Fig 1.
Study locations in (A) Aeration Canal and Control Canal, adjacent to the Grand Canal in Satellite Beach. (B) Control Canal sampling stations (yellow dots: C1 = Control 1; C2 = Control 2). (C) Aeration Canal sampling stations (yellow dots: A1 = Aeration 1; A2 = Aeration 2). CM (Control mouth in Grand Canal) and AM (Aeration mouth in Grand Canal) are intermedia sites in the Grand Canal; blue dots are aeration diffusers and blue lines are sunken aeration tubing. The maps for (A), (B) and (C) were generated from ArcGIS Online basemap [43] (D) A picture of aeration canal with diffusers running.
Fig 2.
(A) Micro-phytoplankton and (B) Nano-phytoplankton densities (Mean ± SD) from surface and bottom waters in aeration canal (A1, A2), control canal (C1, C2) and Grand canal (CM, AM) in different months.
Fig 3.
Surface water (A) Aureoumbra lagunensis cell densities, (B) ammonium concentrations and (C) DO (%) in control vs. aeration canals from February to June 2018. Bottom water (D) A. lagunensis cell densities, (E) ammonium concentrations and (F) DO (%) in control vs. aeration canals from February to June 2018. Average (G) A. lagunensis cell densities, (H) ammonium concentrations and (I) DO (%) in control vs. aeration canals from February to June 2018. Different significance levels were determined via 2-way ANOVA and Fisher’s LSD post-hoc pairwise comparisons (* p < 0.05, ** p < 0.01, ***p < 0.001, ****p < 0.0001).
Fig 4.
Two-dimensional nMDS ordination plots of planktonic assemblages in (A) surface and (B) bottom waters over the study period.
Treatments are canal locations, with aeration canal (A1, A2), control canal (C1, C2) and Grand canal (CM, AM) in different months. The p and R values displayed in the figure were ANOSIM test results.
Fig 5.
(A) Surface water micro-phytoplankton, (B) surface water nano-phytoplankton, (C) bottom water micro-phytoplankton and (D) bottom water nano-phytoplankton compositions in the control Canal (C1, C2), Grand canal (CM, AM) and aeration canal (A1, A2) in different months.
Fig 6.
(A) Correlation analyses of benthic infauna community (both abundance and Shannon’s Diversity Index) and bottom water environmental parameters for all samples during the whole study period. The scale shows the degree of positive correlation (blue) or negative correlation (red) between two variables. Nonsignificant correlations (adjusted p > 0.05) are indicated by blanks. Green rectangles highlight the environmental parameters (Temperature and DO) that correlate to both benthic infauna abundance and Shannon’s Diversity Index. Comparisons of (B) bottom temperature (C) bottom DO (D) benthic infauna abundance (E) benthic infauna Shannon’s Diversity Index compared between the control and aeration canal in different months (2-way ANOVA and Fisher’s LSD post-hoc pairwise comparisons, where * p < 0.05, ***p < 0.001, **** p < 0.0001).
Table 1.
Benthic infauna species composition and abundance (individuals m-2) at each sampling location in different months.
Fig 7.
(A) nitrogen concentrations (Ammonium, Nitrate+Nitrite, Dissolved Organic Nitrogen (DON)), (B) phosphorus concentrations (Phosphate, Dissolved Organic Phosphorus (DOP)), (C) temperature and salinity, (D) Dissolved Oxygen (DO), (E) Silica concentrations and (F)Secchi depth in the control and aeration canals at both surface and bottom layers in different months.
Table 2.
Summary of outcomes of statistical comparisons of control and aeration canals as a function of environmental parameters and temporal changes.
Table 3.
Muck coverage (area), volumes of muck and Loss on Ignition (LOI) of surface muck layers in the control and aeration canals before aeration, after Hurricane Irma and after one-year of aeration.