Comparison of macroalgal (Ulva and Grateloupia spp.) and formulated terrestrial feed on the growth and condition of juvenile abalone William J. Mulvaney & Pia C. Winberg & Louise Adams Received: 11 August 2012 / Revised and accepted: 29 January 2013 / Published online: 5 March 2013 # Springer Science+Business Media Dordrecht 2013 Abstract The culture of abalone is a growth industry in Australia that primarily utilises terrestrial crops to produce formulated pellet feeds. The use of cultivated macroalgae in place of such feeds could provide for better environmental, nutritional and/or economic outcomes for this industry. However, direct comparison trials using macroalgae and formulated crop feeds are rare, and it is therefore difficult to ascertain the benefits and costs of each feed type. This study compares the benefits to growth and performance of the cultivated hybrid abalone cross (Haliotis rubra 1814 Leach and Haliotis laevigata 1808 Donovan) which was fed one of eight dietary treatments, including two commercially formu- lated pellet feeds and six mixed macroalgae dietary treat- ments. Macroalgae dietary treatments comprised the three macroalgae species Grateloupia turuturu Yamada, Ulva aus- tralis Areschoug and/or Ulva laetevirens Areschoug. Four replicate tubs, each containing 40 juvenile abalone (10– 15 mm), were used to test each dietary treatment over a 12- week period. Macroalgae dietary treatments provided for sig- nificantly higher specific growth rates of abalone compared to formulated feeds, by orders of magnitude, for both length (>0.2 % compared to <0.1 %day -1 , F 7, 31 =22.3, p <0.0001) and weight (from <0.4 to >0.8 %day -1 , F 7, 31 =24.4, p < 0.0001). In addition, abalone health and condition increased, and the proximate composition of abalone tissue had a higher carbohydrate/protein ratio, higher ash content and lower lipid content. These findings suggest that the juvenile abalone may benefit from macroalgae diets in comparison to two formulat- ed feeds as a result of optimal proximate composition of the algae biomass and improved condition of the abalone. Keywords Abalone . Aquaculture . Grateloupia turuturu . Nutrition . Seaweed . Specific growth rate . Ulva australis . Ulva laetevirens Introduction Abalone are increasingly being farmed in aquaculture systems in response to their high value, high demand and declining wild harvest (Shpigel et al. 1999; Gordon and Cook 2001; Cook and Gordon 2010). For example, in NSW, Australia, wild harvest production has declined steadily from an annual production of 320 t in 1999 to 110 t in less than a decade (NSW Fisheries data 2010). A challenge in the transition to abalone cultivation in Australia, however, is the availability, cost and nutritional value of feeds that can deliver suitable growth rates and condition of abalone. In other parts of the world where abalone farming has been established, the avail- ability of wild harvested macroalgae, the natural food of abalone, has been practical and cost-effective as an aquacul- ture feed. In contrast, Australia has neither the abundance of macroalgae, regulatory condition or cost-effective solutions that facilitate the use of wild harvest macroalgae as a feed in aquaculture. Therefore, formulated feeds were developed as the preferred feed source for abalone aquaculture in Australia. This paper was presented at the eighth Asia-Pacific Conference on Algal Biotechnology, Adelaide, Australia, 2012. W. J. Mulvaney : P. C. Winberg (*) Shoalhaven Marine and Freshwater Centre, Institute for Conservation Biology, University of Wollongong, Shoalhaven Campus, Nowra, New South Wales 2541, Australia e-mail: pia@uow.edu.au W. J. Mulvaney e-mail: wm963@uowmail.edu.au L. Adams Louise Adams (Ward), National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Newnham Campus, Science Building, Launceston, Tasmania 7250, Australia e-mail: Louise.Adams@amc.edu.au J Appl Phycol (2013) 25:815–824 DOI 10.1007/s10811-013-9998-2