Investigating Rare and Endangered Species: When a Single Methodology Is Not Enough-The Mediterranean Monk Seal Monachus monachus along the Coast of Salento (South Apulia, Italy)

Several factors contributed, over time, to the Mediterranean monk seal's sharp population decline. Despite the relative disappearance of documented breeding sub-populations, sightings have been collected, in recent decades, from most of the species' former habitat. The conservation of this endangered marine mammal should also encompass those areas. We conducted our research along the coast of Salento (South Apulia, Italy) as a case study. To collect data on monk seal presence in the area, expected to be characterized by low numbers, we combined three different methodologies: a questionnaire to fishermen, interviews with witnesses of sightings, and a historical review of the species' presence. The different methodologies allowed us to collect 11 records of recent sightings (after 2000) and 30 records of historical encounters (before 2000), highlighting that the species was already rare in Salento over the last century. Most of the historical information was concentrated between 1956 and 1988 (28 records), suggesting discontinuous occurrence in the area, possibly depending on the lack of monitoring efforts. Furthermore, a broad regional approach should be considered as a more effective path to aid the monk seal recovery, better comprehend the species' abundance and movements, and eventually contribute to the overall health of ecosystems.

Automated summary

Several factors have led to the decline in population of the Mediterranean monk seal over time. Despite the disappearance of documented breeding sub-populations, recent sightings have been reported from most of the species' former habitat. Our research in the Salento coast, Italy, used three different methodologies to collect data on monk seal presence. The study revealed historical and recent records of sightings, suggesting the species' rarity and the need for a regional approach to aid its recovery.