Oxygen Will Not Kill Live Bait or Tournament Fish?

WEBPAGE UPDATED              Tuesday  June 22, 2022
Pure 100% oxygen dissolved in livewell/bait tanks water will not kill, poison or injure live bait or tournament game fish during live transports. Continuous 100% DO Saturation with the livewell chock full of fish or live bait is ideal during live transports.

TOXIC OXYGEN – Yes, tiny pure oxygen micro-bubbles can kill your tournament fish, live bait and game fish! Diffusers that make millions of micro-fine pure oxygen gas bubbles so small they make the livewell/bait tank water look water look milky or cloudy, so tiny they  remain suspended within the water column can be very toxic, deadly for captive live bait and tournament game fish. Beware of all diffusers capable of making those  micro-oxygen gas bubbles that remain suspended in livewell/bait tank water that cannot escape the water surface.

Live bait and tournament game fish exposed to concentrated Toxic Micro-Fine Oxygen Bubbles  in livewell and bait tank water during live transports can kill. Oxygen gas bubbled are powerful oxidizers in contact with delicate gill tissue, cornea tissue, skin, scales and fins. 

Diffusers That Can Make Those Tiny Toxic Micro-Fine Oxygen Gas Bubbles in livewell water are a known precursor to gill damage, infection, tissue scaring, disease and death. Pure gaseous oxygen is highly corrosive. Gill tissue as well as corneas, scales and skin in contact with pure 100% oxygen gas bubbles can cause chemical  burns to delicate organic tissue. Pure oxygen is a very powerful oxidizing agent especially to cell membranes.

Hydrogen peroxide (H2O2) has been used as an antiseptic over 100 years because it effectively kills bacteria by destroying their cell walls. This process is called oxidation because the compound’s oxygen atoms are extremely reactive and destructive to cell walls. Fish contact with livewell water containing H2O2 destroys the cell membranes of fish gills exactly the same way.

Oxygen gas bubbles in livewell water are very different than dissolved oxygen in livewell water (DO). When organic gill tissue is in direct contact with  gaseous oxygen bubbles the cellular oxidation process is incredibly reactive destroying delicate gill cell membranes. Millions of  highly concentrated pure oxygen micro-gas bubbles colace and literally stick to fish tissue.


1. Water and the oxygen gas chemistry – micro-fine oxygen bubbles so tiny they remain suspended in the water column that make livewell water look milky transfer oxygen into solution fast and efficiently, quickly saturating/supersaturating water in seconds in a typical 20-30 gallon livewell or bait tank. Diffusers that make larger bubbles may take an extra minute or two to achieve the same DO saturation/supersaturation, but the final result is the same DO Saturation.

2. Fish Physiology, oxygen gas bubble contact and the Fish Pathology – another matter that is seldom mentioned when live fish and shrimp and other aquatic animals that are being transported using pure oxygen,  diffusers that will produce millions of micro-fine oxygen gas bubbles can negatively affect fish health – oxygen poisoning caused by continuous exposure of gaseous oxygen, those micro-fine oxygen gas bubbles trapped in the livewell water column that cannot escape the water will coalesce to fish gills, cornea’s, scales, skin and fins. The oxidation of cell membranes can cause serious chemical burns and tissue damage resulting in infections, gill failure, blindness, sickness and death. Oxygen toxicity (O2 Poisoning fish with oxygen gas) is caused by the fisherman’s ignorance of the device that makes millions of tiny micro-fine O2 bubbles in livewell water. Oxygen toxicity is not by high dissolved oxygen supersaturation in the water during live transports at ambient barometric pressures.



Micro-pore oxygen diffusers and livewell water pumps that entrain ambient air on the inlet side of a livewell water pump’s impellers via gas venturi device or defective water pumps can and will produce millions of  micro-fine air bubbles trapped within the livewell’s water column as the air is sucked into the pump’s impellers. The size of those air bubble can dramatically affect livewell water chemistry, gas transfer rates and dissolved gas concentrations.

We queried university professors and experts. Our concern is the pathophysiology (oxygen toxicity) occurring when micro-fine oxygen bubbles stick inside fish gills, get into blood, stick in eyes, on scales, fins and skin.

We asked University Professors, Fish Physiologist, the real fish doctors:

When captive fish are forced to breathe in clouds of suspended micro-fine oxygen bubbles (so fine the water looks milky) in livewells with relatively small functional water volumes, can these tiny gas bubbles injure fish or bait?

Is the stress response increased? Is the probability of delayed mortality increased?

Are we actually causing physiologic harm to tournament fish or live bait when holding and transporting them in clouds of bubbles for hours or even all day?

When we transport tournament bass, redfish, snook or live bait for hours or all day, what happens to gill tissue when thousands of tiny oxygen bubbles remain stuck in gills, on scales and fins all day?

Images and examples of these problems – see Ph.D. “Opinions” link.

We thank these university professors for offering their time,  providing their knowledge, expertise and opinions freely so that catch and release tournament anglers, as well as fishermen worldwide, can become better educated and hopefully take better care of live tournament fish and live bait in livewells and bait tanks during live transports.

We appreciate these expert opinions in fish cardiovascular physiology, fish biochemistry, fish pathology, fish physiology, and the principles and practices of modern aquaculture techniques.