Kevin Craley, Mark Schildwatcher, Lauren Wetzell

 A paper for MSCI 375, Biology of Marine Mammals, submitted November 2, 1998

Hawaiian monk seals(Monachus schauinslandi) and Mediterranean monk seals(Monachus monachus) are in grave danger of extinction. There approximate populations are 500 and 1500, respectively. Mediterranean monk seals are found off the coasts of north Africa, Greece, and Turkey. Hawaiian monk seals, as the name suggests, are found exclusively around the Hawaiian islands.

The following general biological characteristics seem to typify both species. Both of these phocids feed on fish and various cephalopods that are found in their habitats. Adults in both species grow to nine feet in length and weigh up to 700 lbs. Pups are 45 lbs and are 3 feet in length at birth. Adult males have a dark grey color on their dorsal sides and are pale yellow on their ventral sides. Females and pups are both much lighter on their dorsal sides. One difference between these two animals is that Hawaiian monk seals exhibit slight sexual dimorphism, with the male being 10 % larger than the female. Both species are nonmigratory.

 Copulation takes place in the water followed by a gestation period of about 11 months. The Mediterranean pups are born on land in September and October which is their peak pupping season. The Hawaiian monk seal gives birth on land as well during its peak pupping season which is during the months of April and May.

Mediterranean monk seals breast feed for approximately 6 to 7 weeks after birth, Hawaiian monk seals breast feed for approximately 5 weeks. Monk seals have a slow rate of reproduction. "Although mating takes place after pupping, ovulation does not occur in recently pupped cows as it does in the majority of pinnipeds, so that cows can only give birth every other year"(Martin, 1977). Both species consist of small groups of individuals. Mediterranean monk seals are usually solitary, pups however, will spend their first three years with their mother. Hawaiian monk seals may form small social groups. In both species, females are spaced far apart.

 The Hawaiian monk seal population decline is a result of low fecundity rate, "mobbing", and shark attacks. Most pinnaped’s fecundity rates range from 80 to 90 percent, however, it is very low in the monk seals (Hawaiian monk seals 16.3 percent and 11.5 percent in the Mediterranean monk seals). This low reproductive rate is suggested to be due the small size and fragility of these seals’ populations. The low fecundity rates are also a result of the sensitivity towards human disturbances. These disturbances cause the seals to give birth in less desirable areas, thus increasing the pup’s mortality rates (Reidman, Marianne 1990). Mobbing is an aggressive activity that may be the lead contributing factor the population decline in Hawaiian monk seals. It occurs when a group o female monk seals attempt to mate with a single female or sometimes immature pups. Male adult Hawaiian monk seals display this ‘mobbing" behavior when attempting to mate. This hostile reproductive approach results in injuring and/or killing these fragile female or immature Hawaiian monk seals. Mobbing most likely occurs in smaller populations (100 – 200 seals), unbalanced sex ratios (male dominated), and in slow growing populations. The aftermath of these mobbing incidents leaves the female or immature seal surrounded in a bloody pool of water; therefore increasing their chances of being preyed upon by sharks (Starfield, 1995).

 The Mediterranean monk seals’ population decline is a result of toxins in their environments, morbillivirus and human disturbances. Paralytic shellfish poisoning (PSP) is a toxin resulting in death, whereas polychlorinated biphenlys (PCB) weakens the seals’ immune systems (Monk Seals, 1998). Saxitoxin is a potent neurotoxin, a result of red tides, killing the monk seals. This toxin was thought to be the lead reason for the population decline. However, during the summer of 1997, the Mediterranean monk seals were exposed to the morbillivirus, an infection resulting in hemagglutin activity. This virus was termed the "mystery disease". In the Mauritania Colony, 2/3 Mediterranean monk seals were killed out of an estimated population of 310 monk seals. Alex Aguilar, biologist from University of Barcelona , found about five dead seals washing onshore daily! After several necropsies, he concluded the morbillivirus was the cause of these deaths. He brought in extra field workers and together attempted to vaccinate the surviving Mediterranean monk seals. Peter Reijnders, chair of the International Task Force, believes that not enough evidence exists in order to increase the survival rate of these monk seals. His reasoning is reflected on the two research teams: Ireland/ Spain found evidence of toxins but no virus, whereas Osterhaus’ team (Frasmus University, Netherlands) found evidence of the virus but no toxins. Human disturbances have also played a major role in the population decline with the Mediterranean monk seals (The Monk Seals Mysterious Maladies, 1997). Disturbances such as over fishing, slaughtering, pollution, development, and tourism have driven these seals from their natural habitats, the coasts, to unnatural habitats, underwater caves. This transformation places more stress on the Mediterranean monk seals’ lifestyles, lowering their chances of survival (Sanctuary, 1998).

 There are two major things that need to be done to preserve the Monk seals. The Mediterranean monk seals is threatened by fisherman who see the seals as competition for declining fish populations. The Fisherman need to stop killing the seals. The other thing that needs to happen is more research. The monk seal is the least known of all the seals.

There are several ways to reduce the animosity the fisherman feel toward the seals. Work could be done to help increase fish densities in the fishery. This will increase the fishermen’s catch. The monk seals will also have more food to eat, and be less likely to eat the fish in the nets of fisherman. This will reduce the damage to the nets and help promote good will from the fisherman. One way to increase the fishery is to re-evaluate amateur fishing laws, and increase the actions against illegal fishing. Another thing that would help remove bad feelings from fisherman is if there was some way to compensate them for their equipment that is damaged by seals. This program would have to be closely monitored, but it could do great things toward removing antagonism from the fisherman.

 Incentive programs could be used to show something positive about the seals' presence. They could come in forms such as adding to the technical infrastructure of the fishery. All theses things should reduce the animosity the fishermen feel toward the monk seals.

Many things about monk seals are unknown. The mobbing actions in the Hawaiian monk seal needs to be studied in order to find ways to counteract the effects of it. The information given in studies like that would help the population increase and stop the disastrous consequences of the mobbing. The mortality rates of monk seals are not well known, and an understanding of these rates would help in the design of conservation programs.

Research into the specific areas where monk seals are located and areas that monk seals are likely to inhabit would help to establish protected areas. This would help give the monk seals areas where they could reproduce in private without human impact. The knowledge of where exactly they live would help in making contingency plans in case of crises such as oil spills.

 The toxins in the waters that are harming the monk seals need to be studied and their sources found. The sources of these toxins and pollutants could be better controlled and regulated. This will help keep the monk seals from having too many adverse affects from the pollution.

A final item that needs a lot of research is the Morbillivirus. Ways to slow or stop the spread of the virus need to be discovered, as well as a way to give the cure or vaccines to the seals. This should reduce the numbers of death by the virus.

There are two major projects in the Mediterranean that are helping the Mediterranean Monk seals. The first is the ‘Gift of the Earth’. This program was started by the Turkish government, and the World Wildlife Foundation. It is a protection act for sites along the Cilician coast of Turkey. Associated with it is a program raising money to create more protected areas around places where monk seals live.  The second program is the Foga Pilot project. It was planned by the National Turkish Committee for Seals in 1990. It was launched in 1993 in conjunction with a national plan of action for the protection of the monk seal. This project has many goals, they are to promote awareness, among the populations that do interact with the seals. It also is helping to collect biology information and evaluate the impact of protection methods. It was also enacted to help find other places that needed to be protected.

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Monk Seals. 1998. http://www.seaweb.org/llupdate/monk.html 

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Panou, A; Jacobs, J; Panos, D. 1993. The Endangered Mediterranian Monk Seal in the Ionian Sea, Greece. Biological Conservation. Vol. 64, 129-140.

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Rigas, G; Ronald, K. 1985. Observations on biology and behavior of Mediterranean Monk Seals. Aquatic Mammals. No. 1, 23-26.

Sanctuary for monk seals: A new gift to the earth on world ocean Day VNR. 9 June 1998. http://www.panda.org/news/dopesheets/sheet2.htm

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"The monk seals mysterious maladies." Academic Press, daily insight 28 July 1997. http://www.apnet.com/insight/08281997/grapha.htm

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