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Remote Sensing for Coastal Management
Sensor Summaries
Applied Uses
Coastal Development
Habitat Management
Water Quality
Monitoring Harmful Algae
Monitoring Phytoplankton Levels
Identifying Non-Point Sources of Fecal Coliform
Impacts of Hurricanes on Coastal Ocean Properties
Living Resources
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Remote Sensing for Coastal Management

Impacts of Hurricanes on Coastal Ocean Properties

Understanding the impacts of hurricanes on near-shore ecosystems is necessary to manage and protect these biologically diverse regions. State coastal managers and researchers are using aircraft remote sensing to monitor phytoplankton abundance in response to the passage of hurricanes and other natural events so they can assess changes to the ecosystem and coastal water quality.

The Project: Monitoring Water Quality Changes Associated with Hurricane Isabel

Estuarine ecosystems play an important buffering role during episodic events; however, hurricanes can affect the physical and biological diversity of an estuarine ecosystem by changing the hydrologic dynamics and biological productivity of a system. Changes to the physical structure and water quality can often be detected by measuring the biological and physical responses of the system using remote sensing techniques. An understanding of the natural temporal and spatial variability of the system is necessary to understand the impacts due to an event such as a hurricane. The Chesapeake Bay is an important habitat for a multitude of plants and animals yet it is also a dynamic system subject to physical impacts due to hurricanes. Following the passage of Hurricane Isabel in September 2003, researchers from the Chesapeake Bay Remote Sensing Program used aircraft remote sensing to map phytoplankton response in the bay.

Mapping Phytoplankton Abundance with Aircraft Remote Sensing

By using aircraft remote sensing to measure ocean color, the investigators could rapidly obtain high spatial and temporal data – critical for monitoring chlorophyll concentration in coastal waters. Light aircraft equipped with the ocean-color sensor SeaWiFS Aircraft Simulator (SAS III) was flown over the study site at an altitude of 500 feet, requiring about five to six hours to cover the entire bay and its tributaries. The SAS III instrument was paired with an infrared temperature sensor to obtain sea surface temperature during the flights.

The SAS III instrument is capable of obtaining data from 13 different spectral bands and provides relatively high spectral resolution data. Spectral resolution refers to a sensor’s ability to define fine wavelength intervals for a particular band or channel. The finer the spectral resolution, the narrower the wavelength range for a particular channel or band.

The Result

A strong phytoplankton response indicated by chlorophyll a concentration was documented in the middle to lower bay following the passage of Hurricane Isabel. Typically, Chesapeake Bay’s phytoplankton dynamics are characterized by low biomass and modest primary productivity; however, aircraft remote sensing revealed a large phytoplankton bloom covering most of the middle to lower Bay 6 days after the passage of Hurricane Isabel. The investigators attributed this increase in phytoplankton biomass to increased nutrient availability and the introduction of deeper seed populations of phytoplankton due to mixing associated with winds and storm surge.

Aircraft remote sensing of chlorophyll is a viable method for measuring biological response to changes in coastal water quality. Ocean color data can help coastal managers assess the impacts of physical drivers associated with hurricanes and other natural events.

For More Information

1Roman, M.R., Adolf, J.E., Bichy J., Boicourt, W.C., Harding Jr. L.W., Houde E.D., Jung S., Kimmel D.G., Miller W.D., and Zhang X. 2005. "Chesapeake Bay Plankton and Fish Abundance Enhanced by Hurricane Isabel," EOS Transactions, American Geophysical Union. Volume 86, (28) Pages 261, 265.

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