Algae might be small, but when they grow out of control, forming harmful algal blooms (HABs), they can cause big problems. Ecosystems and human health can be affected as thick layers of smelly foam form on beaches, toxins potentially enter the food chain, or aquatic oxygen levels become depleted.
Detecting HABs can present a challenge due to the complexity of the coastal environment. Conventional algorithms detect a green pigment in algae but cannot discriminate between an actual bloom and other, similar features in water.
Now, scientists have developed a way to detect HABs early on by using images of Earth from space. Images from the Hyperspectral Imager for the Coastal Ocean (HICO), a remote sensing instrument that operated from 2009 to 2014 from the International Space Station, were used to develop an algorithm that monitors algae by detecting chlorophyll fluorescence. Since the space station covers about 80% of Earth’s surface, including most coastal regions where HABs are a major threat, it helped to provide the ideal data for developing a new algae bloom detection system.
This detection system could allow coastal businesses to minimize the economic hit from an HAB by preparing for a bloom before it reaches the shore.