The ResilienSEA project concludes its series of national trainings on Seagrass Species Identification, Mapping and Monitoring in West Africa

The three final national trainings were successfully held in Senegal, Cape Verde, and Mauritania in February 2020.

The ResilienSEA project started its series of national trainings on Seagrass Species Identification, Mapping and Monitoring in West Africa in Guinea in late October 2019. Since then, national trainings have successfully been held in Guinea-Bissau, Sierra Leone, and in The Gambia, to allow scientists, technicians and managers to learn more about the different seagrass species present in West Africa and to identify the best mapping and monitoring techniques to apply to their pilot sites.

February 2020 has been an intense month for the project team. It saw the holding of the three final trainings at selected sites: in the Saloum Delta National Park (PNDS) in Senegal from the 3^rd to the 7^th; in the Gamboa area of Praia in Cape Verde from the 10^th to the 14^th; and in the Banc d’Arguin National Park (PNBA) in Mauritania from the 17^th to the 21^st. The three trainings were facilitated by Dr. Maria Potouroglou, lead of ResilienSEA’s Scientific Research strategy, supported in Senegal and Mauritania by Mr. Mohammed Ahmed Sidi Cheikh, GIS and seagrass specialist, and in Cape Verde by Prof. Salomao Bandeira, a seagrass expert from Mozambique and member of the Western Indian Ocean Seagrass Network. In the three countries, the workshops were organized around the following modules: Overview of seagrasses – biology and ecology; Importance of seagrasses and threats; and Mapping and monitoring of seagrasses. The modules involved both theoretical lessons and field trips to the selected pilot sites, which provided the participants the opportunity to apply what they had learnt in the classroom.

Saloum Delta National Park (PNDS), Senegal, 3-7 February

The workshop in Senegal proved particularly successful, not only thanks to the high engagement of the participants, but importantly also given the discovery of a vast seagrass site. Located at the mouth of the Diombos river within the PNDS – second largest national park in Senegal and classified Ramsar site since 1984 – where the field work was carried out, the discovered site abounds in seagrass meadows of Halodule wrightii, Cymodocea nodosa, and Zostera noltii species in healthy condition. Dr. Potouroglou stresses: “The confirmation of the presence of Zostera noltii in Senegal is significant for the global seagrass scientific community. This is a temperate species, whose distribution was previously reported to extend from Sweden in the north to Mauritania in the south”. Several similar sites – both intertidal and subtidal – are believed to exist in Senegal, hence offering an interesting unexplored field of investigation to deepen the knowledge of seagrass ecosystems and its species’ distribution.

The next major step for the Senegalese national team is now to decide on its final pilot site, in order to start monitoring seagrasses there as soon as possible. The site at the mouth of the Diombos river in the PNDS is considered to be a better option than the proposed alternative site, the Joal-Fadiouth marine protected area (MPA), within which the subtidal seagrass beds are known to be more degraded – due to local pollution but also to the intense traffic of fishing pirogues and to the impact of their engine propellers. The seagrass beds at the mouth of the Diombos river indeed benefit from a strong legal protection status of the PNDS, from which the subtidal seagrass beds in the Joal-Fadiouth MPA don’t. Mr. Sidi Cheikh hence recommended to rather select the site visited during the training workshop, and to monitor both the intertidal and the subtidal part of the Cymodocea meadows, whose condition was deemed appropriate to become a permanent monitoring site for continued research.The next major step for the Senegalese national team is now to decide on its final pilot site, in order to start monitoring seagrasses there as soon as possible. The site at the mouth of the Diombos river in the PNDS is considered to be a better option than the proposed alternative site, the Joal-Fadiouth marine protected area (MPA), within which the subtidal seagrass beds are known to be more degraded – due to local pollution but also to the intense traffic of fishing pirogues and to the impact of their engine propellers. The seagrass beds at the mouth of the Diombos river indeed benefit from a strong legal protection status of the PNDS, from which the subtidal seagrass beds in the Joal-Fadiouth MPA don’t. Mr. Sidi Cheikh hence recommended to rather select the site visited during the training workshop, and to monitor both the intertidal and the subtidal part of the Cymodocea meadows, whose condition was deemed appropriate to become a permanent monitoring site for continued research.

Praia, Cape Verde, 10-14 February

The second workshop held this month – which saw the encouraging participation of 60% of women – took place in Cape Verde, in the city of Praia, which lies in Gamboa Bay, a site of high historic importance. Indeed, in the bay lies the Ilhéu de Santa Maria, an islet were naturalist, biologist and geologist Charles Darwin stopped in 1832 during his journey to Latin America. Gamboa Bay also happens to be the only documented site with seagrass meadows in Cape Verde today, which generates a sense of pride among Praia’s coastal community. The very same seagrass meadows are however threatened by the ongoing construction of a touristic complex, as well as by pollution from Praia city’s drainage system and wastewaters. The latter may in fact already have altered the health of these meadows, which can’t therefore be considered an intact reference site anymore. The site is however worth being monitored in the long-term, in order to specifically assess the impact of pollution on seagrass.

On a more positive note, the site in Gamboa is also deemed appropriate to conduct applied research related to both climate change adaptation and mitigation, and could hence benefit from pilot restoration initiatives. These would however require the involvement of the relevant authorities, of decision makers, as well as of Praia’s local population, without whom conservation and management measures would not yield successful outcomes. In this light, the theoretical part of the training provided opportunities for the project team to discuss with the trainees the importance of seagrasses in climate change policy, and how their successful management can help countries achieve multiple international commitments and agreements, notably the Paris Agreement’s Nationally Determined Contributions, the Convention on Biological Diversity’s Aichi Targets, as well as the Sustainable Development Goals more broadly. An entire session was therefore dedicated to finding different entries to policy and to formulating strong convincing arguments aimed at policy-makers, from highlighting the multiple benefits and goods provided by seagrasses, to how increasingly vulnerable these ecosystems are to anthropogenic stressors.

Banc d’Arguin National Park (PNBA), Mauritania, 17-21 February

Finally, the workshop in the Islamic Republic of Mauritania was the one concluding the four months-long series of Seagrass Species Identification, Mapping and Monitoring trainings in West Africa. In Mauritania, the workshop participants were hosted in Iwik, a coastal village located on a peninsula within the PNBA. There, seagrass abounded around the participants’ residence, which proved extremely practical with regards to daily field work activities. During the workshop, participants received useful practical advice to guide them in their future monitoring work at their selected national pilot site. The training specifically enabled the Mauritanian team to better identify the different species existing within the PNBA, particularly Halodule wrightii, which proved to not always be easily distinguishable from Zostera noltii. The mission further allowed the PNBA staff to explore monitoring techniques of seagrass meadows, which generally constitute a good indicator of the marine environment’s health. In addition, similarly to the workshop in Cape Verde, participants also discussed issues related to the conservation of seagrass in the light of their paramount role in both climate change adaptation and mitigation.

In line with last year’s activities, including the compilation of existing datasets, the ResilienSEA project team collected in collaboration with all national teams during the workshops, all necessary field data on the presence or absence of seagrasses. If the mapping of intertidal meadows in Mauritania is quite advanced, the mapping of subtidal meadows remains at this stage still embryonic. Much hope therefore rests on the results of a mapping model currently being developed by our remote sensing experts team from Duke University (Northern Carolina, USA), the German Aerospace Center, and the Foundation for Research and Technology in Greece. The state-of-the-art mapping model using Google Earth, employs a range of algorithms globally used in aquatic habitat remote sensing along with image composition and machine learning. These innovative techniques, in combination with seagrass field data, will allow the development of the first ever predictive and actual seagrass distribution maps for West Africa, which will become publicly available in the coming months.

“During this workshop, I had the opportunity to visit one the most pristine and extensive seagrass meadows I have seen in my life. The aquatic life on intertidal as well as subtidal meadows was thriving. Furthermore, it was the first time in this series of workshops that all trainees agreed upon the mapping and monitoring plan that they would follow for the years to come. This included defining roles in the team, identifying the dates, times and places, and practicing on the methods to be used in the field”, positively concluded Dr. Potouroglou at the closing of the workshop. As a final note on the overall workshop series, Mr. Sidi Cheikh for his part concluded, “During this series of workshops, we learned a lot from the different national teams we had the chance to work with. The interactions we had with participants gave us complete satisfaction on the motivation and competences that the national teams and partner institutions possess in order to succeed in setting up a solid system for monitoring seagrass beds in West Africa. The project team will continue to listen and to solicit feedback from the national teams, as well as take stock on a regular basis of the programmed activities’ progress within the framework of each team’s adopted national plan”.

Louis PILLE-SCHNEIDER