2013/730 Refining Yellowtail Kingfish feeds and feed management

By David Stone

Yellowtail Kingfish (YTK), Seriola lalandi, is a relatively new species that has been cultured in South Australia, Western Australia and New South Wales, with over 90% of production from Clean Seas Tuna (CST, Arno Bay, SA). The production of YTK in South Australia was approximately ~3,000 tonnes in 2010 and was anticipated to reach 10,000 by 2015 in the Spencer Gulf region. However, during the expansion process production issues associated with nutrition and fish health led to high mortalities, and as a result, in an attempt to understand the problems CST scaled back YTK sea cage production to 1000 t per year in 2013/2014.

CST has assessed the situation, and identified a solution to the pre-existing problem, and now wishes to consolidate and expand YTK production in their sea cage operations. The approaches taken, and the information gained in this study, will directly address the industry research and development priorities and lead to an improvement in the economical and sustainable production of YTK by CST.

This project aimed to:

1. Identify or improve production diets in a tank based setting using large fish (>1.5kg) to provide information to reduce FCRs for CST YTK production from 2.7 to 2.25 across the entire sea cage production cycle.
2. Identify or improve production diets in a tank based setting using large fish (>1.5kg) to provide information to gain a 10% improvement in growth for CSTs YTK in sea cage production systems.
3. Identify or improve production diets in a tank based setting using large fish (>1.5kg) to provide information to improved YTK health and reduce mortality by 2% in CST sea cage production systems