Show simple item record

dc.contributor.advisorT. C. Shirley
dc.contributor.authorEtnoyer, Peter
dc.date.accessioned2014-11-11T15:41:35Z
dc.date.available2014-11-11T15:41:35Z
dc.date.issued2014-11-11
dc.identifier.urihttp://hdl.handle.net/1969.6/580
dc.descriptionSubmitted to the Office of Graduate Studies of Texas A&M University- Corpus Christi In partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Coastal and Marine System Scienceen_US
dc.description.abstractOctocorals are broadly distributed throughout the world’s oceans, from the shallow intertidal zone to deeper than 5800 meters. Fishermen refer to large colonies as ‘trees’. This is appropriate because colonies provide complex structural habitat for associated species, they are broadly distributed, and they are threatened by industrial practices, such as bottom trawling. Below the warm water layer (50 – 70 m deep), octocorals are presumed to be cosmopolitan in the West Atlantic, with a broadly homogenous distribution. This creates a problem for conservation and management because it is difficult to justify conservation of one place, if all others are the same. This dissertation tested the null hypothesis of no difference in octocoral assemblages at the three spatial scales (referred to as basin, region, and site scale) through meta-analysis of two large, original datasets. The first was 1881 records of octocoral occurrences in the Gulf of Mexico from cruise reports and museums. The second was 8495 seafloor images from six outer continental shelf banks, and one site between banks, in the northwestern Gulf region. Univariate, multivariate, and spatial analysis techniques were used to compare genera, depth zones, regions, and banks within a Geographic Information System framework.Octocoral assemblages in the Gulf of Mexico differed significantly between depth zones and regions, but there was no difference in diversity between depth zones less than 800 m, due to species replacement. Composition of octocoral assemblages varied significantly between sites, and hotspots for richness and abundance were evident within sites. Null hypotheses of no difference between banks, depth zones, and regions were rejected with confidence. The findings support the broad distribution of octocorals in the Gulf of Mexico, but not homogeneity of octocoral assemblages. Based on these results, place-based conservation of deep octocoral habitat is justified, because some sites have higher diversity and abundance of octocorals than others.en_US
dc.language.isoen_USen_US
dc.rightsThis material is made available for use in research, teaching, and private study, pursuant to U.S. Copyright law. The user assumes full responsibility for any use of the materials, including but not limited to, infringement of copyright and publication rights of reproduced materials. Any materials used should be fully credited with its source. All rights are reserved and retained regardless of current or future development or laws that may apply to fair use standards. Permission for publication of this material, in part or in full, must be secured with the author and/or publisher.en_US
dc.subjectOctocoralen_US
dc.subjectdeep-sea coralen_US
dc.subjectmedophoticen_US
dc.titleDISTRIBUTION AND DIVERSITY OF OCTOCORALS IN THE GULF OF MEXICOen_US
dc.typeTexten_US
thesis.degree.disciplineCoastal and Marine System Scienceen_US
thesis.degree.grantorTexas A & M University--Corpus Christien_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
dc.description.departmentPhysical and Environmental Sciencesen_US
dc.description.collegeCollege of Science and Engineeringen_US
dc.type.genreDissertationen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record