Mediterranean monk seal
| Mediterranean Monk Seal | |
|---|---|
.jpg)
| |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Suborder: | |
| Family: | |
| Genus: | |
| Species: | M. monachus
|
| Binomial name | |
| Monachus monachus (Hermann, 1779)
| |
| |
| Mediterranean Monk Seal range | |
The Mediterranean Monk Seal (Monachus monachus) is believed to be the world's rarest pinniped and one of the most endangered mammals of the world.
Description
 |
This species of monk seal grows from approximately 80 cm long at birth to an average of 2.40 m in adults. The latter weigh up to 320 kg, females being slightly smaller than males.
Pups are born in a black natal fur, often with a white patch beneath whose shape can be used to identify individuals for the rest of their lifes. The average lifespan of these animals is unknown, but is thought to be somewhere around 20-25 years.
Reproductive maturity is reached at around age four, and maximum age is over twenty years. Pregnant Mediterranean Monk Seals typically use inaccessible undersea caves while giving birth, though historical descriptions show that they used open beaches until the eighteenth century. There are 8 pairs of teeth in both jaws. Believed to have the shortest hair of any pinniped, the Mediterranean monk seal fur is black (males) or brown to dark grey (females) with a paler belly which is close to white in males. The snout is short broad and flat, with very pronounced, long nostrils that face upward, unlike their Hawaiian relative who tend to have more forward nostrils. The flippers are relatively short, with small slender claws. Monk Seals have two pairs of retractable abdominal teats unlike most all other pinnipeds.
Reproduction
Very little is known of this seal's reproduction. Most everything is assumption. Scientists have suggested that these seals are polygynous, with males being very territorial where they mate with females. Although there is no breeding season since births take place year round, there is a peak in October and November. This is also the time when caves are prone to wash out due to high surf or storm surge, which causes high mortality rates among monk seal pups, especially at the Cabo Blanco colony. Pups make first contact with the water two weeks afterwards their birth, and are weaned at around 18 weeks of age. Most individuals are believed to reach maturity at 5 to 6 years of age. The gestation period lasts close to a year. However, it is believed to be common among monk seals of the Cabo Blanco colony to have a gestation period lasting slightly longer than a year.
Diet
The Mediterranean Monk Seals are diurnal and feed on a variety of fish and mollusks, primarily octopus and squid, up to 3kg per day. They are known to forage, mostly, at depths of 150-230 feet.
Habitat
The habitat of this seal has changed over the years. In ancient times, and up until the 20th century, Mediterranean Monk Seals have been known to congregate, give birth, and seek refuge on open beaches. In more recent times, they have left their former habitat and, now, only use sea caves for such things, and more often than not, these caves are rather inaccessible to humans due to under-water entries, and because the caves are often positioned along remote or rugged coastlines. Scientists have confirmed that this is a recent adaptation, most likely, due to the unwanted excitement of the 20th century. Not only because of two World Wars, but because of a rapid increase in population, tourism, and industry. These have been the ultimate causes of habitat destruction and loss for these animals. Because these seals' shy nature and sensitivity to human disturbance, they have slowly adapted to try avoid contact with humans completely within the last century, and, perhaps, even earlier than that. This change in habitat, however, has not been good for the seals, particularly the young. Coastal caves are dangerous for newborns and are major mortality cause among pups.
Status
This earless seal's former range extended throughout the Mediterranean Sea and Black Sea coastlines including all offshore islands of the Mediterranean, and into the Atlantic and its islands, as far South as Gambia and as far West as the Azores.
Several causes have provoked a dramatic population decrease over the time, mostly commercial hunting (especially during the Roman Empire and Middle Ages) and, during the 20th century, eradication by fishermen – who used to consider it a pest due to the damage the seal causes to fishing nets when it preys on fish caught in those – and coastal urbanisation.
The species has gone extinct in the Sea of Marmara, due to pollution and heavy ship traffic from the Dardanelles and the Bosphorus. In addition, the last report of a seal in Black Sea dates to the late 1990s.[citation needed]
Nowadays its entire population is estimated to be less than 600 individuals scattered throughout a wide distribution range, which qualifies this species as Critically Endangered. Its current very sparse population is one more serious threat to the species, as it only has two key sites which can be deemed viable: the Aegean Sea and, specially, the one in the Western Sahara portion of Cabo Blanco (which may support the small but growing nucleus in the Desertas Islands). These two key sites for the species are virtually in the extreme opposites of its distribution range, which makes natural population interchange impossible. The only other locations in the seal's former range where it can still be found consist of small populations in Madeira, the Desertas Islands, South-Eastern Turkey, and the Ionian Sea, in the coastal waters of Western Greece and Southern Albania and the tiny, virtually relict, Morocco Mediterranean population (a recent confirmed sighting in Majorca[1] indicates that the seal can still be seen in the Balearic Islands if only as a vagrant).
In the summer of 1997, two thirds of the largest surviving single population of Mediterranean monk seals (the one in Cabo Blanco) were wiped out within the space of two months, extremely compromising the species' viable population. While opinions on the precise causes of this epidemic remain sharply divided (the most likely cause being either a morbilivirus or a toxic algae bloom) the mass die-off emphasised the precarious status of a species already regarded as critically endangered throughout its range. While still far below the beginning of 1997, numbers in this all important location have started a slow paced recovery ever since. Currently the population in this location is estimated at 150 individuals, down from approximately 300 in 1997 but still the largest colony by far. The threat of a similar incident that could wipe out this entire population remains.[2]
Preservation
Damage inflicted upon fishermen's nets and rare attacks on off-shore fish farms in Turkey and Greece are known to have pushed local people towards hunting the Mediterranean monk seal, but mostly out of revenge rather than population control. Preservation efforts have been put forth by civic organizations, foundations and universities in both countries since as early as the 1970s. For the past 10 years, many groups have carried out missions to educate locals on damage control and species preservation. Reports of positive results of such efforts exist throughout the area[3].
In the Aegean Sea, only Greece has allocated a vast area for the preservation of the Mediterranean monk seal and its habitat. The Greek Alonissos Marine Park, that extents around the Northern Sporades islands, is the main action ground of the Greek MOm organisation. MOm[4]. MOm is greatly involved in raising awareness in the general public, fundraising for the helping of the monk seal preservation cause, in Greece and wherever needed. Greece, is currently looking into the possibility of declaring another monk seal breeding site as a National park, and also has integrated some sites in the NATURA 2000 protection scheme. It should be stated that the legislation in Greece is very strict towards the hunting of the seal and in general the public is very much aware and supportive of the effort for the preservation of the Mediterranean monk seal.
One of the largest groups among the foundations concentrating their efforts towards the preservation of the Mediterranean monk seal is the Mediterranean Seal Research Group (tr. Akdeniz Foklarını Araştırma Grubu) operating under the Underwater Research Foundation (tr. Sualtı Araştırmaları Derneği) in Turkey (aka. SAD-AFAG). The group has taken initiative in joint preservation efforts together with the Foça municipal officials, as well as phone, fax and email hotlines for sightings.[5]
Preservation of the species requires both the preservation of land and sea, due to the need for terrestrial haul-out sites and caves or caverns for the animal to rest and reproduce. Even though responsible SCUBA instructors hesitate to make trips to known seal caves, just the rumor of a seal sighting quickly becomes a tourist attraction for many. Irresponsible SCUBA trips shy the Mediterranean monk seal away from caves of potential habitation spots for the species.
See also
Notes
References
- Template:IUCN2006 Listed as Critically Endangered (CR C2a v2.3)
- Randall R. Reeves; Brent S. Stewart; Phillip J. Clapham; James A. Powell (2002). National Audubon Society Guide to Marine Mammals of the World. Alfred A. Knopf, Inc. ISBN 0-375-41141-0.
External links
- Mediterranean Monk Seal
- ARKive - images and movies of the Mediterranean monk seal (Monachus monachus)
- The Monachus Guardian
- Hellenic Society for the study and protection of the monk seal
- Madeira Monk Seal Colony
- SAD-AFAG (English version)
- Turkish National Action Plan for the Preservation of the Mediterranean Monk Seal (Monachus monachus)
- Mediterranean monk seal factsheet at the United Nations Environment Programme - World Conservation Monitoring Centre