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Known to the native Hawaiians as '''{{okina}}Ilio-holo-i-ka-uaua''', or "dog that runs in rough water."The Hawaiian monk seal is named after the German scientist [[H.H. Schauinslandi]], who discovered the first skull on [[Laysan Island]] in 1899.<ref name=Reeves>{{cite journal|last=Reeves|first=R.R.|coauthors=Stewert, B.S.|title=National Audubon Society Guide to Marine Mammals of the World|year=2002}}</ref> Its common name comes from the short hairs on its head resembling a [[monk]].<ref name="NOAA Fish">{{cite web|title=Hawaiian Monk Seal (Monachus schauinslandi)|url=http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/hawaiianmonkseal.htm|publisher=NOAA Fisheries Office of Protected Resources|accessdate=11 Mar 2011}}</ref> 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.<ref name="NOAA Fish"/>
Known to the native Hawaiians as '''{{okina}}Ilio-holo-i-ka-uaua''', or "dog that runs in rough water."The Hawaiian monk seal is named after the German scientist [[H.H. Schauinslandi]], who discovered the first skull on [[Laysan Island]] in 1899.<ref name=Reeves>{{cite journal|last=Reeves|first=R.R.|coauthors=Stewert, B.S.|title=National Audubon Society Guide to Marine Mammals of the World|year=2002}}</ref> Its common name comes from the short hairs on its head resembling a [[monk]].<ref name="NOAA Fish">{{cite web|title=Hawaiian Monk Seal (Monachus schauinslandi)|url=http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/hawaiianmonkseal.htm|publisher=NOAA Fisheries Office of Protected Resources|accessdate=11 Mar 2011}}</ref> 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.<ref name="NOAA Fish"/>



The Hawaiian monk seal is the only seal native to [[Hawaii]]<ref name=Nitta>{{cite journal|last=Nitta|first=Eugene|coauthors=Henderson J.R.|title=A review of interactions between Hawaii's fisheries and protected species|journal=Marine Fisheries Review|year=1993|volume=55|series=83|issue=2|accessdate=21 April 2011}}</ref>. It’s grey coat, white belly, and slender physique distinguish them from their cousin, the [[Harbor seal]] (Phoca ‘’vitulina’’)<ref name=nmfs>{{cite web|title=Hawaiian Monk Seal (Monachus schauinslandi)|url=http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/hawaiianmonkseal.htm|publisher=NOAA Fisheries Office of Protected Resources|accessdate=11 March2011}}</ref> . The monk seal’s physique is ideal for hunting its prey: fish, lobster, octopus and squid in deep-water coral beds<ref name=Goodman>{{cite journal|last=Goodman-Lowe|first=G.D.|title=Diet of the Hawaiian Monk Seal ( MonachusSchauinslandi) from the Northwestern Hawaiian Islands during 1991 to 1994|journal=Marine Biology|year=1998|volume=132|series=3|pages=535-46}}</ref> . 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]]<ref name=Baker>{{cite journal|last=Baker|first=J|title=Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands|journal=Biological Conservation|year=2004|volume=116|series=1|pages=103-10}}</ref> . These monk seals are a [[conservation reliant species|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 commercial hunting for skins. There are many methods of [[conservation|conservation biology]] when it comes to endangered species; [[Translocation (wildlife conservation)|translocation]], captive care, habitat clean up, and educating the public about the Hawaiian monk seal are some of the methods that can be employed. <ref name=Boland>{{cite journal|last=Boland|first=R|coauthors=M Donohue|title=Marine Debris Accumulation in the Nearshore Marine Habitat of theEndangered Hawaiian Monk Seal, Monachus Schauinslandi|journal=Marine Pollution Bulletin|year=2003|volume=46|series=11|pages=1385-139}}</ref> <ref name=SchultzExtremely>{{cite journal|last=Schultz J|coauthors=Baker J. , Toonen R. , Bowen B|title=Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)|journal=Journal of Heredity|year=2009|volume=100|series=1|pages=25-33}}</ref> <ref name=SchultzRange>{{cite journal|last=Schultz|first=J|coauthors=Baker J. , Toonen R. , Bowen B.|title=Range-Wide Genetic Connectivity of the Hawaiian Monk Seal and Implications for Translocation|journal=Conservation Biology|year=2011|volume=25|series=1|pages=124-132}}</ref>
The Hawaiian monk seal is the only seal native to [[Hawaii]]<ref name=Nitta>{{cite journal|last=Nitta|first=Eugene|coauthors=Henderson J.R.|title=A review of interactions between Hawaii's fisheries and protected species|journal=Marine Fisheries Review|year=1993|volume=55|series=83|issue=2|accessdate=21 April 2011}}</ref>. It’s grey coat, white belly, and slender physique distinguish them from their cousin, the [[Harbor seal]] (Phoca ‘’vitulina’’)<ref name=nmfs>{{cite web|title=Hawaiian Monk Seal (Monachus schauinslandi)|url=http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/hawaiianmonkseal.htm|publisher=NOAA Fisheries Office of Protected Resources|accessdate=11 March2011}}</ref> . The monk seal’s physique is ideal for hunting its prey: fish, lobster, octopus and squid in deep-water coral beds<ref name=Goodman>{{cite journal|last=Goodman-Lowe|first=G.D.|title=Diet of the Hawaiian Monk Seal ( MonachusSchauinslandi) from the Northwestern Hawaiian Islands during 1991 to 1994|journal=Marine Biology|year=1998|volume=132|series=3|pages=535-46}}</ref> . 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]]<ref name=Baker>{{cite journal|last=Baker|first=J|title=Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands|journal=Biological Conservation|year=2004|volume=116|series=1|pages=103-10}}</ref> . These monk seals are a [[conservation reliant species|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 commercial hunting for skins. There are many methods of [[conservation|conservation biology]] when it comes to endangered species; [[Translocation (wildlife conservation)|translocation]], captive care, habitat clean up, and educating the public about the Hawaiian monk seal are some of the methods that can be employed. <ref name=Boland>{{cite journal|last=Boland|first=R|coauthors=M Donohue|title=Marine Debris Accumulation in the Nearshore Marine Habitat of theEndangered Hawaiian Monk Seal, Monachus Schauinslandi|journal=Marine Pollution Bulletin|year=2003|volume=46|series=11|pages=1385-139}}</ref> <ref name=SchultzExtremely>{{cite journal|last=Schultz J|coauthors=Baker J. , Toonen R. , Bowen B|title=Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)|journal=Journal of Heredity|year=2009|volume=100|series=1|pages=25-33}}</ref> <ref name=SchultzRange>{{cite journal|last=Schultz|first=J|coauthors=Baker J. , Toonen R. , Bowen B.|title=Range-Wide Genetic Connectivity of the Hawaiian Monk Seal and Implications for Translocation|journal=Conservation Biology|year=2011|volume=25|series=1|pages=124-132}}</ref>
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Adult monk seals, like elephant seals, display an unusual type of molt each year in which the outer layer of skin is shed along with the old hair. Adult males molt in late summer and fall. Female monk seals usually molt after [[weaning]] their pups. Molting allows the seals' hair and upper layer of skin, which are subject to constant wear and tear, to be replaced. The new hair which develops is able to provide better insulation for the winter months ahead in the case of the males, or for females, after the nursing period when the mothers have used up much of their fat reserves.
Adult monk seals, like elephant seals, display an unusual type of molt each year in which the outer layer of skin is shed along with the old hair. Adult males molt in late summer and fall. Female monk seals usually molt after [[weaning]] their pups. Molting allows the seals' hair and upper layer of skin, which are subject to constant wear and tear, to be replaced. The new hair which develops is able to provide better insulation for the winter months ahead in the case of the males, or for females, after the nursing period when the mothers have used up much of their fat reserves.

⚫
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.<ref name=Gilmartin>{{cite journal|last=Gilmartin|first=William|coauthors=Forcada, J.|title=Monk Seals|journal=ncyclopedia of Marine Mammals, eds|year=2002|pages=756-759}}</ref> 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.<ref name="NOAA Fish"/> 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 and propel themselves through the water. <ref name=Kenyon>{{cite journal|last=Kenyon|first=K.W.|coauthors=Rice, D.W.|title=Life History Of the Hawaiian Monk Seal|journal=Pacific Science|volume=13}}</ref>


A number of Hawaiian monk seals sport scars from [[shark]] attacks or injuries from fishing gear. Females are often scarred by encounters with males, which can be particularly brutal while mating. Adult males are {{convert|300|to|400|lb}} in weight and {{convert|7|ft}} in length while adult females tend to be much larger, being {{convert|400|to|600|lb}} pounds and {{convert|8|ft}} feet in length. Pups average {{convert|30|to|40|lb}} at birth and {{convert|40|in|m}} in length. They get much larger, weighing in between 150 to 200 pounds before they stop nursing. Life expectancies are 25 to 30 years.
A number of Hawaiian monk seals sport scars from [[shark]] attacks or injuries from fishing gear. Females are often scarred by encounters with males, which can be particularly brutal while mating. Adult males are {{convert|300|to|400|lb}} in weight and {{convert|7|ft}} in length while adult females tend to be much larger, being {{convert|400|to|600|lb}} pounds and {{convert|8|ft}} feet in length. Pups average {{convert|30|to|40|lb}} at birth and {{convert|40|in|m}} in length. They get much larger, weighing in between 150 to 200 pounds before they stop nursing. Life expectancies are 25 to 30 years.

⚫
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.<ref name=Gilmartin>{{cite journal|last=Gilmartin|first=William|coauthors=Forcada, J.|title=Monk Seals|journal=ncyclopedia of Marine Mammals, eds|year=2002|pages=756-759}}</ref> 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.<ref name="NOAA Fish"/> 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 and propel themselves through the water. <ref name=Kenyon>{{cite journal|last=Kenyon|first=K.W.|coauthors=Rice, D.W.|title=Life History Of the Hawaiian Monk Seal|journal=Pacific Science|volume=13}}</ref>

==History and evolution==
==History and evolution==
The evolutionary history of the monk seal is controversial since there are different hypotheses for the [[phylogenetic]] position relative to other [[phocids]].<ref name=Repenning>{{cite journal|last=Repenning|first=C.A.|coauthors=Ray, C.E.|title=he origin of the Hawaiian monk seal|journal=Proc. Biol. Soc. Wash|year=1977|volume=89|pages=667-688}}</ref> 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.<ref name=Repenning/>
The evolutionary history of the monk seal is controversial since there are different hypotheses for the [[phylogenetic]] position relative to other [[phocids]].<ref name=Repenning>{{cite journal|last=Repenning|first=C.A.|coauthors=Ray, C.E.|title=he origin of the Hawaiian monk seal|journal=Proc. Biol. Soc. Wash|year=1977|volume=89|pages=667-688}}</ref> 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.<ref name=Repenning/>
Line 44: Line 43:


==Habitat==
==Habitat==
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.<ref name=Baker>{{cite journal|last=Baker|first=J|title=Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands|journal=Biological Conservation|year=2004|volume=116|pages=103-10}}</ref> These seals spend two-thirds of their time at sea, and one-third on the sandy beaches. A study done at Midway Islands concluded that these seals frequently stayed inside the lagoons rather than in deep water which be contributed to the fact that the lagoons contain coral beds that are rich in fish <ref name=Kenyon/>. Further more, they forage in the deep-water coral beds and breed and haul-out on sand, corals, and volcanic rock. Sandy beaches are more commonly used for pupping.<ref name=Baker/> Unlike the adults who haul at temporary sandpits, newborn pups were above high tide, a few yards from permanent dry land.<ref name=Kenyon/> The Hawaiian monk seal’s habitat is limited to Hawaii and smaller islands like Midway, due to the immense distances from Hawaii to the next landmasses that have the proper resources.
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.<ref name=Baker>{{cite journal|last=Baker|first=J|title=Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands|journal=Biological Conservation|year=2004|volume=116|pages=103-10}}</ref> These seals spend two-thirds of their time at sea, and one-third on the sandy beaches. A study done at the Midway Islands 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 <ref name=Kenyon/>. Further more, they forage in the deep-water coral beds and breed and haul-out on sand, corals, and volcanic rock. Sandy beaches are more commonly used for pupping.<ref name=Baker/> Unlike the adults who haul at temporary sandpits, newborn pups were above high tide, a few yards from permanent dry land.<ref name=Kenyon/> The Hawaiian monk seal’s habitat is limited to Hawaii and smaller islands like Midway, due to the immense distances from Hawaii to the next landmasses that have the proper resources.


==Diet==
==Diet==

Revision as of 21:02, 22 April 2011

Hawaiian Monk Seal
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 the German scientist H.H. Schauinslandi, 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]. It’s grey coat, white belly, and slender physique distinguish them from their cousin, the Harbor seal (Phoca ‘’vitulina’’)[6] . The monk seal’s physique is ideal for hunting its prey: fish, lobster, octopus and squid in deep-water coral beds[7] . 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[8] . 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 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. [9] [10] [11]

Description

Monk seal pups are born with a woolly black coat which is shed through a process called molting at the end of their nursing period. The birth coat is replaced by juvenile pelage which is silvery gray on the back and sides and white on the belly, chest and throat. Under exposure to sunlight and seawater, the juvenile pelage changes gradually in color to a dull brown as is found in adults.

Adult monk seals, like elephant seals, display an unusual type of molt each year in which the outer layer of skin is shed along with the old hair. Adult males molt in late summer and fall. Female monk seals usually molt after weaning their pups. Molting allows the seals' hair and upper layer of skin, which are subject to constant wear and tear, to be replaced. The new hair which develops is able to provide better insulation for the winter months ahead in the case of the males, or for females, after the nursing period when the mothers have used up much of their fat reserves.

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.[12] 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 and propel themselves through the water. [13]

A number of Hawaiian monk seals sport scars from shark attacks or injuries from fishing gear. Females are often scarred by encounters with males, which can be particularly brutal while mating. 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 much larger, being 400 to 600 pounds (180 to 270 kg) pounds and 8 feet (2.4 m) feet in length. Pups average 30 to 40 pounds (14 to 18 kg) at birth and 40 inches (1.0 m) in length. They get much larger, weighing in between 150 to 200 pounds before they stop nursing. Life expectancies are 25 to 30 years.

History and evolution

The evolutionary history of the monk seal is controversial since there are different hypotheses for the phylogenetic position relative 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. The NOAA believes that about 4-11 million years ago (mya) Monk seals made their way to Hawaii through an open water passage between North and South America called the Central American Seaway. Then about 1,400 A.D. Hawaiian monk seal bones were discovered by researchers in the Lapakahi archaeological site. During the 19th century, sealing expeditions reduced the Hawaiian monk seal population 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] Some believe that the species evolved in the Pacific or Atlantic and is endemic to the Hawaiian Islands and some believe that the species came to the islands at a later time. Still, to this day no one knows if the Hawaiian monk seal is the oldest or the youngest seal in the Monachus genus.[15] There are a lot of unanswered questions on the history and evolution of these species and only more experiments and studies on the Hawaiian monk seal can determine the answers.

Habitat

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.[8] These seals spend two-thirds of their time at sea, and one-third on the sandy beaches. A study done at the Midway Islands 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 [13]. Further more, they forage in the deep-water coral beds and breed and haul-out on sand, corals, and volcanic rock. Sandy beaches are more commonly used for pupping.[8] Unlike the adults who haul at temporary sandpits, newborn pups were above high tide, a few yards from permanent dry land.[13] The Hawaiian monk seal’s habitat is limited to Hawaii and smaller islands like Midway, due to the immense distances from Hawaii to the next landmasses that have the proper resources.

Diet

Hawaiian monk seals mainly prey on teleosts (bony fish), but they also prey on cephalopods, and crustaceans. [7] 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. [7] 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.[7]


Mating and Reproduction

The Hawaiian monk seals mate in the water during their breeding season, which occurs between the months of December and August.[6] Females reach maturity at age four and give birth to one pup a year. The Hawaiian monk seal fetus takes nine months to develop. Most pups are born in March and June and usually weigh about 16 kg and are about 1m long.[6] 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.[13] 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. [13]

Ecological Interactions

Tiger sharks and Galapagos sharks are both predators of the Hawaiian monk seals. [16] 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.[17] 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.[17] Additionally, Hawaiian monk seals also have frequent human encounters from commercial fishermen and tourists. [17]

Threats

Photo of seal on the beach, looking directly at the photographer
Hauled-out seal
Underwater photo of seal in profile with open eye and an apparent smile
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.[18] U.S. forces hunted them during World War II while occupying Laysan Island and Midway.[18]

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.[19]

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.[20] It is currently found on Laysan, Midway, Pearl and Hermes Atoll, French Frigate Shoals, and Lisianski.[20]

In the summer of 2009, two monk seals were shot and killed.[21] 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[22], 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.[23]

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

Endangered status

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.[24] 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.[25] 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[26]

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.[27]

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.[28] Anthropogenic or human impacts to monk seals include hunting (during 1800s and 1900s), human disturbance, entanglement in marine debris, and fishery interactions. [28]

Natural Factors

Of 18 pinniped species, the Hawaiian Monk Seal has the lowest level of genetic variability.[10] A study found that this low genetic variability is due to a population bottleneck caused by intense hunting in the 19th century.[10] This lacking in genetic variability reduces the species ability to adapt to environmental pressures and limits natural selection thus increasing their risk of extinction.[10] 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.[29] 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.[29]

Additionally, low juvenile survival rates continue to threaten the species. High juvenile mortality is due to starvation, shark predation, and marine debris entanglement.[10] 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.[28] 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.[28] 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.[28] Additionally, marine debris entanglement can result in mortality because the seals get trapped in debris such as fishing nets and cannot escape.[10]

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.[30] Mobbing leaves the targeted individual with many wounds that lead to septicemia and the seals then die from infection.[30] 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. [31] 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.[31]

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 which then limits population growth.[28] 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.[28]

Entanglement in marine debris is another huge impact from people that cause great damage to the seal populations, despite international law prohibiting the intentional discard of debris from ships at sea.[28] 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 this abating in the future.[28]

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 fed on fish refuse.[28] 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. [28]

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.[29]

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.[28] 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.[28] 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.[9]

In 1909, President Theodore Roosevelt created the Hawaiian Islands Reservation that included all islands in the Northwest Hawaiian islands.[28] 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.[28] 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.[31] 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.[32] 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.[32] 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.[11]

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 these efforts.[33] 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.[11] Although, many of these conservation methods are in practice today, further efforts are needed in order to prevent extinction of the Hawaiian Monk Seal.

References

  1. ^ Template:IUCN2008 Listed as Critically Endangered (CR A3ce+4ce)
  2. ^ Hawaiian Monk Seal, Monachus schauinslandi
  3. ^ Reeves, R.R. (2002). "National Audubon Society Guide to Marine Mammals of the World". {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  4. ^ a b c "Hawaiian Monk Seal (Monachus schauinslandi)". NOAA Fisheries Office of Protected Resources. Retrieved 11 Mar 2011.
  5. ^ Nitta, Eugene (1993). "A review of interactions between Hawaii's fisheries and protected species". Marine Fisheries Review. 83. 55 (2). {{cite journal}}: |access-date= requires |url= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ a b c "Hawaiian Monk Seal (Monachus schauinslandi)". NOAA Fisheries Office of Protected Resources. Retrieved 11 March2011. {{cite web}}: Check date values in: |accessdate= (help)
  7. ^ a b c d Goodman-Lowe, G.D. (1998). "Diet of the Hawaiian Monk Seal ( MonachusSchauinslandi) from the Northwestern Hawaiian Islands during 1991 to 1994". Marine Biology. 3. 132: 535–46.
  8. ^ a b c Baker, J (2004). "Abundance of the Hawaiian Monk Seal in the Main Hawaiian Islands". Biological Conservation. 1. 116: 103–10. Cite error: The named reference "Baker" was defined multiple times with different content (see the help page).
  9. ^ a b Boland, R (2003). "Marine Debris Accumulation in the Nearshore Marine Habitat of theEndangered Hawaiian Monk Seal, Monachus Schauinslandi". Marine Pollution Bulletin. 11. 46: 1385–139. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  10. ^ a b c d e f Schultz J (2009). "Extremely Low Genetic Diversity in the Endangered Hawaiian Monk Seal (Monachus Schauinslandi)". Journal of Heredity. 1. 100: 25–33. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  11. ^ a b c Schultz, J (2011). "Range-Wide Genetic Connectivity of the Hawaiian Monk Seal and Implications for Translocation". Conservation Biology. 1. 25: 124–132. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  12. ^ Gilmartin, William (2002). "Monk Seals". ncyclopedia of Marine Mammals, eds: 756–759. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ a b c d e Kenyon, K.W. "Life History Of the Hawaiian Monk Seal". Pacific Science. 13. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ a b Repenning, C.A. (1977). "he origin of the Hawaiian monk seal". Proc. Biol. Soc. Wash. 89: 667–688. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  15. ^ a b Berta, Annalisa (1999). "Marine Mammals". Evolutionary Biology. Academic Press. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ Bertilsson-Friedman, P. (2006). "Distribution and Frequencies of Shark-inflicted Injuries to the Endangered Hawaiian Monk Seal (MonachusSchauinslandi)". Journal of Zoology. 268 (4): 361–68.
  17. ^ 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. Retrieved 16 Marh 2011. {{cite web}}: Check date values in: |accessdate= (help)
  18. ^ a b Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. p. 194. ISBN 0-06-055804-0.
  19. ^ Hawaiian Monk Seals
  20. ^ a b Ellis, Richard (2004). No Turning Back: The Life and Death of Animal Species. New York: Harper Perennial. p. 195. ISBN 0-06-055804-0.
  21. ^ Federal officials probe deliberate killing of seal. The Maui News. Posted December 19, 2009
  22. ^ Campaign to Protect Turtle Bay (HI)
  23. ^ "Rough Water Pups"
  24. ^ "Feds: Caribbean Monk Seal Officially Extinct". Fox News. 2008-06-09.
  25. ^ The Captive Care and Release Research Project Seeks to Aid Recovery of the Endangered Hawaiian Monk Seal
  26. ^ http://www.pbs.org/kqed/oceanadventures/episodes/kure/oceanscience.html
  27. ^ KHNL NBC 8 Honolulu Hawaii |Hawaiian monk seal is the new state mammal
  28. ^ a b c d e f g h i j k l m n o Antonelis, G.A. (2006). "Hawaiian monk seal (Monachus schauins-landi): status and conservation issues". Atoll Res Bull. 543: 75–101. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  29. ^ a b c Gilmartin, W.G. (1983). "Recovery plan for the Hawaiian monk seal, Monachus schauinslandi". U.S. Department of Com-merce, NOAA, National Marine Fisheries Service.
  30. ^ a b Banish, L. (1992). "Pathological findings in the Hawaiian monk seal". Journal of Wildlife Diseases. 28 (3): 428–434. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  31. ^ a b c Starfield, A.M (1995). "Mobbing in Hawaiian monk seals: the value of simulation modeling in the absence of apparently crucial data". Conserv. Biol. 9: 166–174. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  32. ^ a b Gerrodette, T. (1980). "Demographic consequences of changed pupping and hauling sites of the Hawaiian monk seal". Conservation Biology. 4: 423–430. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  33. ^ Aguirre, A. (2007). "Infectious disease monitoring of the endangered Hawaiian monk seal". Journal of Wildlife Diseases. 43 (2): 229–241. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)


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