Linde Gases has announced the launch of its new SOLVOX® OxyStream solution, a unique low-pressure oxygenation system to help increase fish production volume, optimise fish meat quality and improve operations from an environmental standpoint.
With the trend of moving aquaculture production from sea cages to land-based sites for the full duration of the fish’s lifecycle, the requirements of oxygenating large fish tanks that can accommodate fish stock from infancy to maturity has become a major challenge for fish farm operators.
The patented SOLVOX® OxyStream is a combined oxygenation and flow system which not only dissolves the optimal amount of oxygen in the inlet water flow, but also distributes it evenly at an adjustable flow pattern through the tank, ensuring fish stock physically benefit from exercise against the flow. The flow regime can be fully tailored according to fish size, stock density and fish species, such as salmon or cod.
As an additional benefit, the micro-bubbles created by SOLVOX® OxyStream help to reduce the concentration of dissolved inert gases like nitrogen, argon and CO2. In particular, oversaturation of nitrogen, even in relatively small quantities, can endanger the wellbeing of fish stock, slowing growth and increasing the possibility of disease, and ultimately, even mortality. With the installation of SOLVOX® OxyStream, external degassing units to prevent inert gas build-up will, in many cases, become obsolete.
While SOLVOX® OxyStream has maximum efficiency at between 15 promille (unit of measurement for salinity) of salinity and full sea water salinity - so is optimal in sea water and brackish water - the system is also able to effectively oxygenate fresh water. This will allow fish farmers to operate a single oxygenation system in large tanks running on both fresh water and sea water, significantly saving costs over running separate saline and fresh water oxygenation systems. This was recently demonstrated during trials conducted at Marine Harvest in Norway, the world’s largest fish producer. Results showed that SOLVOX® OxyStream was the only oxygenation source suitable for rearing young salmon hatched in tanks running on fresh water before gradually transitioning them to sea water.
Pumping pressures as low as 0.05 to 0.2 bar are normally sufficient to oxygenate the incoming water, strip nitrogen and create optimal tank hydrodynamics. This low operating pressure makes the system very energy efficient. Moreover, SOLVOX® OxyStream can be easily installed, including retro-fitted to existing fish farm tanks, and is maintenance free. As the system comprises of a standalone unit, water flow and oxygen dosing can be individually controlled for each tank.
Due to its high efficiency, very low energy requirements and the positive effects of creating and maintaining an optimal environment for fish, SOLVOX® OxyStream can significantly contribute to cost efficiencies in on-land fish production. In addition, the ability to produce fish from infancy to maturity in on-land tanks has significant environmental benefits. The water flowing through fish tanks can be recycled to a high extent with excrements and feed residues filtered out effectively. As such, pollution to the marine environment and the possible spread of disease to wild fish is prevented.
“Marine Harvest wants to rear salmon in the best environment possible,” commented Andre Spigseth, Operations Manager, Marine Harvest. “SOLVOX® OxyStream is the perfect solution as it ensures the correct oxygen levels throughout the entire production period and keeps fish stress levels to an absolute minimum. OxyStream is a very efficient system and that high efficiency and very low pressure provide remarkable cost savings.”
