The monk seal (Monachus monachus (Hermann, 1779)) is one of the most threatened and endangered mammal species in the world (Cabral, 2005). According to IUCN, its conservation status is “critically endangered” and, therefore, it’s protected by Annexes II and IV of Council Directive 92/43 / EEC on the conservation of natural habitats and fauna and flora (Karamanlidis, 2016).
Distribution:
Monk Seals (genus Monachus) have a wide distribution (Figure 1), with the Mediterranean Monk Seal species (Monachus monachus) found only in the Mediterranean Sea (Turkey, Greece, Tunisia and Algeria) and in the Atlantic Ocean (Madeira Archipelago, Portugal and Cabo Branco) (Neves & Pires, 1999).
Figure 1 - Areas of distribution of Monk seals in the world, in purple the Mediterranean Monk Seal (taken from Neves & Pires, 1999).
It’s thought that there are no more than 450 Mediterranean Monk seals (Karamanlidis & Dendrinos, 2015), with 130 belonging to the population of Cabo Branco and 300 individuals to the population of the Mediterranean Sea (Aguilar & Lowry, 2010).
The subpopulation of Madeira reached 20 individuals (over the age of 1 year) in 2018. Despite the increase, it remains an extremely vulnerable and endangered population (LAYMAN´S REPORT LIFE13 NAT / ES / 000974, 2019). The small number of individuals in the Monk seal population highlights the importance of mitigating any type of threat or disturbance in its population.
It should be noted that there is no relevant emigration or immigration of individuals, between the subpopulation of Madeira and the rest due to being physically distant, being an unfavorable point for maintaining the genetic diversity of the population (Life Madeira Lobo-Marinho, 2017).
Diet:
According to Neves & Pires (1999), Monk seals adapt their diet to the local food availability, using mainly the marine environment to feed themselves, from the coast to 200 meters deep (LAYMAN´S REPORT LIFE13 NAT / ES / 000974, 2019).
In Greece, cephalopods and fish are the main food for monk seals, namely 50% and 48% of the diet according to the study by Pierce et al. (2011). Fish being the main target of foraging in the vicinity of fish farms in Turkey, mainly the largest individuals (Güçlüsoy & Savas, 2003). This species also feeds on some non-cephalopod molluscs (1.5%) and crustaceans (0.4%) (Pierce et al., 2011).
In the Desertas islands it was verified that the monk seal feeds on cuttlefish (Sepia officinalis), mullet (Mugil auratus), rockfish (Sparisoma cretense), dogfish (Pseudolapidaplois scrofa) and salema (Sarpa salpa). They were also observed feeding on limpets (Patela sp) and crabs (Pachigrapsus sp). The stomach contents of an individual found on the island of Madeira included horse-mackerel (Trachurus trachurus) (about 30 cm), snapper (Pagrus pagrus) (35 cm) and ray (Rajidae sp) (Neves & Pires, 1999).
In the Desertas islands, individuals use two types of diving for predation: in the lowlands they make several dives of 8 to 12 minutes emerging in the same place and in the coastal areas they move while they dive in various places. This second type of diving can also be observed off the coast of Madeira Island and is usually accompanied by behaviors such as social interaction or rest (Neves & Pires, 1999).
The Portuguese sub-population is thought to have a greater foraging activity during the high tide, as this is when there is a greater concentration of fish on the coast and when, due to the rising tide, the water reaches the caves where they rest, in the Desertas (Neves & Pires, 1999).
Behavior:
The social behaviors (reproduction, mating and births) of the Portuguese subpopulation are observed in the southwest area of Deserta Grande (Archipelago of the Desertas islands, Archipelago of Madeira).
These animals are more active during the day and have a solitary lifestyle, becoming more receptive during the breeding season. The average gestation period is 289 days and the sexual maturity of the species occurs at 5/6 years of age. Mating takes place in the water and occurs mainly in March and can occur throughout the year (Karamanlidis et al., 2003)
The birth season takes place between the months of June and January, with a peak in the months of October and November. Usually, only one child is born per couple weighing between 16 to 18 kg. The young is breastfed up to 4 months, and cubs stay with their parents until 3 years old (Pires & Neves, 2001).
In recent years, the reduction of human disturbance has made it possible for females to start using the open beaches for the birth of their descendant. Despite this, high infant mortality continues to occur due to the time of birth coinciding with the period in which the most marine storms occur (Pires & Neves, 2000).
Theire vocalizations are known for their loud and unique sound and are used to warn of danger and show discomfort. Males also use them to attract the attention of females before mating.
Life Monk Seal:
The LIFE Madeira Lobo-Marinho is a project ended at the end of 2019 in Madeira Islands. However, its actions continue on the ground in favor of the conservation of this species, namely: increasing the safety of the places used by the Monk seal; decrease the anthropogenic threat; improve the intervention of the Madeira Natural Park Service in the face of threats; control the conservation status of the animal and its habitat (Life Madeira Lobo-Marinho, 2017).
This type of project is of vital importance due to the strong possibility of extinction of the species, due to the small number of individuals and the persistence of some threats. Thus, the overall objective of the Life Madeira Lobo-Marinho project is the conservation and sustainability of the sub-population of Madeira monk seals and, consequently, an increase in their population and habitat improvement (Life Madeira Lobo-Marinho, 2017).
ABOUT OUR GUEST...
Ana Cecília Amaral, 23 years old Portuguese. She completed her degree in Biology at ISPA - University Institute of Psychological, Social and Life Sciences and is currently doing her Masters in Conservation Biology, at the University of Évora. She works as a science communicator at the Pavilhão do Conhecimento - Centro De Ciência Viva. She participated in several projects, namely in the Erasmus + SHOUTOUT4SDGs Project - SDGs and Cork Oak Montado - Education for the conservation of Montado and SDGS And Social Responsibility, by the University of Évora. In 2018 she was a volunteer in the Life Lobo-Marinho project, where she took the ideal that for the conservation of nature to be carried out, everyone's help is needed.
Bibliography:
· Aguilar, A. & Lowry, L. (IUCN SSC Pinniped Specialist Group). 2010. Monachus monachus. The IUCN Red List of Threatened Species 2010: e.T13653A4305567. Downloaded on 13 June 2020.
· Güçlüsoy, H., & Savas, Y. (2003). Interaction between monk seals Monachus monachus (Hermann, 1779) and marine fish farms in the Turkish Aegean and management of the problem. Aquaculture Research, 34(9), 777-783.
· Karamanlidis, A. A., Pires, R., Neves, H. C., & Santos, C. (2003). Habitat of the endangered Mediterranean monk seal (Monachus monachus) at São Lourenço-Madeira. Aquatic Mammals, 29(3), 400-403.
· Karamanlidis, A. A., Dendrinos, P., De Larrinoa, P. F., Gücü, A. C., Johnson, W. M., Kiraç, C. O., & Pires, R. (2016). The Mediterranean monk seal Monachus monachus: status, biology, threats, and conservation priorities. Mammal Review, 46(2), 92-105.
· Karamanlidis, A. & Dendrinos, P. (2015). Monachus monachus (errata version published in 2017). The IUCN Red List of Threatened Species 2015: e.T13653A117647375
· LAYMAN´S REPORT LIFE13 NAT/ES/000974. (2019). LIFE Madeira Monk Seal.
· LIFE MADEIRA LOBO-MARINHO, 18/12/2017 (oficial website)
· Neves, H. C., & Pires, R. (1999). O lobo-marinho no Arquipélago da Madeira. Parque Natural da Madeira: 1-76.
· Pierce, G. J., Hernandez-Milian, G., Santos, M. B., Dendrinos, P., Psaradellis, M., Tounta, E., ... & Edridge, A. (2011). Diet of the monk seal (Monachus monachus) in Greek waters. Aquatic Mammals, 37(3), 284.
· Pires, R., & Neves, H. C. (2000). Monk seal sightings on open beaches in Desertas Islands–Madeira Archipelago. In 14th Annual Conference of the European Cetacean Society, Cork, Ireland (pp. 2-5).
· Pires, R., & Neves, H. C. (2001). Mediterranean monk seal Monachus monachus conservation: a case study in the Desertas Islands. Mammalia, 65(3), 301-308.