Editing Hawaiian monk seal

{{Short description|Species of carnivore}}
{{Use mdy dates|date=September 2019}}
{{Speciesbox
| name = Hawaiian monk seal
| image = Monachus schauinslandi.jpg
| image_caption = Hawaiian monk seal at [[Kaʻula]]
| status = EN
| status_system = IUCN3.1
| status_ref = <ref name=iucn>{{cite journal |author1=Littnan, C. |author2=Harting, A. |author3=Baker, J. | title = ''Neomonachus schauinslandi'' | journal = [[IUCN Red List of Threatened Species]] | volume= 2015 | page = e.T13654A45227978 | year = 2015 | doi = 10.2305/IUCN.UK.2015-2.RLTS.T13654A45227978.en | doi-access = free }}</ref>
| genus = Neomonachus
| species = schauinslandi
| authority = ([[Paul Matschie|Matschie]], 1905)
| synonyms = 
''Monachus schauinslandi''<br/><small>Matschie, 1905</small><ref name=iucn />
| range_map = Hawaiian Monk Seal area.png
| range_map_caption = Hawaiian monk seal range
}}

The '''Hawaiian monk seal''' ('''''Neomonachus schauinslandi''''') is an [[endangered species]] of [[earless seal]] in the [[family (biology)|family]] [[Phocidae]] that is [[Endemic (ecology)|endemic]] to the [[Hawaiian Islands]].<ref>{{cite web |url=http://www.monachus-guardian.org/factfiles/hawai01.htm |title=Hawaiian Monk Seal, ''Monachus schauinslandi '' |year=2006 |website=monachus-guardian.org |access-date=May 23, 2011}}</ref>

The Hawaiian monk seal is one of two extant [[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]], and, along with the [[Hawaiian hoary bat]], is one of only two mammals endemic to the islands.<ref name=Nitta>{{cite journal|last=Nitta|first=Eugene|author2=Henderson JR |title=A review of interactions between Hawaii's fisheries and protected species |journal=Marine Fisheries Review |year=1993 |volume=55 |series=83 |issue=2 |url=http://spo.nmfs.noaa.gov/mfr552/mfr55210.pdf |access-date=May 23, 2011}}</ref>

''N. schauinslandi'' is a [[conservation reliant species|conservation reliant endangered species]]. The small population of about 1,400 individuals is threatened by human encroachment, very low levels of [[genetic variation]], entanglement in [[fishing net]]s, [[marine debris]], disease, and past commercial hunting for skins.<ref name=":0">{{Cite web|url=http://www.fpir.noaa.gov/PRD/prd_hms_population_threats.html|title=Monk Seal: Population Size and Threats|website=Pacific Islands Regional Office, NOAA Fisheries, Dept. of Commerce.|access-date=February 17, 2017}}</ref><ref>{{Cite news|url=http://hpr2.org/post/hawaiian-monk-seal-population-rise|title=Hawaiian Monk Seal Population On The Rise|last=Solomon|first=Molly|date=January 25, 2017|access-date=June 11, 2018|publisher=Hawaii Public Radio|location=Honolulu, HI|website=hpr2.org}}</ref> There are many methods of [[conservation biology]] when it comes to [[endangered species]]; [[Translocation (wildlife conservation)|translocation]], captive care, habitat cleanup, 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 |author2=Donohue, R |title=Marine Debris Accumulation in the Nearshore Marine Habitat of the Endangered Hawaiian Monk Seal, Monachus Schauinslandi |journal=Marine Pollution Bulletin |year=2003 |volume=46 |series=11 |pages=1385–139 |doi=10.1016/S0025-326X(03)00291-1 |pmid=14607537 |issue=11 }}</ref><ref name=SchultzExtremely>{{cite journal|last1=Schultz J|author2=Baker J |author3=Toonen R |author4=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 |doi=10.1093/jhered/esn077 |issue=1|first1=J. K.|pmid=18815116|doi-access=free }}</ref><ref name=SchultzRange>{{cite journal|last=Schultz|first=J|author2=Baker J |author3=Toonen R |author4=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 |pmid=21166713 |doi=10.1111/j.1523-1739.2010.01615.x|issue=1 |bibcode=2011ConBi..25..124S|s2cid=25475001}}</ref>
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== Etymology ==
Known to native Hawaiians as '''{{okina}}Ilio-holo-i-ka-uaua''', or "dog that runs in rough water", its [[scientific name]] is from [[Hugo Schauinsland]], a German scientist who discovered a skull on [[Laysan Island]] in 1899.<ref name=Reeves>{{cite book |last=Reeves |first=RR |author2=Stewert, BS |title=National Audubon Society Guide to Marine Mammals of the World |year=2002 |publisher=Knopf Doubleday Publishing |isbn=978-0-375-41141-0 |url-access=registration |url=https://archive.org/details/guidetomarinemam00folk }}</ref> Its [[common name]], and the first element of its scientific name, comes from short hairs on its head, said to resemble 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 |website=NOAA Fisheries Office of Protected Resources |access-date=March 11, 2011}}</ref> It is the official state mammal of Hawaii.<ref>{{cite web| title=Haw. Rev. Stat. § 5-12.5 (State mammal) | author=Hawaii State Legislature | url=http://www.capitol.hawaii.gov/hrscurrent/Vol01_Ch0001-0042F/HRS0005/HRS_0005-0012_0005.htm | access-date=November 7, 2014}}</ref>

==Description==
Its grey coat, white belly, and slender physique distinguish them from the distantly related [[harbor seal]] (''Phoca vitulina'').<ref name="NOAA Fish"/> 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=GD |title=Diet of the Hawaiian Monk Seal (''Monachus Schauinslandi'') from the Northwestern Hawaiian Islands during 1991 to 1994 |journal=Marine Biology |year=1998 |volume=132 |series=3 |pages=535–46 |url=http://www.csulb.edu/~ggoodman/files/DietHMS.pdf |access-date=May 23, 2011|doi=10.1007/s002270050419|issue=3|bibcode=1998MarBi.132..535G |s2cid=84310964 }}</ref> When it is not hunting and eating, it generally [[hauling-out|basks]] on the sandy beaches and volcanic rock of the [[Northwest Hawaiian Islands]].<ref name=Baker>{{cite journal|last1=Baker|first1=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|doi=10.1016/S0006-3207(03)00181-2|last2=Johanos|first2=Thea C.|issue=1|bibcode=2004BCons.116..103B}}</ref>

The Hawaiian monk seal is part of the family [[Phocidae]], being named so for its characteristic lack of external ears and inability to rotate its hind [[Flipper (anatomy)|flipper]]s under the body.<ref name=Gilmartin>{{cite book |last=Gilmartin |first=William |author2=Forcada, J. |title=Monk Seals |editor=Encyclopedia of Marine Mammals|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.<ref name=Kenyon>{{cite journal|last=Kenyon |first=KW |author2=Rice, DW |title=Life History Of the Hawaiian Monk Seal |journal=Pacific Science |volume=13 |url=http://scholarspace.manoa.hawaii.edu/handle/10125/7958 |access-date=May 23, 2011|date=July 1959 |hdl=10125/7958 }}</ref>

Adult males are {{convert|300|to|400|lb|kg|order=flip|abbr=off}} in weight and {{convert|7|ft|m|order=flip|abbr=off}} in length while adult females tend to be, on average, slightly larger, at {{convert|400|to|600|lb|kg|order=flip|abbr=on}} and {{convert|8|ft|m|order=flip|abbr=on}} in length. When monk seal pups are born, they average {{convert|30|to|40|lb|kg|order=flip|abbr=on}} and {{convert|40|in|m|order=flip|abbr=on|0}} in length.  As they nurse for approximately six weeks, they grow considerably, eventually weighing between {{convert|150|and|200|lb|kg|-1|order=flip|abbr=on}} by the time they are [[weaning|weaned]], while the mother loses up to {{convert|300|lb|kg|order=flip|abbr=on}}.

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,<ref>{{cite book|last1=Perrin|first1=William F.|author2=Bernd Wursig|author3=J. G. M. Thewissen|title=Encyclopedia of Marine Mammals|url=https://books.google.com/books?id=2rkHQpToi9sC&pg=PA741|date= 2008|publisher=Academic Press|isbn=978-0-12-373553-9|page=741}}</ref> 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 net|fishing gear]]. Maximum life expectancy is 25 to 30 years.

==Evolution and migration==
[[File:MonachusSchauinslandi.jpg|thumb|right|Hauled-out seal on [[Laysan Island]]|alt=Photo of seal on the beach, looking directly at the photographer]]
The monk seals are members of the Phocidae. In an influential 1977 paper, Repenning and Ray proposed, based on certain unspecialized features, that they were the most primitive living seals.<ref name=Repenning>{{cite journal|last=Repenning |first=CA |author2=Ray, CE |title=The origin of the Hawaiian monk seal |url=https://www.biodiversitylibrary.org/page/34554139#page/337/mode/1up|journal=Proc. Biol. Soc. Wash. |year=1977 |volume=89 |pages=667–688}}</ref> However, this idea has since been entirely superseded.

In an effort to inform the public and conserve the seals, the [[National Oceanic Atmospheric Administration]] (NOAA) Fisheries Service developed a historical timeline 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 migrating to Hawaii between 4–11 million years ago (mya) through an open water passage between North and South America called the [[Central American Seaway]]. The [[Isthmus of Panama]] closed the Seaway approximately 3 million years ago.<ref name="FIPR HMS timeline">{{cite web|url=http://www.fpir.noaa.gov/Library/PRD/Hawaiian%20monk%20seal/HMS_natural_history_timelineWEB.pdf|title=Historical Timeline of the Hawaiian Monk Seal|date=June 29, 2011|website=[[National Marine Fisheries Service]], Pacific Islands Regional Office|location=Honolulu, HI, USA|access-date=November 19, 2012}}</ref>

Berta and Sumich ask how this species came to the Hawaiian Islands when its closest relatives are on the other side of the world in the [[North Atlantic]] and [[Mediterranean Sea]].<ref name=Berta>{{cite book|last=Berta |first=Annalisa |author2=Sumich, James L |title=Marine Mammals |work=Evolutionary Biology |publisher=Academic Press |year=1999 | isbn = 978-0-12-093225-2 }}</ref> The species may have evolved in the [[Pacific]] or [[Atlantic]], but in either case, came to Hawaii long before the first [[Polynesians]].

==Ecology==

===Habitat===
[[File:Sleeping seal.JPG|thumb|right|A Hawaiian monk seal observed in [[Kauai]]|alt=A Hawaiian monk seal observed in Kauai]]
[[File:PMNM - monk seal and turtle (27705150490).jpg|thumb|Monk seal with [[green sea turtle]] at Papahānaumokuākea Marine National Monument]]
The majority of the Hawaiian monk seal population can be found around the [[Northwest Hawaiian Islands]] but a small and growing population lives around the main [[Hawaiian Islands]].<ref name=Baker /> These seals spend two-thirds of their time at sea. Monk seals spend much of their time foraging in deeper water outside of shallow lagoon reefs at sub-photic depths of {{convert|300|m|fathom}} or more.<ref name=Parrish>{{cite journal|last1=Parrish|first1=FA|last2=Littnan|first2=CL|title=Changing perspectives in Hawaiian monk seal research using animal-borne imaging|journal=Marine Technology Society Journal|year=2008|volume=41|issue=4|pages=30–34 |url=http://www.pifsc.noaa.gov/library/pubs/Parrish_MTSJ_2008.pdf |access-date=May 23, 2011|doi=10.4031/002533207787441944 }}</ref><ref name=Parrish1999>{{cite book |author=Parrish, Frank A |title=Use of Technical Diving to Survey Forage Habitat of the Endangered Hawaiian Monk Seal |editor=In: Hamilton RW, Pence DF |editor2=Kesling DE Assessment |editor3=Feasibility of Technical Diving Operations for Scientific Exploration |publisher=[[American Academy of Underwater Sciences]] |year=1999 |url=http://archive.rubicon-foundation.org/9003 |archive-url=https://archive.today/20130113044602/http://archive.rubicon-foundation.org/9003 |url-status=usurped |archive-date=January 13, 2013 |access-date=May 23, 2011}}</ref> Hawaiian monk seals breed and haul-out on sand, corals, and volcanic rock; sandy beaches are more commonly used for pupping.<ref name=Baker/> 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 the Hawaiian Islands.

===Feeding===
Hawaiian monk seals mainly prey on reef dwelling [[bony fish]], but they also prey on [[cephalopods]], and [[crustaceans]].<ref name=Goodman/>  Both juveniles and sub-adults prey more on smaller octopus species, such as ''Octopus leteus'' and ''O. hawaiiensis'', nocturnal octopus species, and eels than the adult Hawaiian monk seals,<ref name=Goodman/> while adult seals feed mostly on larger octopus species such as ''O. cyanea''. Hawaiian monk seals have a broad and diverse diet due to [[foraging]] [[Phenotypic plasticity|plasticity]] which allows them to be opportunistic predators that feed on a wide variety of available prey.<ref name=Goodman/>

Hawaiian monk seals can hold their breath for up to 20 minutes and dive more than {{convert|1800|ft|m|order=flip|abbr=on}}; however, they usually dive an average of 6 minutes to depths of less than {{convert|200|ft|m|order=flip|-1|abbr=on}} to forage at the seafloor.<ref>{{cite web |title=Hawaiian Monk Seal |url=https://www.fisheries.noaa.gov/species/hawaiian-monk-seal |website=NOAA Fisheries |access-date=November 26, 2018}}</ref>

===Predators===
[[Tiger shark]]s, [[great white shark]]s and [[Galapagos shark]]s are the main [[predator]]s of the Hawaiian monk seal.<ref name=Bertilsson>{{cite journal|last=Bertilsson-Friedman |first=P |title=Distribution and Frequencies of Shark-inflicted Injuries to the Endangered Hawaiian Monk Seal (''Monachus Schauinslandi'')|journal=Journal of Zoology|year=2006 |volume=268 |issue=4 |pages=361–68 |doi=10.1111/j.1469-7998.2006.00066.x }}</ref>

==Behavior==
[[File:Endangered Hawaiian monk seal sunning on the beach (6741931081).jpg|thumb|Resting on sands at [[Midway Atoll National Wildlife Refuge]]]]

===Reproduction===
Hawaiian monk seals mate in the water during their breeding season, which occurs between June and August.<ref name="NOAA Fish"/> Females reach maturity at age four and give birth to one pup a year. The [[fetus]] takes nine months to develop, with birth occurring between March and June. Pups start around  {{convert|16|kg|lb|abbr=on}} and are about {{convert|1|m|ftin|abbr=on}} long.<ref name="NWF">{{cite web |url=https://www.nwf.org/Wildlife/Wildlife-Library/Mammals/Hawaiian-Monk-Seal.aspx |title=Hawaiian Monk Seal |website=[[National Wildlife Federation]]  |access-date=July 7, 2015}}</ref>

===Nursing===
The pups are born on beaches and nursed for about six weeks. The mother does not eat or leave the pup while nursing. After that time, the mother deserts the pup, leaving it on its own, and returns to the sea to forage for the first time since the pup's arrival.<ref name=Kenyon/>

==Status==
[[File:Hawaiian monk seal Waimea Bay.jpg|thumb|left|A Hawaiian monk seal observed on the [[North Shore of Oahu]], near [[Waimea Bay, Hawaii|Waimea Bay]]|alt=A Hawaiian monk seal observed on the North Shore of Oahu.]]
Most seals are found on the [[Northwestern Hawaiian Islands]].<ref name="EllisNTB"/>

The Hawaiian monk seal is endangered,<ref>{{cite web |url=http://www.pifsc.noaa.gov/psd/captivecareproject.php |title=The Captive Care and Release Research Project Seeks to Aid Recovery of the Endangered Hawaiian Monk Seal |website=NOAA |access-date=May 23, 2011 }}</ref> although its cousin species, the [[Mediterranean monk seal]] (''M. monachus''), is even rarer, and the even more closely related [[Caribbean monk seal]] (''N. tropicalis''), last sighted in the 1950s, was officially declared extinct in June 2008.<ref>{{cite news |agency=Associated Press |url=https://www.foxnews.com/story/feds-caribbean-monk-seal-officially-extinct |work=Fox News |title=Feds: Caribbean Monk Seal Officially Extinct |date=June 9, 2008 |access-date=May 23, 2011}}</ref> In 2010, it was estimated that only 1100 individuals remained. A later estimate in 2016, which included a more complete survey of small populations, was approximately 1400 individuals.<ref name=":0" />

Seals nearly disappeared from the main islands, but the population has begun to recover. The growing population there was approximately 150 as of 2004<ref name="EllisNTB">{{cite book| last = Ellis| first = Richard| author-link = Richard Ellis (biologist) | title = No Turning Back: The Life and Death of Animal Species| url = https://archive.org/details/noturningbacklif00elli| url-access = registration| publisher = Harper Perennial | year = 2004| location = New York| page = [https://archive.org/details/noturningbacklif00elli/page/195 195]| isbn =978-0-06-055804-8 }}</ref> and 300 as of 2016.<ref name=":0" /> Individuals have been sighted in surf breaks and on beaches in [[Kauai|Kaua{{okina}}i]], [[Niihau|Ni{{okina}}ihau]] and [[Maui]]. Community volunteers on Oʻahu have made many anecdotal blog reports of sightings around the island since 2008. In early June 2010, two seals hauled out on [[Oahu|O{{okina}}ahu]]'s popular [[Waikiki]] beach. Seals have hauled out at [[Turtle Bay, O'ahu|O'ahu's Turtle Bay]],<ref name="monksealmania">{{cite web |url= http://monksealmania.blogspot.com/search/label/Turtle%20Bay |title= Turtle Bay |year=2012  |access-date=November 19, 2012|website=MonkSealMania.blogspot.com}}</ref> and again beached at Waikiki on March 4, 2011, by the [[Moana Hotel]].  Another Monk Seal appeared at Punalu'u Black Sands Beach in July 2023. Yet another adult came ashore for a rest next to the breakwater in Kapiolani Park Waikiki on the morning of December 11, 2012, after first being spotted traveling west along the reef break from the Aquarium side of the Park. On June 29, 2017 monk seal #RH58 popularly known as "Rocky" gave birth to a pup on [[Kaimana Beach]] fronting Kapiolani park. Despite the fact Kaimana beach is popular and busy, Rocky has been routinely hauling out on this beach for several years.<ref>{{cite news|last1=Davis|first1=Chelsea|title=In a rare sight, Hawaiian monk seal and her pup make Waikiki beach home|date=June 29, 2017|url=http://www.hawaiinewsnow.com/story/35784989/in-a-rare-sight-hawaiian-monk-seal-and-her-pup-make-waikiki-beach-home|access-date=June 29, 2017|newspaper=HawaiiNewsNow}}</ref>  In 2006, twelve pups were born in the main islands, rising to thirteen in 2007, and eighteen in 2008. As of 2008 43 pups had been counted in the main islands.<ref>{{cite journal |author=Wianecki, Shannon |journal=Maui Magazine |url=http://www.mauimagazine.net/Maui-Magazine/May-June-2009/Rough-Water-Pups |title=Rough Water Pups |access-date=May 23, 2011 |archive-url=https://web.archive.org/web/20110723204104/http://www.mauimagazine.net/Maui-Magazine/May-June-2009/Rough-Water-Pups/ |archive-date=July 23, 2011 |url-status=dead }}</ref>

[[File:MonkSealBlackSandsBeach.jpeg | thumb|220x124px | right | Hawaiian Monk Seal resting at Punalu’u Black Sands Beach in July 2023]]

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 of 1972|Marine Mammal Protection Act]]. It is illegal to kill, capture or harass a Hawaiian monk seal. Even with these protections, human activity along Hawaii's fragile coastlines (and in the world at large) still provides many stressors.<ref>{{cite web |author=Weber, Gretchen |title=A struggle to survive: Environmental threats endanger monk seals |website=PBS |url=https://www.pbs.org/kqed/oceanadventures/episodes/kure/oceanscience.html |access-date=May 23, 2011}}</ref>

===Threats===
[[File:Hawaiian monk seal - Monachus schauinslandi.jpg|left|thumb|Hawaiian monk seal|alt=Underwater photo of seal in profile with open eye and an apparent smile]]

Natural factors threatening the Hawaiian monk seal include low juvenile survival rates, reduction of habitat/prey associated with environmental changes, increased male aggression, and subsequent skewed gender ratios.<ref name=Antonelis>{{cite journal |last=Antonelis |first=GA |title=Hawaiian monk seal (''Monachus schauinslandi''): status and conservation issues |url=https://www.researchgate.net/publication/237470360|journal=Atoll Res Bull |year=2006 |volume=543 |pages=75–101 (88–89)|display-authors=etal}}</ref> Anthropogenic or human impacts include hunting (during the 1800s and 1900s) and the resulting small gene pool, continuing human disturbance, entanglement in marine debris, and fishery interactions.<ref name=Antonelis/>

====Natural threats====
Low juvenile survival rates continue to threaten the species. High juvenile mortality is due to starvation and marine debris entanglement.<ref name=SchultzExtremely/> Another contributor to the low juvenile survival rates is predation from [[shark]]s, including [[tiger shark]]s. Most mature monk seals bear scars from shark encounters, and many such attacks have been observed.<ref name=Antonelis/>

Reduced prey abundance can lead to starvation, with one cause being reduction in habitat associated with environmental change.<ref name=Antonelis/> Habitat is shrinking due to [[erosion]] in the Northwest Hawaiian Islands, reducing the size of islands/beaches.<ref name=Antonelis/> [[Lobster]]s, the seals' preferred food other than fish, have been overfished. Competition from other predators such as sharks, [[Carangidae|jacks]], and [[barracuda]]s leaves little for developing pups. The creation of [[Papahānaumokuākea Marine National Monument]] which encloses these islands may expand food supplies.

''Mobbing'' is a practice among the seals that involves multiple males attacking one female in mating attempts. Mobbing is responsible for many deaths, especially to females.<ref name=Banish>{{cite journal |last=Banish|first=LD |author2=Gilmartin, WG |title=Pathological findings in the Hawaiian monk seal |journal=Journal of Wildlife Diseases |year=1992 |volume=28 |issue=3 |pages=428–434 |pmid=1512875  |doi=10.7589/0090-3558-28.3.428|s2cid=27886224 |doi-access=free }}</ref>

Mobbing leaves the targeted individual with wounds that increase vulnerability to [[sepsis]], killing the victim via infection.<ref name=Banish/> Smaller populations were more likely to experience mobbing as a result of the higher male/female ratio and male aggression. Unbalanced sex-ratios were more likely to occur in slow-growing populations.<ref name=Starfield>{{cite journal |last=Starfield |first=AM |author2=Roth JD |author3=Ralls K  |title=Mobbing in Hawaiian monk seals: the value of simulation modeling in the absence of apparently crucial data |journal=Conserv. Biol. |year=1995 |volume=9 |issue=1 |pages=166–174 |jstor=2386398 |doi=10.1046/j.1523-1739.1995.09010166.x}}</ref><ref>{{cite web |url=http://www.earthtrust.org/wlcurric/seals.html |title=Hawaiian Monk Seals |website=earthtrust.org |access-date=May 23, 2011 |archive-url=https://web.archive.org/web/20110515082831/http://www.earthtrust.org/wlcurric/seals.html |archive-date=May 15, 2011 }}</ref>

[[Postmortem]] examinations of some seal carcasses revealed gastric ulcerations caused by [[parasite]]s.<ref name=Gilmartin1983>{{cite journal|url=https://www.mmc.gov/wp-content/uploads/Recovery_Hawaiian_monkseal_2011.pdf|doi=10.1578/AM.37.3.2011.397|title=Recovery of the Hawaiian Monk Seal (Monachus schauinslandi): A Review of Conservation Efforts, 1972 to 2010, and Thoughts for the Future|journal=Aquatic Mammals|volume=37|issue=3|pages=397–419|year=2011|last1=Lowry|first1=Lloyd|bibcode=2011AqMam..37..397L }}</ref> Some of the infectious diseases that pose a threat to the Hawaiian monk seal populations include distemper viruses, West Nile Virus, ''Leptospira'' spp., and ''Toxoplasma gondii''.<ref>{{cite journal | last1=Honnold | first1=Shelley P. | last2=Braun | first2=Robert | last3=Scott | first3=Dana P. | last4=Sreekumar | first4=C. | last5=Dubey | first5=J. P. | title=Toxoplasmosis in a Hawaiian Monk Seal (''Monachus schauinslandi'') | journal=Journal of Parasitology | volume=91 | issue=3 | year=2005 | pmid=16108571| doi=10.1645/ge-469r | pages=695–697| s2cid=13562317 }}</ref> Protozoal-related mortality,<ref>{{cite journal | last1=Barbieri | first1=MM | last2=Kashinsky | first2=L | last3=Rotstein | first3=DS | last4=Colegrove | first4=KM | last5=Haman | first5=KH | last6=Magargal | first6=SL | last7=Sweeny | first7=AR | last8=Kaufman | first8=AC | last9=Grigg | first9=ME | last10=Littnan | first10=CL | title=Protozoal-related mortalities in endangered Hawaiian monk seals ''Neomonachus schauinslandi'' | journal=Diseases of Aquatic Organisms | volume=121 | issue=2 | date=2016 | pmid=27667806 | doi=10.3354/dao03047 | pages=85–95| s2cid=24981002 }}</ref> specifically due to toxoplasmosis, are becoming a great threat to the recovery of the endangered Hawaiian monk seal and other native Hawaiian marine life.

====Anthropogenic impacts====
In the nineteenth century, large numbers of seals were killed by [[Whaling|whalers]] and [[Seal hunting|sealers]] for meat, oil and skin.<ref name="EllisNTB194">
{{cite book| last = Ellis| first = Richard| author-link = Richard Ellis (biologist) | title = No Turning Back: The Life and Death of Animal Species| url = https://archive.org/details/noturningbacklif00elli| url-access = registration| publisher = Harper Perennial | year = 2004| location = New York| page = [https://archive.org/details/noturningbacklif00elli/page/194 194]| isbn =978-0-06-055804-8 }}</ref> U.S. military forces hunted them during [[World War II]], while occupying [[Laysan Island]] and Midway.<ref name="EllisNTB194"/>

The Hawaiian monk seal has the lowest level of genetic variability among the 18 phocid species.<ref name=SchultzExtremely/> This low genetic variability was allegedly due to a [[population bottleneck]] caused by intense hunting in the 19th century.<ref name=SchultzExtremely/> This limited genetic variability reduces the species ability to adapt to environmental pressures and limits [[natural selection]], thus increasing their risk of extinction.<ref name=SchultzExtremely/> Given the monk seal's small population, the effects of disease could be disastrous.

Monk seals can be affected by the [[toxoplasmosis]] pathogen in cat [[feces]] that enters the ocean in polluted [[Surface runoff|runoff]] and [[wastewater]], a new phenomenon.<ref name=Dawson>{{cite web|last=Dawson |first=Teresa |title=A New Threat to Hawaiian Monk Seals: Cat Parasite Carried by Runoff, Sewage — Environmental Health News |url=http://www.environmentalhealthnews.org/ehs/news/hawaiian-monk-seals |archive-url=https://web.archive.org/web/20150121163746/http://www.environmentalhealthnews.org/ehs/news/hawaiian-monk-seals |url-status=dead |archive-date=January 21, 2015 |date=December 7, 2010|website=Environmental Health News: Front Page |access-date=March 16, 2011}}</ref> Since 2001, toxoplasmosis has killed at least eleven seals.<ref>{{cite news|url=https://www.promedmail.org/post/6608456|title=SEAL DEATHS – USA: (HAWAII) TOXOPLASMOSIS, UPDATE|date=August 8, 2019|work=[[Salon (website)|Salon]]|via=[[ProMED-mail]]}}</ref> Other human-introduced pathogens, including [[leptospirosis]], have infected monk seals.<ref name=Dawson/>

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.  For instance, large beach crowds and beach structures limit the seal's habitat.<ref name=Boland/><ref name=Antonelis/><ref name=Dawson/> Although the WWII military bases in the northwestern islands were closed, minimal human activities can be enough to disturb the species.<ref name=Antonelis/>

Marine fisheries can potentially interact with 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.<ref name=Antonelis/> Although international law prohibits the intentional discarding of debris from ships at sea, entanglement still results in mortality because the seals get trapped in unintentional marine debris such as fishing nets and cannot maneuver or even reach the surface to breathe.<ref name="SchultzExtremely" /> Monk seals have one of the highest documented rates of entanglement of any pinniped species.<ref name="Antonelis" />

===Conservation===
[[File:Sanc1297 - Flickr - NOAA Photo Library.jpg|thumb|Seal pups at [[Papahanaumokuakea Marine National Monument]]]]
[[File:Hawaiian Monk Seal Protection Area - Sign (6225677458).jpg|thumb|Sign denoting monk seal protection area]]
[[File:Pearl Harbor NEX Earth Day Expo Educates Young Minds About the Environment (17201124686).jpg|thumb|Educating the youth about the environment, including Hawaiian monk seals]]
In 1909, President [[Theodore Roosevelt]] created the Hawaiian Islands Reservation that included the Northwest Hawaiian islands. The Reservation later became the [[Hawaiian Islands National Wildlife Refuge]] (HINWR) and moved under the jurisdiction of the [[U.S. Fish and Wildlife Service]] (USFWS).<ref name=Antonelis/> Throughout the 1980s, the [[National Marine Fisheries Service]] completed various versions of an [[Environmental Impact Statement]] that designated the Northwest Hawaiian Islands as a critical habitat for the Hawaiian monk seal. The designation prohibited lobster fishing in waters less than {{convert|10|fathom|m|order=flip|abbr=off}} in the Northwest Hawaiian Islands and within {{convert|20|nmi|km|order=flip|abbr=off}} of Laysan Island.  The National Marine Fisheries Service designated all beach areas, lagoon waters, and ocean waters out to a depth of {{convert|10|fathom|m|order=flip|abbr=on}} (later {{convert|20|fathom|m|order=flip|abbr=on|disp=or}}) around the Northwestern Hawaiian Islands, except for one of the Midway group, Sand Island. In 2006, a Presidential Proclamation established the Papahanaumokuakea Marine National Monument, which incorporated the [[Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve]], the [[Midway Atoll|Midway Atoll National Wildlife Refuge]], the Hawaiian Islands National Wildlife Refuge, and the [[Battle of Midway National Memorial]], thus creating the largest [[marine protected area]] in the world and affording the Hawaiian monk seal further protection.<ref name="HMS Recovery Plan">{{cite web|url=http://www.nmfs.noaa.gov/pr/pdfs/recovery/hawaiianmonkseal.pdf|title=Second Revision of Recovery Plan for the Hawaiian Monk Seal (''Monachus schauinslandi'')|date=January 28, 2010|website=Pacific Islands Fisheries Science Center of the [[National Marine Fisheries Service]], part of the [[National Oceanic and Atmospheric Administration]]|location=Honolulu, HI, USA|orig-year=2007|archive-url=https://web.archive.org/web/20061006075257/http://www.nmfs.noaa.gov/pr/pdfs/recovery/hawaiianmonkseal.pdf|archive-date=October 6, 2006|access-date=November 24, 2012}}</ref>

[[NOAA]] cultivated a network of volunteers to protect the seals while they bask or bear and nurse their young. NOAA is funding considerable research on seal population dynamics and health in conjunction with the [[Marine Mammal Center]].

From NOAA, several programs and networks were formed to help the Hawaiian monk seal. Community programs such as PIRO have helped to improve community standards for the Hawaiian monk seal. The program also creates networks with the [[Native Hawaiians]] on the island to network more people in the fight for conservation of the seals. The Marine Mammal Response Network (MMRN) is partnered with NOAA and several other government agencies that deal with land and marine wildlife.<ref>{{cite web |url=http://www.fpir.noaa.gov/PRD/prd_hms_index.html |title=Hawaiian Monk Seal Recovery Program|website =NOAA Fisheries Service Protected Resources Division |access-date=November 24, 2012}}</ref>

The ''Recovery Plan for the Hawaiian Monk Seal'' identifies public outreach and education as a key action for promoting the conservation of the Hawaiian monk seal and its habitat.<ref name="HMS Recovery Plan"/>

To raise awareness of the species' plight, on June 11, 2008, a state law designated the Hawaiian monk seal as [[Hawaii]]'s official State Mammal.<ref>{{cite web |author=Gladden, Tracy |url=http://www.hawaiinewsnow.com/story/8483697/hawaiian-monk-seal-is-the-new-state-mammal?redirected=true |archive-url=https://web.archive.org/web/20110811102449/http://www.hawaiinewsnow.com/story/8483697/hawaiian-monk-seal-is-the-new-state-mammal?redirected=true |url-status=dead |archive-date=August 11, 2011 |date=June 12, 2008 |website=KHNL NBC 8 Honolulu Hawaii |title=Hawaiian monk seal is the new state mammal |access-date=May 23, 2011 }}</ref>

The task is to identify a manner of alleviation that is possible, cost-effective, and likely to maximize the organic return (in terms of growth potential) until much time has passed and natural conditions allow scientists to observe the effects.<ref name=Antonelis/>

====Protecting female pups====
One key natural factor affecting the seal populations is the male-biased sex-ratio, which results in increased aggressive behaviors such as mobbing.<ref name=Starfield/> These aggressive behaviors decrease the number of females in the population. Two programs effectively aid female survival rates.

A [[headstarting]] project began in 1981, collecting and tagging female pups after weaning and placing them in a large, enclosed water and beach area with food and lacking disturbances.<ref name=Gerrodette>{{cite journal|last=Gerrodette |first=Tim |author2=Gilmartin William G |title=Demographic consequences of changed pupping and hauling sites of the Hawaiian monk seal |journal=Conservation Biology |year=1980 |volume=4 |pages=423–430 |jstor=2385936|doi=10.1111/j.1523-1739.1990.tb00317.x|issue=4|url=https://zenodo.org/record/1230657 }}</ref> The female pups remain during the summer months, leaving at roughly age three to seven months.

Another project began in 1984 at [[French Frigate Shoals]]. It collected severely underweight female pups, placed them in protective care, and fed them. The pups were relocated to [[Kure Atoll]] and released as yearlings.<ref name=Gerrodette/>

Some habitats are better suited to increase survival probability, making relocation a popular and promising method.<ref name=SchultzRange/> Although no direct links between infectious diseases and seal mortality rates have been found, unidentified infectious diseases could prove detrimental to relocation strategies.<ref name=Aguirre>{{cite journal|last=Aguirre|first=A.|author2=T. Keefe |author3=J. Reif |author4=L. Kashinsky |author5=P. Yochem |title=Infectious disease monitoring of the endangered Hawaiian monk seal|journal=Journal of Wildlife Diseases|year=2007|volume=43|issue=2|pages=229–241|pmid=17495307 |doi=10.7589/0090-3558-43.2.229|doi-access=free}}</ref> Identification and mitigation of these and other possible factors limiting population growth represent ongoing challenges and are the primary objectives of the Hawaiian monk seal conservation and recovery effort.<ref name=Gilmartin1983/>

It is also important to consider the mothers who nurse their pups. Seal milk is very rich in nutrients, allowing pups to gain weight rapidly. With the rich milk from the mother, the pup is more likely to quadruple its initial weight before weaning. The mother seal also loses a tremendous amount of weight while nursing.<ref>[https://www.fws.gov/refuge/hawaiian_islands/wildlife_and_habitat/Hawaiian_monk_seal.html Hawaiian Monk Seal]. U.S. Fish and Wildlife Service.</ref>

====Draft environment impact statement====
In 2011, the [[National Marine Fisheries Service]] issued a controversial draft programmatic [[environmental impact statement]] intended to improve protections for the monk seal.<ref>{{cite news|title=Fisheries Service to hold hearings on monk seals|url=http://mauinews.com/page/content.detail/id/553154/Fisheries-Service-to-hold-hearings-on-monk-seals.html|newspaper=[[The Maui News]]|date=September 6, 2011}}</ref> The plan includes:
* Expanded surveys using technology such as remote cameras and unmanned, remotely operated aircraft.
* Vaccination studies and vaccination programs.
* De-worming program to improve juvenile survival.
* Relocation to the Northwestern Hawaiian Islands.
* Diet supplements at feeding stations in the Northwestern Hawaiian Islands.
* Tools to modify undesirable contact with people and fishing gear in the main islands.
* Chemical alteration of aggressive monk seal behavior.

==See also==
{{Portal|Marine life|Mammals}}
*[[Caribbean monk seal]]
*[[Mediterranean monk seal]]

==References==
{{Reflist|refs=
}}

==External links==
{{Commons}}
{{Wikispecies|Monachus schauinslandi}}
*{{cite web |url=http://alohakanaloacoalition.org/ |title=Aloha Kanaloa Coalition |access-date=November 24, 2012}} (public service video)
*{{cite web |url=http://www.mauimagazine.net/Maui-Magazine/Summer-2004/Watching-Out-for-Makana/ |title=Watching Out for Makana – Maui Magazine – Summer 2004 – Maui, Hawaii |last=Bernard |first=Hannah |date=July 8, 2009 |access-date=November 24, 2012  |archive-url=https://web.archive.org/web/20121005025643/http://www.mauimagazine.net/Maui-Magazine/Summer-2004/Watching-Out-for-Makana/ |archive-date=October 5, 2012 }}
*{{cite web |url=http://www.drleisure.com/KokiHawaiianMonkSealDocumentation2009.pdf |title=Some Observations on a Monk Seal Mother and Pup: Field Notes of Observations of Hawaiian Monk Seal (Monachus schauinslandi) |first=George R. |last=Harker |work=Guide to Nude Beaches & Recreation – Dr. Leisure |date=November 27, 2010 |access-date=November 24, 2012 |archive-date=January 20, 2013 |archive-url=https://web.archive.org/web/20130120091242/http://www.drleisure.com/KokiHawaiianMonkSealDocumentation2009.pdf |url-status=dead }}
*{{cite web |url=https://abcnews.go.com/GMA/WeekendWindow/hawaiis-forbidden-island-weekend-window-niihau/story?id=11767576#.ULFnUmcq5yU |title=Hawaii's 'Forbidden Island': Weekend Window to Niihau – ABC News |website=[[ABC News (United States)|ABC News]] |access-date=November 24, 2012|date=October 11, 2010 }}
*{{cite web |url=http://www.kauaimonkseal.com/Home.html |title=Kaua'i Monk Seal Watch Program |access-date=November 24, 2012}}
*{{cite web |url=http://www.monksealfoundation.org/ |title=Monk Seal Foundation |access-date=November 24, 2012  |archive-url=https://archive.today/20130415091303/http://www.monksealfoundation.org/ |archive-date=April 15, 2013 }}
*{{cite web |url=http://www.nameahulu.org/ |title=Na Mea Hulu &#124; Protecting the Hawaiian Monk Seals |access-date=November 24, 2012}}
*{{cite web |url=http://www.pifsc.noaa.gov/media/captivecareproject.php#monkseal |title=NOAA PIFSC 2006–2007 Captive Care and Release Project Seeks to Aid Recovery of the Endangered Hawaiian Monk Seal |access-date=November 24, 2012}}
*{{cite web |url=http://www.pifsc.noaa.gov/hawaiian_monk_seal/ |title=NOAA PIFSC Hawaiian Monk Seal Research |access-date=November 24, 2012}}
*{{cite web |url=http://monksealmania.blogspot.com/ |title=Oʻahu Supporters BLOG}}
*{{cite web |url=http://www.oahudiving.com/monk_seals_in_hawaii.htm |title=Scuba diving with Monk Seals in Hawaii – Oahu Diving in Honolulu |access-date=November 24, 2012}}
*{{cite web |url=http://www.pinnipeds.org/seal-information/species-information-pages/the-phocid-seals/hawaiian-monk-seal | title=Seal Conservation Society – Hawaiian Monk Seal}}

{{Carnivora|C1.}}
{{Taxonbar|from=Q695199}}
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[[Category:Endangered fauna of Hawaii]]
[[Category:Endemic fauna of Hawaii]]
[[Category:ESA endangered species]]
[[Category:Mammals described in 1905]]
[[Category:Mammals of Hawaii]]
[[Category:Monachines]]
[[Category:Natural history of the Northwestern Hawaiian Islands]]
[[Category:Pinnipeds of Oceania]]
[[Category:Species that are or were threatened by being bycatch]]
[[Category:Species that are or were threatened by disease]]
[[Category:Species that are or were threatened by human consumption]]