Koolvis

Koolvis (Gadus morhua) is the Dutch name for haddock, a species of fish in the cod family Gadidae. It is a commercially important demersal species found in cold temperate waters.

Koolvis is native to the North Atlantic, with populations ranging from the western shores of Europe to eastern North America. It occupies coastal and offshore habitats on the continental shelf, typically at depths from about 20 to 200 meters. The species occurs in mixed bottom communities and can be found in both relatively shallow bays and deeper offshore grounds.

The haddock has an elongated, robust body with a light underside and a darker back, and a distinctive lateral line along the flank. It typically measures around 40–60 centimeters in length; individuals can reach up to about 1 meter. The flesh is white and lean, with a mild, slightly sweet flavor and a flaky texture when cooked.

Ecology and diet: koolvis is a benthopelagic predator that feeds on small fish, crustaceans, and other invertebrates. It tends to form schools, sometimes with seasonal migrations related to spawning and feeding.

Fisheries and management: haddock is a major target for commercial fisheries in the North Atlantic, caught by trawls, longlines, and other gear. Some stocks have faced overfishing in the past, leading to management measures such as quotas, size limits, and seasonal closures to support stock recovery and sustainable yields.

Culinary use: the flesh is versatile and widely used in fresh, frozen, salted, or smoked form. Smoked haddock is a common ingredient in various regional dishes, and fresh koolvis is prepared by baking, steaming, or frying.