A novel approach for Mediterranean monk seal conservation: an artificial ledge in a marine cave

Abstract

AbstractThe Mediterranean monk seal Monachus monachus, categorized as Endangered on the IUCN Red List, comprises 600–700 individuals in the eastern Mediterranean Sea and eastern Atlantic Ocean. Habitat degradation is a severe threat to the species. In 2016 and 2017, coastline surveys were conducted in Gökova Bay, south-west Turkey, to identify suitable monk seal habitat. A significant factor hindering recovery of the monk seal population of this Turkish coast and the nearby Greek islands is the limited number of marine caves suitable for resting and/or pupping. We identified four caves as possible monk seal resting and pupping caves. An additional cave with all essential features for seal usage except a ledge was also identified. An artificial ledge was built in this cave in July 2019 and seal usage was monitored by camera trap until September 2020. A total of 405 camera-trap events were analysed to examine presence of any monk seals on the ledge, and to understand the purpose (resting and/or pupping), frequency of use, sex and age group of any individuals using the cave. One juvenile used the cave four times for resting (420 minutes in total), predominantly nocturnally. This is the first construction of a dry ledge in a cave of this kind for monk seals. The camera recordings suggest this approach could provide habitat for this species in areas where there is insufficient dry protected area on land.