Effects of Sea Level on Reef Habitats of Papahanaumokuakea Marine National Monument During the Last Glacial Maximum

dc.contributor.advisor Fletcher, Charles
dc.contributor.author Lopes, Keolohilani
dc.contributor.department Oceanography
dc.contributor.department Global Environmental Science
dc.date.accessioned 2020-04-25T01:38:14Z
dc.date.available 2020-04-25T01:38:14Z
dc.date.issued 2011
dc.description.course OCN 499 - Undergraduate Thesis
dc.identifier.uri http://hdl.handle.net/10125/67765
dc.publisher.place Honolulu
dc.subject corals
dc.subject coral reef ecology
dc.subject sea level rise
dc.title Effects of Sea Level on Reef Habitats of Papahanaumokuakea Marine National Monument During the Last Glacial Maximum
dc.type Thesis
dcterms.abstract Mesophotic Coral Ecosystems (MCE) (50-100m) are not as well understood as their shallower counter-part, the Photic Reef Ecosystem (PRE) (0-50m). The disparity in the level of understanding between the two regions is mainly due to the difficulty in getting observations from these depths. This study used Geographic Information System (GIS) software to calculate habitat increases of 88.53% (5605.34 km2) in the PRE from the Last Glacial Maximum (LGM), when the sea level was 120m below the present day sea level. A statistically similar amount of habitat gain was found between the MCE and PRE (Show stat values). Understanding habitat changes will allow scientists to deduce causes of important differences in ecosystem characteristics between these two environments, such as endemism rates. PRE endemism rates for fish in Papahānaumokuākea Marine National Monument (PMNM) are 20.6% (DeMartini, Friedlander, 2004) while several dives in MCE habitat on Midway atoll recorded endemic fish rates above 90% (NOAA 2010, Unpublished). Similar changes in area between PRE and MCE, coupled with drastically different fish endemism rates suggests a continuous MCE habitat regime while the PRE experienced dramatic changes inducing extinctions or sever loss of biota. Rate of sea level rise may have had the most detrimental impact on the PRE, increasing as much as 25mm/yr during meltwater pulse episodes which lasted as long as 1000 years (Fletcher, Sherman, 1995). These relatively rapid rates are faster than the accretion rate of corals in PMNM, subsequently leading to drowning of the ecosystem. As MCE are not heavily light dependent and probably cover a wider depth range than PRE, likely exhibit more continuity and habitat stability. A stable and long lasting isolated habitat is required for the evolutionary processes to produce unique animals that are found nowhere else in the world. The Continuous Marine Habitat (CoMaH) hypothesis explaining MCE endemism rates looks like the most plausible explanation of the historic events that shaped the current marine environments of the PMNM. CoMaH hypothesis supports the idea that the MCE habitat is able to endure the large fluctuations and rapid increase of sea level providing a continuous habitat for marine organisms to evolve into endemic species.
dcterms.extent 49 pages
dcterms.language English
dcterms.publisher University of Hawaiʻi at Mānoa
dcterms.rights All UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
dcterms.rightsholder Lopes, Keolohilani
dcterms.type Text
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