IRL Health Update

MRC’s IRL Report Card assembles the most accurate data of Lagoon conditions to date. Find out what’s happening in the latest release.

From the IRL Health Update: Indicators assess lagoon health and guide management like a medical doctor uses a patient’s vital signs to diagnose and treat human health issues.

From the 2018 IRL Health Update: Seagrass secures the lagoon bottom, reduces erosion, and is an important primary producer for the ecosystem, providing habitat and food for many types of lagoon life.

From the IRL Health Update: Nitrogen (N) is a key nutrient necessary to the primary production of the system, but can be devastating in excess, causing algae blooms and lowered dissolved oxygen in the water which chokes out life.

From the IRL Health Update: Phosphorus (P) is a key nutrient for lagoon health that can be harmful in excess. Although the Clean Water Act requires phosphorus reductions, concentrations have significantly increased in many lagoon regions.

From the 2018 IRL Health Update: Chlorophyll-a measures the amount of algae in the water and lagoon health declines with increasing algae.

Turbidity is a measurement of water clarity. Dirty water loaded with sediments and disturbed muck increases turbidity and decreases water clarity. Historical recounts describe the clear “turquoise blue” water in the lagoon that one could see through to the bottom.

From the IRL Health Update: IRL health indicators have established Indian River Lagoon regulatory targets that include the following sources.

From the 2018 IRL Health Update: The most reliable data were used in the IRL Health Assessment. More than 3 million records were acquired, processed, and triaged prior to populating the database for mapping and analysis.

From the 2018 IRL Health Update: Offsets measure the difference between actual conditions and the healthy targets for each indicator.

From the 2018 IRL Health Update: The WQI use the four water quality indicators: chlorophyll-a, TN, TP, and turbidity. The WQI was calculated for each sublagoon area by converting annual offsets to a percentage scale, resulting in a final score ranging from 0% to 100%.

From the IRL Health Update: Total Nitrogen (TN) had site-specific targets that used medians and geometric means and the results are reported in offsets from the established target by year and twenty years for each sublagoon.

From the 2018 IRL Health Update: The story of the north lagoon is about decades of pollution discharged into regions of the lagoon that never circulate due to a lack of ocean access.

From the 2018 IRL Health Update: The South Lagoon is somewhat of a special case, where the watershed has been dramatically altered when the C-44 canal was constructed.

From the IRL Health Update: The Habitat Quality Index was developed to normalize the offset percentages from the seagrass transect data to a 0–100 scale, identical to the Water Quality Index scale. Establishing a habitat index allows future indicators to be incorporated into the index using the same normalized approach.

From the IRL Health Update: MRC hired the Integration and Application Network at the University of Maryland Center for Environmental Science (UMCES IAN) to facilitate the Science Assembly in January 2016.