Eco-hydrodynamics of cold water coral habitats across integrated spatial scales

Informations projet

HABISS

N° de convention de subvention: 890815

DOI

10.3030/890815

Projet clôturé

Date de signature de la CE 16 Mars 2020

Date de début 1 Juin 2020

Date de fin 31 Mai 2023

Financé au titre de

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coût total

€ 241 398,72

Contribution de l’UE

€ 241 398,72

Coordonné par

AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS
Spain

Periodic Reporting for period 1 - HABISS (Eco-hydrodynamics of cold water coral habitats across integrated spatial scales)

Période du rapport: 2020-06-01 au 2023-05-31

Résumé du contexte et des objectifs généraux du projet

The growth of deep-sea exploration in the last decades has unveiled the existence of cold water coral (CWC) reefs in deep, nutrient-rich waters off the coasts of almost 50 countries to date. CWC reefs have a strong societal relevance, as they maintain high biodiversity in the ocean, with a biological richness comparable to that of shallow-water tropical reefs. Sadly, these environments are recognized by governments and policy makers as vulnerable marine ecosystems severely endangered by human activity. The EU-funded HABISS project wanted to decipher the still not clear interactions between calcifying corals and the surrounding environment on CWC reefs, to better understand how to monitor and protect these unique ecosystems. Inputs from marine geology, oceanography and benthic ecology have been integrated across different spatial scales through the usage of standard and state-of-the-art equipment, like marine robotics and cabled/moored seafloor observatories. HABISS focused on three different key study area: 1) the unique pristine Cabliers CWC reefs, in the Alboran Sea, SW Mediterranean; 2) the CWC fields of the walls of Blanes submarine canyon, in the NW Mediterranean, subject to the impact of bottom trawling; 3) the CWC fields of the walls of Barkley submarine canyon, in the NE Pacific Oxygen Minimum Zone. Whereas the study of a thriving near-pristine reef such Cabliers has a strong societal implication for marine conservation activities, HABISS also focused on evaluate if and how CWC ecosystems can cope and maintain their state of health under human-induced disturbance (trawling activities in Blanes Canyon) and natural disturbance (hypoxic waters in Barkley Canyon).
The main findings of HABISS can be resumed in the following points:
1) Increase the knowledge of ecologic characters and physical environment of probably the most extended and well preserved CWC reefs in the Mediterranean, the Cabliers reefs.

2) Advances in environmental advocacy towards the protection of Cabliers reefs through the institution of a Fisheries Restricted Area, managed by the UN General Fisheries Commission for the Mediterranean.

3) Define the crucial role of seafloor complexity vs hydrodynamics in forcing food paths to CWC reefs across interactive spatial scales.

4) Advances in understanding the role of physical processes in increasing CWC resilience to human-induced and natural extreme environments, beyond the known thresholds of their living conditions.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

HABISS proposed to tackle three main specific objectives:
1) Large-to-mesoscale interactive processes: Measure on CWC fields the interaction of large and mesoscale water mass properties with the seafloor complexity of prominent geomorphic features such as canyons and mounds.
2) Fine-scale interactive processes: Quantify feedback mechanisms between near-bed hydrodynamics, local seafloor complexity and the associated particulate organic matter dynamics on CWC.
3) Across-scale interactions: Highlight the physical drivers of CWC growth and maintenance, through a chain of interconnected scales and time intervals, applying a multiscale observational approach to the study of the proposed sites.

To address these objectives, an extensive set of data of different typology has been gathered, including seafloor bathymetric maps acquired from standard to very high resolutions, video footage acquired through the use of Remotely Operated Vehicles, CTD casts, water samples, current velocity data acquired with ADCP (Acoustic Current Doppler Profiler), long-time series of sediment traps, ADCP, CTD, turbidity, oxygen from moored instrumentation and cabled seafloor observatories.

Geomorphologic and Habitat Maps have been produced for the study sites, and predominant oceanographic and hydrodynamic processes have been coupled, to identify the main driving mechanisms supplying vital organic-rich particles to coral communities. Main results suggest the great importance of the interactive feedback mechanisms between seafloor complexity and hydrodynamics in forcing food paths to CWC reefs through a cascade effect, from the broad scale down deep to the fine scale of CWC reefs. Results also suggest the crucial role of hydrodynamics in sustaining CWC communities under anthropogenic (trawling) and natural (hypoxia) stress.

The most outstanding scientific insights on HABISS topics have been presented in a total of 10 leaded or co-authored scientific papers and several talks at International conferences and environmental advocacy meetings. HABISS allowed to engage EU-level policy makers and groups of technical experts actively working on implementing measures for the conservation and sustainable use of living marine resources of Mediterranean deep-sea ecosystems.

Finally, results have been disseminated through the creation of outreach material presenting to general public the geomorphology of Blanes submarine canyon and the distribution of the most relevant benthic species, including CWC fields. Finally, the project website (https://www.habiss.eu/) and Social media profiles such Instagram and Twitter (cabliers_reefs) have been regularly updated in order to provide information on the project.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Key HABISS outcomes have been presented at the Scientific Advisory Committee (SAC) in specific GFCM Conferences, within the "Specially Protected Areas/Biodiversity Protocol and its Dark Habitats Action Plan", and the UN treaty negotiations aimed at protecting marine biodiversity in high seas beyond national jurisdiction, as in the case of Cabliers CWC reefs, one of the HABISS study areas. Based on the scientific evidences acquired during HABISS, the proposition of institute a UN Fishery Restricted Area to permanently protect the Cabliers CWC reefs from fishing activities has been submitted. From recent negotiations between UN-GFCM, DG-MARE and institutions of interested countries (Spain, Morocco and Algeria), there high chances that Cabliers will be declared an FRA in 2024.

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