A cleanup crew walk along Huntington Beach looking for spots of oil north of the pier with cargo container ships in the background. More than 125,000 gallons of oil spilled from a pipeline about four miles offshore of Southern California's coast. The spill left a sheen over miles of ocean along the shoreline at Huntington Beach. Xxx News Southern California Oil Spill 033 Jpg A Oth Usa Ca
Los Angeles, California – A cutting-edge NASA instrument designed initially to map minerals in deserts has found an unexpected application: detecting signs of wastewater pollution in the Pacific Ocean. In a recent study, scientists using data from the Earth Surface Mineral Dust Source Investigation, or EMIT, identified a spectral signature of sewage in ocean waters near the mouth of the Tijuana River, just south of Imperial Beach.
Built at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, EMIT orbits Earth aboard the International Space Station, where it analyzes light reflected from the surface in hundreds of color bands. That level of detail, made possible through a process known as imaging spectroscopy, allows researchers to identify specific molecules based on their unique spectral “fingerprints.”
What researchers found was a fingerprint linked to phycocyanin, a pigment found in cyanobacteria—microorganisms that can be harmful to humans and wildlife. According to scientists, the detection lines up with field-based water samples taken from the exact location. Cyanobacteria can bloom in nutrient-rich waters, including those impacted by sewage.
For years, Southern California’s coastal communities have dealt with the chronic problem of wastewater flowing from the Tijuana River. Millions of gallons of treated and untreated sewage are carried across the U.S.-Mexico border each year, affecting not just beachgoers, but also marine ecosystems and U.S. Navy trainees stationed nearby. The new research highlights both the magnitude of the problem and the emerging tools that may help monitor it.
While researchers have used traditional satellite instruments to track algal blooms by identifying changes in ocean color, they lack the resolution to detect many other pollutants. EMIT’s advanced spectrometry provides a sharper picture.
“From orbit you are able to look down and see that a wastewater plume is extending into places you haven’t sampled,” said Christine Lee, a water quality scientist at JPL and coauthor of the study. “It’s like a diagnostic at the doctor’s office that tells you, ‘Hey, let’s take a closer look at this.’”
Lead author Eva Scrivner, a doctoral student at the University of Connecticut who led the study while at San Diego State University, said the findings offer a “smoking gun” for identifying wastewater contamination in the Tijuana River plume. She believes EMIT’s ability to detect pollution remotely could help close gaps in data collection and reduce reliance on expensive, labor-intensive fieldwork.
