Pollution was suspected at first, but oceanographers now believe persistent upwelling during an unusually hot summer led to phytoplankton blooms and then hypoxia. Since 1976 oceanographers have found that low-oxygen events tend to occur in evenly spaced places along the Jersey coast where the bottom topography traps the upwelling water, creating a circular surface current called a gyre. The LEO-15 instruments include optical sensors to detect florescence in phytoplankton. As early as the year 2000, a LEO-like observatory set up in the Gulf of Maine will begin trying to predict red tides, the sudden bloom in the water of a kind of microscopic organism that can kill marine creatures and injure humans. Despite satellites, we still sometimes learn of red tides only when people call their doctors.
People are also sometimes the detectors for a far more deadly presence in the sea.
An autonomous underwater vehicle is just what NASA will need when the time comes to explore the Europan ocean. After censusing fish populations in the back bays and the Mullica, five small boats unload their nets. Scientists, graduate students and postdocs, and undergraduate interns joke about the trials and tribulations of another day at sea. Little by little they disperse, walking down a long causeway to where their cars are parked. The station quiets.