The spatiotemporal distribution and vertical movement of Atlantic cod are driven by several factors such as its physiology and the physical and biological environment. This study investigated the influence of seasonal changes in water temperature on cod residency, frequenting, home range, depth change, and activity level in the BPNS and Scheldt estuary using the acoustic telemetry data from 2010 to 2019. Through Generalized Additive Mixed Modelling, the effects of seasonal change of sea surface temperature and fish length were tested. Residency and frequenting of cod followed a seasonal pattern between sites which was influenced by the seasonal variations of SST. Cod stayed in offshore artificial reefs during the warmer waters of summer (16-17°C). During winter, most fish migrated to the colder waters of the coast and estuary (<15°C). Positional change in the home range followed a similar pattern. Depth change and activity level were also affected by seasonal change in SST wherein the highest was in autumn (10-15°C) and low the rest of the year. Insights on the influence of seasonal water temperature change on the movement patterns of cod in the area will be useful in predicting its distribution in the future state of our warming seas. |
