Hawaiian monk seal

Hawaiian Monk Seal
Conservation status
Critically Endangered (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Phocidae
Genus:	Monachus
Species:	M. schauinslandi
Binomial name
Monachus schauinslandi Matschie, 1905
Hawaiian monk seal range

The Hawaiian monk seal, Monachus schauinslandi, is an endangered earless seal that is endemic to the Hawaiian Islands.^[2]

Known to the native Hawaiians as ʻIlio-holo-i-ka-uaua, or "dog that runs in rough water". The Hawaiian monk seal is named after Hugo Hermann Schauinsland, a German scientist who discovered the first skull on Laysan Island in 1899.^[3] Its common name comes from the short hairs on its head resembling a monk.^[4] Coincidentally, they also act like monks in that they are solitary animals. The Hawaiian monk seal is one of only two remaining monk seal species; the other is the Mediterranean monk seal. A third species, the Caribbean monk seal, is extinct.^[4]

The Hawaiian monk seal is the only seal native to Hawaii.^[5] Its grey coat, white belly, and slender physique distinguish them from their cousin, the Harbor seal (Phoca ‘’vitulina’’).^[4] The monk seal’s physique is ideal for hunting its prey: fish, lobster, octopus and squid in deep-water coral beds.^[6] When the Hawaiian monk seal is not spending its time hunting and eating, it is generally hauling-out on the sandy beaches and volcanic rock of Northwest Hawaiian Islands.^[7] These monk seals are a conservation reliant endangered species. A small population of about 1,000 individuals is threatened by human encroachment, very low levels of genetic variation, entanglement in fishing nets, marine debris, disease, and past commercial hunting for skins. There are many methods of conservation biology when it comes to endangered species; translocation, captive care, habitat clean up, and educating the public about the Hawaiian monk seal are some of the methods that can be employed.^[8][9][10]

Description

The Hawaiian monk seal is part of the Phocidae family, being named so for its characteristic lack of external ears and inability to rotate its hind flippers under the body.^[11] The Hawaiian monk seal has a relatively small, flat head with large black eyes, eight pairs of teeth, and short snouts with the nostril on top of the snout and vibrissae on each side.^[4] The nostrils are small vertical slits which close when the seal dives underwater. Additionally, their slender, torpedo-shaped body and hind flippers allow them to be very agile swimmers.^[12]

Adult males are 300 to 400 pounds (140 to 180 kg) in weight and 7 feet (2.1 m) in length while adult females tend to be slightly larger, at400 to 600 pounds (180 to 270 kg) pounds and 8 feet (2.4 m) feet in length. When monk seal pups are born, they average 30 to 40 pounds (14 to 18 kg) and 40 inches (1.0 m) in length. As they nurse for approximately six weeks, the grow considerably, eventually weighing between 150 to 200 pounds (68 to 91 kg) by the time they are weaned, while the mother loses up to 300 pounds (140 kg).

Monk seals, like elephant seals, shed their hair and the outer layer of their skin in an annual catastrophic molt. During the most active period of the molt, about 10 days for the Hawaiian monk seal,^[13] the seal remains on the beach. The hair, generally dark gray on the dorsal side and lighter silver ventrally, gradually changes color through the year with exposure to atmospheric conditions. Sunlight and seawater cause the dark gray to become brown and the light silver to become yellow-brown, while long periods of time spent in the water can also promote algae growth, giving many seals a green tinge. The juvenile coat of the monk seal, manifest in a molt by the time a pup is weaned is silver-gray; pups are born with black pelage. Many Hawaiian monk seals sport scars from shark attacks or entanglements with fishing gear. Maximum life expectancy is 25 to 30 years.

History and evolution

Hauled-out seal

The evolutionary history of the monk seal is controversial since there are different hypotheses for the phylogenetic to other phocids.^[14] Due to the lack of fossil records, there is little evidence supporting that the Hawaiian monk seal is related to other seals in the Phocidae family; thus, there remains a great deal of debate on the evolution of the Hawaiian monk seal. Based on the prehistoric and unspecialized skeletal and vascular anatomy of the seal, many scientists have stated that the Hawaiian monk seal is considered the most primitive of living seals. These scientists offer the hypothesis that the Hawaiian monk seal was the decedent of the Caribbean species, M. tropicalis; all three monk seals are said to have originated in the North Atlantic and these scientists believe the Hawaiian monk seal became separated from its congeners as early as 15 million years ago.^[14]

In an effort to inform the public and conserve the seals, the National Oceanic Atmospheric Administration (NOAA) Fisheries Service has written a historical timeline of the Hawaiian monk seal to demonstrate that the Hawaiian islands has been home to the seals for millions of years and that the seals belong there. Evidence points to monk seals making their way to Hawaii between 4-11 million years ago (mya) through an open water passage between North and South America called the Central American Seaway.^{[citation needed]} The Central American Seaway was closed by the Isthmus of Panama approximately 3 million years ago so the Hawaiian monk seal has been separated from its congeners for at least to near extinction in the Northwestern Hawaiian Islands, but soon after the population had started to slowly increase in numbers.

Authors of the book Marine Mammals: An evolutionary biology, Annalisa Berta and James Sumich, ask questions about how this Hawaiian monk species came to the Hawaiian Islands when its closest relatives are found on the other side of the world in the North Atlantic and Mediterranean Sea.^[15] No one knows if the Hawaiian monk seal is the oldest or the youngest seal in the Monachus genus.^[15] The species may have evolved in the Pacific or Atlantic, but in either case, it came to Hawaii long before the first Polynesians in approximately

Habitat

A Hawaiian monk seal observed near La'ie, O'ahu.

The majority of the Hawaiian monk seal population can be found around the Northwest Hawaiian Islands but a small and growing population can also be found on the main Hawaiian Islands.^[7] These seals spend two-thirds of their time at sea, and one-third on the sandy beaches. Early studies (done at Midway Atoll) concluded that these seals frequently stayed inside the lagoons as opposed to the deep ocean, because of the larger abundance of fish found in the coral reefs of the lagoons.^[12] However, recent use of animal-born video imaging, temperature/depth recorders, and satellite telemetry has shown that monk seals actually spend much more time foraging in deeper water outside the reefs (sometimes to subphotic depths of 300 meters or more).^[16][17] Hawaiian monk seals breed and haul-out on sand, corals, and volcanic rock; sandy beaches are more commonly used for pupping.^[7] Due to the immense distance separating the Hawaiian Islands from other land masses capable of supporting the Hawaiian monk seal, its habitat is limited to Hawaii and its Northwestern Islands.

Diet

Hawaiian monk seals mainly prey on teleosts (bony fish), but they also prey on cephalopods, and crustaceans.^[6] Both juveniles and sub-adults prey more on smaller octopi species, such as Octopus leteus and O. hawaiiensis, nocturnal octopi species, and eels than the adult Hawaiian monk seals.^[6] While, adult seals feed mostly on larger octopi species such as O. cyanea. Hawaiian monk seals have a broad and diverse diet due to foraging plasticity which allows them to be opportunistic predators that feed on a wide variety of available prey.^[6]

Mating and Reproduction

The Hawaiian monk seals mate in the water during their breeding season, which occurs between the months of December and August.^[4] Females reach maturity at age four and give birth to one pup a year. The Hawaiian monk seal fetus takes nine months to develop, with birth of the pups occurring in March and June. The pups usually weigh about 16 kg and are about 1 m long.^[4] Pups are born with a black coat which they shed at about six weeks and replace with a gray coat on the back and white on the belly.^[12] The pups are born on beaches and nursed by their mothers for about six weeks. After that time, the mother will desert the pup, leaving it on its own, and return to the sea to forage for the first time since the pup’s arrival.^[12]

Ecological Interactions

Tiger sharks and Galapagos sharks are both predators of the Hawaiian monk seals.^[18]

Scars are found on many of the monk seals as a result of their encounters with these predators. Also, female monk seals have scars from aggressive male monk seals. Furthermore, a recent study showed that the monk seals are dying from a pathogen in cat feces (toxoplasmosis) that is carried to the ocean in polluted runoff and sewage water, which is a new threat to this endangered species.^[19] Over the past ten years, the cat parasite has killed at least four monk seals in the main Hawaiian Islands. In addition to toxoplasmosis, other pathogens have infected monk seals with leptospirosis being one of the biggest concerns.^[19] Additionally, Hawaiian monk seals also have frequent human encounters from commercial fishermen and tourists.^[19]

Threats

Hawaiian monk seal

Natural threats include mainly predation by sharks.

Seal populations have declined rapidly in recent years due to the rapid spread of human activity to even the most remote and isolated areas in the Hawaiian Islands. In the nineteenth century, Hawaiian monk seals were clubbed to death by whalers and sealers for meat, oil and skin.^[20] U.S. forces hunted them during World War II while occupying Laysan Island and Midway.^[20]

As the result of human disturbances, ciguatera poisoning, high male to female ratios occurred during the breeding season, and entanglement in fishing nets and debris have killed many animals. In the northwestern Hawaiian islands, starvation is a serious problem. Lobsters, the seals' preferred food other than fish, have been overfished and competition from other apex predators such as sharks, jacks, and barracudas, leaves little left over for developing pups. The creation of Papahānaumokuākea Marine National Monument enclosing these islands may lead to more abundant food supplies.

In areas where male seals outnumber females, several males may compete for a single female, known as mobbing, often accidentally killing the female. Females of any age including pups can become targets.^[21]

These threats have taken a toll on the species. It has been nearly eradicated from the main Hawaiian Islands. The population there is approximately 150.^[22] It is currently found on Laysan, Midway, Pearl and Hermes Atoll, French Frigate Shoals, and Lisianski.^[22]

In the summer of 2009, two monk seals were shot and killed.^[23]

Slowly, however, the monk seals are returning to the main Hawaiian Islands. Lone seals have been sighted in surf breaks and on beaches in Kauaʻi, Niʻihau, Maui, O'ahu's Turtle Bay,^[24] and even spotted on Waikiki beach on March 4, 2011, outside of the Moana Hotel. They often leave the water haul out on busy tourist beaches, where they are vulnerable to disturbance. In early June 2010, 2 seals were seen hauled out on Oahu's popular Waikiki beach. NOAA has cultivated a network of volunteers who protect the seals while they bask or bear and nurse their young. In 2006, twelve pups were born in the main Hawaiian Islands, rising to thirteen in 2007, and eighteen in 2008. As of 2008 43 total pups have been counted in the main Hawaiian islands.^[25] Tiger sharks also prey on them which also damages the monk seal population.

NOAA is funding considerable research on seal population dynamics and health in conjunction with the Marine Mammal Center.

Endangered status

A Hawaiian monk seal observed on the North Shore of Oahu, near Waimea Bay.

The Hawaiian monk seal is among the most endangered of all seal species, although its cousin species the Mediterranean Monk Seal (M. monachus) is even rarer, and the Caribbean Monk Seal (M. tropicalis), last sighted in the 1950s, was officially declared extinct in June 2008.^[26] The population of Hawaiian monk seals is in decline. In 2010, it was estimated that only 1100 individuals remain. It is listed as critically endangered.^[27] The Hawaiian monk seal was officially designated as an endangered species on November 23, 1976, and is now protected by the Endangered Species Act and the Marine Mammal Protection Act. Today, even though the islands are protected, many scientists believe that the effects of human activity along these fragile coastlines (and in the world at large) are still taking their toll^[28] It is illegal to kill, capture or harass a Hawaiian monk seal.

To raise awareness for the species' plight, the Hawaiian monk seal was declared Hawaii's official State Mammal on June 11, 2008 by Lieutenant Governor James Aiona.^[29]

The multitude of factors that play a role in the limitation of population growth seen in the critically endangered Hawaiian Monk Seal can be seen as the primary natural facets and the anthropogenic impact of the past and present. Several natural factors affecting the recovery of the Hawaiian Monk Seal include the low genetic variability observed in populations, low juvenile survival rates, reduction of habitat/prey associated with environmental changes, increased male aggression, and subsequent skewed ratios amongst the sexes.^[30] Anthropogenic or human impacts to monk seals include hunting (during 1800s and 1900s), human disturbance, entanglement in marine debris, and fishery interactions.^[30]

Natural Factors

Of 18 pinniped species, the Hawaiian Monk Seal has the lowest level of genetic variability.^[9] A study found that this low genetic variability is due to a population bottleneck caused by intense hunting in the 19th century.^[9] This lacking in genetic variability reduces the species ability to adapt to environmental pressures and limits natural selection thus increasing their risk of extinction.^[9] One such environmental pressure that may be detrimental to the monk seal would be the presence of an infectious disease;in such small populations the effects of a disease could be disastrous.^[31] One possible infectious agent affecting the overall health of the species could be from ciguatera poisoning. Another possibility arises from postmortem examinations of seal carcasses revealing gastric ulcerations caused by parasites, which would negatively affect the health of the seal.^[31]

Additionally, low juvenile survival rates continue to threaten the species. High juvenile mortality is due to starvation, shark predation, and marine debris entanglement.^[9] A reduction in habitat and subsequently a reduction in prey abundance associated with environmental changes results in a decrease in seal populations due to starvation.^[30] The critical habitat is being lost due to erosion in the Northwest Hawaiian Islands, which is shrinking the islands/beaches and proving to be very problematic for the monk seal.^[30] Another huge contributor to the low juvenile survival rates is the predation from sharks. Most mature monk seals are scarred from previous encounters with sharks and many such attacks have been observed.^[30] Additionally, marine debris entanglement can result in mortality because the seals get trapped in debris such as fishing nets and cannot escape.^[9]

Furthermore, mobbing, a practice among the seals that involves a large number of seals attacking one seal in mating attempts, is responsible for many deaths especially to females.^[32] Mobbing leaves the targeted individual with many wounds that lead to septicemia and the seals then die from infection.^[32] In a study performed by Gilmartin et al., it was found that a small population of monk seals was more likely to experience a mobbing problem as a result of the increased male-biased sex ratio and male aggression.^[33] It was also observed that unbalanced sex-ratios were more likely to occur in slow-growing populations, therefore until the population reaches a large or rapidly growing population state, biased sex-ratios and mobbing will continue.^[33]

Anthropogenic Impacts

Human disturbances have had immense effects on the populations of the Hawaiian Monk Seal. Monk seals tend to avoid beaches where they are disturbed; after continual disturbance the seal may completely abandon the beach, thus reducing its habitat size, subsequently limiting population growth.^[30] Although the military bases from WWII in the Northwestern Hawaiian Islands have been closed down, minimal human activities can be enough to effectively disturb the species.^[30]

Entanglement in marine debris is another huge impact from people that cause great damage to the seal populations, despite international law prohibiting the intentional discarding of debris from ships at sea.^[30] Monk seals have one of the highest documented rates of entanglement of any pinniped species; a huge problem that current studies indicate there is no sign of it abating in the future.^[30]

Marine fisheries can potentially interact with the monk seals via direct and indirect relationships. Directly the seal can become snared by fishing equipment, entangled in discarded debris, and even feed on fish refuse.^[30] While the possible indirect effects have yet to be documented, they include the effect overfishing may have on the prey abundance of the monk seal, negatively effecting the seal’s diet and habitat.^[30]

Identification and mitigation of these and other possible factors (e.g., disease) limiting population growth represent ongoing challenges and are the primary objectives of the Hawaiian monk seal conservation and recovery effort.^[31]

Conservation Methods

It is apparent that the ultimate goal of reversing overall population decline will hinge on a comprehensive, scientifically sound characterization and mitigation of natural and anthropogenic factors limiting population growth in Hawaiian Monk Seals.^[30] It is crucial to understand the delicate life style of the seals in order to better change the harmful factors accounting for the decline in population. Therefore, public outreach and education remain the single most powerful tools for promoting the conservation of the Hawaiian monk seal and the habitat in which it occurs.^[30] With human disturbances and entanglement in marine debris being a leading component in the decline of the seal population, it is clear that debris must be removed and people must become more conscious of small activities that indirectly affect the seal. For instance, large beach crowds and structures on beaches will limit the seal’s habitat and continue to aid in the demise of the population.^[8]

In 1909, President Theodore Roosevelt created the Hawaiian Islands Reservation that included all islands in the Northwest Hawaiian islands.^[30] The Reservation was later renamed the Hawaiian Islands National Wildlife Refuge (HINWR), being a Federal Refuge, it was placed within the jurisdiction of the U.S. Fish and Wildlife Services (USFWS), which would promote the conservation and proper management of the seals.^[30] This is one example of a marine sanctuary that will greatly benefit the survival of seal populations. With an increased level of understanding of the effects humans have on the Hawaiian Monk Seal, better methods of conservation can be put into action to help diminish the detrimental effects people have had over the years.

As the anthropogenic impacts are reduced, the natural factors affecting population growth must also be addressed in order to successfully recover this species. One key natural factor negatively affecting the seal populations is the male-biased sex-ratio observed, which results in increased aggressive behaviors such as mobbing.^[33] These aggressive behaviors result in a decrease in the amount of females present in the population. Two programs have been put forth to aid in female survival rates that appear to be quite effective. One such program, “Headstart,” which began in 1981, collected female pups after weaning, tagged them, and placed the seals in a large, enclosed water and beach area with plenty of food and free of disturbance.^[34] The female pups are held in this enclosure during the summer months and released at roughly three to seven months of age. Another project that began in 1984 at the French Frigate Shoals collected severely underweight female pups, placed them in captive care where they are free from harm, and adequately fed. The pups are then re-released at the yearling age and relocated to the Kure atoll.^[34] These simple programs have proven to be very effective and will help bridge the gap between sex-ratios in the Hawaiian Monk Seal. A key conservation method also mentioned here is the relocation, or translocation of the seals. Some habitats are better suited than others to increase the survival probability in the seals, making translocation a popular and promising method.^[10] Although no direct links between infectious diseases and the high mortality of the seals have been found, it is important to continue disease monitoring because translocation is a major conservation method and unidentified infectious diseases could prove detrimental to those efforts.^[35] Additionally, genetic data analysis is still needed because identifying individuals genetically along with confirming maternity and paternity can provide information about male and female reproductive rates which are crucial to wildlife managers.^[10] Although, many of these conservation methods are in practice today, further efforts are needed in order to prevent extinction of the Hawaiian Monk Seal.

See also

• Mediterranean monk seal
• Caribbean monk seal

References

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2. ^ "Hawaiian Monk Seal, Monachus schauinslandi". monachus-guardian.org. 2006. http://www.monachus-guardian.org/factfiles/hawai01.htm. Retrieved 2011-05-23. 
3. ^ Reeves, RR; Stewert, BS (2002). National Audubon Society Guide to Marine Mammals of the World. ISBN 978-0375411410. 
4. ^ ^{a b c d e f} "Hawaiian Monk Seal (Monachus schauinslandi)". NOAA Fisheries Office of Protected Resources. http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/hawaiianmonkseal.htm. Retrieved 2011-03-11. 
5. ^ Nitta, Eugene; Henderson JR (1993). "A review of interactions between Hawaii's fisheries and protected species". Marine Fisheries Review. 83 55 (2). http://spo.nmfs.noaa.gov/mfr552/mfr55210.pdf. Retrieved 2011-05-23. 
6. ^ ^{a b c d} Goodman-Lowe, GD (1998). "Diet of the Hawaiian Monk Seal (Monachus Schauinslandi) from the Northwestern Hawaiian Islands during 1991 to 1994". Marine Biology. 3 132: 535–46. http://www.csulb.edu/~ggoodman/files/DietHMS.pdf. Retrieved 2011-05-23. 
7. ^ ^{a b c} Baker, J (2004). "Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands". Biological Conservation. 1 116: 103–10. 
8. ^ ^{a b} Boland, R; Donohue, R (2003). "Marine Debris Accumulation in the Nearshore Marine Habitat of the Endangered Hawaiian Monk Seal, Monachus Schauinslandi". Marine Pollution Bulletin. 11 46: 1385-139. doi:10.1016/S0025-326X(03)00291-1. http://www.sciencedirect.com/science/article/pii/S0025326X03002911. Retrieved 2011-05-23. 
9. ^ ^{a b c d e f} Schultz J; Baker J, Toonen R, Bowen B (2009). "Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)". Journal of Heredity. 1 100 (1): 25–33. doi:10.1093/jhered/esn077. http://jhered.oxfordjournals.org/content/100/1/25.full. Retrieved 2011-05-23. 
10. ^ ^{a b c} Schultz, J; Baker J, Toonen R, Bowen B (2011). "Range-Wide Genetic Connectivity of the Hawaiian Monk Seal and Implications for Translocation". Conservation Biology. 1 25: 124–132. doi:10.1111/j.1523-1739.2010.01615.x. PMID 21166713. 
11. ^ Gilmartin, William; Forcada, J. (2002). "Monk Seals". Encyclopedia of Marine Mammals, eds: 756–759. 
12. ^ ^{a b c d} Kenyon, KW; Rice, DW. "Life History Of the Hawaiian Monk Seal". Pacific Science 13. http://scholarspace.manoa.hawaii.edu/handle/10125/7958. Retrieved 2011-05-23. 
13. ^ Perrin, William F.; Bernd Wursig; J. G. M. Thewissen (24 November 2008). Encyclopedia of Marine Mammals. Academic Press. p. 741. ISBN 9780123735539. http://books.google.com/books?id=2rkHQpToi9sC&pg=PA741. Retrieved 26 May 2011. 
14. ^ ^{a b} Repenning, CA; Ray, CE (1977). "The origin of the Hawaiian monk seal". Proc. Biol. Soc. Wash 89: 667–688. 
15. ^ ^{a b} Berta, Annalisa; Sumich, James L (1999). "Marine Mammals". Evolutionary Biology (Academic Press). 
16. ^ Parrish, FA; Littnan, CL (2008). "Changing perspectives in Hawaiian monk seal research using animal-borne imaging". Marine Technology Society Journal 41 (4): 30–34. http://www.pifsc.noaa.gov/library/pubs/Parrish_MTSJ_2008.pdf. Retrieved 2011-05-23. 
17. ^ Parrish, Frank A (1999). "Use of Technical Diving to Survey Forage Habitat of the Endangered Hawaiian Monk Seal.". In: Hamilton RW, Pence DF, Kesling DE, eds. Assessment and Feasibility of Technical Diving Operations for Scientific Exploration. (American Academy of Underwater Sciences). http://archive.rubicon-foundation.org/9003. Retrieved 2011-05-23. 
18. ^ Bertilsson-Friedman, P (2006). "Distribution and Frequencies of Shark-inflicted Injuries to the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)". Journal of Zoology 268 (4): 361–68. doi:10.1111/j.1469-7998.2006.00066.x. 
19. ^ ^{a b c} Dawson, Teresa. "A New Threat to Hawaiian Monk Seals: Cat Parasite Carried by Runoff, Sewage — Environmental Health News". Environmental Health News: Front Page. http://www.environmentalhealthnews.org/ehs/news/hawaiian-monk-seals. Retrieved 2011-03-16. 
20. ^ ^{a b} Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. pp. 194. ISBN 0-06-055804-0. 
21. ^ "Hawaiian Monk Seals". earthtrust.org. http://www.earthtrust.org/wlcurric/seals.html. Retrieved 2011-05-23. 
22. ^ ^{a b} Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. pp. 195. ISBN 0-06-055804-0. 
23. ^ "Federal officials probe deliberate killing of seal". The Maui News. 2009-12-19. http://www.mauinews.com/page/content.detail/id/526868.html. Retrieved 2011-05-23. 
24. ^ Campaign to Protect Turtle Bay (HI)^{[dead link]}
25. ^ Wianecki, Shannon. "Rough Water Pups". Maui Magazine. http://www.mauimagazine.net/Maui-Magazine/May-June-2009/Rough-Water-Pups. Retrieved 2011-05-23. 
26. ^ Associated Press (2008-06-09). "Feds: Caribbean Monk Seal Officially Extinct". Fox News. http://www.foxnews.com/story/0,2933,364241,00.html. Retrieved 2011-05-23. 
27. ^ "The Captive Care and Release Research Project Seeks to Aid Recovery of the Endangered Hawaiian Monk Seal". NOAA. http://www.pifsc.noaa.gov/psd/captivecareproject.php. Retrieved 2011-05-23. 
28. ^ Weber, Gretchen. "A struggle to survive: Environmental threats endanger monk seals". PBS. http://www.pbs.org/kqed/oceanadventures/episodes/kure/oceanscience.html. Retrieved 2011-05-23. 
29. ^ Gladden, Tracy. "Hawaiian monk seal is the new state mammal". KHNL NBC 8 Honolulu Hawaii. http://www.khnl.com/Global/story.asp?S=8483697. Retrieved 2011-05-23. 
30. ^ ^{a b c d e f g h i j k l m n o} Antonelis, GA; et. al. (2006). "Hawaiian monk seal (Monachus schauins-landi): status and conservation issues". Atoll Res Bull 543: 75–101. 
31. ^ ^{a b c} Gilmartin, WG (1983). Recovery plan for the Hawaiian monk seal, Monachus schauinslandi. U.S. Department of Commerce, NOAA, National Marine Fisheries Service. 
32. ^ ^{a b} Banish, LD; Gilmartin, WG (1992). "Pathological findings in the Hawaiian monk seal". Journal of Wildlife Diseases 28 (3): 428–434. PMID 1512875. http://www.jwildlifedis.org/cgi/reprint/28/3/428. Retrieved 2011-05-23. 
33. ^ ^{a b c} Starfield, AM; Roth JD, Ralls K (1995). "Mobbing in Hawaiian monk seals: the value of simulation modeling in the absence of apparently crucial data". Conserv. Biol 9: 166–174. JSTOR 2386398. 
34. ^ ^{a b} Gerrodette, Tim; Gilmartin William G (1980). "Demographic consequences of changed pupping and hauling sites of the Hawaiian monk seal". Conservation Biology 4: 423–430. JSTOR 2385936. 
35. ^ Aguirre, A.; T. Keefe, J. Reif, L. Kashinsky, P. Yochem (2007). "Infectious disease monitoring of the endangered Hawaiian monk seal". Journal of Wildlife Diseases 43 (2): 229–241. 

External links

• Hawaiian Monk Seal Recovery Program, NOAA Fisheries Service Protected Resources Division
• The Monachus Guardian
• NOAA Midway Island Captive Care & Release Project
• Kauai Monk Seal Watch website
• Monk Seal Video in Oahu
• "Watching Out for Makana" feature about Hawaiian monk seals on Maui by Hannah Bernard, Maui No Ka 'Oi Magazine, Vol.8 No.2 (July 2004).
• Weekend Window to Niihau, Hawaii's 'Forbidden Island'
• Field notes and observations on Koki the monk seal born Hana October 9, 2009 by Dr. George R. Harker
• Monk Seal Foundation website