Deep, dark lakes for wild trout

Finding fish in Britain’s vast natural lakes is perhaps the most difficult task the angler faces. Water craft is essential if you are to cut out unproductive fishing in these wild waters.

Basic needs

A trout needs very few creature comforts to be content. Security, cool, well-oxygenated water and food are highest on the list. The volume of water and the extensive areas of deep water mean that oxygen starvation -common in our small, shallow stillwaters -isn’t a big problem; security and cool, oxygenated water are readily available. Rock ledges near deep water offer areas of safety.

Follow the feeding

It would be easy to locate fish if they were evenly distributed throughout the lake. But this is very rarely the case: trout are localized. The major factors governing their whereabouts are food availability, weather and time of year.

During both the early and late season trout have only limited sources of available food. In summer there’s plenty of insects and crustaceans for the fish to feed on -especially in the shallow areas of the lake. Here trout find shrimps, sedges, hoglice, mayfly and olive nymphs and many other aquatic food forms.

In late summer, terrestrial insects such as hawthorn flies, beetles, ants and daddy-long-legs fall or get blown on to the water, adding a bit of variety to their diet.

During the whole of late spring to early autumn, hatches of buzzers occur almost daily, especially in deep water.

Where do you find most of this food? With the exception of buzzers, the answer is simple – in water shallower than 6m (12ft). In fact, most insect activity occurs in water less than 1.8m (6ft) deep. You can find trout in shallow water most of the year. There are exceptions, however. During the early and late season (April and September) trout are in the warmer, deeper water. In mid summer, they retreat to the cool, dimly lit depths.

Most deep lakes are not blessed with extensive shallows, and consequently, the food availability is restricted to relatively small areas which can hold dense populations of fish.

The weather

The weather can affect food stocks and the trout’s security. Trout won’t feed when their security is threatened, and they are very loath to venture into clear, calm, bright shallow areas.

Cloudy days with a warm wind blowing are some of the best times to fish. Ripples -or better still waves – reduce light penetration, encouraging the fish to move into the shallows to feed.

During extremes of temperature – be they hot or cold – trout generally retreat to deep water. Extremely warm water is not normally a problem in deep lakes, but early and late in the season the water is cold, especially in the spring as the snow melts.

Trout become very lethargic and lack-lustre at this time. They are reluctant to expend energy for little in return, and they are also unlikely to feed avidly since the food is limited.

General assessments

So how do you make general assessments about all the variables that affect the trout and its environment? Reviewing tactics over the season provides some general guidelines.

Early season

The water is cold, and food is far from plentiful. The trout are recovering from the trauma of spawning; they’re lethargic, trying to expend as little energy as possible to gather the available food.

Excellent locations to find fish are stream or river inlets with access to deep-water channels. Food is brought to the trout (and other fish) on the current and little energy is spent gathering what’s available. Other areas to try are banks with narrow strips of shallow water next to deep-water shelves. Caddis larvae, shrimps, mayfly nymphs and hoglice are concentrated here.

April and early May

With the longer hours of daylight the water starts to warm. Trout gather where the food is concentrated, but they are far more active in the warmer water and are prepared to cover great distances in search of easy meals. Ideal areas are shallows, especially with weedbeds – which provide habitat for large numbers of nymphs – submerged islands and shallows around fully extended islands. All these areas should contain more fish if they border deep water or have rough, rocky areas.

The main food for trout at this time consists of fry, shrimps, hoglice, olive and mayfly nymphs (and chironomids when the trout resort to deep water under calm conditions). Hatching midges and daphnia are blown to and thus concentrated near the downwind bank.

In mid-summer

At this time there are long hours of sunlight and often calm conditions on the surface of the lake. The trout are fit and very active but reluctant to feed under bright, calm conditions. They are likely to concentrate their feeding during early and late times of the day over the shallows.

Main food items are nymphs and sedges (and chironomids when the trout are in deep water). This is one time in the season when fishing deep water within casting distance of the bank can pay off.

In September

As the water along the shallow areas cools, insect activity decreases, and trout once again move to their early season haunts -the deeper, warmer water — not so much for food quantity or availability but in preparation for running up feeder streams to spawn. Some good-sized fish can be taken at this time, but they should be returned to maintain the population for the future.