What are Lacustrine Fisheries?
The fisheries of the lakes are described as Lacustrine Fisheries. Aquaculture is thought about as a practical resource of relatively affordable healthy protein of high organic value, specifically in developing countries where protein sources are limited. Therefore, artificial lakes and reservoirs are being increasingly used for fish farming. Natural and also the manmade lakes with each other constitute possible fishery source of the country.
Along with food production, the expansion of aquaculture in artificial reservoirs benefits local economic situations by creating work and earnings along the entire reservoir farming production chain.
A lake is defined as;
A lake is defined as an inland depression on the surface of the planet earth, varying from a couple of meters to concerning 150 meters extensive and consisting of standing water (Vern Berg, 1970).
Formation of lakes:
Lake formation depends upon the various aspects. It may be because of
- the activity of glacier creating basins
- by landslide obstructing the open ends of valleys
- by the dissolution of rocks at the base with a succeeding sinking of the portion existing over
- by volcanic rivers, wind, or by crustal action of the earth.
Characteristics of Lake:
Among the essential attributes of its thermal stratification. During summer seasons the leading layer becomes warmer than the bottom layer owning to the low thermal conductivity of water.
Throughout autumn when the temperature of the environment decreases and oxygen concentration of the environment also decreases and oxygen concentration of water increases, (owing to reduced temperature level), the layer of the lake mix with each other.
In winter times, when the climatic temperature further decreases, as well as surface area water, cools down below 4 ° c (winter stratification), Oxygen concentration ultimately decreases owing to the existence of an ice layer on the water surface.
Throughout spring, when the ice melts as well as water sinks as a result of higher temperature of the surface, the water of the lake again blends and oxygen contents become uniform in the entire lake (spring overturn).
Classification of Lakes on the basis of the flow of water
Monomictic Lakes: Such lakes have a single seasonal rescind of water and so the lake might either be cold type or warm type.
Dimictic Lakes: These lakes include two seasonal durations of totally free circulation the autumn overturn and also spring overturn.
Polymictic Lakes: Water circulation in these lakes is continual throughout, including only a short duration of stagnancy. These lakes are located at high altitudes and in equatorial areas.
Oligomictic Lakes: In oligomictic lakes, water temperature continues to be essentially steady as well as the circulation of water is really slow-moving.
The productivity of the lake is primarily controlled by the following aspects.
- Naturalproductivity of water
- Availability of healthy food to fishes
- Accessibility of stocking material
- Capability to catch on a commercial basis
- Prevention of water pollution
Fish species in Lacustrine waters
Although we commonly tend to consider fish in lakes as lake residents, many of these species move to rivers during parts of their life process. Several of the young fish then move back to the lake to mature, whereas others continue to be in the rivers. Some of the most common fish found in lakes are tiny shiners, sunfish, perch, bass, crappie, muskie, walleye, perch, lake trout, pike, eels, catfish, salmon, and also sturgeon. These fish are a source of food for many people. Lakes are a fundamental part of the water cycle; they are where all the water in an area accumulates.
- Lakes in the hill region sustain the cold-water fisheries. Principal fishes of these include the trout, mahseers, snow trouts together with some tropical fish like the brown trout.
- The major freshwater fisheries of plain lakes are the following:
- Eels, perches,
- Catfishes- Mystus species
- Murrels- Channa species
- Major carps- Catla, Rohu, Mirgala, Calbasu
- Small carps- Labeo fimbriatus, L.bata, L. kontius, Cirrhinus cirrhosa.