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Benthic Foraminiferal Assemblages from Pulau Karangmadjat, Mentawai Islands, Indonesia

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Date Issued:
2016
Summary:
Globally, coral reefs are in severe decline (Jackson et al., 2001) and face potential extinction of 1/3 of reef species by 2050 (Veron, 2011). This decline is the result of the inability of coral communities to recover after disturbance events, often resulting in a shift from coral- to macro-algal dominated regimes. Reef resources managers are in need of tools to assess the condition of these ecosystems prior to, during, and post disturbance, especially in regions of the world where coral cover and diversity are high, yet management resources are scarce. Foraminifera have been widely utilized as bioindicators in both modern and paleoenvironments for more than a century due to their abundance, diverse functional morphology, rapid generation time, global distribution, and rich geologic record (Sen Gupta, 1999; Hallock et al., 2003). The FoRAM Index (FI) was developed as a single metric indicator to assess whether water quality supports coral recruitment and reproduction in Caribbean and Western Atlantic coral reefs (Hallock et al., 2003), yet the FI has not been widely applied to Indo-Pacific coral reefs. This study reports benthic foraminiferal assemblages from Pulau Karangmadjat, Mentawai Islands, Indonesia, and is the first to provide in situ foraminiferal assemblages for the Mentawai region. Results revealed overall low Shannon’s H’ and Fisher’s alpha, and low Buzas and Gibson’s evenness values across 13 sample sites selected from a variety of reef habitat zones. Values for the FI were also calculated and were extremely high across all sites due to the dominance of symbiont-bearing calcarinid taxa, suggesting favorable water quality conditions. Q-mode hierarchical cluster analysis revealed 4 clusters, only one of which corresponded in its entirety to a well defined benthic habitat zone. Overall, a high degree of similarity between foraminiferal assemblages was present for most sites sampled due to the dominance of calcarinids, suggesting prevalence of a macro-algal substrate, and potentially a shift from a coral- to macro-algal dominated regime for this study area. Utilization of indices like the FI, when used in conjunction with non-FI analysis of foraminiferal assemblages, may aid managers in deducing drivers of regime shifts on Indonesian coral reefs, which may ultimately facilitate solutions for reef conservation and recovery following natural and anthropogenic disturbance. Further testing of the applicability of the FI on Indian Ocean and Indo-Pacific reefs is needed to in order to test this hypothesis.
Title: Benthic Foraminiferal Assemblages from Pulau Karangmadjat, Mentawai Islands, Indonesia.
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Name(s): Garcia, Christine N., author
Oleinik, Anton E., Thesis advisor
Florida Atlantic University, Degree grantor
Charles E. Schmidt College of Science
Department of Geosciences
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2016
Date Issued: 2016
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 63 p.
Language(s): English
Summary: Globally, coral reefs are in severe decline (Jackson et al., 2001) and face potential extinction of 1/3 of reef species by 2050 (Veron, 2011). This decline is the result of the inability of coral communities to recover after disturbance events, often resulting in a shift from coral- to macro-algal dominated regimes. Reef resources managers are in need of tools to assess the condition of these ecosystems prior to, during, and post disturbance, especially in regions of the world where coral cover and diversity are high, yet management resources are scarce. Foraminifera have been widely utilized as bioindicators in both modern and paleoenvironments for more than a century due to their abundance, diverse functional morphology, rapid generation time, global distribution, and rich geologic record (Sen Gupta, 1999; Hallock et al., 2003). The FoRAM Index (FI) was developed as a single metric indicator to assess whether water quality supports coral recruitment and reproduction in Caribbean and Western Atlantic coral reefs (Hallock et al., 2003), yet the FI has not been widely applied to Indo-Pacific coral reefs. This study reports benthic foraminiferal assemblages from Pulau Karangmadjat, Mentawai Islands, Indonesia, and is the first to provide in situ foraminiferal assemblages for the Mentawai region. Results revealed overall low Shannon’s H’ and Fisher’s alpha, and low Buzas and Gibson’s evenness values across 13 sample sites selected from a variety of reef habitat zones. Values for the FI were also calculated and were extremely high across all sites due to the dominance of symbiont-bearing calcarinid taxa, suggesting favorable water quality conditions. Q-mode hierarchical cluster analysis revealed 4 clusters, only one of which corresponded in its entirety to a well defined benthic habitat zone. Overall, a high degree of similarity between foraminiferal assemblages was present for most sites sampled due to the dominance of calcarinids, suggesting prevalence of a macro-algal substrate, and potentially a shift from a coral- to macro-algal dominated regime for this study area. Utilization of indices like the FI, when used in conjunction with non-FI analysis of foraminiferal assemblages, may aid managers in deducing drivers of regime shifts on Indonesian coral reefs, which may ultimately facilitate solutions for reef conservation and recovery following natural and anthropogenic disturbance. Further testing of the applicability of the FI on Indian Ocean and Indo-Pacific reefs is needed to in order to test this hypothesis.
Identifier: FA00004790 (IID)
Degree granted: Thesis (M.S.)--Florida Atlantic University, 2016.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Foraminifera--Ecology--Indonesia--Mentawai Islands.
Coral reef ecology--Indonesia--Mentawai Islands.
Coastal zone management--Indonesia--Mentawai Islands.
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00004790
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Owner Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.