Two other important factors to consider are bait and weather. During the winter white bait (scaled sardines/pilchards) and Threadfin Herring are difficult to find and often not he bait of choice. During the winter season, shrimp and artificial baits are much more productive and often the go to baits. Fish metabolic rates are also affected by environmental conditions, such as temperature. The metabolism process will speed up with warming temperatures, meaning a fish's metabolic rate increases as the surrounding water temperature increases.
The cold temperatures slow the process. The same is true for presentation of your baits. Work your baits slower- much slower. I often tell clients if you think you are working that jig (bouncing it off the bottom) too slow, slow it down.