In 2020, the west coast of Florida experienced devastating algal blooms that resulted in the death of thousands of tons of marine life and significant economic losses. These blooms also had severe human costs, including increased asthma cases and detrimental effects on various industries. Traditionally, detecting algal blooms from space has been limited to clear sky conditions using the visible spectrum. However, a recent study conducted by scientists at NASA’s Jet Propulsion Laboratory introduces the potential of a space-based instrument called TROPOMI (TROPOspheric Monitoring Instrument) in overcoming these limitations and providing valuable insights into harmful outbreaks.
The study focused on Karenia brevis (K. brevis), the microscopic algae responsible for the 2020 blooms along the West Florida Shelf. These blooms are becoming increasingly prevalent in coastal communities due to nutrient-rich and warm conditions fueled by runoff, fertilizer use, and climate change. K. brevis is particularly concerning because it produces a potent neurotoxin that can harm marine life and pose health risks to humans.
Several states and coastal regions, including the Gulf of Mexico and Great Lakes, have systems in place to monitor and forecast harmful algal blooms. The National Oceanic and Atmospheric Administration (NOAA) collaborates with various partners to issue bloom forecasts similar to weather predictions. These forecasts are crucial in taking preventive measures and minimizing the impact of algal blooms on ecosystems and industries.
TROPOMI, designed to measure air pollution, has demonstrated its potential in detecting algal blooms by capturing solar-induced fluorescence (red SIF) emitted by K. brevis. The instrument gathered twice as much fluorescence information compared to previous methods relying solely on ocean color. Being able to penetrate thin cloud cover and measure the ocean’s surface more frequently, TROPOMI’s advanced imaging capabilities make it a valuable tool for forecasting and managing harmful outbreaks. It can be used independently or in conjunction with other Earth-observing instruments like MODIS (Moderate Resolution Imaging Spectroradiometer) to enhance the accuracy of detection.
Looking ahead, NASA’s upcoming PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) mission, set to launch in 2024, will revolutionize the study of marine ecosystems. PACE will provide detailed observations of phytoplankton, ocean biology, atmospheric aerosols, and clouds in numerous wavelengths. These comprehensive measurements will significantly enhance the ability to forecast harmful algal blooms, monitor fisheries, and understand other factors affecting industries reliant on the ocean.
The value of early warning systems through satellite technology has been proven in real-world scenarios. A case study in Utah Lake demonstrated that early detection of cyanobacteria resulted in substantial cost savings in healthcare, lost work hours, and other economic losses. Timely detection enables prompt actions such as public alerts and beach closures, mitigating the impact of algal blooms on both human health and the environment.
The detrimental effects of algal blooms on coastal communities emphasize the urgency of improving detection and forecasting methods. The utilization of space-based technology, such as TROPOMI and future missions like PACE, opens up new horizons in monitoring harmful algal blooms. These advancements enable more accurate and frequent observations, even under cloud cover, leading to enhanced early warning systems and proactive measures to mitigate the devastating consequences of algal blooms on marine life, human health, and various industries.