A recent underwater survey of the Larvotto marine protected area (MPA) in Monaco has revealed a thriving, seasonally dynamic ecosystem, underscoring the reserve's crucial role in safeguarding marine biodiversity.
Conducted using baited remote underwater video systems (BRUVS), the survey is part of a pioneering research project launched in 2023 through a collaboration between the Prince Albert II of Monaco Foundation, Community Jameel, the Monégasque Association for the Protection of Nature (AMPN), THALASSA Marine Research and Environmental Awareness and Blue Abacus.
The findings, published in a new report, are already helping to shape AMPN’s strategy for managing the Larvotto MPA, reinforcing the importance of adaptive and evidence-based conservation approaches.
The project, which included two survey campaigns conducted in summer 2023 and winter 2024, yielded striking results.
In January 2024, researchers recorded 332 fish individuals in the Larvotto MPA – almost three times the 123 individuals observed during the July 2023 survey.
Remarkably, among the 32 species identified by the project, only 12 appeared in both surveys, highlighting significant seasonal shifts in species composition.
Underwater footage captured during the January survey revealed large schools of blotched picarel (Spicara maena), which alone accounted for 30% of individuals observed.
The common pandora (Pagellus erythrinus) was present in nearly every location during both surveys, providing a rare point of continuity.
Mediterranean eels (Muraena helena) and European congers (Conger conger) also appeared consistently across seasons.
The size and biomass of fish also varied seasonally, with total biomass and species abundance significantly higher in winter than in summer.
The project’s smallest find was a 3.5 cm brown comber (Serranus hepatus), while its largest – a 73 cm common dentex (Dentex dentex) – demonstrated the reserve’s ability to support both juvenile and mature marine life.
Moreover, some ecologically important or rare species – like amberjacks (Seriola dumerili), common dentex (Dentex dentex), seabreams (Diplodus sp.) and John Dory (Zeus faber) – were also observed, highlighting the ecological value of the MPA.
George Richards, director of Community Jameel, said: “We are excited to see how the successful deployment of underwater video systems has revealed the richness of the Larvotto marine reserve.
“The project has delivered important data that is now informing the protection and conservation of marine life in Monaco.”
Jacqueline Gautier-Debernardi, director of AMPN, said: “These seasonal differences highlight the complex ecological dynamics at play and reinforce the need for ongoing, year-round monitoring.”
The BRUVS project has identified several priorities for future research and conservation planning.
Expanding surveys to encompass Posidonia seagrass, rocky substrates and artificial structures could yield a more complete picture of the MPA’s biodiversity.
The continuation of this monitoring could help track changes in fish populations related to species migration and climate change.
As Monaco continues to lead global efforts in ocean protection, this project stands as a powerful example of how innovative tools and international partnerships can support smart and sustainable marine management strategies.