Water quality in the Indian River Lagoon serves as an important piece of the restoration puzzle, as water conditions directly and indirectly influence IRL restoration. Differences in water quality can help to explain why some sites are successful and why other sites or areas may not be as suitable for restoration.

While data is already being collected throughout the lagoon, most existing sensors that track water quality are in deeper water in the middle of the water column. Data from these existing sensors have value in tracking regional trends and answering traditional questions; however, they do not reflect the conditions at restoration sites, which are much shallower and are usually in some way influenced by the sediment and submerged aquatic vegetation. Therefore, we have made efforts to improve water quality monitoring at our project sites through continuous monitoring.

Using HOBO loggers, we continuously monitor dissolved oxygen (DO), water level, salinity, and temperature on adjustable timescales to meet the needs of each project. Continuous monitoring can:

• Capture discrete events (such as a high-water event from a hurricane or a low DO event from an algae bloom).
• Show the impact diel cycling of hypoxia has on a project area.

Water quality loggers are a valuable tool; however, they do require a level of maintenance and care. We use deployment methodologies that limit biofouling and recalibrate sensors approximately monthly.

Working with Dr. Fox and the Florida Tech Biogeochemistry Lab, we have established a network of sensors and quality control protocols. We hope to continue to work with partners to grow this effort in the future.

Dissolved oxygen sensors documented the high oxygen levels of an algae bloom preceding the drop in oxygen production in the water column for a prolonged period, causing an Indian River Lagoon fish kill in Sebastian, FL and later in Malabar, FL.

Water Quality Websites

• St. John’s River Management District Continuous Water Quality Monitoring Portal 
• ORCA Kilroy Continuous Water Monitoring System
• FAU Harbor Branch’s IRLON Database
• FIT’s Dissolve Oxygen Data