Hatchery operators and fish culturists know that three factors control the level of oxygen in their water supply. Salinity, which is rarely a factor, temperature and total gas pressure. Increasing the atmospheric pressure artificially allows the operator to dramatically increase dissolved oxygen.
Redd Zone has been experimenting with oxygen since its founders used it to maintain spring Chinook pre-smolts at the Gnat Creek Salmon Hatchery owned and operated by Oregon Department of Fish and Wildlife. Not only were pre-smolts able to be held through low water periods when supplied with oxygen enhanced water, fish health was dramatically improved and SARs were significantly increased. Eradication of historical disease issues was observed.
Experimenting and testing with different designs we now have a very versatile unit that will reach 300 per cent saturation of oxygen while driving out excess nitrogen. Not all situations are appropriate for the Spike, however, in many cases even the slightest increase in head pressure will have significant improvement over the Low Head Oxygen units developed by Barnaby Watson thirty years ago.
De-gassing Towers, A Thing of the Past?
In many cases the Spike will eliminate the need for a de-gassing tower/LHO with considerable cost savings and the resulting water, well above saturation in oxygen. Erstwhile pristine water supplies have been contaminated with air borne fungal spores in the degassing process, which employ fans to drive out nitrogen and/or carbon dioxide. With the water spike nitrogen and C02 are forced out leaving hyper oxygenated water that remains pathogen free.
In at least one study, CO2 was shown to not be an issue with fish in the presence of elevated 02. This is very encouraging for the world of fish culture as well as for transporting live fish and/or shell fish. (See “The Effects of Oxygen in Fish Growth in Aquaculture” by Yovita John Mallya).
In the picture below a Spike is being tested in a tote where high pressure well water is being stripped of excess nitrogen while oxygen levels are elevated to 200% saturation. Redd Zone has manufactured and installed Spikes that range from three cubic feet per second down to three gallons per minute. Most units are connected to the hatchery’s existing water delivery system, but in some cases a Spike with its own pump can be deployed to effectively increase the atmospheric pressure.
Redd Zone is happy to work with you on your oxygen supplementation needs of whatever nature they may be. Contact Tod Jones at 503-791-9854 or Roger Warren at 503-791-2533.
Yovita, John Mallya, “The Effects of Oxygen in Fish Growth in Aquaculture”
“Therefore, CO2 that is being transported into and out of the red blood cells minimises changes in pH in other parts of the body because of proton binding and proton release from haemoglobin, as it is deoxygenated and oxygenated, respectively. However, carbon dioxide is rarely a problem when dissolved oxygen concentrations are well above saturation levels. Due to these processes, oxygen level should be kept at or a little bit higher during the entire culture period.”