Cleans Seas, which is part of the Stehr Group has evolved to become one of the leading aquaculture companies in Australia producing Hiramasa Kingfish, Suzuki Mulloway and wild-caught South Blue Fin Tuna in the pristine waters of Boston Bay on the Eyre Peninsula. I was recently invited to inspect the Stehr Group’s operations at Port Lincoln both onshore and offshore as part of a visit by Sydney Chefs to the region.

We boarded one of Clean Seas’ trawlers at the Port Lincoln marina and made our way out to the sea cages in Boston Bay approx 7kms offshore. As we arrived to the first sea cage there was a slight ripple effect on the water which was approx 20,000 Hiramasa Kingfish waiting to be fed. After connecting the trawler to the sea cage, the fish began to settle down slightly, but then as soon as the compressor which shoots the feed into the sea cage came to life the Hiramasa Kingfish activity intensified. You’ll see in the photo that some are nearly out of the water anticipating to be fed. The feeding process took about 15 minutes in total and in that time the fish consumed about the equivalent of 350kg of pellets.

The Yellowtail Kingfish, known in Japanese as ‘hiramasa’, inhabits the Great Southern Ocean and Cleans Seas first pioneered the production of disease free juvenile Yellowtail Kingfish in saltwater hatcheries at their Arno Bay aquaculture facility. When the Yellowtail Kingfish are large enough, they are transported from the Arno Bay facility to large nets or sea cages, which are then slowly towed to the Boston Bay location. It’s here in the cages that the Hiramasa Kingfish will fatten up to 4kg to 4.5kg before being harvested.

When the Hiramasa Kingfish have reached their correct weight and ready for harvest, twenty kingfish are scooped from the sea cage at about twenty a time and placed into an ice slurry for about 5 minutes. Then the low stress “Ike Jime” method (or percussion stunning method) is used to ensure maximum flesh quality. The “Ike Jime” method involves the insertion of a spike quickly and directly into the brain thereby causing immediate brain death. The fish immediately ceases all motion and it is believed that this method of preparing fish minimizes fish pain and suffering. Many of the Hiramasa Kingfish will ultimately be sent to Japanese markets and the only accepted method in Japan is the “Ike Jime” method. The Kingfish are then put into another ice slurry and allowed to bleed, before chilling and processing back on land.

The premium quality Hiramasa Kingfish are now exported daily to North America, Europe and Asia as well as being available domestically throughout Australia. The Hiramasa Kingfish offers a firm white flesh and is ideally suited to a variety of cuisines around the world and particularly sought after by the Japanese for sashimi because of the rich, sweet, flavour it possesses.

After the feeding was complete, we moved to sea cages nearby which held the farmed Suzuki Mulloway. We were all surprised to see that the Suzuki Mulloway was hardly interested in being fed compared to the “wild” activity of the Hiramasa Kingfish. After we connected with the sea cage the skipper, took out a rod and went fishing in order to show us a sample of their current size. It took less than 20 seconds for the skipper to hook one and after a few minutes landed a nice 2kg Suzuki Mulloway. After the Suzuki Mulloway was returned to the sea cage, the feeding began in a similar method, although the feed was reduced to about 100kg for the same amount of fish.

The Suzuki Mulloway is a natural inhabitant of South Australia and is considered a prized sashimi fish by Japanese Sashimi Chefs. Apart from just sashimi, the Suzuki Mulloway is particularly suited to frying, roasting and stir-frying in cooked preparations.

Like all farmers and other aquaculture operations in the Eyre Peninsula region it was amazing to see the dedication and commitment to sustainability. Previously the Stehr Group operated long line fishing trawlers with strict government quotas and restrictions on fishing. The only long term strategy for a viable future was to invest in sustainable aquaculture operations. Not only are the Hiramasa Kingfish and Suzuki Mulloway treated like royalty, everything is managed sustainably to ensure that the environment is not harmed in anyway from their operation.

In December 2005, Clean Seas was listed on the Australian Stock Exchange (ASX : CSS ) to raise capital to fund the next stage of breeding Southern Bluefin Tuna fingerlings for commercial production, which would be a world’s first. The Stehr Group has long been recognised for its expertise and innovation in tuna fishing, pioneering of offshore wild-caught Southern Bluefin Tuna fish farming. There were indications given during our visit that we may see in early 2007 the first fully grown Southern Bluefin Tuna being produced, which will provide great long term benefits for the population of wild tuna in the Spencer Gulf.

For more information on Hiramasa Kingfish and Suzuki Mulloway or wild-caught Southern Bluefin Tuna then visit the Stehr Group website or call +61 8 8682 2922