ICES database of trawl surveys

The dataset includes age- and length-based catch per unit effort data for commercial fish species collected during the Irish Ground Fish trawl survey.

The Fisheries and Oceans Canada ecosystem surveys are conducted annually and are a source of integrated ecosystem monitoring data. These survey data are the primary data source for monitoring trends in species distribution, abundance, and biological condition within the region, and also provide data to the Atlantic Zonal Monitoring Program (AZMP) for monitoring hydrographic conditions, along with zooplankton and phytoplankton. The surveys follow a stratified random sampling design, and include sampling using a bottom otter trawl, CTD rosette and vertical plankton tows. Data from the bottom trawl catch are used to monitor the distribution and abundance of fish and invertebrates throughout the Scotian Shelf, Bay of Fundy and Georges Bank.

The Inshore Beam Trawl Surveys include data collected by 4 countries (BE, DE, NL, UK) cover cover most of the coastal and estuarine waters along the continental coast, and are also known as the Youngfish Surveys. Although, the surveys target plaice and sole, composition of the whole catch is analyzed. Responsible survey group is WGBEAM

This is a data product to support state indicators that are based from groundfish biological data, derived using primary data from surveys undertaken in the Northeast Atlantic between 1983 and 2020. Catch records by taxonomic group and by length category in terms of biomass and numbers of fish standardised to duration (per hour) or to the area swept by the haul. Data are available from multiple surveys using data downloaded from the ICES database of trawl surveys (DATRAS) once quality-controlled and standardised following procedures detailed in Greenstreet and Moriarty 2017. Data file names reflect the OSPAR region sampled, country conducting the sampling, fishing gear and time of years of sampling (as defined by Greenstreet and Moriarty 2017), e.g.: BBICFraBT4 refers to Bay of Biscay and Iberian Coast data from France by a Beam Trawl survey in quarter 4 of the year and GNSIntOT3 refers to Greater North Sea data from International (multiple countries) sampling by an Otter Trawl survey in quarter 3 of the year etc. Greenstreet, S.P.R. and Moriarty, M. (2017) OSPAR Interim Assessment 2107 Fish Indicator Data Manual (Relating to Version 2 of the Groundfish Survey Monitoring and Assessment Data Product). Scottish Marine and Freshwater Science Vol 8 No 17, 83pp. DOI: 10.7489/1985-1_ .. _10.7489/1985-1: https://data.marine.gov.scot/dataset/ospar-interim-assessment-2017-fish-indicator-data-manual-relating-version-2-groundfish

The dataset includes age- and length-based catch per unit effort data for commercial fish species collected during the Scottish Rockall Survey. This is a new survey from 2011, replacing historical ROCKALL survey in DATRAS.

The purpose of the sand eel dredge survey is to collect sand eels buried in the seabed and compare catches (number and age composition) with the previous year's collections to assess the year class strength of sand eel in area 1r, 2r and 3r of the different areas adopted by ICES in 2016. Data from the dredge survey is the basis for calculating an index, which is used in the stock assessment for sand eel in the North Sea.

(Obsolete record) The dataset included survey data from the Beam Trawl Survey in the Irish Sea. From 2017, the dataset became a part of the Offshore Beam Trawl Surveys dataset.

The dataset includes length-based catch per unit effort data for deep-water fish species collected during the Central Northeast Atlantic Deep-water trawl surveys by Ireland and Scotland.

The OSPAR (https://www.ospar.org/convention) fish biodiversity assessment concerns sensitive and often rare species in the northeast Atlantic Ocean and marginal seas. All fish species captured during fishing on scientific groundfish (otter and beam trawl) surveys are recorded but not necessarily weighed and measured for length. The biodiversity assessment for sensitive and often rare species thus makes use of the occurrences (presence and absences) of a species only.

A list of sensitive fish species was developed to guide the work for the OSPAR fish biodiversity assessment. The list was created by first collating all sensitive fish species recorded on international and national hard law lists, Regional Seas Conventions lists, International Agreement Lists, relevant IUCN Red List species (classified as EX, CR, VU or EN) and all ICES and academic work to identify sensitive fish species. From this extensive list of species, species were removed if they did not occur in the OSPAR area of the Northeast Atlantic Ocean. Remaining species were divided by region; Bay of Biscay and Iberian Coast, Celtic Seas, Greater North Sea, Norwegian Sea and parts of Macaronesia where data was available. Those species whose normal distribution was at the very edge of an OSPAR region were not assessed within the region.

Species where ICES or ICCAT quantitative stock assessments are conducted in all or part of their distribution were retained on the list, but highlighted so as to avoid duplication of work. The list was then cross-referenced with the ICES WKCOFIBYC (ICES, 2021a) and WKABSENS (ICES, 2021b) sensitive species lists and reviewed by expert members of the OSPAR Fish subgroup to ensure all sensitive species were included.

To overcome the potential for species misidentification for those that are difficult to identify beyond the genus level, some species were grouped by genus for the assessment. These include Hippocampus spp. (combining Hippocampus hippocampus with H. guttulatus), Alosa spp. (combining Alosa alosa and A. fallax), Dipturus spp. (combining Dipturus batis complex, D. batis, D. flossada and D. intermedia), Mustelus spp. (combining Mustelus mustelus and M. asterias), Sebastes spp. (combining Sebastes marinus, S. mentella and S. norvegicus), Dasyatis spp. (combining Dasyatis pastinaca and D. tortonesei), Galeus spp. (combining Galeus melastomus and G. atlanticus), Coregonus spp. (combining Coregonus maraena and Coregonus oxyrinchus), Raja brachyura (including Bathyraja brachyurops) and Deania calcea (including D. profundorum). After grouping, a total of 102 unique taxonomic groups were retained on the OSPAR sensitive fish species list for four OSPAR regions (Greater North Sea, Celtic Sea, Bay of Biscay and Wider Atlantic).

Data file names reflect the OSPAR region sampled, country conducting the sampling, fishing gear and time of years of sampling (as defined by Greenstreet and Moriarty 2017), e.g.: BBICFraBT4 refers to Bay of Biscay and Iberian Coast data from France by a Beam Trawl survey in quarter 4 of the year andGNSIntOT3 refers to Greater North Sea data from International (multiple countries) sampling by an Otter Trawl survey in quarter 3 of the year etc.

Scientific trawl survey data are submitted to the ICES Database of Trawl Surveys (DATRAS):http://www.ices.dk/marine-data/data-portals/Pages/DATRAS.aspx The DATRAS reporting format is detailed online: https://datras.ices.dk/Data_products/ReportingFormat.aspx The metadata relating to the ICES co-ordinated surveys are available here: http://www.ices.dk/marine-data/data-portals/Pages/DATRAS-Docs.aspx

ICES Data Centre host the database of trawl surveys (DATRAS) for groundfish and beam trawl data. DATRAS has an integrated quality check utility. All data, before entering the database, have to pass an extensive quality check. Despite this errors and missing data arise, which are subsequently dealt with by the data submitters from the contributing countries as required. However, this screening process was implemented in 2009 for data from 2004 onwards. Since some survey time-series extend back to the 1960s, historic data (unless re-evaluated and re-submitted by contributing countries) may not have been subject to the same level of quality control as these more recent data. Furthermore, the type of information collected, the level of detail and resolution in the data, has gradually evolved over time. In order to derive a single format, quality assured monitoring programme data product covering the entire Northeast Atlantic region inconsistencies in the datasets required resolution. These corrections are detailed in ICES 2021a,b:Biological data for trawl surveys are downloaded directly from DATRAS in raw exchange format (known as “HL data”). Ancillary data were processed by ICES 2021a,b to create the "SweptAreaAssessmentOuput" (which replaces the “HH data”) and these were downloaded from the same location: https://datras.ices.dk/Data _ products/Download/Download _ Data _ public.aspx) For the biodiversity assessment of sensitive species, the data are processed to create a standalone dataproduct on species occurrence (presence and absence) and haul location. Initially, valid hauls are subset to determine the Standard Monitoring Programme (i.e. excluding hauls of duration shorter than 13 minutes or longer than 66 minutes) and these hauls are used to define the Standard Survey Area (excluding areas sampled infrequently over time) following the methods detailed in Greenstreet and Moriarty 2017). Biological data were accepted with ICES SpecVal of 1, 4, 5, 6, 7, 10 (see http://vocab.ices.dk/ for further information on SpecVal categories). Additional QA/QC is made at this step to determine if species identification issues are present in the raw biological data.

References: Greenstreet S P R and M Moriarty 2017. Manual for Version 3 of the Groundfish Survey Monitoring and Assessment Data Product. Scottish Marine and Freshwater Science Vol 8 No 18. Published by Marine Scotland. ISSN: 2043-7722. DOI: 10.7489/1986-1 ICES. 2021a. Workshop on Fish of Conservation and Bycatch Relevance (WKCOFIBYC). ICES Scientific Reports. 3:57. 125 pp. https://doi.org/10.17895/ices.pub.8194 ICES. 2021b. Workshop on the production of abundance estimates for sensitive species (WKABSENS). ICES Scientific Reports. 3:96. 128 pp. https://doi.org/10.17895/ices.pub.8299

The flatfish species turbot (Scophthalmus maximus) and brill (Scophthalmus rhombus) in the North Sea are important commercial bycatches for the Dutch commercial fleet. Brill is currently a data-limited species, which is why ICES for its stock assessment uses a method based on trends in the commercial landings per unit of effort. For turbot more data are available and the advice for turbot is currently based on a full analytical assessment. Nevertheless, there is still considerable uncertainty in the input data which undermines the overall quality of the assessment. A new standardized survey with higher catch rates for large flatfish is developed to improve assessments for these species. For this reason a dedicated industry survey for turbot and brill was designed and implemented.

The dataset includes age- and length-based catch per unit effort data for commercial fish species collected by the French trawl survey EVHOE.

DATRAS Web Services offer a possibility to search and retrieve data from DATRAS database by granting direct access to the data. DATRAS (getSurveyList) service returns the list of the names of the survey in the DATRAS database.

The Dutch Sole Net Survey (SNS) is carried out annually in September-October in transects in the coastal zone of the south-eastern North Sea, stretching from Scheveningen (NL) up to Esbjerg (DK). The primary objective of the SNS is to provide abundance indices for juvenile North Sea plaice (Pleuronectes platessa) and sole (Solea solea, Solea vulgaris) up to ages 3-4. These indices are used by the ICES Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) for "tuning" the VPAs and for short-term stock and catch projections. The data are hence important for management advice. Additionally, the SNS monitors non-commercial demersal fish species and benthic fauna. The reponsible group for SNS is WGBEAM.

Scottish Marine and Freshwater Science Vol 8 No 16 Monitoring and assessment of fish communities is essential to demonstrating the achievement of GES across the waters of the Northeast Atlantic covered by the MSFD. Coastal MSs bordering the Northeast Atlantic have invariably nominated their groundfish surveys as part of their monitoring programmes to supply the data necessary to derive the indicators that will be used to assess the state of fish communities, both within their national waters and across the whole Northeast Atlantic region. Data obtained by these groundfish surveys are, for the most part, freely available for download from the DATRAS database portal on the ICES website. Data are initially checked by national data centres prior to submission to ICES and a further screening process is applied at ICES before the data are accepted and incorporated into the DATRAS database. However, the DATRAS screening process was implemented in 2009 only for data from 2004 onwards. Some survey time-series extend back to the 1960s and more historic data may not have been subject to the same level of quality control as these more recent data. Data were initially collected to address fisheries management needs, which primarily focused attention on commercial species. Gradual adoption of an ecosystem approach to management has raised the importance of non-target species, in order to facilitate the development and application of ecological indicators for the broader fish community. Thus the type of information collected, the level of detail and resolution in the data, has gradually evolved over time. These historic changes in groundfish survey practices have left a quality assurance legacy in the data that needs to be addressed to ensure that the groundfish survey monitoring programmes are fully fit to meet modern day needs of the MSFD. Historically the surveys operated by different countries have followed their own particular sets of protocols and practices. The procedure for uploading data to DATRAS has tended to preserve these national differences in data format, and this has necessitated the inclusion in DATRAS of numerous additional fields, each informing as to how other fields in the database should be interpreted. Here 19 surveys involving a dozen different countries are examined. In order to derive a single format, quality assured monitoring programme data product covering the entire Northeast Atlantic region, these national, inter-survey, inconsistencies all need resolution. In many instances, particularly in the more historic data, key information is either absent or incorrect, and these missing or erroneous values need replacement by modelled estimates. This document describes the process by which these issues were all resolved to derive 19 separate consistent and fully quality assured survey data products. These data products constitute a unified monitoring programme covering the continental shelf waters of the Northeast Atlantic, from northern Norway to Gibraltar, which can facilitate assessment of the state of fish communities across this whole region. Each survey is first described and a brief history provided. A strict error checking protocol was developed and applied to data in all key fields used in deriving the survey data products. Details of each of these are provided in this document. Detailed descriptions are provided of the two types of file that make up each individual survey data product: "Sampling Information" and "Biological Information".

The dataset includes age- and length-based catch per unit effort data for commercial fish species collected by the French Channel Groundfish Trawl Survey.

The dataset includes age- and length-based catch per unit effort data for commercial fish species collected during the Irish Anglerfish and Megrim survey.

Scottish Marine and Freshwater Science Vol 8 No 18 Coastal European Union (EU) Member States (MS) operate groundfish surveys that cover almost the entire continental shelf of the Northeast Atlantic off Western Europe. Some survey work is also carried out in deeper shelf-edge waters and on sea mounts and plateaus further west in the wider Atlantic Ocean. These surveys use different vessels and different fishing gears, are undertaken at different times of year following various methodological approaches. The data are recorded and archived in a variety of different formats. The data obtained from many of these surveys are routinely uploaded and stored on an open access data portal on the ICES website: the DATRAS portal. The DATRAS portal allows for the uploading of data collected, recorded and archived in a variety of different forms and formats, but the resulting database structure required to accommodate this is far more complicated, and potentially confusing for users, than is really necessary, with many fields in the database simply explaining how other fields should be interpreted. Furthermore, the data stored on the DATRAS database have long been known to be affected by various data quality issues. These have not been addressed in a single co-ordinated process, rather it has been left to individual data users to make any corrections that they deem necessary, effectively resulting in multiple different versions being in circulation of what is in fact a single DATRAS data set. The MSFD requires formal assessment of the state of marine ecosystems in EU waters. Fish communities constitute a key component in the structure and functioning of marine ecosystems, so formal assessment of the state of the fish component is, therefore, mandatory. To meet their MSFD obligations, EU MS have invariably nominated their groundfish surveys as part of their marine monitoring programmes. However, to meet the obligation for formal assessment at the required regional seas spatial scale, these issues of data standardisation and quality assurance noted in the groundfish survey data stored on DATRAS all need to be resolved. The Groundfish Survey Monitoring and Assessment (GSMA) data product sets out to address these issues; to derive a single set of fully standardised and quality assured data products for all the surveys operating in the Northeast Atlantic.

A consistent dataset of bottom trawl survey data spanning 47 years in the Bay of Biscay was assembled. The dataset includes data from the current EVHOE survey from 1987 to 2019 and two previous surveys carried out in 1973 and 1976. The recent EVHOE time-series from 1997 is also available from DATRAS (https://www.ices.dk/data/data-portals/Pages/DATRAS.aspx). The catch in numbers and weight (kg) per haul of all Rajiformes species caught in these surveys is provided. Haul information is provided for all hauls, including those with no catch of Rajiformes. Areas of the sampling strata of the survey and spatial polygones of these strata are provided in separate files.

Base de données du CIEM sur les campagnes au chalut