Fish assemblages surveyed by using underwater visual censuses (UVC) down to 40 m. Transects were performed between 1997 and 2015 in the Azores, Portugal. All mobile fish were identified to the lowest possible taxon. Dates, geographic coordinates and species recorded are provided. Fish assemblages were surveyed using underwater visual censuses (UVC) down to 40 m. Following standard belt transect surveys (Brock 1954), SCUBA divers sampled transects with 50 m length and 5 m width. All mobile fish were identified to the lowest possible taxon and counted. Sampling sites were chosen based on the general representativeness of the habitat. Transects within sites were selected by stratified random sampling: different transects were done in each dive without replicating the depth strata (every 10 m) or overall bottom type or crossing transects during a single dive or day. UVCs were conducted in the scope of projects CLIPE (FCT—Praxis XXI/3/3.2/EMG/1957/95), MARÉ (LIFE B4-3200/98-509), MAREFISH (FCT-POCTI/ BSE/41207/2001), OGAMP (INTERREG IIIb/MAC/4.2/A2 2001), MARMAC (INTERREGIIIb-03/MAC/4.2/A1 2004), EmpaFish (EC-FP6, SSP8-006539), MareFish (FCT, POCTI/BSE/41207/2001), MoniZEC (FRC - M2.1.2/I/018/2011)

Information collected by the observers on board the tuna fishing vessels on tuna fisheries, weather conditions, live bait fisheries, cetaceans, birds and sea turtles. POPA was launched in 1998 with the main goal of certifying the tuna caught around the Azores as a "dolphin safe product". This label is attributed by the non-governmental organization Earth Island Institute to catches made without mortality of cetaceans. POPA has built an extensive database with information collected by the observers on board the tuna fishing vessels. This database includes information on tuna fisheries (e.g., location of fishing events, catches, and fishing effort), weather conditions (e.g., sea surface temperature, wind and visibility), live bait fisheries (e.g., location of fishing events, catches, gears used), cetaceans (e.g., occurrences, interaction with fishing events and association with other species), birds and sea turtles (e.g., occurrences). POPA is also responsible for "Friend of the Sea" tuna fishery certification. In the late 1990’s, it became clear that the tuna industry would be seriously penalized with the absence of a "dolphin safe" certification which instigated new measures from the government and the fisheries sector. In order to achieve this certification, the Azores Fisheries Observer Programme (POPA) was funded in 1998, ensuring the absence of dolphin mortality or injury in tuna fishery. Since then, fishery and fishing products are certified by the Earth Island Institute, through the results presented by POPA. Besides that, the tuna fishery is also certified as "Friend of the Sea" which means that it is extremely selective, doesn’t harm the surrounding environment and is quite sustainable. It became the first tuna fishery in the world achieving that certification. The Programme results from an agreement among Regional Administration, Earth Island Institute, the Tuna Canning Industry Association (Pão do Mar), the Fishing Boat Owners Association (APASA) and IMAR - Instituto do Mar - through the University of The Azores Center (IMAR-DOP/Uaç), which carries out the programme. Until 2003, the Programme was supported by regional funds. Between 2003 and 2005 it became co-financed by the European Commission through the INTERREG IIIb Programme/ ORPAM project. Since then it has been exclusively supported by the regional government through the Regional Secretary of Fisheries.

Other fish species caught during the tuna fishing operation that were commercialized. These species were caught along with the target species (tuna) by using pole and line. POPA was launched in 1998 with the main goal of certifying the tuna caught around the Azores as a "dolphin safe product". This label is attributed by the non-governmental organization Earth Island Institute to catches made without mortality of cetaceans. POPA has built an extensive database with information collected by the observers on board the tuna fishing vessels. This database includes information on tuna fisheries (e.g., location of fishing events, catches, and fishing effort), weather conditions (e.g., sea surface temperature, wind and visibility), live bait fisheries (e.g., location of fishing events, catches, gears used), cetaceans (e.g., occurrences, interaction with fishing events and association with other species), birds and sea turtles (e.g., occurrences). POPA is also responsible for "Friend of the Sea" tuna fishery certification. In the late 1990’s, it became clear that the tuna industry would be seriously penalized with the absence of a "dolphin safe" certification which instigated new measures from the government and the fisheries sector. In order to achieve this certification, the Azores Fisheries Observer Programme (POPA) was funded in 1998, ensuring the absence of dolphin mortality or injury in tuna fishery. Since then, fishery and fishing products are certified by the Earth Island Institute, through the results presented by POPA. Besides that, the tuna fishery is also certified as "Friend of the Sea" which means that it is extremely selective, doesn’t harm the surrounding environment and is quite sustainable. It became the first tuna fishery in the world achieving that certification. The Programme results from an agreement among Regional Administration, Earth Island Institute, the Tuna Canning Industry Association (Pão do Mar), the Fishing Boat Owners Association (APASA) and IMAR - Instituto do Mar - through the University of The Azores Center (IMAR-DOP/Uaç), which carries out the programme. Until 2003, the Programme was supported by regional funds. Between 2003 and 2005 it became co-financed by the European Commission through the INTERREG IIIb Programme/ ORPAM project. Since then it has been exclusively supported by the regional government through the Regional Secretary of Fisheries.

Sightings of birds were recorded daily, at 6 different fixed periods (snap shots), when the boat was in navigation or search mode. POPA was launched in 1998 with the main goal of certifying the tuna caught around the Azores as a "dolphin safe product". This label is attributed by the non-governmental organization Earth Island Institute to catches made without mortality of cetaceans. POPA has built an extensive database with information collected by the observers on board the tuna fishing vessels. This database includes information on tuna fisheries (e.g., location of fishing events, catches, and fishing effort), weather conditions (e.g., sea surface temperature, wind and visibility), live bait fisheries (e.g., location of fishing events, catches, gears used), cetaceans (e.g., occurrences, interaction with fishing events and association with other species), birds and sea turtles (e.g., occurrences). POPA is also responsible for "Friend of the Sea" tuna fishery certification. In the late 1990’s, it became clear that the tuna industry would be seriously penalized with the absence of a "dolphin safe" certification which instigated new measures from the government and the fisheries sector. In order to achieve this certification, the Azores Fisheries Observer Programme (POPA) was funded in 1998, ensuring the absence of dolphin mortality or injury in tuna fishery. Since then, fishery and fishing products are certified by the Earth Island Institute, through the results presented by POPA. Besides that, the tuna fishery is also certified as "Friend of the Sea" which means that it is extremely selective, doesn’t harm the surrounding environment and is quite sustainable. It became the first tuna fishery in the world achieving that certification. The Programme results from an agreement among Regional Administration, Earth Island Institute, the Tuna Canning Industry Association (Pão do Mar), the Fishing Boat Owners Association (APASA) and IMAR - Instituto do Mar - through the University of The Azores Center (IMAR-DOP/Uaç), which carries out the programme. Until 2003, the Programme was supported by regional funds. Between 2003 and 2005 it became co-financed by the European Commission through the INTERREG IIIb Programme/ ORPAM project. Since then it has been exclusively supported by the regional government through the Regional Secretary of Fisheries.

Sightings (snap shots) of marine mammals collected by Biosphere Expeditions collaborators specifically for POPA. Since 2004 Biosphere Expeditions (www.biosphere-expeditions.org) collects data for POPA in the Azores central group in April and May. POPA was launched in 1998 with the main goal of certifying the tuna caught around the Azores as a "dolphin safe product". This label is attributed by the non-governmental organization Earth Island Institute to catches made without mortality of cetaceans. POPA has built an extensive database with information collected by the observers on board the tuna fishing vessels. This database includes information on tuna fisheries (e.g., location of fishing events, catches, and fishing effort), weather conditions (e.g., sea surface temperature, wind and visibility), live bait fisheries (e.g., location of fishing events, catches, gears used), cetaceans (e.g., occurrences, interaction with fishing events and association with other species), birds and sea turtles (e.g., occurrences). POPA is also responsible for "Friend of the Sea" tuna fishery certification. In the late 1990’s, it became clear that the tuna industry would be seriously penalized with the absence of a "dolphin safe" certification which instigated new measures from the government and the fisheries sector. In order to achieve this certification, the Azores Fisheries Observer Programme (POPA) was funded in 1998, ensuring the absence of dolphin mortality or injury in tuna fishery. Since then, fishery and fishing products are certified by the Earth Island Institute, through the results presented by POPA. Besides that, the tuna fishery is also certified as "Friend of the Sea" which means that it is extremely selective, doesn’t harm the surrounding environment and is quite sustainable. It became the first tuna fishery in the world achieving that certification. The Programme results from an agreement among Regional Administration, Earth Island Institute, the Tuna Canning Industry Association (Pão do Mar), the Fishing Boat Owners Association (APASA) and IMAR - Instituto do Mar - through the University of The Azores Center (IMAR-DOP/Uaç), which carries out the programme. Until 2003, the Programme was supported by regional funds. Between 2003 and 2005 it became co-financed by the European Commission through the INTERREG IIIb Programme/ ORPAM project. Since then it has been exclusively supported by the regional government through the Regional Secretary of Fisheries.

Demersal surveys performed with bottom longline during research cruises around Azorean islands and several seamounts. Surveys conducted annually (few exceptions) from 1996 to 2013. Sampling is performed using a "stone-buoy longline" similar to the one used in the commercial demersal fishery in the Azores. The sampling is stratified and random based on depth and geographic areas from 25 meters to 1200 meters mostly, but few sets down to 2000 meters. In some sets a different longline design was used (see Menezes et al. 2009). Soak time was usually 2 to 3 hours, but deeper sets (below 1000 meters) have longer soaks times. Chopped and salted sardines were used as bait.

Moving 10-years analysis of Chlorophyll-a -1.0-ANA at Northeast Atlantic Ocean for each season: - winter: January-March, - spring: April-June, - summer: July-September, - autumn: October-December. Every year of the time dimension corresponds to the 10-year centred average of each season. Decades span from 1985-1994 until 2005-2014. Observational data span from 1970 to 2015. Depth range (IODE standard depths): -300.0, -250.0, -200.0, -150.0, -125.0, -100.0, -75.0, -50.0,-40.0, -30.0, -20.0, -10.0, -5.0, -0.0 Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network. Description of DIVA analysis: Geostatistical data analysis by DIVA (Data-Interpolating Variational Analysis) tool. GEBCO 1min topography is used for the contouring preparation. Analyzed filed masked using relative error threshold 0.3 and 0.5 DIVA settings. Signal to noise ratio and correlation length were optimized and filtered vertically and a seasonally-averaged profile was used. Logarithmic transformation applied to the data prior to the analysis. Background field: the data mean value is subtracted from the data. Detrending of data: no, Advection constraint applied: no. Units: mg/m^3