The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary
The Indian River Lagoon (IRL) on Florida’s east-central coast is a highly developed eutrophic estuary, experiencing harmful algal blooms (HABs). Beginning in 2011, the IRL experienced multiple phytoplankton HABs that were followed by widespread seagrass losses and expanding blooms of the rhizophytic...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-12-01
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| Series: | Ecological Indicators |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X23011779 |
| _version_ | 1797644745688743936 |
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| author | Rachel A. Brewton Brian E. Lapointe |
| author_facet | Rachel A. Brewton Brian E. Lapointe |
| author_sort | Rachel A. Brewton |
| collection | DOAJ |
| description | The Indian River Lagoon (IRL) on Florida’s east-central coast is a highly developed eutrophic estuary, experiencing harmful algal blooms (HABs). Beginning in 2011, the IRL experienced multiple phytoplankton HABs that were followed by widespread seagrass losses and expanding blooms of the rhizophytic macroalga Caulerpa prolifera. To better understand factors related to the changing benthic cover, long-term monitoring data spanning 2011–2020 for seagrass and C. prolifera percent cover at six locations in the northern IRL and Banana River Lagoon were considered in multivariate analyses with environmental parameters (temperature, salinity, pH, dissolved oxygen, etc.), dissolved nutrient and chlorophyll-a concentrations, and macroalgal carbon (δ13C) and nitrogen (δ15N) stable isotopes, elemental composition (%C, %N, %P), and nutrient ratios (C:N:P). Data reduction using the global Bio-Env + STepwise (BEST) procedure followed by linkage tree (LINKTREE) analyses indicated the variable most correlated to annual differences in benthic cover was macroalgal C:P. Following seagrass losses, P availability increased, as the result of heavy rainfall, increased sediment flux, and/or more bioavailable P due to seagrass losses. The most correlated variables among differences in location were C:P, δ13C, and salinity, which could be related to less urbanization at the northernmost sites that had lower percent cover of C. prolifera. While not identified as a significant variable, the increase in C. prolifera was associated with four years (2016–2019) of high ammonium concentrations (6.26 µM) and macroalgal δ15N values (+8.67 ‰), linking the blooms to the influence of human waste. The variables identified in this work as related to benthic cover suggest that reducing stormwater runoff and inputs of human waste will promote the recovery of seagrasses in the IRL. These findings have implications for urbanized estuaries experiencing seagrass loss globally. |
| first_indexed | 2024-03-11T14:35:24Z |
| format | Article |
| id | doaj.art-376070ac74db4c98bec6077ad561594b |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-03-11T14:35:24Z |
| publishDate | 2023-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-376070ac74db4c98bec6077ad561594b2023-10-31T04:08:54ZengElsevierEcological Indicators1470-160X2023-12-01156111035The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuaryRachel A. Brewton0Brian E. Lapointe1Corresponding author.; Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USAHarbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USAThe Indian River Lagoon (IRL) on Florida’s east-central coast is a highly developed eutrophic estuary, experiencing harmful algal blooms (HABs). Beginning in 2011, the IRL experienced multiple phytoplankton HABs that were followed by widespread seagrass losses and expanding blooms of the rhizophytic macroalga Caulerpa prolifera. To better understand factors related to the changing benthic cover, long-term monitoring data spanning 2011–2020 for seagrass and C. prolifera percent cover at six locations in the northern IRL and Banana River Lagoon were considered in multivariate analyses with environmental parameters (temperature, salinity, pH, dissolved oxygen, etc.), dissolved nutrient and chlorophyll-a concentrations, and macroalgal carbon (δ13C) and nitrogen (δ15N) stable isotopes, elemental composition (%C, %N, %P), and nutrient ratios (C:N:P). Data reduction using the global Bio-Env + STepwise (BEST) procedure followed by linkage tree (LINKTREE) analyses indicated the variable most correlated to annual differences in benthic cover was macroalgal C:P. Following seagrass losses, P availability increased, as the result of heavy rainfall, increased sediment flux, and/or more bioavailable P due to seagrass losses. The most correlated variables among differences in location were C:P, δ13C, and salinity, which could be related to less urbanization at the northernmost sites that had lower percent cover of C. prolifera. While not identified as a significant variable, the increase in C. prolifera was associated with four years (2016–2019) of high ammonium concentrations (6.26 µM) and macroalgal δ15N values (+8.67 ‰), linking the blooms to the influence of human waste. The variables identified in this work as related to benthic cover suggest that reducing stormwater runoff and inputs of human waste will promote the recovery of seagrasses in the IRL. These findings have implications for urbanized estuaries experiencing seagrass loss globally.http://www.sciencedirect.com/science/article/pii/S1470160X23011779EutrophicationCaulerpaHalodule wrightiiEstuarineSeagrassMacroalgae |
| spellingShingle | Rachel A. Brewton Brian E. Lapointe The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary Ecological Indicators Eutrophication Caulerpa Halodule wrightii Estuarine Seagrass Macroalgae |
| title | The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary |
| title_full | The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary |
| title_fullStr | The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary |
| title_full_unstemmed | The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary |
| title_short | The green macroalga Caulerpa prolifera replaces seagrass in a nitrogen enriched, phosphorus limited, urbanized estuary |
| title_sort | green macroalga caulerpa prolifera replaces seagrass in a nitrogen enriched phosphorus limited urbanized estuary |
| topic | Eutrophication Caulerpa Halodule wrightii Estuarine Seagrass Macroalgae |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X23011779 |
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