MEDITERRANEAN MONK SEAL (MONACHUS MONACHUS)
HABITAT IN VIS ARCHIPELAGO, THE ADRIATIC SEA

Jasna Antolovic

The Mediterranean Monk Seal Group
The Association for the Research and the Protection of Nature
Kresimirov trg 15, 10 000 Zagreb, Croatia

 

INTRODUCTION

The Mediterranean monk seal (Monachus monachus Hermann, 1779) used to be widespread throughout the Adriatic Sea but today is very rare in this area1. Only a few individuals were noticed recently, passing by the outermost Croatian islands. Biology and population ecology of this endangered marine mammal have been little studied scientifically in the Croatian part of the Adriatic Sea so far2.

The Mediterranean monk seal, the largest species among seals, could reach about 3 m in length and 450 kg as recorded in the Vis archipelago3. Its fur is greyish-brown or dark brown with white spots especially on the ventral side. Sexual intercourse and fertilization take place under the sea. It has been recorded that one male fertilizes more females during the mating season4. Females give birth to only one cub per year who is, for 3 to 4 weeks, completely dependent on the mother. Sexual maturity is reached in the fourth year and individuals can live up to 20 or 30 years. A grown up individual eats 10-12 kg of food, predominantly fish and cephalopodes5.

According to recent studies in the field and the results of fishermen questionnaires, there is no resident monk seal population in the Croatian part of the Adriatic Sea at present3. This species, like all seals, needs land for bearing young and for rest5. In the Adriatic habitats, there are suitable rock beaches and caves that have entrances at or below sea level6.

The aim of this survey was to investigate the known former habitats of the Mediterranean monk seal in the Vis archipelago and gather as much knowledge as possible about natural caves and beaches where individuals of this species were encountered in the last 50 years.


Fig 1: The Vis archipelago

METHODS

Two methods were used in this study: a survey among fishermen in the fishing village of Komiza, and direct examination of known former habitats of the monk seal. In the survey, 44 fishermen were interviewed about encounters with the monk seal: sites, behaviour, number of individuals, and damage to fishing gear which might be attributed to the species. In the direct examination, all known habitats were visited, measured and described.

 

RESULTS AND CONCLUSIONS

In this survey, 8 caves and 2 pebble beaches known as former habitat of the Mediterranean monk seal were measured and described. Seals used rocky coastal areas, caves with pebble beaches and flat rocks as well as sandy beaches surrounded by steep rocks for resting and reproduction.

No sign of the animal’s recent presence at these localities was found.

According to the survey of fishermen, the monk seal has been only temporarily present in this area during the last two decades (Table 1 & Figure 2).

Table 1: To view click on thumbnail. Fig. 2: To view click on thumbnail.

Caves surveyed during the study have not changed since the time when this species inhabited them, and they are still suitable as potential monk seal habitat. As far as beaches are concerned, those surveyed are no longer fully suitable as resting sites for this species, due to intense nautical traffic in the area during the summer.

Repopulating the area with Mediterranean monk seals would be possible only through the establishment of specially protected areas, such as marine parks at certain localities.

Monachus Science continues...

REFERENCES

1. Jardas I., Draganovic E. 1987: Rasprostranjenost, brojnost i zastita populacije sredozemne medvjedice (Monachus monachus Hermann, 1779) s posebnim osvrtom na Jadransko more. Akademija nauka i umjetnosti Bosne i Hercegovine, 83, 81-94.

2. Gomercic H., Huber D. 1984: Prisutnost sredozemne medvjedice (Monachus monachus Hermann, 1779) u istocnom dijelu Jadrana. Zbornik sazetaka priopcenja, Drugi kongres biologa Hrvatske. Hrvatsko biolosko drustvo, Zagreb 157-148.

3. Antolovic J., Skakelja N., Huber D. 1997: Stanje sredozemne medvjedice (Monachus monachus Hermann) u Hrvatskom dijelu Jadrana s posebnim osvrtom na populaciju u podrucju Viskog otocja (analiza ankete), Zbornik sazetaka priopcenja, Sesti kongres biologa Hrvatske. Hrvatsko biolosko drustvo, Zagreb 268-362.

4. Sergeant D., Ronald K., Boulva J., Berkes F. 1978: The Recent Status of Monachus monachus, the Mediterranean Monk Seal. Biol. Conserv., England, 14 : 259 – 287.

5. Marchessaux D. 1989: Recherches sur la biologie, l’ecologie et le statut du Phoque moine Monachus monachus, GIS Posidonie Publ, Marseille.

6. Antolovic J., Huber D. 1997: Stanista sredozemne medvjedice (Monachus monachus) u podrucju Viskog otocja. Zbornik sazetaka priopcenja, Sesti kongres biloga Hrvatske. Hrvatskao biolosko drustvo, Zagreb 269 – 369.

 

                                    

Copyright © 1998 Jasna Antolovic, The Monachus Guardian. All Rights Reserved