This description covers a wide range of lakes, many of which have been created by man. Lowland lakes are usually capable of supporting a wide variety of fish. The richness of the water depends on several factors.
The most important of these is whether the water is acid or alkaline.
This is often referred to in terms of ‘soft’ or ‘hard’ water. Most lowland lakes are ‘hard’ or alkaline waters. Acid or ‘soft’ waters usually occur on higher ground where the water seeps through peat bogs. Alkaline waters are much the richest and are capable of supporting a wide variety of insect, crustacean and fish life. The richest of all lowland lakes are those where the water percolates through chalk rock before running into the lake. Some lakes are totally enclosed but others are fed by a small stream. A few lakes have been created by damming a small stream or river so that the water has risen and flooded over an area of low lying land.
Plant life is usually abundant in lowland lakes. The bankings and margins will support reeds and rushes, whilst the shallows will contain a number of varieties of soft walerweed. Many anglers con fuse the tall reedmace with the bulrush. The reedmace is the tall plant which grows in thick clumps and develops a brown cigar-shaped head on the main stem. In winter, when the leaves die away, these stems remain upright and the brown seed head begins to disintegrate, scattering seeds out into the water.
Reedmace grow in places where the bottom is soft silt or mud. And can spread in shallow lakes so that thev eventually cover a large area. True bulrushes have a single green stem which grows to a height of five or six feet (1.5 or 1.82 metres). The narrow stem develops a tiny flower towards its top. Bulrushes grow best where the bottom of the lake is gravelly. Knowing the difference between these two plants is useful because they indicate a different type of lake bed. Advice that tench feed alongside bulrushes is wasted if you can:t tell the difference and spend your time fishing alongside reedmace beds. Both these plants are a helpful indication of depth as m they seldom growin water deeper than 2-5 feet (0.75 metres).
This will often indicate where the depth increases alongside a bed of rushes. Lowland lakes in summer In early summer, as the shallow water warms up quickly, gases will escape from the lake bed, causing bubbles to rise to the surface, often accompanied by bits of mud dislod-ged from the lake bed. The water may become a rich tea colour as this warming-up process takes place. In heatwave conditions rapid growth and spread of algae may occur, causing the lake to appear green. The surface layer of “water warms up very much quicker than the deeper water. In between the layer of warm water and cold water there is a short depth where the temperature changes suddenly. This is called the thermocline. In hoi, calm weather this thermocline is very noticeable. The surface layer of water will be warm. Green and thick with algae and plankton. If you place your arm into the lake you will be able to feel the sudden change in temperature at the ihermocline.
The plankton and algae will be confined to the top layer of warm water so that if you paddle your hand around you will be able to see I he clear water below the ther-mocline. Fish avoid the warm layer of water which contains very little dissolved oxygen. In windy weather the action of the wind will cause the algae and plankton to drift to the windward side of the lake. In these hot weather conditions, it pays to fish with your back to the wind.
The thermoelinc tills so that the cooler water will rise towards the surface on the sheltered side of the lake and this is where the fish will be. It is easy to tell when there is very little oxygen in the surface layer of a lake during hot weather. Waft a landing net handle around on the surface and it will create large bubbles which are a pale green colour and take a long time to burst. You will also find that your keepnet will not stay extended and keeps folding up and rising to the surface. If you encounter these conditions dont keep your fish in the net or they are likely to die. These conditions are most likely to be encountered in June or carlyjuly. In normal summer conditions, when there is no algae or plankton explosion in’the lake, the best fishing is likely to be found when casting into the wind.
The warm surface layer will contain enough dissolved oxygen for the fish because of the action ol’ the waves. In small lakes the tilting of the thermocline is not nearly so noticeable as it is in larger waters. Water in the shallows will be very warm during the day but cool down slightly al night, fish often take advantage of this and move into very shallow water to i’vvd after dark. Lowland lakes in winter During the colder months of the year. A reversal of this process takes place when the surface layer of water is the coldest. At this time of year fish with your back to the wind as the water layers tilt and the warmer water comes towards the surface on the sheltered side of the lake. Also, it is not much fun trying to fish into the teeth of a January gale! The fish are generally in the deeper parts of the lake.
Trees round the margins of a lake I an cause problems. When the leaves are shed in the autumn they will eventually become waterlogged and end up on the windward side of the lake. The leaves will form a thick carpet on the lake bed and, as they decompose, they release gases which cause distress to the fish. Avoid these areas during late autumn and winter because you are unlikely to catch many fish.