By Ezgi Saydam, 22nd March 2023
The Mediterranean monk seal Monachus monachus is one of the most threatened marine mammals. Prior to being recognized as the only member of the genus Monachus, this seal was thought to have more in common with its two closest relatives: the Hawaiian and Caribbean monk seals (Neomonachus schauinslandi and Neomonachus tropicalis; the latter is believed to be extinct). Once scientists determined that the Mediterranean monk seal is evolutionarily distinct, its uniqueness became even more significant.
The Mediterranean monk seal is an apex predator, and its occurrence is therefore indicative of a healthy marine ecosystem. Characteristically, the seals are playful and curious creatures with big black eyes and long whiskers. Unlike most marine mammals, they depend on dry land for pupping. In ancient times, Mediterranean monk seals hauled themselves out of the sea to give birth, raise their pups, and rest on open beaches. Now, following centuries of human disturbances and pressure, they use marine caves with entrances above or below water level. Mediterranean monk seals have become elusive animals seeking refuge in marine caves on isolated rocky shores and islands.
The Mediterranean monk seal has disappeared from most of its historical range, and its current range consists of only three subpopulations. The largest subpopulation is in the eastern Mediterranean, followed by Cabo Blanco and the archipelago of Madeira of the North Atlantic. Today, the Mediterranean monk seal is categorized as Endangered on the IUCN Red List, with fewer than 700 individuals remaining globally. Of even greater concern is its Critically Endangered status in the Mediterranean.
Among the main threats to the species, the most significant are habitat deterioration, destruction and fragmentation. Caves that are available for pupping have become increasingly uninhabitable, mainly as a result of pressure from tourism, residential and commercial coastal development and collapses caused by earthquakes.
In the Eastern Mediterranean, the monk seal population is currently increasing, consequently boosting competition for suitable caves amongst pregnant females. These caves appear to have a maximum carrying capacity dependent on the size of the internal dry area. Thus, most monk seals are left with less suitable caves to give birth in, resulting in pups being swept away by waves and separated from their mothers.
In an effort to combat these threats, we aimed to create an artificial dry platform for monk seals to see if they would favour such an alternative over unsuitable caves.
The Mediterranean Conservation Society is a Turkish NGO working with local and governmental stakeholders to contribute to the management of marine protected areas by enhancing regulations, conducting scientific research, and communicating conservation priorities. The Mediterranean Conservation Society has carried out the Mediterranean Monk Seal Monitoring Program in Gökova Bay on the south-west coast of Turkey since 2016.
We began by surveying coastlines to identify caves potentially suitable for monk seals. Along a 322 km coastline, we located three caves suitable for reproduction and one cavern suitable for resting only. We set up camera traps in the designated caves to investigate the number of monk seals using the caves, by identifying them individually and monitoring their cave use patterns.
In 2017, our team found an additional cave suitable for monk seal use but with no dry area inside, and so we decided to build a dry ledge. In July 2019, after a long effort, the ledge was complete. Eight months later, in 2020, we couldn’t believe our eyes—on the camera footage was a juvenile resting on the artificial ledge for the first time. To date, we have identified four monk seals using the artificial dry ledge. What hopeful news!
Alongside the implementation of physical resources like this artificial ledge, it is important to consider the impacts of man-made structures on existing habitats, and to hold discussions with monk seal experts, responsible government agencies and local stakeholders. Moving forward, we recommend this study is replicated in other marine protected areas.
Upon completion of the ledge, I found myself reflecting on a particular day during the project. The weather hit us with a storm that day, leaving us at the mercy of the relentless thrashing of the sea as we were reaching the cave. Our eldest member looked at us, squinting as drops of water sprayed over the jaunty expression on his face, and said, ‘what business does a wise person have out on the sea on a day like this?’. We sheepishly looked at each other, each of us dishevelled and soaked with salty water, then burst out laughing as our discomfort dissolved into playfulness. It was a moment evocative of the nature of a monk seal, reminding us of how important these peaceful, intelligent, and inspiring creatures are.
If we want to keep sharing waters with Mediterranean monk seals, we must give them space and conserve their habitats. Thus, the Mediterranean Conservation Society aims to gather data on monk seal activity in Gökova Bay and to use these data for designating conservation zones specific to Mediterranean monk seal habitats.
The article ‘A novel approach for Mediterranean monk seal conservation: an artificial ledge in a marine cave’ is available in Oryx—The International Journal of Conservation.