Oxygen Manipulation for Fisheries Management

Authors: David Ward, Eric Frye

Year: 2022

Abstract

Sodium Sulfite can be used to remove the oxygen out of pond or stream causing the fish to come to the surface so they can be caught. Any fish that are desired to be kept can be revived in fresh water. Sodium sulfite is a powerful oxygen scavenger that is used to preserve meat and dried fruit and is non-toxic and approved for people to eat. We quantified the effective dose of sodium sulfite in the laboratory for fish removal and then conducted replicated field trials in a small-lined research pond. Sodium sulfite dispensed at 1.3 g/L rapidly (< 15 min) decreased dissolved oxygen to < 1 mg/L causing fish to gulp at the surface allowing them to be captured with a hand net. Oxygen levels typically return to baseline conditions within 24-hours. Manipulation of dissolved oxygen may have advantages over other fish removal methods in that water quality conditions quickly return to pre-treatment conditions with no harmful residues and minimal impact to non-target species or the environment. Additional tools for control of invasive aquatic species are sorely needed and although this particular tool may only be effective in small, isolated bodies of water, the addition of any new tool for invasive fish management is helpful in the ongoing battle to prevent extinctions of southwestern native fishes.