Harmful Algal Bloom Forecast Project

Application of Remote Sensing to Red Tide Forecasts in the Gulf of Mexico: Proceedings of a Workshop

Executive Summary

Concerns about harmful algal blooms (HAB) have increased over the last decade largely because of the effects on fisheries and, in many cases, the associated decline in air and water quality. The toxins produced by these species create finfish and shellfish poisoning, and mass mortality of marine animals, including mammals, fish, and waterfowl. Toxic concentrations have caused public health emergencies, closing of shellfish beds, loss of tourism, and severe economic distress in coastal communities. Development of an operational HAB forecasting system to predict the occurrence and track the progression of blooms is requisite to mitigation and future control of HAB effects.

Remote sensing technology is essential to this forecasting effort because of the large spatial scale and high frequency of observations required to assess bloom location and movements. The Coastal Remote Sensing (CRS) program at the National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center identifies promising new remote sensing technologies and provides remote sensing data products that address critical coastal resource issues such as HAB.

In support of this mission, CRS hosted a workshop in July 1997 entitled, "Application of Remote Sensing to Red Tide Forecasts in the Gulf of Mexico." The Gulf of Mexico has been identified as a region that would benefit from a forecasting system. This area has experienced intense blooms of the dinoflagellate species Gymnodinium breve in at least 22 of the last 23 years. Many of the oceanographic features thought to affect G. breve accumulations and high concentrations of G. breve are detectable on the ocean surface. The Gulf of Mexico provides a relatively well-studied system with a high potential for a successful forecasting project.

Experts in the region’s ocean circulation, in phytoplankton physiology, and in remote sensing techniques were invited to discuss the potential of a Harmful Algal Bloom Forecast project. The workshop had the following objectives:

• Review the current state of knowledge on the history, prior management responses, ecology, biology, and bloom dynamics of G. breve red tides that initiate in the Gulf of Mexico.

• Assess the potential of a variety of remote sensing platforms to predict, monitor, and track G. breve red tides.

Bloom development and movement can be monitored using data from several platforms. Satellite coverage will provide large-scale information on oceanographic features. Periodic aircraft flights and mooring information can be used to monitor movements towards shore. A method of continuous measurement, as could be provided by moorings, would be desirable for an operational predictive capability; however, continuous measurements could be limited to strategic areas and times of year to minimize costs.

An effort based on remote sensing methods to track and monitor HAB events is the next step to effectively manage fisheries, public health, and ecosystems related to harmful algae. A remote sensing approach provides a mechanism to establish a routine monitoring schedule and to develop a database containing the type, location, frequency, and duration of an HAB. A strategically designed multi-platform, multi-sensor approach is required that will address the prediction, detection, and verification of bloom events. The plan must be flexible enough to include current capabilities and allow for the incorporation of new capabilities as they develop.