The development of this Remote Professional Practices has been conducted within the academic framework of the International Master of Science in Marine Biological Resources (IMBRSea). The project has been done along seven weeks and four people have been involved: the supervisor Dr. Nadine Le Bris, and three IMBRSea students, Marion Vial, Pierre Liboureau, and myself (Olivia Saiz Muñoz). The project was offered by the Observatoire Océanologique de Banyuls Sur Mer (OOB), specifically within the Ecogeochemistry Laboratory (LECOB) group, at which Dr. Le Bris belongs. This marine station is affiliated to the Sorbonne University (SU), which is a partner university of the IMBRSea.
The original aim of the project was the development of the scientist advise considered for monitoring a vulnerable deep sea ecosystem to support MPA (Marine Protected Area) managers. However, the project has been further developed as several aspects regarding the scientific expertise needed to establish the designation proposal for an MPA have been also considered. All the addressed contents have been gathered in a scientist report “Vulnerability assessment report: scientific bases and guidelines for monitoring of La Fonera Submarine Canyon”.
Why do canyons need protection?
Target area: La Fonera canyon
La Fonera (also known as Palamos) is a submarine canyon located in the Northwestern Mediterranean Sea, in the North Catalan Margin, within the Spanish Exclusive Economic Zone. The canyon has 110 Km of length, 2550m and 300-400 of depth and width, respectively. It is mainly fed by three medium-small rivers (Muga, Fluviá and Ter), and its general circulation pattern is dominated by the Northern Current. This is a cyclonic mesoscale current flowing south-westwards over the outer shelf and the canyon. However, the circulation within the canyon is constrained by the local bathymetry and the canyon shape.
The head of the canyon is relatively close to the shore (800m in its closest point), and it is divided into three branches, Cap de Begur, Illa Negra and San Sebastiá. Cap de Begur and Illa Negra have a similar geographical orientation N-S and NW-SE respectively, which differ from the W-E orientation of the Sant Sebastiá branch.
Cold-Water Corals (CWC’s)
The ecological role of Cold-Water Corals (CWCs) is widely known, they provide ecological niches and substrates, working as refugees for prey and nursery areas, which determines their high biodiversity. Colonies of three CWC species have been found in the head of La Fonera canyon: Madrepora oculata, which is the dominant species; Corallium rubrum; and Dendrophyllia cornigera.
The CWC colonies of La Fonera canyon are characterized by not being homogeneously distributed; the dominance of middle-sized, fragile M. oculata colonies; the poor development of the small-sized D. cornigera colonies; the lack or low occurrence of gorgonians and other usual species of these communities; and the absence Lophelia pertusa (Linnaeus, 1758), a species that, however, has been found in proximal canyons, such us Cap de Creus or Lacaze- Duthiers canyons. These characteristics may suggest non-optimal habitat conditions in La Fonera canyon and potentially “non-good” status of the community, suggesting that these colonies may develop close to their environmental limits, due to natural and anthropogenic stressors.
Main Threats
Monitoring Programe
Due to the key ecological roles of CWC’s and their vulnerability to disturbances (i.e very restricted movement and slow growth rates), the goal of the creation of an MPA in La Fonera canyon is to protect cold water corals from threats. Therefore, the decision to protect the area at its best would be to limit every human activity that is directly impacting the cold-water corals and associated ecosystems.
Therefore, Cap de Begur branch is suggested to be the area within the MPA will be created. Furthermore, in order to discriminate regional changes from those from a specific pressure, comparison with a reference site with similar characteristics but different level of protection is needed. Hence, Illa Negra branch is proposed to be the control area.
LIMITATIONS
It should be considered that although the protected area would not prevent negative effects from climate change, it could lessen the damage caused by such interactions between threats. Furthermore, disturbances associated with the bottom trawling activity that occur outside of the proposed MPA and control area, could reach both regions (e.g. sediment gravity flows triggered by bottom trawling resuspension). Therefore, more research needs to be done to assess the scope of this impact in the MPA/ control area.
The long- term monitoring strategy is based on 5 out of the 11 descriptors of the Marine Strategy Framework Directive. However, indicators have been specifically selected regarding the ecological characteristics of La Fonera and its main threats (marine litter, fishing, and climate change). Therefore, the proposed monitoring strategy will follow the guidelines of a European Directive, which will make it easier to compare results between other regions, but its approach is adapted to the specific context of La Fonera.