Below the yachts, beach clubs and crowded coastal roads of Monaco, another population is being quietly observed.
Divers working with the Association Monégasque pour la Protection de la Nature are continuing the scientific monitoring of brown groupers and corbs inside the Principality’s marine protected areas.
Both species were once common across the Mediterranean but suffered severe declines during the last century, largely because their calm, inquisitive behaviour made them particularly vulnerable to fishing and underwater hunting.
Their capture has been prohibited in Monaco and France since 1993. The monitoring taking place today is intended to establish whether those protections are working, and whether the fish are gradually reclaiming the waters from which they had almost disappeared.
The surveys are conducted around two distinct locations: the educational marine area extending between Pointe Saint-Martin and the fishermen’s beach beneath the Oceanographic Museum, and the rocks surrounding the Sporting seawall within the Larvotto marine protected area.
Rather than simply recording whether the fish are present, researchers assess their numbers, size and distribution. Repeated surveys allow scientists to identify long-term changes that a single dive could never reveal.
The work has been carried out regularly since 2018 in collaboration with marine research specialists, with surveys traditionally undertaken twice each year.
For the casual swimmer, a grouper may simply be an impressive fish glimpsed between the rocks. For marine scientists, its presence can reveal far more.
Large, mature groupers indicate that fish have been able to survive undisturbed for many years. An increase in younger individuals may suggest that the population is reproducing successfully. Corbs, recognisable by their dark bodies and distinctive fins, provide another valuable indication of the health of rocky Mediterranean habitats.
Their return is important not only for biodiversity but for the balance of the wider ecosystem. Large fish occupy key positions within marine food chains, and their disappearance can alter the relationships between predators, prey and habitat.
Monaco’s coastline is an unusual setting for such conservation work. It is intensely urban, densely populated and surrounded by construction, maritime activity and tourism. Yet beneath that pressure, protected pockets of sea continue to function as refuges.
The Larvotto reserve, established during the 1970s, is often described as one of the earliest examples of a protected marine area situated within a heavily urbanised environment. Its longevity makes it particularly valuable to researchers studying how nature responds when human activity is restricted over several decades.
Earlier observations have already suggested that grouper populations increased around Larvotto and beneath the Oceanographic Museum over the years. Scientists remain cautious, however. Marine recovery is rarely a straight line, and populations can be influenced by water temperature, habitat disruption, pollution, fishing beyond protected boundaries and changes elsewhere in the Mediterranean.
That is why continued monitoring matters.
Conservation is often announced through grand pledges and international conferences. Its real success, however, is measured slowly: one dive, one count and one returning fish at a time.
In a country recognised around the world for what rises above the water, some of Monaco’s most encouraging progress may currently be taking place below it.