Main objective: MapGES 2024 continues our longstanding commitment to map deep-sea biodiversity and identifying Vulnerable Marine Ecosystems (VMEs) in the Azores with the Azor drift-cam imagery system. Our 2024 expedition aimed to enhance the data collected in previous surveys by conducting new video transects along the slopes of several islands in the archipelago, including São Miguel and the northern Mar da Prata, Graciosa, Ponta da Ilha N in the Southeast of Pico Island, as well as Flores, Corvo, and Terceira Islands. This fieldwork focused on under-sampled areas and deeper strata. Additionally, we planned to explore two new areas, specifically Ilha Azul W and Raio Seamount. Our ultimate goal is to achieve a comprehensive understanding of the deep-sea fauna dwelling on the slopes, banks, and seamounts in these areas. Like previous MapGES cruises, our objectives included: (i) mapping benthic communities in previously unexplored seamounts, ridges, and island slopes; (ii) identifying new areas that meet the FAO definition of Vulnerable Marine Ecosystems; and (iii) determining the distribution patterns of deep-sea benthic biodiversity in the Azores. The results of this cruise added to the previous contributions to identify the environmental drivers that determine the spatial distribution of deep-sea benthic biodiversity in the Azores. It also provides valuable information in the context of Good Environmental Status (GES), Marine Spatial Planning (MSP) and new insights on how to sustainably manage deep-sea ecosystem. Methodology: We conducted several underwater video transects along the seafloor using the Azor drift-cam, a cost-effective drifting camera system developed by IMAR and Okeanos at the University of the Azores. This system is capable of recording high-quality underwater video images of the seabed down to 1000 m depth, and it was deployed from the MT Physeter. Cruise summary: The MapGES 2024 cruise aboard MT Physeter consisted of 4 legs aimed at exploring and revisiting slopes, banks, ridges, and seamounts surrounding São Miguel, Graciosa, Pico, Flores, Corvo, and Terceira Islands. A total of 150 successful dives were conducted out of 153 planned, covering 28 sampling areas and approximately 80km of the seafloor and generated more than 150 hours of video footage for analysis. During Leg 1, from 30th June to 17th July 2024, we performed 40 successful dives with the Azor drift-cam. This first Leg surveyed the deep-sea benthic communities dwelling on the slopes of the geomorphological structures around São Miguel Island and the north part of the Mar da Prata seamount. This was a challenging leg due to the bad weather conditions throughout the mission. During the Leg 2, from 21st July to 1st August 2024, we performed 48 successful dives with the Azor drift-cam around Graciosa Island slopes and some adjacent geomorphological structures such as Ilha Azul and Mar da Fortuna. We also revisited the south of Pico Island namely the northernmost part of a seamount chain area called Ponta da Ilha. The explorations of the Ponta da Ilha N was unexpectedly challenging due to its geomorphology, being even more difficult when operating with a small vessel such as MT Physeter. During Leg 3, from 9th to 22sd August 2024, we performed 43 dives in the island slopes around Flores and Corvo. During Leg 4, from 26th August to 7th September we performed a total of 22 dives with the Azor drift-cam, a little less than the usual number because of the constant bad sea conditions. Nevertheless, we were able to revisit the Terceira Island slopes and the adjacent banks and seamounts. Main achievements: During the MapGES 2024 survey conducted aboard the MT Physeter, 153 stations were completed using the Azor drift-cam. The stations spanned depths ranging from 100 to 1130 m, encompassing a broad spectrum of marine strata. The survey covered approximately 80km of the seafloor and generated more than 150 hours of video footage for analysis. These numbers represent a big achievement considering that (i) we successfully operated, once again, the Azor drift-cam for deep-sea exploration on board a small vessel and (ii) a great part of the days at the sea were characterized by an extremely challenging weather, especially during Leg 1 and 4 around São Miguel and Terceira Islands. This year’s survey included a diverse set of locations, involving Ilha Azul, Raio seamount, and the northern extension of the Ponta da Ilha volcano chain. This volcanic structure, extending nearly 40 nautical miles from the eastern tip of Pico Island, is still just slightly explored due to the time and vessel limitations and definitely deserves a more in-depth exploration. Due to its particular geomorphology, which is made up of a chain of many narrow seamounts, deploying the Azor drift-cam and passing over the top of the seamounts was a very difficult task, as most of the time the structure only passed along one flank of the hill. For the second consecutive year of the MapGES survey on-board the MT Physeter, no entire Azor drift-cam structures were irretrievably lost despite entanglements with discarded fishing lines or contact with big basaltic outcrops. The successful retrieval of all deployed gear, with only minor damage during all the campaign, underscores the team’s preparedness and their effective response to challenging situations. The MapGES 2024 survey was substantially focused on investigating deeper strata in areas already visited during the previous campaigns. Exploration of these deeper zones provided a more comprehensive understanding of deep-sea biodiversity, so that we can manage to fill some knowledge gaps about the benthic communities present in some of the areas. Several rare or less frequently encountered species were observed using the Azor drift-cam, notablyincluding swordfish (Xiphias gladius), the European spiny lobster (Palinurus elephas), the smalltooth sandtiger shark (Odontaspis ferox), and a species of sponge tentatively identified as cf. Hertwigia falcifera. Wealso had the opportunity to record two different species belonging to the genus Halosaurus, being this fact notable because it was only recorded for the first time with the Azor drift-cam during MapGES 2023 survey. Although no particularly large or spectacular coral communities were detected, several diverse coralgardens were identified, particularly around Terceira Island. These included notable gorgonian species such as Dentomuricea aff. meteor, Acanthogorgia spp., Viminella flagellum, and Paracalyptrophora josephinae. Outstanding coral gardens dominated by the octocoral Dentomuricea aff. meteor had been reported during the MapGES 2023 survey around Terceira Island, and this year, revisiting nearby areas, it wasn’t possible to observe exemplars as a large as last year, probably mainly due to explorations at deeper sectors. During this year campaign, when in São Miguel, we were able to witness what it could be one of the most extensive and with the largest individuals of the gorgonian Candidella cf. imbricata ever recorded with the Azor drift-cam. These aggregations were sighted on Mar da Prata N, and the observation is particularly relevant because of the apparently good coral status and because this area is strongly known for the concentration of significant part of the bottom fishing effort in the Azores region. We detected an extraordinary aggregation of the “bird’s nest” sponge Pheronema carpenteri in Ponta daIlha N (Southeast of Pico Island). There is a high chance that this is one of the densest and largest fieldsmainly composed by this sponge, that we have recorded with the Azor-drift cam, growing on a large flatarea characterized by soft and unconsolidated substrate. This reinforces the idea that this is most certainly the sponge species we encounter most frequently and in higher densities, across a relatively large depth range.

Main objectives: MapGES 2025 continues our longstanding commitment to map deep-sea biodiversity and identifying Vulnerable Marine Ecosystems (VMEs) in the Azores with the Azor drift-cam imagery system. Our 2025 expedition aimed to enhance the data collected in previous surveys by conducting new video transects along the slopes of several islands in the archipelago, including Faial, Pico, Graciosa and Terceira. This fieldwork focused mostly on under-sampled areas and deeper strata. Additionally, we planned to explore one new area, specifically Vasco Gil seamount. Our ultimate goal is to achieve a comprehensive understanding of the deep-sea fauna dwelling on the slopes, banks, and seamounts in these areas. Like previous MapGES cruises, our objectives included: (i) mapping benthic communities in previously unexplored seamounts, ridges, and island slopes; (ii) identifying new areas that meet the FAO definition of Vulnerable Marine Ecosystems; and (iii) determining the distribution patterns of deep-sea benthic biodiversity in the Azores. The results of this cruise added to the previous contributions to identify the environmental drivers that determine the spatial distribution of deep-sea benthic biodiversity in the Azores. It also provides valuable information in the context of Good Environmental Status (GES), Marine Spatial Planning (MSP) and new insights on how to sustainably manage deep-sea ecosystems. Methodology: We conducted several underwater video transects along the seafloor using the Azor drift-cam, a cost-effective drifting camera system developed by IMAR and Okeanos at the University of the Azores. This system is capable of recording high-quality underwater video images of the seabed, and it was deployed from the MT Physeter. This year, the operation capabilities of the Azor drift-cam was expanded to ~1500 m depth. In each sampling area, we performed a representative number of dives using the video system, ranging from approximately 1200 m to the shallowest point of each structure. The objective was to capture underwater images that would effectively characterize the biodiversity across the entire bathymetric gradient and various substrate types. The video transects were strategically planned based on the most accurate bathymetric data available, allowing the camera system to drift from deeper to shallower regions. This methodology was designed to ensure optimal image quality by maximizing light incidence and minimizing attenuation in the water column, a challenge typically encountered during descending transects. Each transect with the Azor drift-cam was planned for approximately 60 to 120 minutes on the seafloor, with the system drifting over benthic habitats at an average speed of 0.5 to 1 knot. Under favourable conditions, each working day facilitated 3 to 5 dives, corresponding to approximately 5 kilometres of seafloor explored daily. Cruise summary: The MapGES 2025 cruise aboard MT Physeter consisted of 1 leg, divided in 3 parts, aimed at exploring and revisiting slopes, banks, ridges, and seamounts surrounding Faial, Pico, Graciosa and Terceira Islands. A total of 40 successful dives were conducted out of 41 planned, covering 11 sampling areas. During Leg 1a, on the 4th of June, we performed 2 successful dives with the Azor drift-cam. These first deployments surveyed the deep-sea benthic communities dwelling on the slopes of the geomorphological structures on the north flank of Faial Island. These first dives were also a practical test to experience some add-ons on our structure, such as the external feeding of the GoPro camera, the implementation of a second spotlight, the use of a 1500m umbilical cable and the USBL system. During the Leg 1b, from 21st June to 1st of July, we performed 35 successful dives with the Azor drift-cam around Graciosa and Terceira Island slopes and some adjacent geomorphological structures such as Vasco Gil, Ilha Azul E and João de Melo. Several deep dives (>1000 m) were performed during this leg with no major problems across the components of the drift-cam. During the Leg1c, on the 25th of July, we performed 3 successful dives with the Azor drift-cam on the deeper sectors of the NW slopes in Pico Island. During this year’s survey we observed diverse benthic and fish communities, from which we may highlight impressive and extensive aggregations of the primnoid corals Narella versluysi and N. bellissima, in Ilha Azul E, the notably large specimens of the octocoral Callogorgia verticillata, in Maçarico, the black corals Leiopathes expansa, in Beirada de Fora, and Antipathes dichotoma, in Vasco Gil. Also, an incredible and most likely record-breaking aggregation of anguilliform fishes Halosauridae was recorded at approximately 900 m depth in Graciosa S area. Main achievements: During the MapGES 2025 survey conducted aboard the MT Physeter, 41 stations were completed using the Azor drift-cam. The stations spanned depths ranging from 205 to 1130 m, encompassing a broad spectrum of marine strata. The survey covered approximately 31 km of the seafloor and generated more than 49 hours of video footage for analysis. These numbers represent a big achievement considering that we successfully operated, once again, the Azor drift-cam for deep-sea exploration on board a small vessel and this year with several improvements on our system including an umbilical cable of 1500m, the underwater positioning system (USBL), the external power feeding of the GoPro camera and the addition of a second spotlight. This year’s survey aimed to complete the coverage of selected Island slopes around Faial, Graciosa, Terceira and Pico Islands. We successfully accomplished nearly all our objectives in each one of the areas re-visited and were also able to explore the Vasco Gil seamount for the first time. For the third consecutive year of the MapGES survey onboard the MT Physeter, no Azor drift-cam structures were lost, despite that we were challenged by an entanglement on a lost fishing line, the unexpected encounter of the largest basaltic wall recorded with the Azor drift-cam dive (around 300m high) and an incident where the umbilical cable became entangled in the vessel’s propeller. As one of our key objectives this year was to explore deeper strata previously unsampled in certain areas, the drift-cam was repeatedly deployed at depths exceeding 900 m and performed outstandingly with minimal issues across all components. Ilha Azul E exhibited impressive and extensive aggregations of the primnoid corals Narella versluysi and N. bellissima. Exploration of several areas East of Terceira Island continue to reveal interesting communities. Notably, large specimens of the octocoral Callogorgia verticillata and large black corals Leiopathes expansa were observed in the Maçarico area and Beirada de Fora areas, respectively. The first exploration of Vasco Gil seamount revealed large black corals Antipathes dichotoma. Remarkable geological features were observed across the surveyed areas: around the Vasco Gil seamount a heterogenous seafloor composed of contrasting black and white rock types suggests a complex geological origin in this geomorphological structure. Interesting geological patterns of the seafloor was sighted in Ilha Azul E and Beirada de Fora areas, where evidence of ancient stratification was recorded. A deceased undetermined shark was observed on a sandy bottom in Graciosa S area, probably resulting from fisheries discards. This marks the first recorded shark carcass during an Azor drift-cam deployment. The rarity of such observations rise questions about the visibility and persistence of large organic falls in deep-sea environments. An incredible and most likely record-breaking aggregation of anguilliform fishes Halosauridae was recorded at approximately 900 m depth in the southern area of Graciosa Island. An unusually high number of angler fish (Lophius piscatorius) was repeatedly observed along the slopes of Graciosa Island. The decapod Cancer bellianus was observed on top of the vase-shaped Characella pachastrelloides while holding another sponge. This behaviour is likely uncommon for this species of crustacean.

Abstract Ecosystem-based marine spatial planning is an approach to managing maritime activities while ensuring human well-being and biodiversity conservation as key pillars for sustainable development. Here, we use a comprehensive literature review and a co-development process with experts to build an assessment framework and tool that integrates the fundamental principles of an ecosystem approach to management and translates them into specific actions to be undertaken during planning processes. We illustrate the potential of this tool through the evaluation of two national marine spatial plans (Spain and France), in consultation with the representatives involved in their development and implementation. To ensure more coherent future planning, socio-ecological system evolution in a climate change scenario and the future marine space needs of maritime sectors should be considered, as well as improving the governance structure and knowledge of ecosystem processes. This framework provides a consistent and transparent assessment method for practitioners and competent authorities.