Could be K.
But part of me believes fish follow the conservation of energy principle all year round, suspending a great majority of the time even with metabolism changes up or down depending on water temperature. I've seen many videos of suspended fish milling around, ignoring nearby bait fish until a lure's surface splash breaks them out of their trance. The only movement was fish slowly swimming from one area to the next. No video showed fish attacking bait fish and then a lure or vice versa.

Some times I wish I had pursued skin diving and underwater photography so I could document fish activity at different times of day. With spy technology reaching the masses via drone cameras, I wouldn't be surprised if that equipment becomes cheaper so more anglers can study underwater fish activity similar to that in Glen Lau videos. A remote controlled spy submarine .....