“It is a ruthless robber,” says inland fisherman Frans Komen firmly. Just as some ranchers have little sympathy for the wolf, professional fishermen talk about the catfish. With a length of over two meters, the European catfish is the largest predatory fish in Dutch inland waters.
The catfish population has increased significantly over the past ten years, partly due to rising water temperatures in our major rivers. Sports fishermen catch large catfish more often and professional fishermen also see more catfish in their traps.
The Ministry of Agriculture, Nature and Food Quality and Rijkswaterstaat are concerned about the rise of the catfish. “The catfish is a top predator that is at the top of the food pyramid in the river system,” a ministry spokesperson explains. “With sharply increasing numbers in inland waters and rivers, this could well have a substantial impact on fish stocks of vulnerable species. Particularly on rare migratory fish on the rivers such as salmon, shad, sea trout and sea lamprey.”
Catfish are omnivores. Their prey consists of crayfish, fish and birds, which they pull from the water surface into the depths with their large mouth with a suction mouth. They particularly target young geese, coots and ducks. According to inland fisherman Komen, who has almost 50 years of experience as a professional fisherman on the IJssel, Waal, Lower Rhine and the Randmeren, the rise of the catfish has an influence on the fish stock.
“The species diversity of fish in our major rivers has plummeted to an all-time low. We used to catch 41 different fish species, now we only see a maximum of 14. The catfish is partly the culprit,” says Komen. A scientific practical study commissioned by the ministry and Rijkswaterstaat must show to what extent the catfish poses a threat to fish stocks on the rivers.
To gain insight into what catfish eat, researchers will dissect the stomach contents of a number of catfish. “This gives us an idea of what these animals eat,” says ecologist Jacco van Rijssel of Wageningen Marine Research. “Catfish may also have a positive effect because they eat invasive exotic species such as mitten crabs, crayfish and gobies.”
Catfish are also provided with a transmitter. This happens at the weir in the Maas near Lith. Researcher Maximiliaan Claus from Waardenburg Ecology: “Fish often accumulate at weirs in the large rivers. Here, catfish could relatively easily eat away other rare fish species that migrate upstream or downstream.”
The catfish is officially a protected fish that must be released after capture. The fish can live up to 80 years. Just like the wolf, there is a myth about the catfish that this giant predatory fish attacks people. That has never been proven.
Colleagues catch catfish of almost 2 meters
Recreational fishermen Hansie Rast and Alex de Jong have made an impressive catch.
The din of pike, bullhead and burbot
Pisces seem like those silent types, but appearances can be deceiving. However, what they all say has not yet been deciphered.
Jelle Reumer discussed the catfish as a large mouth with a long fish behind it
#ruthless #predatory #fish #catfish #disastrous #aquatic #life