Catfish are not picky eaters. They are known to eat a wide variety of foods, including seeds, crawfish, insects, frogs and other fish. When food is scarce they will even scour the bottom for decomposing fish or bugs. So when some pigeons wander too close to the shore it's no surprise these European catfish have learned to seize the opportunity for a hearty meal.
Not surprising. But still disturbing. Check out the video.