Report Date - January 16th to January 22nd, 2023

Project Name: Florida Department of Environmental Protection Grant INVO14: Remote Sensing of Harmful Algal Blooms in the Indian River Lagoon and Connected Waterways in Brevard County

Prepared By: Andrew Kamerosky

For the week of January 16th, 2023, to January 22nd, 2023, there was minor HAB activity continuing from the previous week primarily within the Banana River. There was increased activity throughout the IRL apart from the Northern and Central regions of the Banana. There were 1 Sentinel-2 and 5 Sentinel-3 usable scenes during this period.

The estimated Chlorophyll A (ChlA) in the southern Mosquito Lagoon increased from a median of 9.53 µg/L on January 16th to 13.62 µg/L on January 22nd. The North-North IRL increased from a median of 7.37 µg/L on January 16th to 18.30 µg/L on January 22nd. The Central-North IRL increased from a median of 11.04 µg/L on January 16th to 13.91 µg/L on January 22nd.

The estimated ChlA in the northern section of Banana River decreased from a median of 22.71 µg/L on January 16th to 20.77 µg/L on January 22nd. The middle section of Banana River also decreased with a median of 23.84 µg/L on January 16th to 20.97 µg/L on January 22nd. The southern section of the Banana River increased from a median of 9.00 µg/L on January 16th to 14.88 µg/L on January 22nd.

In the South-North IRL there was an increase from a median of 8.17 µg/L on January 16th to 15.13 µg/L on January 22nd. The North-Central IRL there was an increase from a median of 7.12 µg/L on January 16th to 22.39 µg/L on January 22nd.

The availability and usability of satellite imagery is contingent upon both the satellite being overhead and low cloud cover. The orbits of the Sentinel satellites will on occasion cover a portion of the Indian River Lagoon. Likewise, cloud cover can also result in only portions of the Indian River Lagoon (IRL) being visible. Table 1 below lists the availability of Sentinel imagery and its usability for Harmful Algal Bloom (HAB) analysis.

Table 1 - Sentinel 2 and 3 imagery availability for January 16th-January 22nd, 2023

N - Imagery Not Available

Y - C - Imagery Available, Cannot Use Due to Cloud Cover

Y - P - Imagery Available, Only Partial Imagery of IRL

Y - G - Imagery Available, No Issues Over the IRL

17 January 2023 - Sentinel 3B

18 January 2023 - Sentinel 3B

19 January 2023 - Sentinel 3A

20 January 2023 - Sentinel 2B

SJRWMD IRL Continuous Monitoring Stations

The St. John River Water Management District (SJRWMD) Continuous Monitoring (CM) stations measured generally stable Chlorophyll Reflective Fluorescence Units (RFU) at all sites except for IRLI21 which experienced a significant increase by the end of the week (Figure 1, Table 2). 

IRLI21 began the week with 8.06 RFU on January 16th and increased to 19.16 RFU by January 22nd. All other sites were below 6.5 RFU the entire week. Sites IRLI13 and IRLI04 all started to experience a slight decrease in ChlA levels beginning January 20th.

Current and historical data are added to the SJRWMD’s database continuously; subsequent visits may reflect such additions or revisions. SJRWMD provides no warranty as to the accuracy, reliability, or completeness of these data.

Figure 1 - St Johns River Water Management District (SJRWMD) Indian River Lagoon Continuous Monitoring Station Relative Chlorophyll A (ChlA) readings from January 16th-January 22nd, 2023, as described in Table 2.

Table 2 - St Johns River Water Management District (SJRWMD) Indian River Lagoon Continuous Monitoring Station Relative Chlorophyll A (ChlA) Relative Fluorescence from January 16th-January 22nd, 2023.

European Space Agency Sentinel Satellite Estimated Chlorophyll A

Sentinel 2

One scene from Sentinel 2 was usable for detection of HAB activity from January 16th, 2023, to January 22nd, 2023. The following analysis will utilize the scenes from January 20th. 

The north section of the Banana River from State Road 528 to the NASA Parkway East causeway on January 20th had an estimated ChlA median of 24.02 µg/L, 3rd Quartile of 26.84 µg/L, and maximum of 149.99 µg/L. This was a decrease from the previous estimated median of 40.63 µg/L on January 15th.  

The central section of the Banana River from Cocoa Beach to State Road 520 on January 20th had a median estimated ChlA of 22.22 µg/L, 3rd Quartile of 25.14 µg/L, and maximum of 110.96 µg/L. This was a decrease from the estimated ChlA median of 42.73 µg/L observed on January 15th. 

On January 20th the southern section of the Banana River between Cocoa Beach and Patrick Space Force Base there was a median estimated ChlA of 13.41 µg/L, 3rd Quartile of 15.70 µg/L, and maximum of 122.96 µg/L. This was a decrease from the estimated ChlA median 26.05 on January 15th. 

All three sections of the Banana River experienced decreases in median ChlA levels. The south section of the Banan River also continued to have the lowest estimated ChlA of the Banana River. Further investigation is needed to determine why this location is less supportive of the current HAB taxa. 

On January 20th in the South North IRL (NIRL) from State Roads 528 to 404 there was an estimated ChlA median of 14.67 µg/L, 3rd Quartile of 18.64 µg/L, and maximum of 116.13 µg/L. This was a decrease from the estimated ChlA median of 20.72 µg/L on January 15th. 

On January 20th in the North Central IRL (CIRL) from State Road 404 to Turkey Creek there was an estimated ChlA median of 18.73 µg/L, 3rd Quartile of 26.66 µg/L, and maximum of 85.50 µg/L. This was a decrease from the estimated ChlA median of 22.51 µg/L on January 15th. 

Sentinel 3

Five scenes from Sentinel 3 were usable for detection of HAB activity from January 16th, 2023, to January 22nd, 2023. The following analysis focuses on the scenes from January 16th and January 19th (Table 3, Table 4).

Of the 5 SJRWMD CM stations, the highest mean estimated ChlA concentrations on January 16th was observed at IRLB04 with 23.99 µg/L. Then on January 19th IRLB21 had the highest estimated ChlA at 27.21 µg/L, an increase of 15.43 µg/L since January 16th. Both IRLML02 and IRLTITUS experienced a 4 µg/L increase between January 16th and January 19th, from 9.56 µg/L to 13.31 µg/L and 14.82 µg/L to 19.28 respectively µg/L. IRLI13 remained steady between a mean estimated ChlA of 4.45 µg/L and 5.78 µg/L. IRLB04 was the only station to experience a decline in estimated ChlA with a mean of 22.26 µg/L on January 19th. 

On January 16th the southern Mosquito Lagoon had an estimated ChlA median of 9.53 µg/L, 3rd Quartile of 10.86 µg/L, and maximum of 32.77 µg/L. This was a decrease from the estimated ChlA median of 21.08 µg/L on January 15th. By January 19th the estimated ChlA median further increased to 13.62 µg/L, 3rd Quartile of 18.41 µg/L, and maximum of 32.22 µg/L. 

There was an uptick in bloom activity in the North NIRL section. On January 16th the North NIRL had an estimated ChlA median of 7.37 µg/L, 3rd Quartile of 8.30 µg/L, and maximum of 54.90 µg/L. This was a decrease from the estimated ChlA median of 17.42 µg/L on January 15th. By January 19th the estimated ChlA median increased to 18.30 µg/L, 3rd Quartile of 22.43 µg/L, and maximum of 32.24 µg/L. 

On January 16th in the Central NIRL, between Titusville and the State Road 528, there was an estimated ChlA median of 11.04 µg/L, 3rd Quartile of 12.92 µg/L, and maximum of 36.03 µg/L. This was a decrease from the estimated ChlA median of 20.43 µg/L on January 15th. By January 19th the estimated ChlA median increased to 13.91 µg/L, 3rd Quartile of 18.62 µg/L, and maximum of 36.71 µg/L. 

The northern section of the Banana River from State Road 528 to the NASA Parkway East causeway on January 16th had an estimated ChlA median of 22.71 µg/L, 3rd Quartile of 24.98 µg/L, and maximum of 55.06 µg/L. This was a decrease in the median estimated ChlA of 34.05 µg/L on January 15th. By January 19th the estimated ChlA median was 20.77 µg/L, 3rd Quartile of 23.85 µg/L, and maximum of 44.71 µg/L. 

The middle section of the Banana River from Cocoa Beach to the NASA Parkway East causeway on January 16th had an estimated ChlA median of 23.84 µg/L, 3rd Quartile of 27.64 µg/L, and maximum of 48.50 µg/L. This was a decrease in the median estimated ChlA of 36.57 µg/L on January 15th. By January 19th the estimated ChlA median was 20.97 µg/L, 3rd Quartile of 24.80 µg/L, and maximum of 58.78 µg/L. 

The southern section of Banana River from Cocoa Beach to Patrick Space Force Base on January 16th had a median of 9.00 µg/L, 3rd Quartile of 10.30 µg/L, and maximum of 43.60 µg/L. This was a decrease in the median estimated ChlA of 20.14 µg/L on January 15th. By January 19th the estimated ChlA median was 14.88 µg/L, 3rd Quartile of 16.50 µg/L, and maximum of 52.93 µg/L.

This suggests a decrease in bloom activity in the Banana River between January 16th and January 19th, with the southern section still reporting the lowest ChlA levels. 

On January 16th in the South NIRL from State Roads 528 to 404 there was an estimated ChlA median of 8.17 µg/L, 3rd Quartile of 12.27 µg/L, and maximum of 48.81 µg/L. This was a decrease from the estimated ChlA median of 12.83 µg/L on January 15th. By January 19th the estimated ChlA had a median of 15.13 µg/L, 3rd Quartile of 21.75 µg/L, and maximum of 53.83 µg/L. 

On January 16th in the North Central IRL (CIRL) from State Road 404 to Turkey Creek there was an estimated ChlA median of 7.12 µg/L, 3rd Quartile of 9.45 µg/L, and maximum of 43.60 µg/L. This was a decrease in the median estimated ChlA of 17.26 µg/L on January 15th. By January 19th the estimated ChlA had a median of 22.39 µg/L, 3rd Quartile of 26.99 µg/L, and maximum of 55.37 µg/L. 

Table 3 - Sentinel 3A estimated Chlorophyll A (ChlA) statistics in Micrograms/Liter (µg/L) for January 16, 2022, over the St. John River Water Management District (SJRWMD) Indian River Lagoon (IRL) Continuous Monitoring Stations.

Table 4 - Sentinel 3A estimated Chlorophyll A (ChlA) statistics in Micrograms/Liter (µg/L) for January 19, 2022, over the St. John River Water Management District (SJRWMD) Indian River Lagoon (IRL) Continuous Monitoring Stations.

Methods

HAB’s observed by this project are defined as over 80 Micrograms/Liter (µg/L) Chlorophyll A (ChlA) (as estimated by a calibrated Normalized Difference Chlorophyll Index (NDCI)) and persistent across the week in review. The algorithms that transform the NDCI index value to estimated ChlA concentrations were developed using a second-order polynomial equation. The Sentinel 2 (S2) equation has a Root Square (R2) of 0.81 with a Root Mean Square Error (RMSE) of 14.14 ug/L of ChlA. The Sentinel 3 (S3) equation has an R2 of 0.92 and an RMSE of 9.92 ug/L ChlA. The RMSE is a measure of the accuracy of a model in estimating values, ChlA in this instance, where a lower value is indicative of higher accuracy. It does not identify if the model consistently over or underestimates the modeled values. The equations are below:

• S2 Estimated ChlA = 297.36(NDCI)2 + 313.98(NDCI) + 36.152

• S3 Estimated ChlA = 437.07(NDCI)2 + 348.98(NDCI) + 33.928

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