Dataset: Blue crab acoustics

The potential pathways of tagged crabs were estimated using a center of activity analysis following Simpfendorfer et al (2002). Estimates of latitude and longitude were made from the mean center of detections within the receiver array over 15-minute intervals for each transmitter. The mean center at a given time was weighted relative to how many receivers detected a transmitter during an interval (e.g., if a crab transmitter was recorded 3 times, 2 times and 15 times on receivers A, B and C respectively then the mean would be the average position of 3 × receiver A + 2× receiver B + 15 × receiver C). Bearings and velocities were calculated from the position estimate at the last interval. If a transmitter was not detected during the previous analysis interval, a position estimate would be recorded, but no bearing or velocity would be recorded, and the crab was considered inactive. This ensured that velocities and bearings were only recorded during times at which a crab was actively moving to best couple the appropriate environmental data. If a crab was absent for many sequential intervals while within the array, it was assumed to have buried or otherwise masked its transmitter. Analysis was conducted between the first and last position estimate for each crab within the array to encompass only the timespan when the crab was known to be detected by the array.