The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

The primary sampling unit (PSU) in the Belgian at sea sampling programme is vessel x trip (as a proxy for trip). A vessel x trip (PSU) for the TBB_DEF_>221 kW fleet segment is selected ad hoc or standard quota sampling is conducted (non-probability-based sampling). The vessels that are willing to take observers onboard and those that are logistically suited, are included in the vessel list, that currently contains ± 15 vessels over which the sampling will be spread. ILVO introduced 2 types of sampling: 1. Ad hoc sampling: for those strata with a lower sampling coverage (based on previous years) 2. Quota sampling: sampling effort is proportionally to the fleet effort (based on previous year) A vessel x trip (PSU) for the TBB_DEF_<=221 kW fleet segment is selected ad hoc. More than half of TBB_DEF vessels with a capacity <=221 kW flying the Belgian flag are regularly fishing for shrimp (TBB_CRU). Belgium has a derogation for sampling the TBB_CRU métier until the end of 2021. The TBB_DEF_<=221 kW vessel list proved too small to ensure random PSU selection. Therefore, ad hoc sampling of 2 euro cutters and 2 coastal vessels is carried out. The observer coordinator keeps track of the vessels in the vessel list but ILVO considers collecting non-responses and refusals on PSU (trip) level not relevant. Every other haul is sampled by an observer. For the TBB_DEF_<=221 kW fleet segment, the aim is to sample all hauls during the short trips of the coastal vessels. The crew sorts the marketable fish from the conveyor belt. In the meantime, the observer is sampling the discarded fraction of the catch by sorting all commercially important species. The total weight per species in each haul is determined and lengths are measured. When a species is extremely abundant, a smaller representative subsample (TSU) is measured. The marketable part of the catch (landings) is sampled later on in the same way as the discarded part of the catch. For selected species (depending on the area), otoliths from minimum 3 fish per cm-size class per species per area, are collected (except for 1 fish per cm-size class for cod) for age estimations. Otoliths are collected throughout the whole trip (several hauls) until the quota for otoliths is achieved. For the discarded part of the catch, otoliths are being removed on board. For the retained part (landings) of the catch, the fish are purchased. Coordination takes place within the Regional Coordination Groups (RCG NA/RCG NSE).

1) Satellite based chlorofyl a: - Frequency of sampling: daily, provided that cloud cover and quality flagging allow measurements. - Geographic scope: 100% satellite coverage (e.g. SeaWifs, MERIS, MODIS, Sentinel-3). - Approximate number of samples: number of samples varies per region and is dependent on cloud cover, quality flagging, etc. For the Belgian coastal zone, there are between 25 and 50 samples per growing season (March-October). Methodology based on satellite data as elaborated in regional context in the frame of JMP Eunosat (https://www.informatiehuismarien.nl/projecten/algaeevaluated/information/results/ ) and in review by OSPAR. Joint data collection, satellite and in-situ, with the Netherlands. 2) Chlorophyll a monitoring based on in situ data: monthly sampling at fixed measuring stations, simultaneously with the nutrients (ANSBE-P15- Nutrients). Additional sampling at time of satellite overpass.

A total 17 stations in the Belgian part of the North Sea are being sampled since May 2017. On a monthly basis, 9 stations are sampled in near-shore areas. Additionally, 8 offshore stations are sampled on a seasonal basis. Essential ocean variable: Phytoplankton Biomass and Diversity (http://goosocean.org/index.php?option=com_oe&task=viewDocumentRecord&docID=17507). This monitoring programme is dependant on the continuation of funding starting from 2021.

A total 17 stations in the Belgian part of the North Sea are being sampled since 2012. On a monthly basis, 9 stations are sampled in near-shore areas. Additionally, 8 offshore stations are sampled on a seasonal basis. Essential ocean variable: Zooplankton Biomass and Diversity (http://goosocean.org/index.php?option=com_oe&task=viewDocumentRecord&docID=17509) This monitoring programme is dependant on the continuation of funding starting from 2021.

1. BTS During the BTS 62 fixed stations are fished for 30 min at 4 knots using a beam trawl as standard gear (beam length 4 m, cod-end mesh size 40 mm). Although the target species are plaice and sole, all fish and commercially important cephalopods and crustaceans are sorted, weighed and measured since 2010. Since 2009, a subsample of the catch is taken of which all epibenthic species are recorded in numbers and sample weight. The data collected during the BTS are used in analytical population studies of several species/stocks, mainly serving as tuning indices in the stock assessments leading to the fishing quota. Additionally, several other investigations are planned, such as (a) the construction of "age-length-keys" for a number of commercially important flatfish, and (b) documenting distribution and abundance of all commercial and non-commercial (bycatch) invertebrate species. 2. DYFS All 33 DYFS sampling stations are fished for approximately 30 min, with a standard shrimp beam trawl (beam length 6 m; cod-end mesh size 22 mm, no tickler chains), at 3 knots against tide. Several fish species (cod, whiting, plaice, flounder, dab, sole, brill and turbot) are hand-picked from the catches, sorted by species, weighed and measured in mm (by the in-house developed SmartFish measuring board). From 2009 onwards, the species list was extended to cover a larger range of commercial fish species (e.g. including lesser spotted dogfish, gurnards, lemon sole, horse mackerel, etc.). In this way, a total of 18 species are documented. From 2018 onwards, the species list has been extended with all elasmobranch species that are weighed and measured (by sex). The brown shrimp from the catches are first sorted into a ‘small’ and ‘large’ fraction by means of a rotating shrimp riddle (same type used on commercial shrimp trawlers). From each of these two fractions, 1-2 liter samples are taken (depending on the amount of shrimp and other organisms in the fractions). Samples are further sub-sampled in the lab to approximately 250 shrimps, which are then measured in mm using an in-house developed system.

1. BTS During the BTS 62 fixed stations are fished for 30 min at 4 knots using a beam trawl as standard gear (beam length 4 m, cod-end mesh size 40 mm). Although the target species are plaice and sole, all fish and commercially important cephalopods and crustaceans are sorted, weighed and measured since 2010. Since 2009, a subsample of the catch is taken of which all epibenthic species are recorded in numbers and sample weight. The data collected during the BTS are used in analytical population studies of several species/stocks, mainly serving as tuning indices in the stock assessments leading to the fishing quota. Additionally, several other investigations are planned, such as (a) the construction of "age-length-keys" for a number of commercially important flatfish, and (b) documenting distribution and abundance of all commercial and non-commercial (bycatch) invertebrate species. 2. DYFS All 33 DYFS sampling stations are fished for approximately 30 min, with a standard shrimp beam trawl (beam length 6 m; cod-end mesh size 22 mm, no tickler chains), at 3 knots against tide. Several fish species (cod, whiting, plaice, flounder, dab, sole, brill and turbot) are hand-picked from the catches, sorted by species, weighed and measured in mm (by the in-house developed SmartFish measuring board). From 2009 onwards, the species list was extended to cover a larger range of commercial fish species (e.g. including lesser spotted dogfish, gurnards, lemon sole, horse mackerel, etc.). In this way, a total of 18 species are documented. From 2018 onwards, the species list has been extended with all elasmobranch species that are weighed and measured (by sex). The brown shrimp from the catches are first sorted into a ‘small’ and ‘large’ fraction by means of a rotating shrimp riddle (same type used on commercial shrimp trawlers). From each of these two fractions, 1-2 liter samples are taken (depending on the amount of shrimp and other organisms in the fractions). Samples are further sub-sampled in the lab to approximately 250 shrimps, which are then measured in mm using an in-house developed system.

1. BTS During the BTS 62 fixed stations are fished for 30 min at 4 knots using a beam trawl as standard gear (beam length 4 m, cod-end mesh size 40 mm). Although the target species are plaice and sole, all fish and commercially important cephalopods and crustaceans are sorted, weighed and measured since 2010. Since 2009, a subsample of the catch is taken of which all epibenthic species are recorded in numbers and sample weight. The data collected during the BTS are used in analytical population studies of several species/stocks, mainly serving as tuning indices in the stock assessments leading to the fishing quota. Additionally, several other investigations are planned, such as (a) the construction of "age-length-keys" for a number of commercially important flatfish, and (b) documenting distribution and abundance of all commercial and non-commercial (bycatch) invertebrate species. 2. DYFS All 33 DYFS sampling stations are fished for approximately 30 min, with a standard shrimp beam trawl (beam length 6 m; cod-end mesh size 22 mm, no tickler chains), at 3 knots against tide. Several fish species (cod, whiting, plaice, flounder, dab, sole, brill and turbot) are hand-picked from the catches, sorted by species, weighed and measured in mm (by the in-house developed SmartFish measuring board). From 2009 onwards, the species list was extended to cover a larger range of commercial fish species (e.g. including lesser spotted dogfish, gurnards, lemon sole, horse mackerel, etc.). In this way, a total of 18 species are documented. From 2018 onwards, the species list has been extended with all elasmobranch species that are weighed and measured (by sex). The brown shrimp from the catches are first sorted into a ‘small’ and ‘large’ fraction by means of a rotating shrimp riddle (same type used on commercial shrimp trawlers). From each of these two fractions, 1-2 liter samples are taken (depending on the amount of shrimp and other organisms in the fractions). Samples are further sub-sampled in the lab to approximately 250 shrimps, which are then measured in mm using an in-house developed system.

1. BTS During the BTS 62 fixed stations are fished for 30 min at 4 knots using a beam trawl as standard gear (beam length 4 m, cod-end mesh size 40 mm). Although the target species are plaice and sole, all fish and commercially important cephalopods and crustaceans are sorted, weighed and measured since 2010. Since 2009, a subsample of the catch is taken of which all epibenthic species are recorded in numbers and sample weight. The data collected during the BTS are used in analytical population studies of several species/stocks, mainly serving as tuning indices in the stock assessments leading to the fishing quota. Additionally, several other investigations are planned, such as (a) the construction of "age-length-keys" for a number of commercially important flatfish, and (b) documenting distribution and abundance of all commercial and non-commercial (bycatch) invertebrate species. 2. DYFS All 33 DYFS sampling stations are fished for approximately 30 min, with a standard shrimp beam trawl (beam length 6 m; cod-end mesh size 22 mm, no tickler chains), at 3 knots against tide. Several fish species (cod, whiting, plaice, flounder, dab, sole, brill and turbot) are hand-picked from the catches, sorted by species, weighed and measured in mm (by the in-house developed SmartFish measuring board). From 2009 onwards, the species list was extended to cover a larger range of commercial fish species (e.g. including lesser spotted dogfish, gurnards, lemon sole, horse mackerel, etc.). In this way, a total of 18 species are documented. From 2018 onwards, the species list has been extended with all elasmobranch species that are weighed and measured (by sex). The brown shrimp from the catches are first sorted into a ‘small’ and ‘large’ fraction by means of a rotating shrimp riddle (same type used on commercial shrimp trawlers). From each of these two fractions, 1-2 liter samples are taken (depending on the amount of shrimp and other organisms in the fractions). Samples are further sub-sampled in the lab to approximately 250 shrimps, which are then measured in mm using an in-house developed system.

Benthos (animals retrieved on a 1mm sieve) is collected by a Van Veen grab at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system (3-yearly) + depending on where the activity is going on). Samples are also taken at control stations, locations outside the direct impact sphere of the activity. Besides, a few long-term monitoring locations are regularly sampled. Details of sampling records in the past and what is expected the coming years is given in annex. Monitoring is ongoing since 1979, but with a more standardized, comparable design from 2006 onwards. International cooperation is currently limited to knowledge exchange within OSPAR COBAM, benthic expert group.

Benthos (animals retrieved on a 1mm sieve) is collected by a Van Veen grab at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system (3-yearly) + depending on where the activity is going on). Samples are also taken at control stations, locations outside the direct impact sphere of the activity. Besides, a few long-term monitoring locations are regularly sampled. Details of sampling records in the past and what is expected the coming years is given in annex. Monitoring is ongoing since 1979, but with a more standardized, comparable design from 2006 onwards. International cooperation is currently limited to knowledge exchange within OSPAR COBAM, benthic expert group.

Benthos (animals retrieved on a 1mm sieve) is collected by a Van Veen grab at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system (3-yearly) + depending on where the activity is going on). Samples are also taken at control stations, locations outside the direct impact sphere of the activity. Besides, a few long-term monitoring locations are regularly sampled. Details of sampling records in the past and what is expected the coming years is given in annex. Monitoring is ongoing since 1979, but with a more standardized, comparable design from 2006 onwards. International cooperation is currently limited to knowledge exchange within OSPAR COBAM, benthic expert group.

The epibenthos and demersal fish are collected by 8m beam trawl with 22mm mesh at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system + depending on where the activity is going on). The windfarm area is sampled every year, but with variation in the specific concession areas sampled. In addition, a number of long-term monitoring stations are sampled on a regular basis. The epibenthos and demersal fish are determined to species level, counted and weighted (not fish) or length measured (fish). The dab (Limanda limanda) in the tracks (up to a maximum of 500 individuals for respectively the coastal and offshore assessment area) are investigated for external fish diseases, following the ICES TIMES guidelines. This programme is covering the environmental targets long-living species (D6.6), alien species (D2.1) and fish diseases (D8.5). From 2006 onwards, monitoring is executed following a more standardized, comparable design.

The epibenthos and demersal fish are collected by 8m beam trawl with 22mm mesh at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system + depending on where the activity is going on). The windfarm area is sampled every year, but with variation in the specific concession areas sampled. In addition, a number of long-term monitoring stations are sampled on a regular basis. The epibenthos and demersal fish are determined to species level, counted and weighted (not fish) or length measured (fish). The dab (Limanda limanda) in the tracks (up to a maximum of 500 individuals for respectively the coastal and offshore assessment area) are investigated for external fish diseases, following the ICES TIMES guidelines. This programme is covering the environmental targets long-living species (D6.6), alien species (D2.1) and fish diseases (D8.5). From 2006 onwards, monitoring is executed following a more standardized, comparable design.

The epibenthos and demersal fish are collected by 8m beam trawl with 22mm mesh at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system + depending on where the activity is going on). The windfarm area is sampled every year, but with variation in the specific concession areas sampled. In addition, a number of long-term monitoring stations are sampled on a regular basis. The epibenthos and demersal fish are determined to species level, counted and weighted (not fish) or length measured (fish). The dab (Limanda limanda) in the tracks (up to a maximum of 500 individuals for respectively the coastal and offshore assessment area) are investigated for external fish diseases, following the ICES TIMES guidelines. This programme is covering the environmental targets long-living species (D6.6), alien species (D2.1) and fish diseases (D8.5). From 2006 onwards, monitoring is executed following a more standardized, comparable design.

The epibenthos and demersal fish are collected by 8m beam trawl with 22mm mesh at different locations and habitats within the Belgian part of the North Sea. The spatial and temporal distribution of those samples depends on the occurrence and intensity of human activities in different areas. The exact number of samples per year and area depends on which sand extraction and disposal area is visited (certain rotation system + depending on where the activity is going on). The windfarm area is sampled every year, but with variation in the specific concession areas sampled. In addition, a number of long-term monitoring stations are sampled on a regular basis. The epibenthos and demersal fish are determined to species level, counted and weighted (not fish) or length measured (fish). The dab (Limanda limanda) in the tracks (up to a maximum of 500 individuals for respectively the coastal and offshore assessment area) are investigated for external fish diseases, following the ICES TIMES guidelines. This programme is covering the environmental targets long-living species (D6.6), alien species (D2.1) and fish diseases (D8.5). From 2006 onwards, monitoring is executed following a more standardized, comparable design.

The macrobenthos (animals retrieved on a 1mm sieve) are collected by a Van Veen grab at different locations and habitats within the OWFs C-Power and Belwind at the Belgian Part of the North Sea. These samples are compared to reference areas close to the studied OWFs. From each Van Veen grab, a sediment sample is retrieved for benthic habitat characterization (granulometric measurements: median grain size (µm) and fine sediment fraction (% within 125-250 µm); total organic matter content (%)). Frequency: from T0 (before construction) onwards, yearly except when windfarm in construction phase. Since 2005 onwards in C-Power (Thornton bank and Goote Bank); since 2008 onwards in Belwind (Bligh Bank), mainly in autumn, with different sampling schemes.

The macrobenthos (animals retrieved on a 1mm sieve) are collected by a Van Veen grab at different locations and habitats within the OWFs C-Power and Belwind at the Belgian Part of the North Sea. These samples are compared to reference areas close to the studied OWFs. From each Van Veen grab, a sediment sample is retrieved for benthic habitat characterization (granulometric measurements: median grain size (µm) and fine sediment fraction (% within 125-250 µm); total organic matter content (%)). Frequency: from T0 (before construction) onwards, yearly except when windfarm in construction phase. Since 2005 onwards in C-Power (Thornton bank and Goote Bank); since 2008 onwards in Belwind (Bligh Bank), mainly in autumn, with different sampling schemes.

The macrobenthos (animals retrieved on a 1mm sieve) are collected by a Van Veen grab at different locations and habitats within the OWFs C-Power and Belwind at the Belgian Part of the North Sea. These samples are compared to reference areas close to the studied OWFs. From each Van Veen grab, a sediment sample is retrieved for benthic habitat characterization (granulometric measurements: median grain size (µm) and fine sediment fraction (% within 125-250 µm); total organic matter content (%)). Frequency: from T0 (before construction) onwards, yearly except when windfarm in construction phase. Since 2005 onwards in C-Power (Thornton bank and Goote Bank); since 2008 onwards in Belwind (Bligh Bank), mainly in autumn, with different sampling schemes.

The monitoring consists of a periodic assessment of benthic communities at fixed locations. Four stations have been designated in the Northern Exploration Area (area overlapping with area designated for the exploration of the potential of marine aggregate extraction and for the protection of the seabed in Marine Spatial Plan 2020-2026). A transect station will be established in the Hinderbanken. Sampling is implemented by Hammon grab and underwater videography. In-situ samples are stored and processed at RBINS facilities (Oostende) according to in-house protocols of faunal analysis. Tabulation of species data (count, abundance and richness). Underwater videography: stored and processed at RBINS (Brussels) according to currently developing methodologies w.r.t. semi-automated image classification and feature extraction.

The monitoring consists of a periodic assessment of benthic communities at fixed locations. Four stations have been designated in the Northern Exploration Area (area overlapping with area designated for the exploration of the potential of marine aggregate extraction and for the protection of the seabed in Marine Spatial Plan 2020-2026). A transect station will be established in the Hinderbanken. Sampling is implemented by Hammon grab and underwater videography. In-situ samples are stored and processed at RBINS facilities (Oostende) according to in-house protocols of faunal analysis. Tabulation of species data (count, abundance and richness). Underwater videography: stored and processed at RBINS (Brussels) according to currently developing methodologies w.r.t. semi-automated image classification and feature extraction.