This study, conducted on the Cap-Vert peninsula (Dakar, Senegal), examines the epifaunal communities associated with macroalgae, revealing significant variations depending on the species of algae. In 2023 (in situ samples), amphipods dominated most macroalgae, particularly Coralina officinalis (29.40%) (Rhodophyceae), Chlorophyceae (30.38%), and Codium sp. (29.38%) (Chlorophyceae). In 2022, copepods (76–92%) were most abundant on Sargassum spp. and Ulva spp., which had washed up on the beach. A significant link between epifaunal abundance and macroalgae species highlighted their ecological interdependence. These findings are of relevant interest for West Africa’s blue economy, where the growing exploitation of wild macroalgae could disrupt these ecosystems. Sustainable management must take into account epifaunal species, particularly those found on structurally important macroalgae (e.g., Corallina sp., Codium sp.). The study recommends including macroalgae-epifauna associations in biodiversity inventories, particularly in marine protected areas, and continuing research on influencing factors (e.g., algal morphology, environmental conditions). Mass strandings of Sargassum spp. and Ulva spp. can cause mortality in marine larvae and eggs, leading to a local reduction in recruitment. Future research integrating these conclusions could allow a more detailed analysis of the epifauna on macroalgae. Ecosystem approach is essential to strike a balance between economic development and biodiversity conservation.

This study from Cap-Vert (Dakar, Senegal) examines epifaunal communities associated with macroalgae, revealing key variations based on algal species and sampling period. In 2023 (in situ samples), amphipods (24–30%) dominated, particularly on Corallina officinalis (Rhodophyceae), while 2022 (beached samples) showed copepods (76–92%) as the most abundant on Sargassum and Ulva spp. The highest epifaunal density was recorded on 2023 Ulva spp. (Chlorophyceae). Univariate analysis confirmed a significant link between epifaunal abundance and macroalgae species, highlighting their ecological interdependence. These findings are critical for West Africa’s blue economy, where expanding macroalgae exploitation could disrupt these ecosystems. Sustainable management should account for species-specific epifaunal dependencies, particularly for structurally important algae (Corallina, Codium). The study recommends integrating macroalgae-epifauna associations into biodiversity inventories, especially in marine protected areas, and further research on influencing factors (algal morphology, environmental conditions). An ecosystem-based approach is essential to balance economic development and biodiversity conservation.

Mesopelagic fish communities remain under studied in the highly dynamic Canary Current Ecosystem. We analyzed mesopelagic fish assemblage structure based on 2,153 specimens representing 98 species across two distinct marine zones: Mauritania, characterized by high oxygen and chlorophyll-a concentrations, and Senegal, distinguished by high temperatures and low salinities. Our findings reveal clear biogeographic patterns, with Diaphus vanhoeffeni, Diaphus dumerilii, Argyropelecus gigas, and Sternoptyx diaphana showing high abundance in Senegalese waters but limited presence in Mauritania waters. Conversely, Diaphius rafinesquii, Benthosema glaciale, Argyropelecus hemigymnus, Lobiancha dofleini, and Hygophum taaningi exhibited higher abundances in Mauritania waters. Statistical analyses revealed significant correlations between species abundance patterns and physicochemical parameters specific to each marine zone. This pioneering study of mesopelagic fish community composition and structure in relation to environmental factors in the Canary Current Ecosystem provides valuable insights into a marine fauna, which holds potential for sustainable exploitation in aquaculture feed production and nutritional supplements, beyond its crucial role in the carbon cycle and marine food web.Keywords: Mesopelagic fish, Canary Current Ecosystem, Upwelling, Environmental factors, West Africa.

The association of epifaunal communities with marine macroalgae has not yet been studied on the Cape Verde Peninsula (Dakar, Senegal). Macroalgae were collected at sea during the warm season (July) from stations around the Cape Verde Peninsula to investigate their association with epifaunal organisms. A predominance of amphipods was noted across the entire epifaunal community. The abundance of this order was higher on the macroalgae Corallina officinalis. The highest epifaunal density was observed on the genus Ulva sp. A significant relationship was observed between the diversity and abundance of epifaunal communities and macroalgal species. However, there was no significant relationship between the biomass of the macroalgae and the biomass of the epifauna. The methodology used in this study could be replicated on a larger spatial and temporal scale. This would provide deeper insights into the communities hosted by macroalgae within the context of the growing blue economy, encouraging future exploitation of macroalgae and addressing biodiversity loss.Keywords: Epifauna, Macroalgae, Dakar, Senegal.