scholarly journals Cyclical Patterns and a Regime Shift in the Character of Phytoplankton Blooms in a Restricted Sub-Tropical Lagoon, Indian River Lagoon, Florida, United States

2021 ◽  
Vol 8 ◽  
Author(s):  
Edward J. Phlips ◽  
Susan Badylak ◽  
Natalie G. Nelson ◽  
Lauren M. Hall ◽  
Charles A. Jacoby ◽  
...  
Keyword(s):  
Regime Shift ◽  
Light Attenuation ◽  
Indian River Lagoon ◽  
Brown Tide ◽  
Nutrient Concentrations ◽  
Phytoplankton Blooms ◽  
Algae Biomass ◽  
Tropical Lagoon ◽  
Peak Biomass ◽  
Stochastic Events

This paper examines the character of phytoplankton blooms in a restricted sub-tropical lagoon along the Atlantic coast of central Florida. The results of the 23-year study (1997–2020) provide evidence for multiple types of variability in bloom activity, including cyclical patterns, stochastic events, and most prominently a regime shift in composition and intensity. Cyclical patterns (e.g., El Niño/La Niña periods) and stochastic events (e.g., tropical storms) influenced rainfall levels, which in turn impacted nutrient concentrations in the water column and the timing and intensity of blooms. In 2011, a major change occurred in the character of blooms, with a dramatic increase in peak biomass levels of blooms and the appearance of new dominant taxa, including the brown tide species Aureoumbra lagunensis and other nanoplanktonic species. Results of quantitative analyses reveal system behavior indicative of a regime shift. The shift coincided with widespread losses of seagrass community and reduced drift algae biomass. A combination of exceptionally low water temperatures in the winters of 2009/2010 and 2010/2011, hypersaline conditions associated with drought conditions, and high light attenuation caused by blooms appear to have contributed to the widespread and protracted decline in seagrass and drift macroalgal communities in the lagoon, leading to shifts in distribution of internal and external nutrient sources toward phytoplankton.

scholarly journals Bivalve Feeding on the Brown Tide Aureoumbra lagunensis in a Shallow Coastal Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Eve Galimany ◽  
Jessica Lunt ◽  
Christopher J. Freeman ◽  
I. Segura-García ◽  
M. Mossop ◽  
...  
Keyword(s):  
Clearance Rate ◽  
Indian River Lagoon ◽  
Brown Tide ◽  
Bivalve Species ◽  
Clearance Rates ◽  
Interspecific Differences ◽  
Brown Tides ◽  
Indian River ◽  
Aureoumbra Lagunensis ◽  
Fish And Shellfish

Brown tides formed by Aureoumbra lagunensis decrease light penetration in the water column and are often followed by hypoxic events that result in the loss of fish and shellfish. To understand the ability of bivalve filter feeders to control and prevent A. lagunensis blooms, we exposed eastern oysters (Crassostrea virginica), hooked mussels (Ischadium recurvum), and hard clams (Mercenaria mercenaria) to a naturally co-occurring brown tide in the Indian River Lagoon (IRL), Florida, United States. Bivalves were exposed in the laboratory to multiple concentrations (104 to 106 cells mL–1) of isotopically labeled (13C and 15N) A. lagunensis cells. The standard clearance rate (herein clearance rate) of each bivalve species was calculated using flow cytometry to quantify A. lagunensis cell removal. The highest clearance rates were at 104 cells mL–1, but values varied across bivalve species (2.16 ± 0.30, 3.03 ± 0.58, and 0.41 ± 0.12 L h–1 for C. virginica, I. recurvum, and M. mercenaria, respectively). Although clearance rates decreased with increasing bloom concentrations, bivalves were still consuming algal cells at all concentrations and were retaining and assimilating more cells at the highest concentrations, as revealed by δ13C and δ15N values. We highlight interspecific differences among bivalve species in the removal of A. lagunensis, supporting the importance of healthy and diverse filter feeding communities in estuaries, especially as threats of brown tides and other HABs are increasing in the Anthropocene.

Predicting Cyanobacteria dominance in lakes

2001 ◽  
Vol 58 (10) ◽  
pp. 1905-1908 ◽  
Author(s):  
John A Downing ◽  
Susan B Watson ◽  
Edward McCauley
Keyword(s):  
Field Experiments ◽  
Nutrient Concentrations ◽  
Strongly Correlated ◽  
Total N ◽  
Algae Biomass ◽  
Cyanobacteria Blooms ◽  
Freshwater Resource ◽  
Toxic Blooms ◽  
Total P ◽  
Controversial Concept

A controversial precept of aquatic ecology asserts that low ratios of nitrogen to phosphorus (N:P) lead to noxious and sometimes toxic blooms of Cyanobacteria. Cyanobacteria dominance is a major risk to human and ecosystem health. The stoichiometric control of Cyanobacteria therefore has become central to freshwater resource management. This controversial concept is based on observed Cyanobacteria dominance in lakes with low N:P and the results of lab and field experiments. Here we analyze data from 99 of the temperate zone's most studied lakes and show that this model is flawed. We show that the risk of water quality degradation by Cyanobacteria blooms is more strongly correlated with variation in total P, total N, or standing algae biomass than the ratio of N:P. Risks associated with Cyanobacteria are therefore less associated with N:P ratios than a simple increase in nutrient concentrations and algal biomass.

scholarly journals Regime Transition Shapes the Composition, Assembly Processes and Co-Occurrence Pattern of Bacterioplankton Community in a Large Eutrophic Freshwater Lake

2021 ◽  
Author(s):  
Xinyi Cao ◽  
Dayong Zhao ◽  
Lisa Röttjers ◽  
Karoline Faust ◽  
Hongjie Zhang
Keyword(s):  
Community Composition ◽  
Regime Shift ◽  
Alpha Diversity ◽  
Illumina Miseq ◽  
Nutrient Concentrations ◽  
Rrna Gene ◽  
Network Clustering ◽  
Regime Transition ◽  
Bacterioplankton Community ◽  
Occurrence Pattern

Abstract At certain nutrient concentrations, shallow freshwater lakes are generally characterized by two contrasting ecological regimes with disparate patterns of biodiversity and biogeochemical cycles: a macrophyte-dominated regime (MDR) and a phytoplankton-dominated regime (PDR).To reveal ecological mechanisms that affect bacterioplankton along the regime shift, Illumina MiSeq sequencing of the 16S rRNA gene combined with a novel network clustering tool (Manta) were used to identify patterns of bacterioplankton community composition across the regime shift in Taihu Lake, China. Marked divergence in the composition and ecological assembly processes of bacterioplankton community were observed under the regime shift. The alpha diversity of bacterioplankton community was observed to consistently and continuously decrease with the regime shift from MDR to PDR, while the beta diversity presents the opposite. Moreover, as the regime shifted from MDR to PDR, the contribution of deterministic processes first decreased and then increased again closer to the PDR, most likely as a consequence of differences in nutrient concentration. The topological properties of bacterioplankton co-occurrence networks along the regime shift differed, and the co-occurrences among species changed in structure and were significantly shaped by the environmental variables along the regime transition from MDR to PDR. The divergent environmental state of the regimes with diverse nutritional status may be the most important factor that contributes to the dissimilarity of bacterioplankton community composition along the regime shift and could be represented by phosphorus concentrations as well as several indicator species.

Neural network-based light attenuation model for monitoring seagrass population in the Indian river lagoon

2007 ◽  
Vol 29 (1) ◽  
pp. 63-77 ◽  
Author(s):  
M. T. Musavi ◽  
H. Ressom ◽  
S. Srirangam ◽  
P. Natarajan ◽  
R. W. Virnstein ◽  
...  
Keyword(s):  
Neural Network ◽  
Light Attenuation ◽  
Indian River Lagoon ◽  
Attenuation Model ◽  
Indian River

scholarly journals Field‐Validated Detection of Aureoumbra lagunensis Brown Tide Blooms in the Indian River Lagoon, Florida, Using Sentinel‐3A OLCI and Ground‐Based Hyperspectral Spectroradiometers

GeoHealth ◽  
2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Taylor J. Judice ◽  
Edith A. Widder ◽  
Warren H. Falls ◽  
Dulcinea M. Avouris ◽  
Dominic J. Cristiano ◽  
...  
Keyword(s):  
Indian River Lagoon ◽  
Brown Tide ◽  
Indian River ◽  
Aureoumbra Lagunensis

scholarly journals Soft-Sediment Communities of the Northern Indian River Lagoon, FL, United States

2021 ◽  
Vol 8 ◽  
Author(s):  
Jessica Lunt ◽  
Christopher J. Freeman ◽  
Dean S. Janiak ◽  
Katrina Bayliss ◽  
Michelle Stephens ◽  
...  
Keyword(s):  
United States ◽  
Community Composition ◽  
Indian River Lagoon ◽  
Interspecific Variation ◽  
Structure And Function ◽  
Brown Tide ◽  
Food Sources ◽  
Infaunal Community ◽  
Indian River ◽  
And Function

Understanding the structure and function of infaunal communities is useful in determining the biodiversity and ecosystem function of shallow estuaries. We conducted a survey of infaunal communities within three separate water basins [Mosquito Lagoon (ML), Indian River (IR), and Banana River (BR)] in the larger Northern Indian River Lagoon, FL, United States to establish a database of infaunal community structure and function. Twenty-seven sites were sampled quarterly from 2014 to 2016. Analysis of all samples determined that basin, season, and sediment composition were the primary drivers of macrobenthic community composition. Diversity was highest in the ML, and lower in spring compared to other seasons. The occurrence of a brown tide (Aureoumbra lagunensis) in 2016 allowed a comparison of winter and spring communities before (2015) and during (2016) a bloom event. Community composition and diversity at the BR sites were the most affected by the bloom event with the lowest diversity and abundances during the bloom. Diversity in the IR was also lower during the bloom, while the ML was unaffected by the bloom. Species of all feeding groups were affected by the bloom, with lower abundances found in all groups. In addition, to determine the overall trophic diversity of infaunal communities, we collected infaunal organisms from two of the quarterly sampled sites for isotope analyses. Values of δ13C and δ15N from infaunal tissue were compared to those of potential food sources at each site. Substantial interspecific variation in isotope values of infaunal organisms within a site suggests the presence of diverse nutritional modes that include suspension and deposit feeding and predation. Together, these data suggest that infaunal communities contribute to benthic pelagic coupling and nutrient cycling within the estuarine communities, but the overall function of these communities may be tightly linked to their species composition.

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