Measuring the “dead zone”

The Houston Chronicle reports that a team of Texas scientists are releasing four torpedo-like, remote- controlled gliders into the northern Gulf of Mexico to measure oxygen levels, bringing researchers closer to a long-cherished goal of broadly monitoring the health of the world’s oceans.

“The community of scientists that study oceans have long dreamed of deploying these silent sentinels of the sea,” said Steve DiMarco, an oceanographer at Texas A&M University.

On Tuesday DiMarco, aboard the research vessel Manta, departed Pelican Island in Galveston Bay on his annual June cruise to monitor the northern Gulf for hypoxia, or low levels of oxygen in the water that are harmful to marine life.

As part of the cruise he will deploy four of the gliders, each costing about $200,000, which are autonomous vehicles that measure temperature, salinity and oxygen levels. Traveling at a speed of about 8 mph, they can go as deep as 1,000 feet.

The gliders, packed with D-cell and lithium batteries, will stream their data back to Texas A&M. Those batteries, which provide all the onboard power, will last about a month before the gliders must surface to replace battery packs.