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Brewton RA, Lapointe BE. Eutrophication leads to food web enrichment and a lack of connectivity in a highly impacted urban lagoon. Mar Pollut Bull 2023; 195:115441. [PMID: 37683393 DOI: 10.1016/j.marpolbul.2023.115441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/18/2023] [Accepted: 08/19/2023] [Indexed: 09/10/2023]
Abstract
Nitrogen (N) loading can affect estuarine food webs through alteration of primary producers. In the Indian River Lagoon (IRL), Florida there has been long-term N enrichment, worsening phytoplankton blooms, large-scale macroalgal blooms, and catastrophic seagrass losses. To investigate how N enrichment affects higher trophic levels and food webs in the IRL, nutrient availability was compared to primary producer and faunal stable N (δ15N) isotope values. Seawater samples were collected in the IRL for dissolved nutrient, chlorophyll-a, and particulate organic matter δ15N analyses. Macrophytes and fauna were also collected for δ15N analyses. Throughout the IRL, N was elevated but was highest in the northern IRL and Banana River Lagoon. δ15N was enriched in these segments for most samples to levels characteristic of human-waste impacted estuaries. Variability in δ15N among lagoon segments suggests a low level of trophic connectivity. Decreasing N loading to the IRL and other eutrophic estuaries may help improve resiliency.
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Affiliation(s)
- Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, Florida 34946, USA.
| | - Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, Florida 34946, USA
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Tyre KN, Brewton RA, Kreiger LB, Lapointe BE. Widespread human waste pollution in surface waters observed throughout the urbanized, coastal communities of Lee County, Florida, USA. Sci Total Environ 2023; 879:162716. [PMID: 36921859 DOI: 10.1016/j.scitotenv.2023.162716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 05/17/2023]
Abstract
The coastal communities of Lee County, Florida, USA have grown rapidly since the 1970s. In this county, drainage ditches, canals, creeks, and the Caloosahatchee River Estuary often have high concentrations of nutrients and bacteria limiting their designated uses. Septic systems have previously been identified as a major pollution source in some areas of Lee County; therefore, this study sought to identify the extent of this issue throughout the county. To accomplish this, surface water samples were collected at 25 ditch, creek, or canal sites suspected of human waste contamination from septic systems in various drainage basins throughout Lee County during January 2020-January 2021. Water samples were analyzed for nutrients, dual stable nitrate isotopes (δ15N-NO3-, δ18O-NO3-), fecal indicator bacteria (enterococci, Escherichia coli), a molecular tracer of human waste (HF183), and chemical tracers of human waste (the artificial sweetener sucralose, pharmaceuticals). Particulate organic matter (POM) and macrophytes were also collected and analyzed for stable carbon (δ13C) and nitrogen (δ15N) isotopes, as well as elemental composition (C:N:P). To broaden the assessment of stable isotope values and C:N:P, archived macrophyte samples from 2019 were also included in analyses. Ammonium concentrations were high (> 4.3 μM) in 55 % of samples. Fecal bacteria were high in 66 % of samples. HF183 was detected in 50 % of samples and positively correlated with enterococci (r = 0.32). Sucralose concentrations were high (> 380 ng/L) in 54 % of samples, while carbamazepine was detected in 40 % of samples. Human waste N sources were indicated by δ15N > 3.00 ‰ at 44 % of sites by δ15N-NO3-, 68 % of sites by POM, and at 100 % of sites where macrophyte samples were collected. This large-scale study provides evidence of widespread human waste pollution throughout Lee County and can help guide infrastructure improvements to promote sustainable development. These findings should be applicable to urbanized regions globally that are experiencing declines in water quality and harmful algal blooms due to development with inadequate infrastructure.
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Affiliation(s)
- Kevin N Tyre
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 N US Highway 1, Fort Pierce, FL 34946, United States of America; Geosyntec Consultants, 3504 Lake Lynda Dr., Suite 155, Orlando, FL 32817, United States of America
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 N US Highway 1, Fort Pierce, FL 34946, United States of America.
| | - Lisa B Kreiger
- Lee County Department of Natural Resources, 1500 Monroe Street, Fort Myers, FL 33901, United States of America
| | - Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 N US Highway 1, Fort Pierce, FL 34946, United States of America
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Lapointe BE, Brewton RA, Wilking LE, Herren LW. Fertilizer restrictions are not sufficient to mitigate nutrient pollution and harmful algal blooms in the Indian River Lagoon, Florida. Mar Pollut Bull 2023; 193:115041. [PMID: 37356131 DOI: 10.1016/j.marpolbul.2023.115041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 06/27/2023]
Abstract
In Florida's Indian River Lagoon (IRL), anthropogenic eutrophication has resulted in harmful algal blooms and catastrophic seagrass losses. Hoping to improve water quality, policy makers enacted fertilizer bans, assuming that this would reduce the nitrogen (N) load. To assess the effectiveness of these bans, seawater and macroalgal samples were collected at 20 sites "pre" and ~ five-years "post" bans and analyzed to determine concentrations of dissolved nutrients and stable nitrogen isotope values (δ15N). Higher concentrations of ammonium and nitrate were observed post-ban and macroalgal δ15N values increased. A comparison of nutrient concentrations and δ15N between brown tide (Aureoumbra lagunensis) blooms indicated that the post-ban bloom was more strongly N-enriched with higher δ15N values than the pre-ban bloom, which had depleted values in the range of fertilizers. These data indicate a primary role of human waste influence in the IRL, suggesting that current management actions have been insufficient at mitigating eutrophication.
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Affiliation(s)
- Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA.
| | - Lynn E Wilking
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA; Consolidated Safety Services, Inc. under contract to National Oceanic and Atmospheric Administration Beaufort Lab, 101 Pivers Island Rd, Beaufort, NC 28516, USA
| | - Laura W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA
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Brewton RA, Kreiger LB, Tyre KN, Baladi D, Wilking LE, Herren LW, Lapointe BE. Septic system-groundwater-surface water couplings in waterfront communities contribute to harmful algal blooms in Southwest Florida. Sci Total Environ 2022; 837:155319. [PMID: 35452738 DOI: 10.1016/j.scitotenv.2022.155319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
As human population growth has expanded in Southwest Florida, water quality has become degraded with an increased occurrence of harmful algal blooms (HABs). Red tide (Karenia brevis) originating offshore, intensifies in nearshore waters along Florida's Gulf Coast, and blue-green algae (Microcystis spp.) originating in Lake Okeechobee is discharged into the Caloosahatchee River. These HABs could be enhanced by anthropogenic nitrogen (N) and phosphorus (P) from adjacent watersheds. North Fort Myers is a heavily developed, low-lying city on the Caloosahatchee River Estuary serviced by septic systems with documented nutrient and bacterial pollution. To identify sources of pollution within North Fort Myers and determine connections with downstream HABs, this multiyear (2017-2020) study examined septic system- groundwater- surface water couplings through the analysis of water table depth, nutrients (N, P), fecal indicator bacteria (FIB), molecular markers (HF183, GFD, Gull2), chemical tracers (sucralose, pharmaceuticals, herbicides, pesticides), stable isotopes of groundwater (δ15N-NH4, δ15N-NO3) and particulate organic matter (POM; δ15N, δ13C), and POM elemental composition (C:N:P). POM samples were also collected during K. brevis and Microcystis spp. HAB events. Most (>80%) water table depth measurements were too shallow to support septic system functioning (<1.07 m). High concentrations of NH4+ and NOx, up to 1094 μM and 482 μM respectively, were found in groundwater and surface water. δ15N values of groundwater (+4.7‰) were similar to septic effluent (+4.9‰), POM (+4.7‰), and downstream HABs (+4.8 to 6.9‰), indicating a human waste N source. In surface water, FIB were elevated and HF183 was detected, while in groundwater and surface water sucralose, carbamazepine, primidone, and acetaminophen were detected. These data suggest that groundwater and surface water in North Fort Myers are coupled and contaminated by septic system effluent, which is negatively affecting water quality and contributing to the maintenance and intensification of downstream HABs.
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Affiliation(s)
- Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA.
| | - Lisa B Kreiger
- Lee County Division of Natural Resources, 1500 Monroe St, Fort Myers, FL 33901, USA
| | - Kevin N Tyre
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Diana Baladi
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Lynn E Wilking
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Laura W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
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Lapointe BE, Brewton RA, Littlejohn JM. Distributed wastewater treatment offers an environmentally preferable alternative to conventional septic systems in Central Florida. Water Sci Technol 2022; 86:432-444. [PMID: 35960828 DOI: 10.2166/wst.2022.223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Wastewater management is a critical issue globally. In Florida, the importance of this issue is heightened by the proximity to sensitive ecosystems. Distributed wastewater treatment units (DWTU) are a recent, state-approved alternative to septic system conversions to centralized sewer infrastructure. In this study, the performance of a DWTU was tested at a new residence in Lake Hamilton, FL. A monitoring well was installed downgradient of the DWTU absorption field to establish baseline groundwater conditions prior to occupation of the residence. The residence was occupied, after which groundwater, DWTU influent, and effluent samples were collected. Many effluent parameters significantly decreased compared to influent, including ammonia (NH3; 97%), total Kjeldahl nitrogen (TKN; 95%), total nitrogen (TN; 88%), the TN:TP ratio (84%), fecal coliforms (92%), carbonaceous biochemical oxygen demand (CBOD; 96%), and total suspended solids (TSS; 96%). In the groundwater, nutrient concentrations initially increased compared to the baseline data, but eventually decreased, demonstrating that the DWTU was effective at improving quality of wastewater effluent. These systems could be especially effective in sensitive areas where advanced wastewater treatment has been mandated or is needed.
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Affiliation(s)
- Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, Florida 34946, USA E-mail:
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, Florida 34946, USA E-mail:
| | - Jeffrey M Littlejohn
- OnSyte Performance, LLC., 2282 Killearn Center Blvd., Tallahassee, Florida 32309, USA
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Herren LW, Brewton RA, Wilking LE, Tarnowski ME, Vogel MA, Lapointe BE. Septic systems drive nutrient enrichment of groundwaters and eutrophication in the urbanized Indian River Lagoon, Florida. Mar Pollut Bull 2021; 172:112928. [PMID: 34706476 DOI: 10.1016/j.marpolbul.2021.112928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 05/07/2023]
Abstract
Effluent from septic systems can pollute groundwater and surface waters in coastal watersheds. These effects are unknown for the highly urbanized central Indian River Lagoon (CIRL), Florida, where septic systems represent > 50% of wastewater disposal. To better understand these impacts, water quality was assessed along both canals and a tributary that drain into the CIRL. Dissolved nutrient concentrations were higher near septic systems than in natural areas. δ15N values of groundwater (+7.2‰), surface water (+5.5‰), and macrophytes (+9.7‰) were within the range for wastewater (>+3‰), as were surface water concentrations of the artificial sweetener sucralose (100 to 1700 ng/L) and fecal indicator bacteria density. These results indicate that septic systems are promoting eutrophication in the CIRL by contributing nutrient pollution to surface water via groundwater. This study demonstrates the need to reduce reliance on septic systems in urbanized coastal communities to improve water quality and subsequently mitigate harmful algal blooms.
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Affiliation(s)
- L W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA
| | - R A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA.
| | - L E Wilking
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA
| | - M E Tarnowski
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA; Merck, 770 Sumneytown Pike, West Point, PA 19486, USA
| | - M A Vogel
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA; Division of Microbial Ecology, Centre for Microbiology and Ecosystem Science, University of Vienna, 14 UZA I Biozentrum Althanstrasse, Althanstraße, 1090 Vienna, Austria
| | - B E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US-1, Fort Pierce, FL 34946, USA
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Lapointe BE, Brewton RA, Herren LW, Wang M, Hu C, McGillicuddy DJ, Lindell S, Hernandez FJ, Morton PL. Nutrient content and stoichiometry of pelagic Sargassum reflects increasing nitrogen availability in the Atlantic Basin. Nat Commun 2021; 12:3060. [PMID: 34031385 PMCID: PMC8144625 DOI: 10.1038/s41467-021-23135-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/09/2021] [Indexed: 11/25/2022] Open
Abstract
The pelagic brown macroalgae Sargassum spp. have grown for centuries in oligotrophic waters of the North Atlantic Ocean supported by natural nutrient sources, such as excretions from associated fishes and invertebrates, upwelling, and N2 fixation. Using a unique historical baseline, we show that since the 1980s the tissue %N of Sargassum spp. has increased by 35%, while %P has decreased by 44%, resulting in a 111% increase in the N:P ratio (13:1 to 28:1) and increased P limitation. The highest %N and δ15N values occurred in coastal waters influenced by N-rich terrestrial runoff, while lower C:N and C:P ratios occurred in winter and spring during peak river discharges. These findings suggest that increased N availability is supporting blooms of Sargassum and turning a critical nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health.
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Affiliation(s)
- B E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA.
| | - R A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - L W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - M Wang
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - C Hu
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | | | - S Lindell
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - F J Hernandez
- Division of Coastal Sciences, University of Southern Mississippi, Ocean Springs, MS, USA
| | - P L Morton
- Florida State University/National High Magnetic Field Lab, Tallahassee, FL, USA
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Laureano-Rosario AE, McFarland M, Bradshaw DJ, Metz J, Brewton RA, Pitts T, Perricone C, Schreiber S, Stockley N, Wang G, Guzmán EA, Lapointe BE, Wright AE, Jacoby CA, Twardowski MS. Corrigendum to Dynamics of microcystins and saxitoxin in the Indian River Lagoon, Florida Harmful Algae 103C (2021) 102012. Harmful Algae 2021; 104:102035. [PMID: 34023077 DOI: 10.1016/j.hal.2021.102035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Abdiel E Laureano-Rosario
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA.
| | - Malcolm McFarland
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - David J Bradshaw
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Jackie Metz
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Tara Pitts
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Carlie Perricone
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Stephanie Schreiber
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Nicole Stockley
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Guojun Wang
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Esther A Guzmán
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Amy E Wright
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Charles A Jacoby
- St. Johns River Water Management District, PO Box 1429, Palatka, Florida 32178, USA
| | - Michael S Twardowski
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
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Laureano-Rosario AE, McFarland M, Bradshaw DJ, Metz J, Brewton RA, Pitts T, Perricone C, Schreiber S, Stockley N, Wang G, Guzmán EA, Lapointe BE, Wright AE, Jacoby CA, Twardowski MS. Dynamics of microcystins and saxitoxin in the Indian River Lagoon, Florida. Harmful Algae 2021; 103:102012. [PMID: 33980451 DOI: 10.1016/j.hal.2021.102012] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Harmful algal blooms that can produce toxins are common in the Indian River Lagoon (IRL), which covers ~250 km of Florida's east coast. The current study assessed the dynamics of microcystins and saxitoxin in six segments of the IRL: Banana River Lagoon (BRL), Mosquito Lagoon (ML), Northern IRL (NIRL), Central IRL (CIRL), Southern IRL (SIRL), and the St. Lucie Estuary (SLE). Surface water samples (n = 40) collected during the 2018 wet and 2019 dry season were analyzed to determine associations between toxins and temperature, salinity, pH, oxygen saturation, concentrations of dissolved nutrients and chlorophyll-a, presence of biosynthetic genes for toxins, relative abundance of planktonic species, and composition of the microbial community. The potential toxicity of samples was assessed using multiple mammalian cell lines. Enzyme-Linked Immunosorbent Assays were used to determine concentrations of microcystins and saxitoxin. Overall, the microcystins concentration ranged between 0.01-85.70 µg/L, and saxitoxin concentrations ranged between 0.01-2.43 µg/L across the IRL. Microcystins concentrations were 65% below the limit of quantification (0.05 µg/L), and saxitoxin concentrations were 85% below the limit of detection (0.02 µg/L). Microcystins concentrations were higher in the SLE, while saxitoxin was elevated in the NIRL and BRL. Cytotoxicity related to the presence of microcystins was seen in the SLE during the wet season. No significant patterns between cytotoxicity and saxitoxin were identified. Dissolved nutrients were identified as the most highly related parameters, explaining 53% of microcystin and 47% of saxitoxin variability. Multivariate models suggested cyanobacteria, flagellates, ciliates, and diatoms as the subset of microorganisms whose abundances were maximally correlated with saxitoxin and microcystins concentrations. Lastly, biosynthetic genes for microcystins were detected in the SLE and for saxitoxin in the BRL and NIRL. These results highlight the synergistic roles environmental and biological parameters play in influencing the dynamics of toxin production by harmful algae in the IRL.
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Affiliation(s)
- Abdiel E Laureano-Rosario
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA.
| | - Malcolm McFarland
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - David J Bradshaw
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Jackie Metz
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Tara Pitts
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Carlie Perricone
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Stephanie Schreiber
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Nicole Stockley
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Guojun Wang
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Esther A Guzmán
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Amy E Wright
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
| | - Charles A Jacoby
- St. Johns River Water Management District, PO Box 1429, Palatka, Florida 32178, USA
| | - Michael S Twardowski
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 N, Fort Pierce, Florida 34946, USA
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Lapointe BE, Herren LW, Brewton RA, Alderman PK. Nutrient over-enrichment and light limitation of seagrass communities in the Indian River Lagoon, an urbanized subtropical estuary. Sci Total Environ 2020; 699:134068. [PMID: 31683214 DOI: 10.1016/j.scitotenv.2019.134068] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/06/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Historically, extensive seagrass meadows were common throughout the Indian River Lagoon (IRL) in east-central Florida, USA. Between 2011 and 2017, widespread catastrophic seagrass losses (~95%) occurred in the IRL following unprecedented harmful algal blooms (HABs), including persistent brown tides (Aureoumbra lagunensis). Little is known about how dissolved nutrients and chlorophyll a are related to light limitation or how biochemical factors, such as the elemental composition (C:N:P) and stable isotope signatures (δ13C, δ15N), of seagrasses within the IRL relate to coverage. Accordingly, we conducted a survey from 2013 to 2015 at 20 sites to better understand these relationships. Results showed a negative correlation between DIN and salinity, indicating freshwater inputs as a DIN source. Seawater N:P ratios and chlorophyll a concentrations were higher in the urbanized, poorly-flushed northern IRL segments. Kd values were higher in the wet season and often exceeded seagrass light requirements (0.8 m-1) for restoration, demonstrating light limitation. Species distribution varied by location. Halodule wrightii was ubiquitous, whereas Syringodium filiforme was not found in the northernmost segments. Thalassia testudinum was only present in the two southernmost segments that had the lowest TDN and highest light availability (Kd). Blade %N and %P also frequently exceeded critical values of 1.8% and 0.2%, respectively, especially in the northern segments. Further, δ15N was positively correlated with ammonium, suggesting wastewater as a major N source. The δ13C values indicated a trend of increasing light limitation from south to north, which helps explain the recent catastrophic loss of seagrasses in the northern IRL. Overall, elemental composition reflected high N-availability and seagrass species distributions were relatable to spatial trends in N and light limitation. For effective restoration, resource managers must reduce N-loading to the IRL to diminish HABs and increase light availability. Regular biochemical monitoring of seagrass tissue should also be implemented during restoration efforts.
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Affiliation(s)
- Brian E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA.
| | - Laura W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Rachel A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
| | - Pamela K Alderman
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1, Fort Pierce, FL 34946, USA
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Gain IE, Brewton RA, Reese Robillard MM, Johnson KD, Smee DL, Stunz GW. Macrofauna using intertidal oyster reef varies in relation to position within the estuarine habitat mosaic. Mar Biol 2017; 164:8. [PMID: 0 DOI: 10.1007/s00227-016-3033-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 11/08/2016] [Indexed: 05/28/2023]
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