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NITROGEN ENRICHMENT, EUTROPHICATION, AND BOTTOM-UP TROPHIC SHIFTS IN ECOSYSTEMS OF THE INDIAN RIVER LAGOON

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Date Issued:
2023
Abstract/Description:
Eutrophication of urbanized estuaries is a global issue that continues to worsen as coastal development increases. The Indian River Lagoon (IRL) on Florida’s east-central coast is a eutrophic estuary that is experiencing harmful algal blooms of macroalgae and phytoplankton, as well as widespread seagrass losses. This is concerning as seagrasses provide many ecosystem services, including the provision of essential habitat. These alterations in benthic cover can have ecosystem level effects and require further investigation. Thus, drivers and effects of primary producer alterations in the IRL were investigated through analysis of long-term monitoring data, field surveys of faunal densities inhabiting macroalgae and bare bottom habitats, and stable nitrogen isotope (δ15N) analyses of primary producers, primary consumers, and secondary consumers. Long-term monitoring data from the northern IRL (NIRL) and Banana River Lagoon (BR) demonstrated there have been major seagrass losses coupled with increases in occurrence of the rhizophytic green macroalgae Caulerpa prolifera, which is now the dominant benthic cover in many locations. Multivariate analyses of long-term monitoring data spanning 2011-2020 suggested that the carbon to phosphorus ratio (C:P) of macroalgae is an important factor related to annual changes in benthic cover in the NIRL and BR; increased P-availability is correlated with these primary producer shifts. In situ collections of macroinvertebrates and resident fishes showed the current function and importance of macroalgae as habitat in the NIRL and BR, particularly in the relative absence of seagrass.
Title: NITROGEN ENRICHMENT, EUTROPHICATION, AND BOTTOM-UP TROPHIC SHIFTS IN ECOSYSTEMS OF THE INDIAN RIVER LAGOON.
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Name(s): Brewton, Rachel A. , author
Lapointe, Brian , Thesis advisor
Florida Atlantic University, Degree grantor
Department of Geosciences
Charles E. Schmidt College of Science
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2023
Date Issued: 2023
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 171 p.
Language(s): English
Abstract/Description: Eutrophication of urbanized estuaries is a global issue that continues to worsen as coastal development increases. The Indian River Lagoon (IRL) on Florida’s east-central coast is a eutrophic estuary that is experiencing harmful algal blooms of macroalgae and phytoplankton, as well as widespread seagrass losses. This is concerning as seagrasses provide many ecosystem services, including the provision of essential habitat. These alterations in benthic cover can have ecosystem level effects and require further investigation. Thus, drivers and effects of primary producer alterations in the IRL were investigated through analysis of long-term monitoring data, field surveys of faunal densities inhabiting macroalgae and bare bottom habitats, and stable nitrogen isotope (δ15N) analyses of primary producers, primary consumers, and secondary consumers. Long-term monitoring data from the northern IRL (NIRL) and Banana River Lagoon (BR) demonstrated there have been major seagrass losses coupled with increases in occurrence of the rhizophytic green macroalgae Caulerpa prolifera, which is now the dominant benthic cover in many locations. Multivariate analyses of long-term monitoring data spanning 2011-2020 suggested that the carbon to phosphorus ratio (C:P) of macroalgae is an important factor related to annual changes in benthic cover in the NIRL and BR; increased P-availability is correlated with these primary producer shifts. In situ collections of macroinvertebrates and resident fishes showed the current function and importance of macroalgae as habitat in the NIRL and BR, particularly in the relative absence of seagrass.
Identifier: FA00014231 (IID)
Degree granted: Dissertation (PhD)--Florida Atlantic University, 2023.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Indian River (Fla. : Lagoon)
Estuarine eutrophication
Nitrogen
Harmful Algal Bloom
Estuarine ecology
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00014231
Use and Reproduction: Copyright © is held by the author with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Host Institution: FAU