises (survey 0415S and 1115S) undertaken in 2015 by Marine Scotland Science also covered the UK and Irish section of Rockall Bank (Figure 2.7). Bycatch of benthic species was recorded. In the UK/Irish section of Rockall bank in one haul, 35 kg of dead Lophelia was taken as bycatch in an area to the east of Rockall (highlighted in Figure 2.7 with a red circle and also in Figure 2.8). This is an area where Lophelia has been reported in the past and further suggests this was once an important area. Attention is also drawn to a large bycatch of seapens (estimate of around 3000 individuals, combined weight = 26 kg) taken further south on the east side of Rockall (Figure 2.8). The Marine Scotland deep-water slope survey (survey 1215S) was carried out in September 2015 and covered the continental slope within the UK/Irish EEZ. This trawl survey includes benthic sampling through the use of groundgear bags attached to the trawl. VME indicators were recorded, but none were in sufficient quantity to confidently suggest the presence of a VME. Agassiz trawl sampling was also undertaken in two areas, Rosemary Bank and Hebrides Terrace Seamount. Sampling at Rosemary Bank was aimed at taxonomically validating deep-sea sponge aggregations visually identified in 2014 (ICES, 2015) and yielded quantities of sponges (approximately 250 kg of mixed species of Porifera in ten minutes bottom time), in keeping with the area being classed as a VME).

16 12 ICES WGDEC REPORT 2016 Figure 2.7. Rockall Bank and the adjacent continental slope. VME indicators taken as bycatch in fish stock assessment surveys by Marine Scotland in The red circle highlights a large haul of dead Lophelia (35 kg) taken as trawl bycatch to the east of Rockall on survey 0415S. Figure 2.8. East of Rockall Bank. VME indicators taken as bycatch in fish stock assessment surveys by Marine Scotland in 2015 (survey 0415S). The bold orange triangle marks a large haul of dead Lophelia (35 kg) taken as trawl bycatch, while the bold blue circle marks a large bycatch of seapens (estimate of around 3000 individuals, combined weight = 26 kg).

17 ICES WGDEC REPORT Greenland Within the Greenland EEZ a number of observations of VME indicator species were made from during Russian bottom-trawling operations (with an observer on board) in September October 2015 on the continental slope west of Greenland. Catches of the soft corals Acanella arbuscula, Keratoisis omata, the black corals Stauropathes arctica, some Anthoptilum sp. Seapens and number of sponges species including Geodia sp., Stelletta sp. and Euplectella sp. were recorded at depths of m (see Figure 2.9). The total haul catches of VME indicator species in the area did not exceed 1 kg per haul. No recommendations for bottom fishing closures are made. Figure 2.9. New Russian VME indicator records from west coast of Greenland. Black lines indicate Russian trawl tracks Bill Baileys Bank Within the Faroese EEZ a number of observations of VME indicator species were made during Russian bottom-trawling operations (with an observer on board) in May June 2015 on the slopes of the Bill Baileys Bank (Figure 2.10). Catches of the scleractinian coral Lophelia pertusa and soft coral Primnoa resedaeformis were recorded at depths of m (Kanishchev and Zavoloka, 2016). The catches of VME species indicators ranged from 0.2 to 0.5 kg. No recommendations for bottom fishing closures are made.

18 14 ICES WGDEC REPORT 2016 Figure New Russian VME indicator records from Bill Baileys Bank. Black lines indicate Russian trawl tracks. 2.4 Areas within the NAFO regulatory area Flemish Cap Bank, Grand Banks and Flemish Pass Basin New bycatch data on VME indicator species were submitted to WGDEC 2016 from the Flemish Cap Bank, the Grand Banks of Newfoundland, and the Flemish Pass Basin. These data were recorded during Russian commercial trawling operations (with an observer on board) from March September 2015 at depths between m (see Figure 2.11). Small numbers of VME indicator species were recorded in the area including Alcyonacea (soft and branched corals) and seapen species such as Pennatulacea sp. with Anthoptilum sp., Duva florida and Funiculina quadrangularis predominant in the trawls. In addition, small numbers of Nephtheidae and Umbellula sp. were observed. Twentythree species of sponges were also found among which Phakellia sp., Iophon piceum, Geodia sp., Forcepia sp., Polymastia sp. and Haliclona sp. predominated. The total haul catches of VME indicator species in the area did not exceed 1 kg per haul.

19 ICES WGDEC REPORT Figure Map of the Flemish Cap Ban. Current NAFO closures are shown as pink boxes. 2.5 References ICES ICES Advice Vulnerable deep-water habitats in the NEAFC Regulatory Area. ICES Report of the ICES/NAFO Joint Working Group on Deep-water Ecology (WGDEC), February 2015, Horta, Azores, Portugal. ICES CM 2015/ACOM: pp. Kanishchev and Zavoloka Russian catches of cold-water corals and sponges in the North Atlantic based on the data of observations by fishing vessels in Working Document to the ICES/NAFO WGDEC Copenhagen.

20 16 ICES WGDEC REPORT Refinement of the VME Indicator Weighting System 3.1 Background In 2015, while significant progress was made by WGDEC in implementing a weighting system for the VME indicator records, it was acknowledged this was still a work under development. The report of 2015 was peer reviewed by an ICES review group and further comments and critiques were provided by the advice drafting group and WGDEC members. Furthermore in 2015, the Workshop on the Vulnerable Marine Ecosystem Database (WKVME) further reviewed the ICES VME database (ICES, 2016) and made further recommendations that affect the implementation of the weighting system. WGDEC considered these reviews and suggestions. Here we detail the revisions made and provide greater clarifications of the methods and explain how the weighting system has been revised and further developed. 3.2 How expert judgement was used to score each VME indicator against the FAO criteria The 2015 WGDEC group thinking on the scoring system was very detailed and included fourteen of the most recognized experts in the field. However the report of 2015 did not describe in detail the process by which this was done. It is important to appreciate that since WKVME in 2015, the ICES database is now comprised of two main types of records; 1) those that are 'VME habitat types' which represent bona fide records such as high quality ROV imagery of coral reefs, and 2) 'VME Indicators' which represent records for which there is are varying degrees of uncertainty, such as trawl bycatch records. The two data types are treated separately and only the VME indicators are now included in weighting system. Twelve VME indicators were agreed for inclusion in the ICES VME database by ICES WKVME in 2015 (ICES, 2016: Annex 4). This list reflects the main types of VME indicators in the NE Atlantic. There will naturally be some inter-taxa inconsistencies, for example, not all species of Gorgonian will be equally vulnerable, but in general these VME indicator categories were considered to be the best compromise between a manageable list with a range of vulnerabilities that was not excessive. There was one exception, however, the category sponges. In this case assigning one value to all species is particularly problematic, because the category sponges includes all sponges from small encrusting species such as Alpsylla sulphuria to the massive, aggregation forming species such as Geodia atlantica. The reason a general sponges category was created was because there is often much uncertainty in species identification and many records in the database are simply identified to the Phylum level of Porifera. Nevertheless there are records in which identifications have been made and WGDEC was of the opinion this information should be used. WGDEC decided that the weighting algorithm would be modified to use information on genera in this specific case. WGDEC used literature sources and expert opinion to decide on those genera of sponges that contain species that can be described as massive and forming aggregations. All species belonging to the following genera were classed as Large Sponge (for the purposes of the weighting system) and as such would receive a different VME score than all other sponges in the weighting algorithm: Asconema, Chonelasma, Geodia, Pheronema, Polymastia, Stryphnus, Tetilla, Thenea, and Vazella. All others species of sponges, and those for which no information of Genus were provided, were ranked according to the scores in Sponges.

21 ICES WGDEC REPORT VME indicators were assigned a score of between 1 5 based on expert judgement for each of the five FAO criteria for what classes a habitat as a VME (Table 3.1). Elements of each criteria considered in deriving the final score are detailed below. Uniqueness or rarity: if the indicator is a) red listed by IUCN; b) known to be endemic; c) is assessed to be rare; d) is assessed to be threatened or declining. Functional significance of the habitat: if the indicator is a) known to form a breeding habitat for other species; b) has a higher level ecosystem role, for example nutrient cycling and water filtration. Fragility: if the indicator a) is considered fragile and easily broken by physical contact; b) grows to a height well above the seabed. Life history: if the indicator a) has a slow growth rate; b) has a late age of maturity; c) has a low or unpredictable recruitment d) is long-lived. Structural complexity: if the indicator is a) frame-building and creates structural habitat; b) has commensal or closely associated species.

22 18 ICES WGDEC REPORT 2016 Table 3.1. Scores for VME Indicators occurring in deep water in the ICES/NAFO areas, derived from expert judgement, used for each of the five FAO habitat-related criteria. Scores range from 1 (low) to 5 (high). FAO habitat criteria VME VME indicator Uniqueness / Rarity Functional Fragility Life History Structural complexity Indicator score Black coral Cup coral Gorgonian Stylasterids Seapen Soft coral Sponge Large Sponge Stony coral Anemones Xenophyophores Stalked crinoids Chemosynthetic spp. (seeps and vents) Choice of descriptive statistic for 'c-square' C-squares (acronym for the concise spatial query and representation system) is a system of geocodes (a type of global grid) that provides a basis for simple spatial indexing of geographic features or data (Rees, 2003). The purpose of aggregating multiple records at the resolution of a 'c-square' is to obtain a value that is meaningful for the purpose of identifying VME. There were some concerns of WGDEC's choice of the maximum value of VME indicators within each cell was appropriate. The maximum was chosen because if a high value score is present in a cell, that cell retains a high score irrespective of other records. For example, a cell with a high scoring stony coral and lower scoring anemones is not down weighted just because it has low scoring anemones present. If the mean or median was chosen this coral record would be down weighted by the presence of anemones. The square-root of the sum of squares was also suggested as an alternative. However, this measure fails to distinguish between a small number of important records and a large number of less important ones. 3.4 Method of classifying low, medium and high categories for a c-square In the first iteration of the weighting system in 2015, the method of classification was somewhat subjective. In 2016 WGDEC decided to implement the Jenks natural breaks classification method (Jenks, 1967) for determining the VME index and equal interval for the uncertainty score. The final outcome of the weighting system was presented as VME habitat for these grid cells containing bona fide records and as three nominal categories of VME index scores, indicating the likelihood of encountering a VME in the assessed grid cells. These three categories were: Low VME index, for total scores <2.6;

23 ICES WGDEC REPORT Medium VME index, for total scores between 2.6 and 3.7; High VME index, for total scores >3.7. These categories for VME index were computed using the Jenks natural breaks classification method (Jenks, 1967). 3.5 Method of calculation of the uncertainty index The uncertainty score in each cell was changed to be derived from only the records that contributed to the maximum VME score in each cell (or the mean of highest scoring VME index if there was more than 1 record of maximum value). The rest of the methodology remained as was detailed in ICES WGDEC 2015 report (ICES, 2015). 3.6 Deciding on spatial resolution of the c-square The c-square of 0.05 degree x 0.05 degree was selected; this is the same as that used in other ICES groups such as the ICES WGSFD (Working Group on Spatial Fisheries Data), therefore allowing overlapping of different layers. Decreasing the c-square grid size (increasing the grid resolution ) is possible, but the amount of high resolution data is very limited and it would decrease the number of data-points per cell, thereby increasing the uncertainty in many cells. Additionally, compared to the length of one commercial trawl (usually at least 5 nautical miles) it makes little sense to decrease further the size of the cells. 3.7 Implementation of the revised weighting system The implementation of the revised weighting system can be illustrated schematically by generating maps of VME index and associated Uncertainty indices (Figure 3.1). By combining these two schematic maps, cells with VME habitats and cells with high VME index scores and different uncertainties can be shown. In Figure 3.1 Panel A, bona fide VME habitats with no uncertainty are highlighted. In Figure 3.1 Panel B, we highlighted those grid cells scoring high in the VME index but with all uncertainty categories. In Figure 3.1 Panel C, we highlight grid cells scoring high in the VME index but excluding those cells with a high uncertainty index. In Figure 3.1 Panel D, we highlight only those grid cells scoring high in the VME index and low uncertainty.

24 20 ICES WGDEC REPORT 2016 VME Index Uncertainty index Panel A VME Habitats Panel B High VME Index Panel C All Uncertainty Index Excluding high Uncertainty Index Panel D N N N N Low Uncertainty Index Figure 3.1. Representation of the usefulness of the VME and Uncertainty indices maps. The VME index hypothetical map contains VME habitats in blue, cells with high VME index scores in red, medium in yellow, and low in green. The Uncertainty index map contained cells with no uncertainty in white, low uncertainty score in light grey, medium uncertainty score in medium grey, and high uncertainty score in dark grey. When applying the multi-criteria analysis (MCA) approach to the revised ICES database, the VME index ranged from 1.44 to 4.46, with 5.0 being assigned to the bona fide VME habitats while the Uncertainty index ranged from 0.29 to 1.00, with a zero value being assigned to the bona fide VME habitats records (Figure 3.2).

25 ICES WGDEC REPORT Frequency VME Index Frequency Uncertainty Index Figure 3.2. Resulting distribution of the VME index (above) and the Uncertainty Index (below) when applied to the ICES VME database, including certain VME habitats (VME index of 5 and Uncertainty index of 0; n= 202). Each value represents one c-square (0.05 degrees x 0.05 degrees). 3.8 Illustrative case study of implementation (Hatton-Rockall area) For illustrative purposes a series of four maps using the revised methodology were produced for the Rockall-Hatton Bank (Figure 3.3). These maps illustrate several important aspects of the weighting system. Firstly, it clearly highlights known VME habitat types shown as blue c-squares in the top left panel. There are also some very obvious high value VME index areas (red c-squares): inside the NW and SW Rockall NEAFC Closures (top left panel). Secondly, there are areas of medium value VME index (orange c-squares) that reflect the records of VME indicators that are below the NEAFC catch threshold. Thirdly, in the top right panel, it is obvious that the intensive sampling on the Rockall plateau yields high confidence (low uncertainty), whereas the less-well sampled Hatton bank yields a lower overall confidence (medium uncertainty).

26 22 ICES WGDEC REPORT 2016 Figure 3.3. C-squares categorised using the VME Index and Uncertainty in the Rockall and Hatton Bank. 3.9 Summary of the main changes implemented on the weighting system Known VME habitats are now treated separately. In the maps, c-squares containing these records are coloured differently; A new updated and improved (corrected) ICES VME database was used (v. 18 February 2016); A revised list of VME indicators was used based on the work WKVME completed in December 2015 (ICES, 2016); VME indicator group Sponges was divided in two, to represent major differences in the FAO criteria between taxa; Revised scores for VME indicators were implemented. These scores resulted from a broader expert consultation; VME indicator scores, previously being re-scaled to 5, were not rescaled. The actual maximum value is 4.40; An extra threshold for abundance below the NEAFC catch threshold was implemented; The Jenks Natural breaks (Jenks, 1967) methodology was implemented to define VME Index classes of high, medium or low. Equal breaks were used for dividing the uncertainty index into three classes; Uncertainty score in each cell was changed to the uncertainty associated with the records contributing to the maximum VME Index score in each cell (or the mean of highest scoring VME index if there was more than one record of maximum value); The uncertainty index was assumed to be multiplicative.

27 ICES WGDEC REPORT References ICES Report of the ICES/NAFO Joint Working Group on Deep-water Ecology (WGDEC), February 2015, Horta, Azores, Portugal. ICES CM 2015/ACOM: pp. ICES Report of the Workshop on the Vulnerable Marine Ecosystem Database (WKVME), December 2015, Peterborough, UK. ICES CM 2015/ACOM: pp. Jenks, G. F "The Data Model Concept in Statistical Mapping", International Yearbook of Cartography 7: Rees, T C-squares, a new spatial indexing system and its applicability to the description of oceanographic datasets. Oceanography, 16(1),

28 24 ICES WGDEC REPORT Development of a consolidated approach for the delineation of bottom fishing closures in light of recent work undertaken by WGDEC 4.1 Background For a number of years, WGDEC has fulfilled a standing request which requires the Working Group to provide all available new information on Vulnerable Marine Ecosystems (VMEs) in the North Atlantic, with a view to advising on new closures to bottom fishing. The following chapter aims to provide some guiding principles in order to help standardise the delineation of bottom fishing closures when considering a range of different data types. Due to the differing levels of certainty associated with different data types (e.g. trawl bycatch of VME indicatorsvs.in situ observations of bona fide VME), it is not appropriate to apply one method of boundary delineation to all data types. Instead, a suite of approaches are required such as buffer zones, minimum distance spacing criterion for VME indicators and geo-statistical approaches to estimating patch size, detailed below. These should be considered across a range of data layers, in order to ensure that a consolidated, consistent approach is achieved. 4.2 Buffer zones Clear guidance around the use of buffer zones has been published in ICES Advice (2013a) and can be seen in Figure 4.1. Figure 4.1. Buffer zones around the known VME locations (ICES, 2013a). Example 1: isolated VME detection with low geospatial certainty (e.g. trawl track); Example 2: isolated VME detection with high geospatial certainty (e.g. ROV observation); Example 3: area identified as hosting a VME. 4.3 Minimum distance spacing criterion for VME Indicator records In 2015, Russia presented a working document to WGDEC detailing a method of delimiting bottom fishing closures. The method integrated the use of buffer zones (see Section 4.2 above) with the distance travelled by the vessel between the two observed VME locations according to the Vessel Monitoring System (VMS). Assuming a vessel speed (when bottom fishing) of between knots, the vessel will travel no more than 3.5 nautical miles in one hour. Thus, 3.5 nautical miles (nm) could be considered a minimum distance criterion for uniting the VME encounter locations within a single bottom fishing closure. Specifically, this led to the following decision process;

29 ICES WGDEC REPORT if the distance between the buffer zones of nearby VME is less than 3.5 nm, those should be united into a single closure (Figure 4.2, a d); if the distance between the buffer zones of nearby VME is greater than 3.5 nm, it is reasonable to establish several (two or more) separate closures (Figure 4.2, e); simplified closure shapes (such as squares/rectangle/trapeze/triangle, etc.) are preferred over complex shapes. Figure 4.2. Variants of establishing the closures depending on the VME indicator species locations distribution. When only fisheries-dependent information, such as bycatch VME indicator records, are available to assess the likelihood of VMEs, WGDEC considers that the minimum distance spacing approach proposed by the Russian delegation is an acceptable way to delimit closure boundaries. 4.4 Bona fide VME Habitat records The Working Group considered that while the minimum distance spacing approach (detailed in Section 4.3) is appropriate to delineating bottom fishing closures around VME indicator records (such as trawl bycatch), it is not appropriate to use this method when there is visual confirmation of a VME from an ROV transect or towed camera transect; referred to as bona fide VME occurrences. With these types of data, it should be possible to adopt geostatistical (variogram) approaches to assess the patch size of the VME. Geostatistics is a class of spatial statistical techniques commonly used to characterize the spatial autocorrelation found in natural systems (Cressie, 1993). The assessment of patch size and spatial autocorrelation provides a more objective, repeatable method for deciding how far apart patches are likely to be and therefore where two VME occurrences should be joined up as one unit (and within a single bottom fishing closure) or considered independent occurrences (potentially forming two or more bottom fishing closures). The field of geostatistics, and its use in objectively deciding the patch size of VMEs, is a new area for WGDEC to explore. As

30 26 ICES WGDEC REPORT 2016 greater numbers of bona fide VME records are included within the database, there will be an increasing need to move away from using expert judgement in deciding patch size of VME. It is proposed that a review of how geostatistical approaches to assess patch size could be undertaken as a dedicated term of reference for a future WGDEC meeting. 4.5 Conclusions In summary, it is proposed that a consolidated approach using a combination of all three methods (buffer zones, minimum distance and assessment of patch size from visual observations) are used when attempting to delineate bottom fishing closure boundaries. During the process of closure delineation, a range of data layers such as actual VME data (as plotted from the database), a layer showing buffer zones around VME indicator records, VME weighting algorithm output layers, bathymetry (if available to aid the identification of VME Elements such as seamounts/knolls (ICES, 2013b)) and the outputs of any geostatistical analysis of bona fide VME records should be viewed in a spatial environment; an objective, evidence led process for delineating bottom fishing closure boundaries. 4.6 References Cressie, N Statistics for Spatial Data (New York: John Wiley). ICES. 2013a. Evaluation of the appropriateness of buffer zones. Advice 2013, Book 1. Advice June ICES. 2013b. Assessment of the list of VME Indicator species and elements. Advice 2013, Book 1. Advice June 2013.

31 ICES WGDEC REPORT Development of the ICES VME Database and ICES VME Data Portal 5.1 Introduction A combination of the Vulnerable Marine Ecosystem (VME) data call in summer 2015 and new VME data submissions by Working Group members ahead of WGDEC 2016 resulted in the addition of 487 records to the ICES VME database; the database now contains almost records. The database has evolved from a flat structure to a relational database. Figure 5.1 shows the Entity Relationship Diagram of the database. 5.2 Workshop on the Vulnerable Marine Ecosystem Database (WKVME) Following agreement at WGDEC 2015 (ICES, 2016a), a workshop focused purely on the ICES VME database was hosted by JNCC in December Eleven deep-sea and database experts participated; the report is now available online (ICES, 2016b). WKVME reviewed the current ICES Vulnerable Marine Ecosystem (VME) database, and agreed a set of modifications to the list of VME Indicators/Habitats and the associated lists of representative taxa. A revised VME Database Schema was agreed and implemented (Annex 3). 5.3 Controlled vocabularies A number of improvements have been made to the database in order to facilitate quality assurance and validation. One of these has been the introduction of controlled vocabularies. If a data supplier submits data in these fields which are not within the controlled vocabulary, their submission will not be accepted. This facilitates the quality checking of new data which are submitted to the database, and build capability for automation within the data ingestion process. The following fields are now ICES controlled vocabularies: VME_Indicator ( ) VME_Habitat_Type ( ) VME_Habitat_Subtype ( ) SurveyMethod ( ) VesselType ( ) Ship ( ) The contents of the GeneralTaxonDescriptor field were checked against World Register of Marine Species (WoRMS Editorial Board, 2016); this was a manual process and some of the names required updating to comply with the WoRM list. Annex 2 shows the submitted and (where required) corrected scientific names within the General- TaxonDescriptor field. The originally submitted names have been retained within the database, providing an audit trail for any corrections. The species names in the VME database are now directly derived from WoRMS and thus will update if there is future taxonomic revision.

32 28 ICES WGDEC REPORT Other modifications to the database Records of Tubularia (hydroid) were removed from the database, as they did not conform to the revised VME Database schema agreed at WKVME (ICES, 2016b). Figure 5.1. Entity Relationship Diagram of the VME database. 5.5 Data availability through the ICES VME Data Portal Data contained within the VME database, on the distribution and abundance of VMEs (and organisms considered to be indicators of VMEs) considered by WGDEC, is now available via the ICES VME Data Portal ( From here, users can either download the data, or view the data in the mapper. Approximately 61% of the records within the database are now public (see Table 5.1). This is a significant improvement in data accessibility over previous years, when a greater proportion of the records were restricted. Table 5.1. Current data availability in the database. DATA ACCESS NO. OF RECORDS % OF THE ENTIRE VME DATABASE Public Restricted

33 ICES WGDEC REPORT An updated data agreement was agreed in plenary during WGDEC 2016 (Annex I), and is now in use on the VME Data Portal. The data agreement follows the ICES data policy for public records, but highlights that there are also restricted data shown on the portal. The VME Data Portal has three main areas: 1 ) Homepage - describes the content of the website and why it was created; 2 ) Download area - where users can select records to download, choosing their criteria. Only public records will be fully downloadable, the restricted records will only come with metadata and point of contact; 3 ) Mapping area - where the users can view the data in a grid (0.05 x0.05 ) and can display the data according to a range of criteria. The user has also access to additional layers such as ICES Advice, NEAFC closed areas and the OSPAR threatened and declining habitat layer. 5.6 References ICES. 2016a. Report of the ICES/NAFO Joint Working Group on Deep-water Ecology (WGDEC), February 2015, Horta, Azores, Portugal. ICES CM 2015/ACOM: pp. ICES. 2016b. Report of the Workshop on the Vulnerable Marine Systems Database (WKVME), December 2015, Peterborough, UK. ICES CM 2015/ACOM: pp. WoRMS Editorial Board World Register of Marine Species. Available from at VLIZ. Accessed

34 30 ICES WGDEC REPORT Recommending options for sensitivity assessments of deep-sea habitats (contribution to WKFBI) 6.1 Introduction Member countries and Regional Sea Conventions (RSCs) are developing indicators of impacts on benthic habitats from anthropogenic activities, particularly bottom trawling, for Marine Strategy Framework Directive (MSFD) purposes (D1 biodiversity and D6 seabed integrity). EU projects are also developing approaches across European seas (including the Mediterranean and Black Sea). As part of this process, ICES has provided bottom fishing pressure maps using VMS and logbook data to OSPAR and HELCOM. The next challenge for the process of developing indicators is to interpret what these fishing pressure maps mean in terms of impact on benthic habitats and their utility in management. In 2016, ICES received a special request from European Commission s Environment Directorate-General (DGENV) on the Common Implementation (CIS) of the MSFD to provide guidance on the interpretation of these pressure maps in relation to impacts on benthic habitats and the related indicators across an EU regional scale. A workshop on Fishing Benthic Impacts (WKFBI) will be held to produce this guidance, chaired by Adriaan Rijnsdorp, The Netherlands, and will meet in Copenhagen, Denmark on 31 May 1 June In preparation for the workshop, the Chair, together with five ACOM approved invited attendees are facilitating coordination and consolidation of work from respective ICES working groups (Benthic Ecology Working Group - BEWG, Working Group on Marine Habitat Mapping - WGMHM, Working Group on Deep-water Ecology - WGDEC and Working Group on Spatial Fisheries Data - WGSFD). It was proposed by WKFBI attendees that the method for interpretation of pressure maps in relation to impacts should identify both the exposure of benthic habitats to bottom fishing pressures, and the sensitivity of these habitats to fishing pressures in order to understand which habitats are likely to be negatively impacted. Sensitivity encompasses a measure of the effect of a pressure (sometimes referred to as disturbance, perturbations or stress), on a receptor. The degree of effect of an impact will depend on the tolerance (and conversely, the intolerance) of the receptor and the ability of the receptor to recover. It can simply be defined as a measure of tolerance (or intolerance) to changes in environmental conditions (Tillin and Tyler-Walters, 2010). At present, the proposed method for the work will follow these steps (brackets indicate which group will undertake each step): 1 ) Collation of existing benthic habitat maps for all MSFD regions (WGMHM). 2 ) Collation and/or development of sensitivity information for each benthic habitat to fishing pressure (BEWG for shelf seas, WGDEC for deep seas). 3 ) Development of combined habitat/sensitivity maps (WGMHM). 4 ) Collation of bottom fishing pressure maps for the MSFD regions (WGSFD). 5 ) Creation of maps of impact of bottom fishing on benthic habitats and confidence in these maps (WKFBI). 6 ) Guidance on how to interpret these products (WKFBI).