The Importance of the Regions

Hagen Stehr lives in Port Lincoln, South Australia where he made ages his business interests in fishing and aquaculture, most notably Southern bluefin tuna fishing and offshore ranching in the Spencer Gulf for export markets. The Stehr Group also propagates and grows Australian Yellowtail Kingfish and Australian Mulloway through its aquaculture division, Clean Seas Aquaculture Growout Pty. Ltd. One of the wealthiest men in South Australia, Stehr is also the founder and chairman of the Australian Maritime and Fishing Academy. The Stehr Group has a commercial fleet of nine vessels.

Stehr is sometimes referred to colloquially as a "tuna baron" or "tuna king" a term representative of the profitability of the business. He has previously boasted that when he sits down with his friends Sime "Sam" Sarin, Mario Valcic and Joe Puglisi, they are worth more than a billion dollars between them. According to the BRW Australian rich list, his personal wealth was approximately $US135 million in 2009 after peaking the previous year at AUD$271 million. In 2015, Stehr's business Clean Seas Tuna Limited was ranked number 88 in InDaily's Top 100 SA Businesses, with annual revenue of $20,133,000. Stehr's son Marcus is the managing director of Clean Seas. In November 2016, shareholders of Clean Seas voted to change the company's name to Clean Seas Seafood Limited.

Hagen Stehr was awarded Officer of the Order of Australia on Australia Day, 1997. He received the award for service to the commercial fishing industry and to education and training, particularly through the South Australian Fishing and Seafood Industry Skills Centre Inc. He also received the Centenary Medal for services to the community in 2000. Stehr was awarded an Honorary Doctorate of the University of the Sunshine Coast in 2010 and was included in the "three wise men" ceremony together with diplomat Richard Woolcott and Deputy Chancellor of the University, Tim Fairfax. He was named Seafood Icon, South Australia in 2009 and initiated into the National Seafood Hall of Fame in 2013.

Stehr has appeared in the 60 Minutes episode Drovers of the Deep (2004), his business was the subject of the documentary film Tuna Wranglers (2007) and his attempt to close the life-cycle of the Southern bluefin tuna featured in the documentary Sushi - The Global Catch (2012).