The vertical green line shows time of last detection inside Breede River, before sharks commenced migrations through the upwelling zone. Detections are coloured based on whether they occurred within the upwelling zone (differentiated between inside and outside Breede River) or past the upwelling zone. Temperature and depth records from PSAT tags are given. Horizontal blue lines indicate 19 C. For when a shark was present in and around Breede River (not migrating), a cyan blue temperature curve from a logger outside the river was added and the total number of upwelling events matched with PSAT temperature records indicated. Upon departing the river, if PSAT tags recorded rapid temperature declines and this could be matched with an upwelling event at a local temperature logger, additional cyan blue lines were added to show temperatures recorded at that logger. BR, Breede River; PB, Plettenberg Bay; PE, Port Elizabeth; PA, Port Alfred. For shark ID1 and ID5, see Supplementary Fig. 14.
