What kind of fish is considered weed? These are low-value species, unprofitable for fishing and harmful to other populations. Their unprofitability is determined by slow growth, small size and low nutritional value. In fish farms, such a trifle complicates sorting, clogs the cells in seines and reduces the profitability of the catch.
Weedy fish crowd out other, more valuable species in water bodies, eating their caviar and resources of the common food supply. However, some of them, despite their small size, are of gastronomic interest.
Harm
Reproducing rapidly and keeping in large flocks, weedy fish threaten the populations of other, larger and more valuable species, eating up to 80% of their eggs for spawning, and sometimes completely destroying it. Larvae and fry of bream, pike, carp, ruff, zander also become food for small predators.
The surviving juveniles of game fish that feed on phyto- and zooplankton may not survive due to lack of food if their natural food is consumed by trash fish. This situation is a particularly acute problem for small closed reservoirs. In addition, these small numerous fish oftenbecome carriers and pathogens of diseases caused by parasites or bacteria.
Benefit
Some anglers and fishermen find this hard to believe, but freshwater weedy fish, also called wild fish, has a number of advantages:
- She supports the biological diversity of water bodies.
- It is a food base for valuable predatory fish such as perch, asp, pike, catfish.
- Waterfowl-ichthyophages (storks, herons and others) feed on it.
- It eats huge amounts of silt, single-celled algae and bacteria that form biological fouling of water bodies.
- Loach, ruff, minnow and some other types of weedy fish have good taste and are valued in recreational fishing.
- In some regions, ruff, bleak, roach may be of commercial importance due to their large share.
But such a wild fish tends to multiply excessively and quickly. This problem is especially relevant in small closed water bodies, for example, in ponds. Therefore, the number of its population must be controlled.
Types of wrestling
Despite some advantages, weed fish can do more harm than good. Among the methods of dealing with it, dust traps are used - devices in the form of boxes of various shapes with a metal mesh. They are installed on the watercourse (channel, pipe) during the filling of ponds. Careful annual fishing will also give a good result. Reducesthe number of weed fish and increases the productivity of commercial ponds, the cultivation of predatory fish. These are one-year-old pike, two-year-old large perch.
Where and what kind of fish is considered weed
In Russia today, the most malicious parasite is rotan, which has become a real disaster in many reservoirs. Abroad, these may be other types, even those that are considered delicacy in our country.
In some states, the list of weeds includes crucian carp, catfish and other fish, enviable for the Russian fisherman. For example, in Australia, for some time now, carp has been ranked as such, which in most European countries is bred in commercial ponds. But in the warm Australian climate, it breeds too quickly, making dangerous competition for the original inhabitants of local lakes.
In non-commercial reservoirs, not all small fish are considered weed, but only those that threaten the existence of other inhabitants. Many of these species have quite high taste qualities and are deservedly appreciated by culinary specialists. The main quality that gives the right to call fish weed is the reduction in its number or the displacement of other species.
Which of these representatives are common in Russian reservoirs? The most "harmful" can be called rotan-firebrand, ruff, bleak, perch, stickleback. The list of "wild" small fish also includes char, loach, gudgeon, goby, three-spined smelt, Amur grouse, minnow, quicksand, spined loach and others.
Rotan-head
The original habitat of this voracious fish was FarEast. In the middle of the 20th century, rotan spread to other regions of Russia. Having successfully acclimatized, he penetrated most water basins. As a rapidly breeding predator, rotan in a small pond is able to quickly exterminate all other species of fish, eating their caviar and fry. They also attack adults, but small-sized inhabitants of the reservoir.
Rotans are cannibals. Catching them, you can often find the so-called nesting dolls, when another fish is in the mouth of one. Sometimes you can count up to 4 - 6 individuals swallowed in a chain.
The size of the fish is 10-15 cm and weighs about 200 grams. Sometimes the largest specimens weighing up to 500 grams can reach 35 cm. This species has an amazing ability to survive in polluted water bodies, withstands complete freezing and partial drying of ponds. During the season, rotan lays up to a thousand eggs. Its number can be regulated by predatory fish: perch, pike, catfish, eel, pike perch, asp, trout. Tender dense meat of rattan has an excellent taste. As bait, this hardy fish is able to "work" all day long.
Ruff
This is the most common weedy fish in Russia, very voracious and unpretentious. The length of her body is no more than 20 cm, and her weight is 100 grams. Ruffs love cool water. They rarely rise to the surface during the day, but keep in large flocks at a rather great depth, closer to the bottom of the reservoir. They spend most of their time in ambush, looking for prey. At night, the ruff shows increased activity and swims up to shallow places.
He feeds during the day and at night. As it grows, it eats large quantities of caviar of other fish, which it drives away from their feeding places, until it gorges itself. Therefore, in some ponds and lakes, ruff becomes the predominant or only species. Large perch, zander, pike, burbot are the natural enemies of these weedy fish and regulate their populations.
Stleback
This is a very small and ubiquitous fish. It can become a real scourge of the fish industry. Its size is 4-10 cm, and life expectancy does not exceed 3 years. The stickleback lays no more than 250 eggs, but it is an extremely greedy and voracious weed fish.
She not only eats eggs of valuable commercial species, but also deprives them of food, which she herself absorbs in huge quantities. Thanks to the spines on the dorsal fin and on the abdomen, the fish remains invulnerable to predators such as perch and pike.
Bleak
Insignificant fish. Its body is no longer than 20 cm. Keeping in flocks, the bleak prefers slowly flowing deep water. Being heat-loving, these weedy fish usually keep in the upper layers of water bodies in areas free from vegetation.
Bleak is very voracious. She spends all day hunting. It feeds on plankton, lower crustaceans, insects and pollen that have fallen to the surface of the water. Large specimens eat eggs and juveniles of other fish species. During spawning, the bleak lays up to 4000 eggs.
Conclusion
If one of the species disappears in nature, others begin to develop rapidly. Weed fish are the natural food of freshwater predators. When they are actively caught from water bodies, a trifle begins to multiply rapidly. Every fisherman dreams of catching a big fish. Many people throw change back into the water.
Over the past decades, many new devices and methods of fishing have appeared, fishing has become more efficient. This has led to a catastrophic increase in the number of small fish, which is very difficult to get rid of in reservoirs.
