Fig. 4

Positioning probability (black line) of sync tag S003, the southernmost transmitter in the Drummond Island Vemco Positioning System (VPS) array (see Fig. 1), relative to the median number of unique fish transmitters detected on receivers with line of sight and within 500 m of S003 and thermal stratification (bottom graph in each panel). Temperature profiles were interpolated from two separate temperature lines deployed in the array. Poor positioning probability at the end of the 2012 season was due to widespread receiver memory saturation, which began on 06 October. Each point on the graphs represents a 6-h time window. Temperatures are in °C