There are two basic habitat types in the mesocosm: eelgrass and sand/sediment. At Right are views of a lobster in each habitat type.
The lobster in Figure 2 is equipped with an ultrasonic transmitter and it was residing in a pit in the sand. Below the pictures are videos of the same lobsters.Fitting a Lobster with a Transmitter
We use the VEMCO VRAP telemetry system to track up to 5 lobsters, and one reference pinger, at a time. Three buoys are moored in a triangle around the mesocosm. Hydrophones in each buoy detect pulses from one of the transmitters, and then relay this information, via radio-transmission, to a receiver on shore. The base-station is connected to a computer and the VRAP software calculates the position of the lobsters based on time of arrival of the pulses at each of the buoys. The system is capable of simultaneously tracking up to 6 different transmitters, each of which is operating at a different frequency. Typically, we obtain a fix for each lobster every 2 minutes. When buoy movement and other factors are taken into account, the system appears to have an accuracy of approximately 1 meter.