San Francisco " A National Oceanic and Atmospheric Administration (NOAA) grant awarded to Advanced Design Consulting (Lansing, NY) will allow scientists to track the movement of lobsters across the ocean floor. The grant calls for the development of RF transmitters that will sense-and-record the temperature differentials that portend the movement of the red crustaceans.
Just as northern hunters follow the movements of reindeer herds, so commercial fishermen track the migrations of lobster populations. They do it by correlating water temperatures at the bottom of the ocean with locations where lobsters are most abundant.
Currently, lobster hunters use thermal measuring devices that feed the temperature to data loggers attached to the traps. The data is available only when the traps are retrieved and the loggers taken to a remote site for downloading. Though these devices have proven useful, they don't provide any real-time temperature information, nor do they produce any data about the ocean depth where the temperatures were recorded.
Advanced Design Consulting, Inc. proposes to change that. The NOAA grant funds development a miniaturized environmental monitoring system that will transmit ocean floor data to an inexpensive hand-held computer. "The system will not only instantly plot temperatures, says Alex Deyhim, president of Advanced Design Consulting, "It will also have a pressure sensor to record depth changes. In addition, we plan to develop a way to recharge the batteries within the system so it remains completely sealed."
When finally designed, the sensor will operate from a circuit card roughly the size of a quarter and be housed in a case two inches long and one-inch wide. Two antennas coils will surround the case, one to facilitate charging and the other to read the data and radio it to a hand-held or a laptop computer.
Power consumption is an issue, reminds Eric Johnson, Advanced Design Consulting's vice president of research. The sealed device must be recharged by radio induction, he said.
Lowered to the ocean bottom on lobster traps, the sensor will measure water temperature and pressure hourly, up to a depth of 1,300 feet (400 meters). With a useable life of at least 10 years, it will be able to operate on battery power for a year without external recharging.
"Incorporating radio frequency communication and charging into an existing low-power sensor will be a challenging task," Deyhim says. "But once we complete it, professional lobstermen will have detailed, real-time information that will be of critical economic importance to them."