Aquaculture diet development subprogram: diet validation and feeding strategies
Final report
Barramundi origins: determining the contribution of stocking to the Barramundi catch on Queensland's east coast
Aquaculture diet development subprogram - Dietary requirements and optimal feeding practices for Barramundi (Lates Calcarifer)
Final report
Feed is by far the single largest cost component of barramundi farming and accounts for about 35% of on-farm operating costs. Reducing feed costs by better tailoring dietary specifications to the nutrient requirements of the fish, by providing these nutrients at least cost and by adopting feeding practices that optimise productivity will greatly assist farm profitability. In Australia, barramundi are pond-reared over latitudes from 5°S to 22°S and this results in large seasonal variations in water temperature and consequently, in growth rate of the fish.
The research conducted in this project sought primarily to characterise the effect of water temperature on fish productivity and how modification of dietary nutrient specifications and/or feeding practices could assist in improving farming profitability. This entailed research to define the fish's response to changes in dietary supply of critical nutrients over a range of water temperatures. Research examining the efficacy of crystalline amino acids in diets for barramundi was carried out in a supplementary project (FRDC 95/69); research on the nutritive value of terrestrial feed ingredients and their suitability as replacements of fishmeal in diets for barramundi is reported in FRDC 93/120-04.
Aquaculture Diet Development Subprogram - Replacement of fishmeal in diets for barramundi - improving nutritive value of alternative feedstuffs using crystalline amino acids
Final report
Australia has an abundant supply of terrestrial animal and vegetable protein feeds which has the potential to at least partly if not fully replace the fishmeal presently used in compounded aquaculture diets. A major difference between marine and terrestrial protein sources is the marked difference in the amino acid make up of the protein. Compared to fishmeal with an amino acid index of 100, terrestrial plant protein sources are very low in methionine (Met; 20 to 80), lysine (Lys; 20 to 85) and threonine (Thr; 55 to 85). Terrestrial animal protein sources score higher but the same three essential amino acids are often deficient. An imbalanced essential amino acid profile of the protein markedly reduces the nutritive value of the diet for terrestrial monogastric animals such as pigs and poultry. In these species, crystalline amino acids (C-AAs) are a proven and cost-effective way of restoring the dietary amino acid balance. However, the efficacy of C-AAs in aquaculture diets is quite equivocal. A clear understanding of the essential amino acid requirements of barramundi and the extent to which C-AA can improve the nutritive value of terrestrial protein feed ingredients is pivotal to further diet development for this species.
Keywords: Amino acids, Amino acid efficacy, Nutrient retention, Meat meal, Sensory evaluation, Fishmeal replacement
Effects of Trawling Subprogram: commercialisation of bycatch reduction strategies and devices in northern Australian prawn trawl fisheries
Final report
Knowledge to improve the assessment and management of Giant Mud Crabs (Scylla serrata) in Queensland
Tactical Research Fund: Reducing the impact of discarded recreational fishing tackle on coastal seabirds
This proposal will address the FRDC Recfishing Research priority area "Assessing the impact of recreational fishing methods on conservation values of aquatic habitats" as announced in the 2012 Annual Competitive Round Call for Expressions Of Interest. After making inquiries with seabird rescue organisations, it has become apparent that seabird entanglements in discarded fishing tackle is of major concern. Australia Zoo Wildlife Hospital report that their rescue unit responded to approximately 300 calls for bird entanglements in discarded fishing tackle in 2011 (to August 1). Further, the Rescue Hotline of Pelican and Seabird Rescue Inc. have received approximately 400 calls in 2011 (to the time of writing - 10/9/2011). These figures are unacceptable and measures need to be taken to decrease the incidence of seabird interactions with discarded recreational fishing tackle. The injuries that result from these interactions are often catastrophic, with a high proportion of entangled animals being euthanised. Healthy Waterways has produced a provocative poster, attached, depicting a pair of budgerigars surrounded by fishing line and hooks. Such negative stereotypes need to be addressed and, as such, there is a need to educate recreational fishers as to the consequences of the careless discarding of fishing tackle. This subject was recently highlighted in a Queensland recreational fishing publication, Queensland Fishing Monthly (see attachment). Both recreational fishing representative groups, Sunfish and Ecofishers, have expressed concern regarding this issue. A fifteen minute search at a secluded recreational fishing location in the northern suburbs of Brisbane by two people resulted in the collection of the fishing tackle pictured in the attachment (13/09/2011 - Tingalpa Creek). Although this could be construed as an environmental problem and beyond the purview of FRDC, it certainly reflects poorly on recreational fishers and, as such, an extension/educational project would help alleviate the problems highlighted in this proposal.