overflatefôring

overflatefôring is a feeding technique commonly used in aquaculture, particularly for species kept in marine or brackish water. The term is Norwegian and translates literally to “surface feeding.” It involves depositing feed pellets or other food substrates onto the surface of the water column rather than sinking them to the bottom. The feed is typically formulated to float or to rise quickly after being released, ensuring that it is accessible to surface‑swimming fish such as salmon, trout or sea bass.

This method is advantageous because it reduces benthic waste and sedimentation. By keeping feed above the substrate, the technique limits the amount of uneaten feed that settles on the seafloor, thereby reducing nutrient loading and the risk of bottom‑water eutrophication. It also improves feeding efficiency; fish that feed near the surface can consume the feed more quickly, which can lead to better growth rates and feed conversion ratios.

overflatefôring is usually performed using specialized feeding rigs or manually by divers or surface vessels. Pellets may be coated with expander agents or emulsifiers that increase buoyancy. Some farms use timed release devices to deliver feed at regular intervals, synchronizing feeding with the daily activity patterns of the cultured species.

Critics of overflatefôring argue that it can increase susceptibility to predation. Birds, gulls, and marine mammals may be attracted to surface‑floating feed, leading to loss of feed and potential ecological disturbances. Additionally, in highly turbulent water, the feed can disperse widely, requiring large quantities to achieve desired intake.

.overflatefôring remains a widely adopted and evolving practice in the global aquaculture industry.