THE NATURAL DISAPPEARANCE OF A TOP CARNIVORE AND ITS IMPACT ON AN INTERTIDAL INVERTEBRATE COMMUNITY: THE INTERPLAY OF TEMPERATURE AND PREDATION ON COMMUNITY STRUCTURE (GULF OF CALIFORNIA).

Persistent Link:
http://hdl.handle.net/10150/184109
Title:
THE NATURAL DISAPPEARANCE OF A TOP CARNIVORE AND ITS IMPACT ON AN INTERTIDAL INVERTEBRATE COMMUNITY: THE INTERPLAY OF TEMPERATURE AND PREDATION ON COMMUNITY STRUCTURE (GULF OF CALIFORNIA).
Author:
BOYER, EDWARD HENRI.
Issue Date:
1987
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The predatory sea star, Heliaster kubiniji, has been hypothesized to be a "keystone species" that is instrumental in maintaining diversity in the intertidal zones of the northern Gulf of California (Paine 1966). Four hundred and one Heliaster stomach samples collected in 1974-1976 from Station Beach, Puerto Penasco, Sonora, Mexico indicated that Heliaster consumed a variety of prey but preferred barnacles, Chthamalus anisopoma (93% of all prey items). The catastrophic decline of Heliaster in the Gulf of California in 1978 resulted in mortalities approaching 100% (Dungan et al 1982). Pre-die-off community data from the intertidal reef at Station Beach (Mackie and Boyer 1977) were compared with post-die-off (1981-1984) data to determine effects of the Heliaster disappearance. Community structure data included abundance and intertidal distributions of 20 species of macro-invertebrates including 11 Heliaster prey and 9 non-prey species and consisted of 6 carnivores, 7 herbivores, 5 detritivores and 2 filter feeders. Comparisons were made in two distinct habitats: a basalt boulder habitat (Heliaster's preferred habitat) and a reef flat habitat. In the reef flat zone three prey species increased density while seven were unchanged; two non-prey species decreased while seven were unchanged. In the boulder zone six prey species increased, three decreased and two were unchanged; one non-prey increased, three decreased and five were unchanged. An examination of prey vs. non-prey guild structure indicated an increase in prey guild density in the boulder zone from 1976 to 1981 and a reshuffling of rank order of prey density. Analysis of trophic guild structure revealed an increase in carnivore guild density (but no change in ranks) in the boulder zone only and an increase in herbivore guild boulder density (with change in ranks) between 1976 and 1981. No significant changes in species diversity were observed during the study. Heliaster did not act as a keystone species in this community, but it influenced the abundance and structure of prey species and trophic guilds. A continuum is proposed for the potential effects of predation on community structure.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Intertidal ecology -- Mexico -- California, Gulf of.; Biotic communities -- Mexico -- California, Gulf of.; Starfishes -- Ecology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Ecology and Evolutionary Biology; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Thomson, Donald

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTHE NATURAL DISAPPEARANCE OF A TOP CARNIVORE AND ITS IMPACT ON AN INTERTIDAL INVERTEBRATE COMMUNITY: THE INTERPLAY OF TEMPERATURE AND PREDATION ON COMMUNITY STRUCTURE (GULF OF CALIFORNIA).en_US
dc.creatorBOYER, EDWARD HENRI.en_US
dc.contributor.authorBOYER, EDWARD HENRI.en_US
dc.date.issued1987en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe predatory sea star, Heliaster kubiniji, has been hypothesized to be a "keystone species" that is instrumental in maintaining diversity in the intertidal zones of the northern Gulf of California (Paine 1966). Four hundred and one Heliaster stomach samples collected in 1974-1976 from Station Beach, Puerto Penasco, Sonora, Mexico indicated that Heliaster consumed a variety of prey but preferred barnacles, Chthamalus anisopoma (93% of all prey items). The catastrophic decline of Heliaster in the Gulf of California in 1978 resulted in mortalities approaching 100% (Dungan et al 1982). Pre-die-off community data from the intertidal reef at Station Beach (Mackie and Boyer 1977) were compared with post-die-off (1981-1984) data to determine effects of the Heliaster disappearance. Community structure data included abundance and intertidal distributions of 20 species of macro-invertebrates including 11 Heliaster prey and 9 non-prey species and consisted of 6 carnivores, 7 herbivores, 5 detritivores and 2 filter feeders. Comparisons were made in two distinct habitats: a basalt boulder habitat (Heliaster's preferred habitat) and a reef flat habitat. In the reef flat zone three prey species increased density while seven were unchanged; two non-prey species decreased while seven were unchanged. In the boulder zone six prey species increased, three decreased and two were unchanged; one non-prey increased, three decreased and five were unchanged. An examination of prey vs. non-prey guild structure indicated an increase in prey guild density in the boulder zone from 1976 to 1981 and a reshuffling of rank order of prey density. Analysis of trophic guild structure revealed an increase in carnivore guild density (but no change in ranks) in the boulder zone only and an increase in herbivore guild boulder density (with change in ranks) between 1976 and 1981. No significant changes in species diversity were observed during the study. Heliaster did not act as a keystone species in this community, but it influenced the abundance and structure of prey species and trophic guilds. A continuum is proposed for the potential effects of predation on community structure.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectIntertidal ecology -- Mexico -- California, Gulf of.en_US
dc.subjectBiotic communities -- Mexico -- California, Gulf of.en_US
dc.subjectStarfishes -- Ecology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineEcology and Evolutionary Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorThomson, Donalden_US
dc.identifier.proquest8715710en_US
dc.identifier.oclc698484014en_US
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