With the first frosts of the year, the water has started to cool although the mist above my local reservoir would indicate that the water is still clinging on to its Autumn temperature for as long as possible.
Water temperature is probably one of the most important factors in the behavior of our quarry. Firstly as a cold-blooded creature, the water temperature governs the blood temperature of the trout and therefore governs its metabolism. The colder the temperature, the slower the metabolism and the less active the fish will become.
The temperature of the water also has a direct correlation to the amount of Oxygen that can be saturated in the water. Cooler water can hold more saturated Oxygen than warmer water – and the more Oxygen the better. So you can see that cooler water can be a positive and a negative for fishing- It’s never straightforward, is it!
Throughout cooler weather, hatches of insects will become less frequent and less food will be available on the surface meaning that feeding fish can be looking for food near the bottom.
On the rivers, efforts will be concentrated around Grayling fishing as the Trout season is closed. For Trout fishing, most of the bigger deeper reservoirs will close through the winter and Trout fishing in very cold weather can be difficult on these large expanses of water as the can be deep – putting low lying fish out of range. Smaller still waters, however, can provide some great fly fishing for trout through the winter months. I’ve had plenty of good days with sheets of ice floating near my line.
So, what does this all mean? Well, what it means is that you can still catch fish but don’t expect lots of dry fly fishing and don’t expect fish to be chasing and attacking flies in very cold water temperatures. On rivers, Grayling will tolerate even the coldest winters day but it’s likely that deep nymph fishing or heavy Czech style bugs will be required. For the small stillwater, midges will be the only consistent hatching insect of the winter months so I like to concentrate my efforts around fishing deep and slow with bloodworms, midges and small nymphs such as Diawl Bachs. Stripping bright lures during cold weather may not be particularly successful as fish are less likely to chase and attack these patterns.
On both rivers and still water milder spells may encourage small hatches of flies and if you can target your fishing around the warmer parts of the day (around lunch time) when the fish are likely to be at their most active then better results can be achieved.
Wherever you are fishing, don’t forget some thermal socks, neoprene gloves and a good flask of hot soup!