The Bear is in the Igloo

The marine glider ready for deployment.

By Darvene Adams

It sounds like a story of Arctic homesteading gone awry, but it actually takes place in the coastal waters off of New York and New Jersey. “The Bear is in the Igloo” is a catchphrase used by Rutgers University oceanographers to signify that an “Autonomous Underwater Vehicle” or ocean glider has been successfully retrieved from its mission gathering water quality data in the ocean.

State and federal agencies have long recognized that low dissolved oxygen in the waters off the coast of NY and NJ is a major concern. Fish, clams, crabs, etc. all need a relatively high amount of dissolved oxygen (D.O.) in the water to survive and reproduce. Effectively measuring dissolved oxygen levels in the ocean is a complex task. There is a lot of territory to cover (approximately 375 mi² just off of NJ) and the D.O. levels change constantly. NJ and EPA have conducted some “grab” sampling which resulted in the entire coastal zone being declared “impaired,” even though the existing sampling didn’t cover the whole area. The New Jersey Department of Environmental Protection asked EPA for help to address this dilemma.

Glider tracks off the coast of New Jersey.

Enter the glider, better known as RU28, a relatively new technology but one that is being rapidly adopted by the military and water researchers. Part fish, part robot, it “glides” through the water column, using a pump to take in or expel water, allowing displacement to lift or sink the glider. It is programmed to surface approximately every two hours and “phones home” to send some of the water quality data it has collected and its operational status. Parameters include dissolved oxygen, temperature, salinity, chlorophyll a(pigments indicative of algae), CDOM (colored dissolved organic matter), and depth. As the glider moves in a zig-zag pattern down the coast, it is also moving vertically in the water to profile the water column. Each deployment is approximately three weeks in length.

A glider was in the water off of NJ when Hurricane Irene impacted the area in 2011. The data collected by the joint glider mission produced the first water quality data ever collected under a hurricane. The National Weather Service was able to use these data to revise their hurricane modelling to account for the effect of a tropical hurricane entering temperate zone waters.

The second mission of this summer was deployed last month, so click on:http://marine.rutgers.edu/cool/auvs/index.php?did=422&view=imagery and follow the journey.

About the Author: Darvene Adams is EPA Region 2’s Water Monitoring Coordinator. She provides technical assistance to states and the public regarding ambient monitoring activities in marine, estuarine and freshwater systems. Darvene also designs and implements monitoring programs to address relevant resource management questions in the region. She has coordinated monitoring projects in the NY/NJ Harbor, Barnegat Bay, Delaware Bay, and coastal NJ, as well as the region’s involvement with EPA’s National Aquatic Resource Surveys. Darvene received her Master’s Degree in Environmental Science from Rutgers University and is based in the Edison, NJ field office.

Editor’s Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.