Black Coral Forests – unexplored biodiversity hotspots in Macaronesia

The LIFE4BEST project titled B-CHARMED, which stands for “Black Coral forests as unexplored biodiversity Hotspots in the MAcaronesia Region: EcosysteM functions and Services analysed”, is being implemented in a Key Biodiversity Area (KBA) off the southern coast of Lanzarote Island in the Eastern Atlantic Ocean.

In the Canary Islands, the expanding costal development, linked to several anthropogenic activities like tourism, fishing, aquaculture, marine biotechnologies or ocean energy, is affecting local marine biodiversity, and the extent to which black corals are impacted remains unknown. Black coral communities (Antipathella sp.) can form underwater forests at a depth ranging from 30 to 150 m. They function as “ecosystem engineers”, as they generate a physical & chemical environment, and influence the distribution of other species. However, there is scarce data and insufficient understanding of the black corals’ spatial extent and of the ecosystem services they provide.

The B-CHARMED project is therefore bridging this information gap and gathering robust scientific information on black corals to ensure the sustainable use of costal resources and help decision makers to adopt proper conservation measures. The project entails the development of new acoustic methodologies to detect coral distribution, the characterization and mapping of black coral forests (BCF), in a case study area located off the south-eastern coasts of Lanzarote, while also defining a minimal conservation Unit (MCU) able to preserve their ecosystem function and services.

The project is coordinated by the Lanzarote-based “Biodiversidad Atlantica y sostenibilidad (ABAS)” association in collaboration with the German “Leibnitz Institute for Baltic Sea Research Warnemünde”,andis financed by the LIFE4BEST program (LIFE Programme of the European Commission together with OFB and AFD).

B-CHARMED is using in-situ surveys (ROVs and technical deep diving), automatic data loggers able to record environmental variables, and underwater visual census and bait-cameras to estimate ichthyofaunal biodiversity associated with BCF. The four main outcomes are integrating BCF in the current conservation policies of the Canary Islands, fostering the valorisation of their ecosystem functions & services, defining long-term strategies for their biodiversity conservation, and raising the environmental awareness of locals, specially on Lanzarote Island, but also across the entire European space.

Exploratory dive (credit: Asociación Biodiversidad Atlántica y Sostenibilidad)

The project started in July 2020 and was planned to last one year. The pandemic and related travel restrictions affected the timeline and determined the team to extend the project duration until December 2021. The initial workplan was adapted accordingly. The study of acoustic characteristics of BCF, the BCF MCU and the identification of fish species inhabiting BCF, initially planned for the first period of the project, were postponed to October 2021 for the first one, and February 2021 for the other two. Preliminary work on planning logistics and fine-tuning methodologies initially planned for the second part of the project were moved forward and developed in late 2020 and early 2021, when two explorative dives allowed the identification of the sampling sites (for the instalment of sediment traps and temperature dataloggers).

This preliminary action allowed the characterization of the deeper bathymetrical range of BCF dominated by the species Antipathella wollastoni, initially reported as present down to a depth of 100 m. Underwater explorations and surveys were performed with the help of local stakeholders. According to preliminary observations, A. wollastoni distribution is limited to 75-80 m, at least in the working sites. Past the 80 m mark, other species of black corals, such as A. furcata or Stichopathes spp dominate the community.

Moreover, the first results on fish communities associated with these ecosystems showed clear differences with shallower areas, promising interesting and applicable results at the end of the project.

The project communication plan has already been strongly implemented, and demonstrated results beyond expectations. The project identity toolkit and social networks were developed, thus ensuring a large media coverage at local, national, and international level. The main dissemination environment was digital media (online journals and magazines) with 70 controlled impacts, 5 radio interviews disseminated at regional and national level, and 7 articles in regional journals. One scientific publication (Czechowska et al. 2020) was produced and published in an open access journal (Remote sensing). Finally, the project website and social networks (Facebook, Twitter and Instagram) have been also used to promote project-related information. During the first implementation period, Facebook logged 1378 interactions and 32 page visits, Twitter – 470 interactions, and Instagram – 61.

The project has already drawn the attention of a large international audience. Thus, several collaborations and synergies have been planned for fieldwork, such as with the University of Genova (Italy), University of Cagliari (Italy), CHORUS enterprise (France) and the Université Libre de Bruxelles (Belgium). Although not initially planned, an additional brief video episode (1-2’) was produced to present the daily activity of the project during fieldwork campaigns.

Black Coral Forest close-up (credit: Asociación Biodiversidad Atlántica y Sostenibilidad)

As an illustration of the international impact, the April issue of Diario de Lanzarote (N.133) newspaper highlighted the visit of the underwater photojournalist Roberto Rinaldi, former part of Jacque Cousteau’s team, who recorded images of the black corals at Playa Chica and was “amazed” by the forests’ beauty and size. The article points out that it should not be easy to awake this feeling in a veteran professional who has participated in more than fifteen international expeditions aboard Jacques Cousteau’s vessel “Calypso”. The result of his dives in Puerto del Carmen in Lanzarote will become a documentary to be broadcast on RAI-1, the main channel of the Italian public television.

Other dissemination activities were also held, such as an open day to celebrate the UN’s “International day of Forests” on March 21st. A short video using images filmed by Roberto Rinaldi was disseminated through project channels to show the beauty of this different type of forest.

Besides the communication channels, B-CHARMED also published a preliminary scientific study(*)presenting some promising initial attempts at detecting black coralsby utilizing multibeam echosounder water column scatter, 0.75 m to 1 m above the seafloor. This study helped determine the acoustic characteristics of BCF, contributing at the same time to increasing the limited knowledge on their biological features. In this study, two acoustic tools (side-scan sonar and multibeam echosounder) were coupled with ground-truthing video surveys to determine habitat characteristics of a black coral species, A. wollastoni. This preliminary work will serve as a basis to define mapping tools able to determine the extent of these marine habitats.

In collaboration with technicians from the island government (the Biosphere Reserve and Cabildo de Lanzarote), educational workshops were proposed to several local schools. These workshops bring students closer to research applied to the marine environment, promote the island’s natural resources, and foster coral biodiversity and conservation.

You can learn more about B-CHARMED by visiting this website:

(*) Czechowska, K; Feldens, P; Tuya, F; Cosme de Esteban, M; Espino, F; Haroun, R; Schönke, M; Otero-Ferrer, F. (2020). Testing Side-Scan Sonar and Multibeam Echosounder to Study Black Coral Gardens: A Case Study from Macaronesia. Remote sensing. MDPI. 12-3244