Monachus monachus 

Scope: Europe
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Carnivora Phocidae

Scientific Name: Monachus monachus (Hermann, 1779)
Regional Assessments:
Common Name(s):
English Mediterranean Monk Seal
French Phoque-moine Méditerranéen
Spanish Foca Monje
Phoca monachus Hermann, 1779
Taxonomic Source(s): Scheel D.M., Slater G.J., Kolokotronis S-O., Potter C.W., Rotstein D.S., Tsangaras K., Greenwood, A.D. and Helgen, K.M. 2014. Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology. ZooKeys 409: 1-33.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered C2a(ii) (Regional assessment) ver 3.1
Year Published: 2007
Date Assessed: 2007-02-25
Assessor(s): European Mammal Assessment team
Reviewer(s): Craig Hilton-Taylor and Helen Temple
The Mediterranean monk seal has a very small population (<250 mature individuals) in the European Mammal Assessment area. There is only one breeding population remaining in the region, so it is presumed that all animals belong to the same subpopulation. There are ongoing declines as a result of fisheries bycatch, persecution, human disturbance, and other threats. Consequently the species is assessed as Critically Endangered.

Geographic Range [top]

Range Description:Mediterranean monk seals were once widely and continuously distributed in the Mediterranean, Black and adjacent seas, in North Atlantic waters off northwest Africa south to Cap Blanc, and possibly Senegal and Gambia. They also were found at the Cape Verde Islands, Canary Islands, Madeira Islands and Azores, and north as vagrants to Portugal (Ronald and Healey 1982), and Atlantic France (Israels 1992).

Today the distribution is wide but extremely fragmented with three surviving small breeding populations located at opposite ends of the historic range. In the Mediterranean, the stronghold for the species is on islands in the Ionian and Aegean Seas, and along the coasts of Greece and western Turkey. The two surviving colonies in the southeastern North Atlantic are at Cabo Blanco (also known as Cap Blanc or Ras Nouadhibou) on the border of Mauritania and Western Sahara, and the small colony at the Desertas Islands in the Madeira Islands group (Gilmartin and Forcada 2002). Many locations where seals are infrequently or regularly seen, or were seen in the recent or historic past, are reported in the literature and cataloged in reviews and status updates, see Sergeant et al. (1978), Israels (1992), UNEP/MAP (2005).
Countries occurrence:
Cyprus; France; Greece; Portugal; Turkey
Possibly extinct:
Albania; Bosnia and Herzegovina; Bulgaria; Croatia; Italy; Malta; Montenegro; Romania; Russian Federation; Serbia; Slovenia; Spain; Ukraine
FAO Marine Fishing Areas:
Atlantic – eastern central; Mediterranean and Black Sea
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The Mediterranean monk seal is the most threatened pinniped species in the world, with an estimated population of 350-450 animals. The largest remaining population is that of the eastern Mediterranean, with 250-300 individuals, of which c.100 occur in Turkish waters (Güçlüsoy 2004). Approximately 100 to 130 seals are found at Cabo Blanco in Western Sahara and Mauritania, and approximately 20-23 at Desertas Island, Madeira (Pires and Neves 2001, Gilmartin and Forcada 2002, UNEP/MAP 2005). The population at Cabo Blanco was estimated at 317 seals before the loss of an estimated 70% in a mass mortality event in 1997 (Forcada 2000). Following this event, 24 pups were born at Cabo Blanco in 1997, comparable to the rate of births in 2004 and 2005, but this number rose significantly in 2006 to 46 births (Cedenilla and de Laminoa 2006). A recent review of monk seal occurrences reported at all other locations and countries from 1999-2005 yielded a minimum of 14 additional seals, with 10 of the 14 in Algeria, plus an unspecified number of vagrants (UNEP/MAP 2005).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Mediterranean monk seals are medium-sized phocids that reach 2.3-2.8 m (Gilmartin and Forcada 2002). Adults weigh from 240-300 kg, and newborns 15-26 kg (Boulva 1979, Gilmartin and Forcada 2002), with records of a male reaching 400 kg and a pregnant female reaching 302 kg (Sergeant et al. 1978).

Mediterranean monk seals once hauled out on open beaches, but this is now rare, and throughout their range they use caves with sea entrances for hauling out and pupping (Gilmartin and Forcada 2002). Sea caves used by seals often have submerged entrances or some other barrier to provide protection from waves. In a study that covered 250 km of coastline inhabited by monk seals in the Cilician Basin region of southern Turkey, 282 caves were searched. Of these, 39 showed evidence of monk seals, including 3 that were used for pupping and 16 that were actively being used. Use of these caves increased in October coincident with the autumn pupping season in Turkey (Gucu et al. 2004). The maximum number of seals from this small Turkish population found in a cave in at one time was 3 (Gucu et al. 2004).

Sea caves are also used extensively at Cabo Blanco, particularly northwest of the cape. Two caves separated by 1.1 km accounted for 84% of the births in the area from 1993-1997 (Gazo et al. 1999). In contrast to the situation in Turkey, counts at one cave in the Las Cuevecillas section of the Cabo Blanco colony recorded up to 89 seals hauled out at one time, and never less than 5 animals present (Gonzalez et al. 1997).

Female Mediterranean monk seals probably become sexually mature at three to four years. One female at Cabo Blanco became pregnant at 2.5 years and gave birth at 3.7 years, the youngest age known for this species (Gazo et al. 2000b). Females can give birth in successive years. The annual reproductive rate in Mediterranean monk seals is very low at 0.3-0.43 pups to each sexually mature female (Gazo et al. 1999). Pup survival is low (Gazo et al. 2000a).

Mediterranean monk seals take a wide variety of prey primarily from shallow water habitats (Sergeant et al. 1978, Kenyon 1981). In the eastern Mediterranean, they have been reported to take a variety of fish, octopus and loggerhead sea turtles (Caretta caretta) (Margaritoulis et al. 1996). Examination of two seals from the Aegean Sea yielded five species of prey. By weight 94% of the contents were cephalopods including musky octopus (Eledone moschata) and globose octopus (Bathypolypus sponsalis) (Salman et al. 2001).
Systems:Terrestrial; Marine

Threats [top]

Major Threat(s): Mediterranean monk seals have a long history of interaction with humans that includes exploitation for subsistence needs, commercial harvest, and persecution as a competitor for fisheries resources. Once abundant, monk seals were written about and illustrated in the literature and depictions of classical antiquity. They became the target of a commercial harvest for skins and oil by the Portuguese as early as the 15th century along the coast of northwest Africa (Israels 1992).

Reasons given for the recent population decline include increased human population displacing seals from their habitat, mortality due to fisheries bycatch and persecution, and the possible effects of toxics and pollutants (Boulva 1979). Exacerbating these factors are political instability and wars, the challenge of implementing effective conservation for a species in a complex multi-national environment, weak enforcement of agreements and international laws, diseases, genetic consequences of inbreeding, and other catastrophes such as oil spills and collapse of occupied pupping caves (Israels 1992).

Interactions with fisheries are of great conservation concern, particularly for the population in the eastern Mediterranean, where seals are killed through net entanglement and deliberately killings by fishermen. They possibly suffer from depletion of fish stocks, anti-seal methods designed to protect aquaculture facilities, and illegal dynamite fishing (Güçlüsoy 2004). Monk seals have been entangled in a wide variety of fisheries gear including set-net, trawl net, and long-line. They seem most vulnerable to set-nets placed on the bottom, and can also become entangled in abandoned and discarded nets (Tudela 2004).

The deaths of 130 seals over a 10-year period ending in 1999 highlighted the significance of deliberate killing as a source of mortality (Tudela 2004). Deliberate killing of monk seals by humans was attributed to 1/3 of all mortalities of 79 stranded animals in Greece, and is considered the single most important source of mortality (Androukaki et al. 1999).

The genetic diversity of Mediterranean monk seals is amongst the lowest found in pinnipeds. Only Hawaiian monk seals and northern elephant seals have lower diversity. The consequences of mating between closely-related individuals include congenital defects leading to stillborn pups and a decreased reproductive rate, both of which have been documented in the Cabo Blanco colony. Additionally, low fitness and increased susceptibility to disease may be a problem (Pastor et al. 2004).

Morbillivirus was isolated from Mediterranean monk seals after the mass mortality at Cabo Blanco in 1997. The virus most closely resembled dolphin morbillivirus (DMV) that was previously implicated in the 1991 mass mortality of striped dolphins in the Mediterranean Sea (Osterhaus et al. 1992, Van de Bildt et al. 1999). Although this virus was already circulating in monk seals prior to the mass mortality, there is doubt that it caused the deaths. Dinoflagellate-produced saxitoxins were found in tissues from animals that died during the 1997 event, and the suddenness of death of the animals and other symptoms suggest that the cause of death was from the toxins rather than an epidemic of morbillivirus. Additionally, toxic algal blooms (red tides) are favored by oceanographic conditions near Cabo Blanco, and were reported from nearby Morocco the southeastern North Atlantic during a 25-year period leading up to the mass mortality. Canine distemper virus is present in stray dog populations in Aegean Turkey at a level of approximately 9% in the population. This may be a source for future infections of wild carnivores, including monk seals through contacts in harbors and along shorelines (Gencay et al. 2004).

Contaminant burdens have always been suspected to be a threat to the Mediterranean monk seal, and should be investigated and routinely monitored (Boulva 1979, Reijnders et al. 1993). Tissues collected during the 1997 mass mortality and analyzed for PCBs and DDT detected levels of pollutants comparable to those found in other marine mammals not believed to be experiencing contaminant related health or reproductive effects (UNEP 2005).

Mediterranean monk seals are at an unknown but suspected high level of risk from oil tanker and other ship accidents, spills and groundings. Animals could be oiled or coated in fuels and lubricants, exposed to other toxic or environment-altering chemicals or products, and experience disturbance at haul outs or coastal feeding areas. Mauritania is planning to explore offshore oilfields which would lead to increased vessel traffic in the area, and greater chance for accidents, disturbance, and collisions near important habitat. Three accidents or spills have occurred near monk seal habitat in the recent past, including a supertanker that spilled oil off of Morocco in 1989 (Israels 1992), an oil spill in the Madeira Islands in 1994 (UNEP 2005), and the grounding of a bulk carrier near Cabo Blanco in 2003 (UNEP 2005). None of these spills or accidents had any known impacts on monk seals, but they underscore the threat of significant impacts from a major maritime accident near an important monk seal site (UNEP 2005).

Human disturbance has been identified as a primary factor in the decline in numbers of monk seals through displacement of animals from habitat. Traditionally, this was the result of expanding human populations and coastal development. Since the 1970s, a new threat has emerged in the form of people seeking out monk seals to view at the few remaining locations. Tourism has grown to become one of the most significant hazards faced by monk seals, particularly in the eastern Mediterranean (Johnson and Lavigne 1999). Besides disturbance, tourist activities increase the risk of vessel accidents, spills, transmission of disease, and the discharge of pollutants and waste near the seals.

Conservation Actions [top]

Conservation Actions: The Mediterranean monk seal is protected throughout its range. Two protected areas have been established for monk seals, the Desertas Islands in the Madeira archipelago, and the Northern Sporades Islands national marine park in Greece. There are future plans to set up nature reserves to protect more habitat for monk seals in the region.

Numerous agreements, conventions, and treaties are in force to protect monk seals internationally, and many workshops and conferences have brought together scientists and managers to discuss monk seal conservation issues and problems. Israels (1992) summarizes 30 years of this conservation history, and provides details on accomplishments and failures to meet objectives. Other measures in place include Action Plans completed in 1978 and 1988 for the conservation and management of monk seals, and the 2005 plan for the recovery of the monk seal in the eastern Atlantic.

Many actions have been taken on a local scale including outreach and education programs, restrictions on gear and location for fisheries, development of monitoring programs and protocols, and increasing the capability to rehabilitate sick and injured animals (Gonzalez 2004).

Citation: European Mammal Assessment team. 2007. Monachus monachus. The IUCN Red List of Threatened Species 2007: e.T13653A4305994. . Downloaded on 23 February 2018.
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