Measurement of seagrass standing crop using satellite and digital airborne remote sensing

ABSTRACT

Seagrass standing crop is highly sensitive to environmental disturbance. We evaluate three optical remote sensing methods for measuring standing crop in the tropical Western Atlantic.

Extensive field measurements of standing crop were used to define empirical relationships with imagery from satellite sensors (Landsat Thematic Mapper and SPOT - Système Probatoire de l’Observation de la Terre - XS (multispectral), and the digital airborne imager, CASI (Compact Airborne Spectrographic Imager).

Predictions of standing crop from processed imagery had high coefficients of determination; 0.74, 0.79 and 0.81 respectively. Using a bootstrap method to measure standard error, the 95% confidence interval of predictions was found to have a similar order of magnitude to quadrat sampling in situ at a precision (standard error / mean) of 10%.

Explicit cost-benefit and monitoring considerations are discussed