Whoops, I just googled �Why do fish go deep in the winter� and the first hit said this:
� Fish descend into the bottom of streams and lakes where the warmer water is in winter. Density of warm water is higher, causing it to sink to the bottom in winter. This is the same reason that ice cubes float in a glass of water. ... During the cold of winter fish become less active.�
Sorry for the misinformation, the internet let me down this time!
