Prawn hatchery modifications and adaptions for temperate marine fish culture in northern NSW, Australia

Accepted Manuscript Title: Prawn hatchery modifications and adaptions for temperate marine fish culture in northern NSW, Australia Author: Jeffrey A. Guy Kenneth L. Cowden PII: DOI: Reference:

S0144-8609(15)00032-1 http://dx.doi.org/doi:10.1016/j.aquaeng.2015.05.002 AQUE 1801

To appear in:

Aquacultural Engineering

Received date: Revised date: Accepted date:

22-10-2014 4-5-2015 5-5-2015

Please cite this article as: Guy, J.A., Cowden, K.L.,Prawn hatchery modifications and adaptions for temperate marine fish culture in northern NSW, Australia., Aquacultural Engineering (2015), http://dx.doi.org/10.1016/j.aquaeng.2015.05.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Highlights • We evaluated two existing prawn hatchery facilities for conversion to marine fish culture.

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• Both hatcheries were easily adapted with minimal cost and modification. • The Australian design was the simplest and cheapest to convert with a theoretical

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fingerling output of 630,000 x 40 mm (1 g) per batch.

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• The Taiwanese design required more work due to the built-in nature of the concrete tanks

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with a fingerling output of 320,000 x 40 mm (1 g) per batch.

• Use of these facilities would resolve the current poor availability and high cost of juveniles

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for grow-out.

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Prawn hatchery modifications and adaptions for temperate marine fish

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culture in northern NSW, Australia.

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Jeffrey A. Guy a, b, *, Kenneth L. Cowden a

National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450,

Marine Ecology Research Centre, School of Environment, Science and Engineering,

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b

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Australia.

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Southern Cross University, Lismore, New South Wales, Australia.

*Corresponding author: National Marine Science Centre, Southern Cross University, Bay Drive (P.O. Box 4321), Coffs Harbour, NSW 2450, Australia. Telephone: +61-2-6648-3913; Fax: +61-2-6656-1580; E-mail: [email protected]

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Abstract Marine fish culture is a new farming opportunity for NSW prawn farmers. To address current seed-stock supply issues two Palmers Island brackish-water prawn hatcheries (of

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Australian and Taiwanese design) were examined for conversion to mulloway (Argyrosomus

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japonicas) production. Both hatcheries were easily adapted with minimal cost and modification; the Australian design (1062 m2) was the simplest and cheapest to convert. The

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Taiwanese design (695 m2), required more work due to the permanent built-in nature of the

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concrete tanks, their rectangular shape and drainage. Fingerling output from the Australian hatchery was calculated at 630,000 x 40 mm (1 g) fingerlings or 150,000 larger 100 mm (12

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g) fingerlings using a single annual hatchery run of 3 or 5 months, respectively, at a water temperature of 20-250C. The smaller Taiwanese hatchery had a theoretical maximum

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production of 320,000 x 40 mm (1 g) per batch or 50,000 x 100 mm (12 g); if pure oxygen

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was used in the nursery area this could be increased to 100,000 x 100 mm. Both hatcheries

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could operate with 3 to 4 staff and use of these facilities, in conjunction with staff training, would resolve the current poor availability and high cost of juveniles for grow-out.

Keywords: Aquaculture, hatchery design, green-water culture, production costs, jewfish, shrimp

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1. Introduction The Australian prawn farming industry is concentrated on the east coast of Australia and produces more than 4,000 tonnes of prawns per year, valued at AU$61.5 million in

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2011-2012, making it the fifth most valuable species in Australian aquaculture (Savage, 2014). The New South Wales (NSW) industry is situated in Palmers Island, near Yamba, on

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the Clarence River and is the state’s most valuable land-based aquaculture sector (Creese

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and Trenaman, 2014). Production is based on the black tiger prawn (Penaeus monodon) and all farms have established hatchery infrastructure, are managed intensively and produce

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one summer crop per year (Queensland Department of Primary Industries and Fisheries (QDPIF), 2006).

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The NSW prawn industry, however, is in decline due to increased competition from cheaper imported Asian product and rising wage, water and energy costs (Guy et al., 2014;

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Kerr and O'Sullivan, 2005) and needs to explore diversification opportunities to remain

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competitive (Basurco and Abellán, 1999; McMaster et al., 2007). In 2008 the National

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Marine Science Centre (NMSC) commenced research to determine the feasibility of farming mulloway (Argyrosomus japonicus), a carnivorous, temperate, euryhaline finfish of the family Sciaenidae, in prawn ponds (Guy and Cowden, 2012; Guy and Nottingham, 2014) and an emerging industry is developing (O'Sullivan, 2010a). Several other government, academic and industry research projects also commenced at this time which explored tropical species such as cobia (Rachycentron canadum), Flowery Rockcod (Epinephelus fuscoguttatus), the Gold-spot Rockcod (E. coioides) and giant grouper (E. lanceolatus), for diversification within the Queensland prawn industry (O'Sullivan, 2010b). The temperate research initiative on mulloway identified several factors that were likely to limit the expansion and profitability of land-based farming in northern NSW. One

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key constraint was the poor availability and high costs of juveniles for grow-out (Guy and Cowden, 2014). This has been recognised internationally as one of the main bottlenecks to commercial expansion for emerging species (Schwarz et al., 2009 ). At present Port Stephens

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Fisheries Institute (PSFI), is the only facility in NSW that maintains broodstock of mulloway (Fielder and Heasman, 2010) and fertilised eggs can be purchased at a commercial price of

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AU$0.012 per egg or AU$1.05 per 35 mm fingerling (Allan, 2008). This high cost for

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fingerlings is currently acting as a disincentive for prawn farmers to invest in mulloway farming. This has also been the case for cobia, which sells in the southern USA for about

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US$2.0-2.75 per fingerling, restricting development (Alvarez-Lajonchère et al., 2007; Schwarz, 2004). By contrast, barramundi (Lates calcarifer) fingerlings, a highly regarded and

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established farmed product in Australia, are sold commercially for AU$0.012—0.015 per mm (AU$0.48—0.60 per 40mm fingerling; 2015 price) (David Borgelt, hatchery manager,

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Jungle Creek Aquaculture Pty. Ltd., personal communication). PSFI is also located at least six

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hours away from Yamba (by road), and at times high mortalities have occurred in transport.

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One option, to reduce cost and achieve reliability, is to adapt existing on-site prawn

hatchery facilities to finfish production, as many of the requirements of prawn and estuarine fish hatcheries are similar. Both require similar water quality in terms of filtration, disinfection and acceptable levels of contaminants; both require production of algae and require laboratory facilities for holding axenic cultures, and scaling up production to tens of thousands of litres; both require Artemia as a live food for the larval stages, requiring both hatching and enriching facilities; both require similar aeration infrastructure throughout the hatchery complex (Colt and Huguenin, 1992; Huguenin and Colt, 2002). For full marine fish species, this is more complicated, as the rotifer-brine shrimp combination alone is often inadequate, and specialised copepod production facilities are required (Lee et al., 2005).

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Clearly, applied research is needed, as fertilised eggs can be purchased at a costeffective price and there is the added possibility of making use of existing facilities and services; but at present no detailed information exists on the potential of using this existing

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prawn hatchery infrastructure for mulloway fingerling production. Additionally, reliable supplies of cheap, high quality fingerlings are also essential for developing a viable industry

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(Schwarz et al., 2009 ). The strategy here is to build a new supply capacity in northern NSW

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by providing prawn farmers with the knowledge to produce their own fingerlings from purchased eggs. This is expected to provide growers with another option for annual farm

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stocking that would potentially halve their fingerling cost, eliminate transport issues, and help increase profitability, sustainability and viability of farms while also providing a basis

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for expansion of the industry (Bird, 2010).

Presently within Australian aquaculture there is a lack of information on the

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potential for temperate marine fish culture in aerated brackish-water prawn ponds,

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especially species selection, seed availability, cost of production, viability and market. There

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are also few published hatchery design studies, although important information exists for the juvenile production of tropical species such as barramundi (Anderson, 2004; Schipp et al., 2007).

This paper was motivated by the desire to inform industry how a possible change

from prawn to finfish culture could be implemented and to our best knowledge, presents the first technical information on how the prawn hatchery infrastructure of Palmers Island can be utilised for mulloway production. It provides details of the production facilities and support systems necessary for estuarine fish larviculture and documents conversion and production costs.

This information will be useful for commercial decision making by

Australian prawn farmers, potential investors or developers.

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2. Existing prawn hatchery facilities and layout 2.1 Location and climate Both hatcheries are located at Palmers Island, in the warm temperate coastal zone of

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northern NSW, about 10 minutes inland from the east coast town of Yamba (29.4°S, 153.3°E). Since the 1980s prawn farms have been established on land adjacent to the

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Clarence River, which is the source of brackish-saline water at the farms. Palmers Island

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varies in altitude/elevation from about 5 m to 7 m above sea level and has typical summer (November to April) air temperatures of 25–35 °C. The prawn farms and Palmers Island

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have been previously described in Smith (1996) and Kankaanpää et al., (2005).

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2.2 Australian hatchery

The Australian hatchery is part of Tru Blu prawn farm (36.93 hectare (ha)) which has

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been in production since 1984 and is the oldest farm specializing in culture of black tiger

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prawns in NSW. At the peak of production in 2003 Tru Blu had 26 ponds with a total area of 21.6 ha. The hatchery was built in 2002 to fulfil the requirements of producing 20 million

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postlarvae 15 days from the megalopa stage (PL15s); the preferred age as PLs are easier to harvest, transport and stock at this size . The hatchery was operated only four times before the downturn in the industry; it is currently idle with a recorded maximum output of around 8 million PL 15s. Site visits were conducted during 2012 and information gathered from interviews with current owners, past managers and employees. 2.2.1 Layout, descriptions and dimensions Exterior: The hatchery building is a 21.19 m x 48.45 m t-clad COLORBOND® steel shed anchored to a concrete slab. These industrial buildings are common in rural Australia with numerous sliding doors for entry and transparent walls and roofing used to assist in light

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penetration. There is also an adjacent building (26 m x 9 m) with an insulated broodstock and hatching room and accommodation (kitchenette and a bedroom) (Fig. 1).

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of water to the two hatchery supply ponds is by an aqueduct system that is fed directly from

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the pump station situated on the nearby banks of the Clarence River. The supply ponds are lined with a black high density polyethylene plastic and equipped with a centrifugal pump

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and 80 mm supply lines to the hatchery. The water, prior to hatchery use, passes through an

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enclosed top mount sand filter (300 L capacity) and then a series of four cartridge and two fine bag filters. There is also a water temperature control and heating system (using a

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bottled gas boiler) to ensure that the water temperature remains between 26 -300C which is stored in 3 x 30,000 L polyethylene rain water tanks, adjacent to the hatchery (Fig. 1). An

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aeration bank (3 x side channel blowers; 50 Hz 3 phase electric motor) behind the storage

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tanks provides air to the hatchery and storage tanks via a network of PVC pipes.

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Interior: The main sectors are shown in Fig. 1 and include areas for storage and cold stores,

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laboratory and office (for refrigeration, washing of glassware as well as general service to the hatchery including benches for microscope work), algae laboratory (to maintain pure stocks of Chaetoceros, Skeletonema, Tetraselmis and Chlorella and equipped with a laminar flow cabinet and sink), algae room (for open–topped cost effective mass production of algae which is pumped directly into the 20,000 L half barrel tanks for larval rearing), Artemia production and packing. All slopes are 1 in 200 (i.e. 5 cm every 10 m) draining to plastic grated drains. The hatchery is dominated by the 20 x 20,000 L half barrel larval rearing tanks (7.5 m long x 2.4 m wide x 1.54 m high; AU$8,350 each -2012 pricing) (Fig.1 (b)). All larval rearing (nauplii to PL15) is conducted in these tanks (stocking density 100 nauplii per litre with around 50% survival rate to PL 7-10) and there is no separate nursery stage. There

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are also 6 x 1 000 L white translucent tanks (for mass culture of algae), 7 x 1 000 L (black) and 4 x 3 000 L Artemia hatching tanks, an alarm system to the accommodation as well as an air and water delivery system to all tanks which passes through a wall-mounted ultra-

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violet (U-V) lamp system (single lamp, 185 watt, magnetic ballast).

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2.3. Taiwanese hatchery

The Taiwanese hatchery was previously part of Pearler Pty. Ltd. prawn farm and built in

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1998 to fulfil the requirements of producing 15 million PL15s. In 2008 the 18 ha site (12 ha

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of ponds) was purchased and began operation as Palmers Island Mulloway (PIM). The farm has an office complex, hatchery building, processing shed, house and a larger effluent-

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settlement discharge pond. This represents the current level of land-based investment and activity in mulloway aquaculture in NSW and has been previously described in Guy et al.,

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(2014). Site visits were conducted as for Tru Blu prawn farm.

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2.3.1 Layout, descriptions and dimensions

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Exterior: The hatchery building (33.6 m x 20.7 m) is a well-insulated steel shed with concrete slab and sections of transparent roofing over the algal raceways allowing natural light to penetrate (Fig. 2(a)). There are four access points, but no sliding doors. The pumping station, situated by the Clarence River, delivers seawater directly to a small elevated reservoir which gravity feeds into the hatchery. Water flows through an open and then closed sand filter before entering the hatchery where it passes through an in-line U-V lamp system.

Interior: The main sectors are shown in Fig. 2 and include 25 concrete tanks of various sizes for the different stages of penaeid culture (separate rather than community tank method).

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The tanks, either rectangular or square, are constructed from concrete blocks cemented together with a smooth interior epoxy coating. This design differs from the Tru Blu hatchery in that broodstock are housed within the hatchery which includes a 25 000-L broodstock

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holding area and two adjacent 12 000-L hatching tanks. Other areas include the algal raceways (6 x 12 000-L tanks), for mass cultivation of algae (50 to 60 t) and for larval (10 x 20

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000-L tanks) and nursery rearing (6 x 30 000-L tanks). The larval rearing tanks (5 m x 3.2 m x

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2 m) were stocked at a density of 150 nauplii per litre (higher than Tru Blu), for a total of 3 million nauplii per tank. Survival was between 50-60%, as for Tru Blu. These tanks had a flat

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bottom which sloped gently to a corner drain set at the side of the tank and intensive aeration was provided by one air stone for every 60-70 cm2 of bottom area. Water

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temperature was maintained at 28 to 31oC with immersion heaters. At the Mysis 2 or 3 stage or the PL 4 or 5 stage larval rearing was terminated and PLs were harvested and

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reared in the 6 nursery tanks for 2 to 4 weeks before final stocking in grow-out ponds at >PL

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20. The nursery system design (where young PLs are acclimated to environmental

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conditions similar to grow-out) allowed for major water exchanges or flow through.

3. Methods and assumptions for marine fish culture The production calculations for each hatchery are based on the following methods,

assumptions and production scenarios (based on the size of fingerlings for stocking) for mulloway. The two anticipated scenarios assume a water temperature of 20-25°C and one month hatchery preparation time. I.

40mm fingerlings (1 g) which can be stocked directly into ponds or on-grown in a nursery pond.

II.

100mm fingerlings (12 g) which can be stocked directly into grow-out ponds.

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The choice is a personal management decision, although, our experience with smaller fingerlings (1 g) is that they can be more sensitive and prone to swim bladder stress syndrome (SBSS); a malfunction of the swim bladder (hyper inflated) when stocked directly

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into ponds after road transport (Guy and Cowden, 2012). 3.1 Live food production

Monospecific batch culture is used and axenic stocks of

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Microalgae:

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Nannochloropsis oculata (Eustigmatophyceae) are maintained in an algae laboratory. Pure culture can be obtained from the Australian National Algae Culture Collection, C.S.I.R.O.,

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Hobart, Tasmania. Subsequent up-scaling to larger volumes takes place into 20 L plastic carboys which are used to inoculate still larger volumes (tanks or bags). All water used for

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algae production is micro-filtered (1 micron), Ultra-Violet (UV) treated, enriched with nitrogen (ammonium sulphate) and phosphorous (superphosphate) commercial fertilisers

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and kept between 20-22oC. High wattage lights (1500 watt metal halide) can be used to

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cultures.

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lengthen the photoperiod. A minimum 10% inoculum of N. oculata is applied to new

Rotifers: L-strain (130 to 340 mm lorica length) rotifers (Brachionus plicatilis) are

grown using a batch culture method and fed a complete rotifer diet that enables densities of up to 5,000 rotifers per ml to be maintained (Tamaru et al., 2003). We have previously used a dry powder (Culture Selco Plus) with good results and no live algae are required. Further enrichment is also possible at this stage, but for mulloway larviculture, the enrichment of rotifers beyond that achieved in a green-water culture has been shown to be an unnecessary step (Guy and Cowden, 2012). The same water treatment described for microalgae culture is applied with the following additions: best output is obtained under strong aeration conditions (to keep food particles and rotifers in suspension) and pure

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oxygen is used at densities over 3,000 rotifers per mL and temperatures in the vicinity of 25°C. Artemia and enrichment: Artemia are hatched at approximately 1 gram per litre,

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despite higher stocking being possible (2.5 g per litre). To separate nauplii from unhatched cysts and shells, brine shrimp eggs treated with a magnetic coating are used (SEP-Art

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Technology, INVE Aquaculture). A 24-hour post-hatch yolk-absorption phase is also assumed

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and our previous work has indicated that the enrichment of Artemia with the commercial product “DC DHA Selco” was adequate for high survival of mulloway larvae. Used at the

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manufacturer’s recommended rate, levels of total HUFA and DHA of 53.5 mg/g and 24.4 mg/g, respectively, and a DHA:EPA:ARA ratio of 7.9:5.3:1 can be achieved (Guy and Cowden,

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2012). The same water treatment described for microalgae culture is applied with the following additions: best output is obtained under strong aeration and light conditions (2 000 lux at

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the water surface) and higher temperatures in the range of (27-30°C) at 35 ppt. salinity.

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3.2 Egg supply, hatch and tank stocking

No allowance has been made for broodstock facilities as fertilised mulloway eggs can

be readily obtained from PSFI (Fielder and Heasman, 2010). Here fertilised eggs are disinfected by exposure to ozone (Ballagh et al., 2011) before being packed in insulated boxes at a water temperature and salinity of 22.0⁰C and 34 ppt salinity, respectively, before road transport. Upon arrival, eggs are stocked in 540 litre round conical tanks at densities of up to 500,000 eggs and incubated in UV-treated seawater (10 litres per min flow rate) at the same temperature and salinity. After hatch, the egg shells are siphoned off and the larvae concentrated, ready for immediate stocking into aerated conical-bottomed tanks.

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3.3 Larviculture The intensive green-water larval culture method practiced is adapted from Palmer et al. (2007) and assumes a stocking density of 30 larvae per litre. The basic physical

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parameters required for mulloway are 22.0⁰C, 10-25 ppt salinity at low light intensities (<100 lux) (Ballagh et al., 2008; Fielder and Heasman, 2010). At 2 days post-hatch, a

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floating oil skimmer is added to the surface of tanks to remove oil and to facilitate proper

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swim bladder inflation and removed at 5 days post-hatch. Algae (N. oculata) is added daily to maintain a density of approximately 1 x 106 cells per ml. Total ammonia nitrogen is kept

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at or below 1.0 mg per litre through water exchange (if necessary). L-strain rotifers (B. plicatilis) are offered for approximately 8 days post-hatch, followed by enriched Artemia for

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a further 10 days post-hatch before weaning commences onto dry crumble food (Skretting Gemma 0.5 mm) (Table 1). Tanks are drained, harvested, and fish graded and counted to

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determine survival and minimise cannibalism at approximately 25-30 days post-hatch when

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post-larvae are fully weaned and 20-25 mm TL. Water consumption during this phase is

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minimal, 40% survival is assumed (Guy and Cowden, 2012). The larger size grade is transferred to nursery tanks where they can be on-grown to 40mm (1g) without further grading, using automatic belt feeders and commercial high protein diets formulated for marine fish fingerlings. The smaller size grades are retained and on-grown in the hatchery until their size exceeds 25 mm TL.

3.4 Pond stocking For stocking ponds a method used by the Queensland Barramundi industry would be adopted (O'Sullivan, 2009). Here about 5% of the pond area is fenced off with bird netting to

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keep predators out. Once the fish are large enough to escape cormorants they can be

4.0 Modification and adaption for marine fish culture 4.1 Large scale production at Tru Blu (Australian design)

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released into the main part of the pond. This should reduce the cost of netting large areas.

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The major hatchery components have been left unaltered; the algae and food

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laboratory, office, storage and cold storage facilities retain their original function. The larval area becomes dual purpose – larval rearing and nursery as does the Artemia area –

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producing rotifers and hatching and enriching brine shrimp.

Production estimates: Under scenario (I) 630,000 x 40 mm fingerlings produced

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(maximum) using 3 x 20, 000 L half barrel tanks for larval rearing, 16 for nursery and one for algae production (moved into the algae area) with a run time of two months post-hatch.

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Under scenario (II) 150,000 x 100 mm fingerlings produced, or double this through use of

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pure oxygen in all nursery tanks. Only one 20,000 L half barrel is required as a larval tank

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with the remaining 19 as nursery tanks. No extra algae production is necessary with a run time of four months post-hatch.

Live food production: Axenic stocks of N. oculata are maintained in the algae lab,

scaled up to 20-L carboys which are used to inoculate tanks in the algae room (open–topped mass culture) and then the 20,000 L half barrel tanks (Fig. 1). The algae production facilities are more comprehensive than necessary, but this could be useful if other species of fish or invertebrate are cultured in the future (e.g. sea urchin, sea cucumber, abalone, oyster), or if copepods or rotifer enrichment with live algae such as T. iso is desired. Seven 1,000 L and 4 x 3 000 L tanks are available for growing rotifers and Artemia. The use of the same tanks for both applications is possible as larval fish progress quickly from one live food to the next.

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Larviculture: Stocking density for the green-water phase is 600,000 larvae per 20,000 L half barrel tank. The 20,000 L tanks designated as nursery tanks are stocked with 40,000 x 25 mm fingerlings and grown to 40 mm (1 g) without further grading, using automatic belt Water consumption would peak at 1,800 litres

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feeders and commercially available feeds.

per minute (Lpm). For scenario (II), fingerlings would be grown to 100 mm in the same

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nursery tanks, if desired. These tanks would be stocked with 8,000 x 40 mm fingerlings and

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grown for a further 2 months to 100mm (12 g). Alternatively tanks could be stocked with 16,000 x 40 mm fingerlings and a network of pure oxygen diffusers installed to keep oxygen Water consumption would peak at 2,300 Lpm and maximum

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levels above 5 ppm.

production is 300,000 x 100mm using pure oxygen.

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Staffing: Three full-time staff could run the hatchery and nursery described above. This includes a hatchery manager (oversee operation, egg delivery and hatching, larval tank

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stocking and daily maintenance, first harvest/grade/count); live feeds technician

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(maintenance of stock algae cultures, scale-up of algae, maintenance of rotifer production

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and enrichment, and brine shrimp hatching/enrichment) and; a nursery technician/manager (maintenance of all nursery tanks – daily feeding, tank bottom cleaning, water quality and disease monitoring). These positions are only required for the single annual hatchery cycle (June-October); 3 months for scenario (I) and 5 months for scenario (II) then the hatchery closes.

Conversion costs: These include increasing water supply capacity from the present

500 to 2,000 Lpm through installation of a 150mm (minimum) diameter pipe from the supply pond, appropriate pump unit and matching sand filter (nominal 50 microns). Also, installing a fine high pressure stainless steel pipe network throughout the nursery area to provide access to pure oxygen at every tank; useful in emergencies, and very convenient

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when harvesting fish and necessary in scenario (II) when maximising nursery production from each tank. The purchase of fingerling grading and counting equipment is also necessary; automatic graders and fish counters would be justified in a hatchery this size,

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although initially hand graders and estimating fish numbers through weight-counting would be possible although labour-intensive. Appropriate methods (summarised in Moretti et al.

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(1999)) would need to be developed (trolleys and small vehicles/trailers) to move fish in

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bulk to transport and thereafter ponds. Finally, although no new tank purchases are necessary, the use of large half barrel tanks as nursery tanks may not be ideal because of

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their inability to self-clean in the way that round conical-bottom tanks can. The half barrel tanks will require a greater labour input to keep cleaned, and for this reason it may become

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necessary to replace them with 10,000 L round tanks if waste removal becomes impractical. The need to culture rotifers does not require additional infrastructure as the Artemia tanks

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are suitable. Total cost for this upgrade would be around AU$20,000 to $25,000. Some

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costing’s include AU$7,000 for water supply (including 150 mm piping @$140 per 6 m,

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trench and 3 phase pump AU$3,000), a stainless steel pure oxygen network (AU$3,000), grading and counting equipment (AU$8,000). Cost of production: The cost of production includes labour and consumables for

larval production, the cost of live food production, purchase of eggs and transport from PSFI but not capital expenditure (e.g. cost of tanks, pumps and grading equipment for hatchery conversion and interest on capital) as this can be highly variable (Moretti et al. (2005). The cost breakdown (Table 2) is based on the production system employed at the NMSC, but using the Tru Blu hatchery to full capacity. On a per fish basis it was three times more expensive (AU$0.284) to produce a smaller quantity of larger sized fish (150,000 x 100mm) than 630,000 x 40mm fish (AU$0.095). For a comparison of production costs to produce red

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sea bream (Pagrus auratus) and black bream (Acanthopagrus butcheri) fingerlings in

Australia, see Partridge et al. (2003). 4.2 Smaller scale production at PIM (Taiwanese design)

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There were a number of additional issues associated with the Taiwanese-design conversion to marine fish culture: the water supply and treatment infrastructure was

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inadequate; the water supply is directly from the river, with no storage capacity, making the

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water supply vulnerable to rapid changes in river quality; the main algae production is in large concrete raceways which have deteriorated and are difficult to disinfect; the larval and

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nursery tanks are rectangular concrete with flat bottom which is not a desirable shape for finfish larval rearing and nursing and the Artemia hatching and enrichment capacity is less

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than required.

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These can be solved but at greater expense than the conversion of the Tru Blu

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hatchery and a large part involves: demolishing the concrete tanks to the bare concrete slab, and then bringing in purpose-built fibreglass or polyethylene tanks; replacing the

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existing concrete larval rearing tanks with 6 x 5,000 L round conical tanks; replacing the existing concrete algae raceways with 2 x 20,000 L round conical nursery tanks; converting the broodstock holding and hatching tanks to a live food production area; and replacing the large concrete nursery tanks with 4 x 20,000 L round conical nursery tanks (Fig 2). Production estimates: Under scenario (I) 320,000 x 40mm fingerlings produced,

using 6 x 5000 L tanks for larval rearing and 6 x 20,000 L nursery tanks with a run time of approximately two months post-hatch. Under scenario (II) 50,000 fingerlings produced, or double this through use of pure oxygen in all nursery tanks. Only one 5,000 L larval rearing tank is required with a run time of approximately four months post-hatch. The requirement

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to fully stock grow-out ponds at PIM is 80,000 fingerlings, which can be achieved in this hatchery if either pure oxygen is used in the nursery area (increasing capacity to approximately 100,000 x 100 mm), or some of the nursing is done in the ponds.

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Live food production: Given the poor algae production facilities and the past history

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(see discussion), it is more realistic that live algae is not produced in this hatchery, but instead modern algae pastes be used in green-water larval tanks for rotifer production. This

but potentially at cost of some loss in reliability.

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greatly simplifies and minimises expense associated with the conversion of the hatchery, The algae production area is then

an

converted to greater nursery capacity (2 x 20,000 L tanks). A large number of 300 L round

M

conical tanks are available for live feed production (x 11); a further two 1000 L and two 2,000 L general purpose tanks are purchased to raise the live food production capacity in

d

proportion with the larval rearing capacity. The four new general purpose live food tanks

te

recommended above can be shared between rotifer and Artemia production, both of which

Ac ce p

are not in high demand simultaneously.

Larviculture: Stocking density for the green-water phase is 150,000 larvae per 5,000

L tank. The 20,000 L nursery tanks are stocked with 40,000 x 25mm fingerlings and grown to 40mm (1g) as for Tru Blu. Water consumption peaks at approximately 800 Lpm. In scenario (II), fingerlings would be grown to 100mm in the same nursery tanks, if desired. These tanks would be stocked with 8,000 x 40mm fingerlings and grown for a further 2 months to 100mm (12 g). Alternatively tanks could be stocked with 16,000 x 40mm fingerlings and a network of pure oxygen diffusers installed as for Tru Blu.

Water

consumption peaks at 800 Lpm and 50,000 x 100mm fish could be produced, or 100,000

Page 18 of 32

through use of oxygen. Alternatively nursing to 100mm could be carried out in a dedicated nursery pond of approximately 0.1 ha. Staffing: Two full-time staff (hatchery manager and a nursery and live food

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technician) could run the hatchery and nursery at maximum capacity, one fewer than the

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Tru Blu hatchery because of the smaller size, and the fact that live algae are not being used.

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Conversion costs: These include: establishing a substantial hatchery water supply holding pond (a minimum of 0.1ha, 2m deep and plastic lined) and increasing the water

an

supply capacity from the present 450 to 800 Lpm through installation of a 100mm (minimum) diameter pipe from the supply pond, appropriate pump unit and matching sand

M

filter (nominal 50 microns). Further filtration through cartridge filters to approximately 5 microns, and UV disinfection, would also be necessary for a proportion of this water

d

(approximately 200 Lpm) to supply the larval rearing and live food areas. A large number of

te

purpose-built fibreglass or polyethylene tanks would also have to be purchased. This

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includes 6 x 5,000 L larval rearing tanks, 6 x 20,000 L nursery tanks, 2 x 1000 L live food tanks, and 2 x 2000 L live food tanks. The use of the same tanks to produce both rotifers and Artemia is possible and a fine high pressure stainless steel pipe network would need to be installed throughout the nursery area, as for Tru Blu, to provide access to pure oxygen. The final capital investment relates to the fingerling grading and counting operations as for Tru Blu. In the suggested conversion, the algae production facilities are replaced by greater nursery capacity, but this could be reversed if other species of fish or invertebrate are cultured in future which require live algae. Total cost for this would be more than double that of Tru Blu around AU$55,000, with the main costs attributed to the purchase of 6 x 20,000 L fibreglass conical tanks (AU$5,000 each) and 6 x 5,000 L (AU$1,500 each), 2 x 1,000

Page 19 of 32

L (AU$895 each) and 2 x 2,000 L (AU$1,200 each) polyethylene conical tanks totalling AU$43,190. A stainless steel pure oxygen network (AU$3,000) and grading and counting equipment (AU$8,000) take the complete conversion to over AU$50,000.

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5.0 Discussion

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Our preliminary findings indicate that both prawn hatcheries could be easily adapted with moderate cost and modification as no broodstock facilities are required. Many of the

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above suggestions have already been implemented by our commercial partner (PIM) and approximately AU$20,000 has been spent on construction and lining of a hatchery supply

an

pond, pump and piping to the hatchery, enclosed top mount sand filter, UV disinfection and

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2 x 5,000 L tanks. This is due in part to the availability of large commercial quantities of mulloway eggs, available year-round from the government hatchery, who developed the

d

technology of spawning broodstock and rearing mulloway larvae and juveniles in the late

te

1990s (Battaglene and Talbot, 1994; Fielder and Bardsley, 1999). This is not always the case with emerging species, which may require long periods of R&D to develop spawning and

Ac ce p

larval rearing protocols and often start from an inconsistent supply/high production cost position (Guy et al., 2014).

However, if broodstock were to be held on-site, the

requirements for prawns and mulloway are substantially different and major (costly) modifications would be required. Details of the capital required for a dedicated broodstock holding facility are contained in Fielder and Heasman (2010). Despite the ease of conversion and culture (from prawns to mulloway) we identified a number of key points of difference between penaeid prawn and marine fish larviculture which need to be addressed in any hatchery re-design. These were:

Page 20 of 32

 Estuarine fish larviculture requires less sophisticated algae growing facilities, requiring less species to be maintained (often only one such as the green microalgae N. oculata,). The exception to this is when it is necessary to culture copepods,

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required by some full marine species.

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the essential first food for most marine fish larvae.

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 Prawn larviculture does not require the production of rotifers, whereas rotifers are

 Larval tank shapes are traditionally different – prawn larvae are commonly grown in

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half barrel tanks, fish in round conical tanks.

 Although both require similar water exchange capacity in the larval culture phase,

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fish culture requires a substantially greater capacity to exchange water in the

d

nursery phase when fish are feeding vigorously on pellet diets.

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 Fish are normally harvested, counted, graded and moved to larger nursery facilities

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after metamorphosis and weaning, at 15-20mm, and on-grown to 40-100mm before pond stocking.

The grading and counting process requires some specialised

equipment. Prawn larvae are grown to PL15 stage in larval tanks, and then moved straight out into the ponds.

On-farm fingerling production trials Our commercial partner began trials with mulloway fingerling production in 2012.

The NMSC provided expert advice, training and quantities of the green microalgae (N. oculata) for the algal raceways while fertilised eggs were sourced from PSFI. The on-farm production of microalgae was not successful with numerous batches contaminated by protozoans and this prompted the use of a commercially available concentrated algal paste

Page 21 of 32

for rotifer production (Nanno 3600, Reed Mariculture Inc., San Jose, California, USA), mainly because of its ease of use. Culture Selco Plus is a dry powder alternative. This method is gaining wide acceptance in marine fish larval culture (Lee, 2003; Pfeiffer and Ludwig, 2007)

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and algal paste has effectively replaced live algae during the green water stage of cobia fingerling production in the USA with no negative impact upon growth, survival, or resultant

cr

weaning production per unit volume (Schwarz et al., 2008). Despite this finding, on-farm

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mulloway fingerling survival was much lower (20% compared to 40% survival to 25 mm TL) than commercial trials using live algae at the NMSC (Guy and Cowden, 2012). Further work

an

is required to determine the cause of this, although it has been shown that larval tanks with algal paste can show a higher abundance of bacteria and a higher share of cultivable

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bacteria and TCBS counts than tanks with live algae, which could affect survival (Attramadal

d

et al., 2012).

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Mortalities (from bacterial infection) also occurred during the initial on-farm fingerling production trials and were associated with poor water quality from the build-up

Ac ce p

and inadequate removal of solid waste from flat bottom concrete tanks, especially during weaning. To address this in 2011 the algal raceways were demolished (to create space) and replaced with circular 5000 L tapered bottom polyethylene tanks that could effectively remove waste with good results. Despite these initial setbacks, fingerling production is now a regular part of the production cycle at PIM and the feedback from prawn hatchery technicians, now rearing mulloway, is that it is much easier than the black tiger prawn for the following reasons: no live algae required; minimal disease; simple life cycle; easy to wean and observe.

Page 22 of 32

Multispecies strategy Despite the fact that both Palmers Island hatcheries were easily adapted with

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minimal cost and modification for mulloway production they are still faced with long periods of inactivity during which maintenance costs are not covered by production. Prawn farmers

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should aim to make the most profitable use of this asset and the preferred long-term

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strategy, to achieve this, is to become a multispecies hatchery; where production is based on a number of different species with partially overlapping spawning seasons (Alvarez-

an

Lajonchère et al., 2007; Moretti et al., 2005). This has been the case in sub-tropical Mediterranean aquaculture, where production was based on the winter spawning of

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European seabass (Dicentrarchus labrax) and the gilthead seabream (Sparus aurata) but has

d

now expanded to include springtime spawners such as the sharpsnout seabream (Puntazzo

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puntazzo), white seabream (Diplodus sargus sargus), the common dentex (Dentex dentex) and the shi drum (Umbrina cirrosa), allowing the use of hatchery facilities for nine to ten

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months per year (Moretti et al., 1999).

In Australia (Taylor et al., 2005), and more recently NSW, there has been growing

interest in the release of marine fish into estuaries or impoundments (dams or lakes) to enhance wild stocks and recreational fishing (Taylor et al., 2009). Four finfish species have been proposed for the NSW marine stocking program; mulloway, yellowfin bream, Acanthopagrus australis (family: Sparidae), dusky flathead, Platycephalus fuscus (family: Platycephalidae) and sand whiting, Sillago ciliata (family: Sillaginidae) which are all highly regarded and support important commercial and recreational fishing along much of the east coast of Australia (Cardno Ecology Lab, 2011). Additionally, an established Australian bass

Page 23 of 32

(Macquaria novemaculeata) government and private stocking program exists in NSW. While spawning occurs mainly during winter for yellowfin bream (Pollock, 1982) and Australian bass (Fielder and Heasman, 2010), the dusky flathead and sand whiting are reported to

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spawn during summer in NSW (Burchmore et al., 1988; Gray and Barnes, 2008), allowing for the potential hatchery production of two or more species over an extended period. These

cr

species also have potential for aquaculture because of their market place acceptance,

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economic value and their ability to tolerate wide variations in both salinity and temperature (Taylor et al., 2005). Additionally the captive spawning and hatchery production of these

an

species is well advanced (Black and Black, 2013; Cowden, 1995; Fielder and Heasman, 2010; Palmer et al., 2007) and their production would be an additional step towards the

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optimization of hatchery facilities in this area.

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Future work

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While studies have investigated the optimal conditions for growing the juvenile stage of mulloway (Ballagh et al., 2010; Ballagh et al., 2008) few have looked at the factors

Ac ce p

contributing to the modest survival of the larvae (between 20-40%). To increase hatchery profitability the factors which contribute to this need to be investigated further, especially the main mortality peak.

At present, we also have no data on whether modern algae pastes, used in green-

water larval tanks and rotifer production, are cost effective, especially as cheaper alternatives for rotifer production, such as Culture Selco Plus, are available. Although this greatly simplifies and minimises expense associated with the conversion of the hatchery, this may affect reliability and larval quality. Further work is required on the effectiveness of these frozen concentrates, before recommending the wide scale use of them.

Page 24 of 32

Acknowledgements This work formed part of a project (PRJ-005806) funded by the Australian

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Governments Rural Industries Research and Development Corporation (RIRDC) New Animal

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Products R&D program. We thank Mr Andrew and Peter Carroll, Palmers Island mulloway Pty. Ltd. and Mr Frank Roberts of Tru Blu Prawn Farms Pty. Ltd. for access to their farms. We

us

would also like to thank David McNamara (General Manager of Ponderosa Prawn Farm near Cairns) and Dylan Walker for information on the Tru Blu and Pearler hatchery, respectively.

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an

Dr Gay Marsden also provided expert advice on Australian prawn hatchery operation.

References

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Allan, G.L., 2008. Business Plan - Proposal for the commercial sale of marine fish eggs and fingerling from Port Stephens Fisheries Centre (PSFC), 6 pp. Alvarez-Lajonchère, L., Reina Cañez, M.A., Camacho Hernández, M.A., Kraul, S., 2007. Design of a pilot-scale tropical marine finfish hatchery for a research center at Mazatlán, Mexico. Aquac. Eng. 36, 81-96. Anderson, T.A., 2004. Commercial practices for the production of barramundi, Lates calcarifer, fingerlings: An industry summary, The Second Hatchery Feeds and Technology Workshop, Sydney, September 30-October 1, 2004, pp. 117-120. Attramadal, K.J.K., Tøndel, B., Salvesen, I., Øie, G., Vadstein, O., Olsen, Y., 2012. Ceramic clay reduces the load of organic matter and bacteria in marine fish larval culture tanks. Aquac. Eng. 49, 23-34. Ballagh, D.A., Fielder, D.S., Pankhurst, P.M., 2010. Weaning requirements of larval mulloway, Argyrosomus japonicus. Aquaculture Research 41, 493-504. Ballagh, D.A., Pankhurst, P.M., Fielder, D.S., 2008. Photoperiod and feeding interval requirements of juvenile mulloway, Argyrosomus japonicus. Aquaculture 277, 52-57. Ballagh, D.A., Pankhurst, P.M., Fielder, D.S., 2011. Embryonic development of mulloway, Argyrosomus japonicus, and egg surface disinfection using ozone. Aquaculture 318, 475-478. Basurco, B., Abellán, E., 1999. Finfish species diversification in the context of Mediterranean marine fish farming development. Options Méditerranéennes, Series B 24, 9-25. Battaglene, S.C., Talbot, R.B., 1994. Hormone induction and larval rearing of mulloway, Argyrosomus hololepidotus (Pisces, Sciaenidae) Aquaculture 126, 73-81. Bird, J., 2010. New and Emerging Industries National Research, Development and Extension Strategy, RIRDC Publication No 10/159, 42 pp. Black, B.J., Black, M., 2013. Efficacy of two exogenous hormones (GnRHa and hCG) for induction of spontaneous spawning in captive yellowfin bream, Acanthopagrus australis (Sparidae) and influence of sex ratio on spawning success. Aquaculture 416–417, 105-110.

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Ac ce p

te

d

M

an

us

cr

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Burchmore, J., Pollard, D., Middleton, M., Bell, J., Pease, B., 1988. Biology of four species of Whiting (Pisces: Sillaginidae) in Botany Bay, NSW. Mar. Freshw. Res. 39, 709-727. Cardno Ecology Lab, 2011. Marine Fish Stocking in NSW. Environmental Impact Statement. Vol I. Prepared for NSW Department of Primary Industries November 2011. Colt, J., Huguenin, J., 1992. Shrimp hatchery design: Engineering considerations. In: Fast, A.W., Lester, J.L (Ed.), Marine Shrimp Culture: Principles and Practices. Developments in aquaculture and fisheries science, volume 23, pp. 245- 285. Elsevier Science Publisher B.V., The Netherlands. Cowden, K., 1995. Induced Spawning and Culture of Yellowfin Bream, Acanthopagrus australis (Gunther, 1959) and Mangrove Jack, Lutjanus argentimaculatus (Forsskal, 1775)(PhD thesis) James Cook University. Creese, A., Trenaman, R., 2014. Aquaculture Production Report 2012–2013. NSW Department of Primary Industries. Fielder, D.S., Bardsley, W., 1999. A preliminary study on the effects of salinity on growth and survival of mulloway Argyrosomus japonicus larvae and juveniles. J. World Aquacult. Soc. 30, 380387. Fielder, D.S., Heasman, M.P., 2010. Hatchery manual for the production of Australian Bass, Mulloway and Yellowtail Kingfish. Industry and Investment NSW, pp. 168. Gray, C.A., Barnes, L.M., 2008. Reproduction and growth of dusky flathead (Platycephalus fuscus) in NSW estuaries., NSW Department of Primary Industries – Fisheries Final Report Series No. 101. Guy, J.A., Cowden, K.L., 2012. Re-invigorating NSW prawn farms through the culture of mulloway, Final Report PRJ-002273 to the Rural Industries Research and Development Corporation (RIRDC), Publication No. 11/178, 136 pp. Guy, J.A., Cowden, K. L..,2014. Optimising mulloway farming through better feed and hatchery practices. Final Report PRJ-002273 to RIRDC, Publication No. 14/109, 102 pp. Guy, J.A., McIlgorm, A., Waterman, P., 2014. Aquaculture in regional Australia: responding to trade externalities. A northern NSW case study. Journal of Economic and Social Policy 16 (1), Article 6., 1-29. Guy, J.A., Nottingham, S., 2014. Fillet yield, biochemical composition and consumer acceptance of farmed and wild mulloway. Journal Aquatic Food Product Technology 23, 608-620. Huguenin, J.E., Colt, J., 2002. Design and Operating Guide for Aquaculture Seawater Systems, 2nd ed. Elsevier, Amsterdam. Kankaanpää, H.T., Holliday, J., Schröder, H., Goddard, T.J., von Fister, R., Carmichael, W.W., 2005. Cyanobacteria and prawn farming in northern New South Wales, Australia—a case study on cyanobacteria diversity and hepatotoxin bioaccumulation. Toxicology and Applied Pharmacology 203, 243-256. Kerr, P., O'Sullivan, D., 2005. Government polices – are they destroying the Australian prawn industry? Austasia Aquaculture 19, 39-43. Lee, C.-S., 2003. Biotechnological advances in finfish hatchery production: a review. Aquaculture 227, 439-458. Lee, C.-S., O'Bryen, P. J., Marcus, N.H. (Ed.) 2005. Copepods in Aquaculture. Blackwell Publishing Professional, Ames, Iowa, USA, 269 pp. McMaster, M.F., Kloth, T.C., Coburn, J.F., Stolpe, N.E., 2007. Florida pompano, Trachinotus carolinus, is an alternative species for low salinity shrimp pond farming. World Aquaculture 38, 50-54, 66. Moretti, A., Pedini Fernandez-Criado, M., Cittolin, G., Guidastri, R., 1999. Manual on hatchery production of seabass and gilthead seabream. Volume 1. FAO. Rome, 194 pp. Moretti, A., Pedini Fernandez-Criado, M., Vetillart, R., 2005. Manual on hatchery production of seabass and gilthead seabream. Volume 2. FAO. Rome, 152 pp.

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te

d

M

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us

cr

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O'Sullivan, D., 2009. Great Barrier Reef barramundi still expanding since cyclone. Austasia Aquaculture 24 (4), 12-15. O'Sullivan, D., 2010a. Success in marine fish culture in ponds (1). Austasia Aquaculture 24 (3), 39-42. O'Sullivan, D., 2010b. Success in marine fish culture in ponds (2). Austasia Aquaculture 24 (4), 42-46. Palmer, P.J., Burke, M.J., Palmer, C.J., Burke, J.B., 2007. Developments in controlled green-water larval culture technologies for estuarine fishes in Queensland, Australia and elsewhere. Aquaculture 272, 1-21. Partridge, G.J., Jenkins, G.I., Frankish, K.R., 2003. Hatchery manual for the production of Snapper (Pagrus auratus) and Black bream (Acanthopagrus butcheri). Fremantle, W.A. : Aquaculture Development Unit, Challenger TAFE. Pfeiffer, T.J., Ludwig, G.M., 2007. Small-scale system for the mass production of rotifers using algal paste. North American Journal of Aquaculture 69, 239-243. Pollock, B.R., 1982. Spawning period and growth of yellowfin bream, Acanthopagrus australis (Günther), in Moreton Bay, Australia. Journal of Fish Biology 21, 349-355. Queensland Department of Primary Industries and Fisheries (QDPIF), 2006. Australian Prawn Farming Manual: health management for profit. Information series , Queensland Department of Primary Industries and Fisheries, Brisbane, QLD, Australia, 157 pp. Savage, J., 2014. Status of Australian Aquaculture in 2011/2012. Austasia Aquaculture Trade Directory 2014, pp. 6-25. Turtle Press, Hobart, Tasmania. Schipp, G., J. Bosmans, J., Humphrey, J. 2007. Northern Territory Barramundi Farming Handbook. Department of Primary Industry, Fisheries and Mines. Darwin, 71 pp. Schwarz, M.H., 2004. Fingerling production still bottleneck for cobia culture. Global Aquaculture Advocate 7, 40-41. Schwarz, M.H., Craig, S.R., Delbos, B.C., McLean, E., 2008. Efficacy of concentrated algal paste during greenwater phase of cobia larviculture. Journal of Applied Aquaculture 20, 285-294. Schwarz, M.H., Delbos, B.C., Craig, S.R., McLean, E., 2009 Strategies for rapid technology development, assimilation and transfer to the aquaculture Industry. World Aquaculture 63, 62-64. Smith, P.T., 1996. Physical and chemical characteristics of sediments from prawn farms and mangrove habitats on the Clarence River, Australia. Aquaculture 146, 47-83. Tamaru, C.S., Ako, H., Sato, V.T., Weidenbach, R.P., 2003. Advances in the culture of rotifers for use in rearing marine ornamental fish. In: Cato, J.C., Brown C.L.(Ed.), Marine Ornamental Species: Collection, Culture and Conservation, chapter 19, pp. 263-274. Blackwell Publishing Company, Ames, Iowa, USA. Taylor, M.D., Fielder, D.S., Suthers, I.M., 2009. Growth and viability of hatchery-reared Argyrosomus japonicus released into open and semi-closed systems. Fisheries Manag. Ecol. 16, 478-483. Taylor, M.D., Palmer, P.J., Fielder, D.S., Suthers, I.M., 2005. Responsible estuarine finfish stock enhancement: an Australian perspective. Journal of Fish Biology 67, 299-331.

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Tables

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Table 1 Typical feeding regime used for rearing mulloway at the national Marine Science Centre at a water temperature ranging from 18.5-23.3 o C. Note a static water system operates to 15 days post-hatch.

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__________________________________________________________________________________ Days after hatching (ah) 0 5 10 15 20 25 30 35 40 __________________________________________________________________________________ Feeding regime N. oculata ----------------------------------------L-rotifer (5-20 ind/ml) ------------------Artemia (1-2 ind/ml) --------------------------------Artificial diet ------------------------------------------Water management Water exchange 50% ---------Flow-through ------------------------------------------Bottom siphoning ------------------------------------------__________________________________________________________________________________

Page 28 of 32

QUANTITY

1. Eggs (95% hatch, 40% larval Survival, 90% nursery survival). 1.9 x 106 2. Transport of eggs 3. Microalgaea

Ea

(i) 1.9 million (ii) 0.44 million

km litre

4. Rotifersb

1 x 106

5. Artemiac

454g can 1-L

700 (i) 62,000 (ii) 20,000 (i) 1,200 (ii) 287 (i) 76 (ii) 18 (i) 22 (ii) 5 (i) 480 (ii) 240 850

(ii) Tru Blu 150,000x 100mm $5,280

$315 $112

$315 $36

$0.31

$372

$89

$80

$6,080

$1,440

$220

$4,840

$1,100

$35

$16,800

$8,400

$2.50-9.50

$3,800

$905

(i) 240 (ii) 107 1,980

$35

$8,400

$3,745

$1.80-2.50

NAe

$3,960

hr

400

$35

NA

$14,000

kWhr

(i) 8,333 (ii) 14,333

$0.20

$1,667

$2,867

M

d

hr

hr kg

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kg

an

$0.45 $0.0018

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6. Artemia enrichment 7. Larviculture labour (to 15mm) 8. Nursery feed (20 to 40mm)d 9. Nursery labour (20 to 40mm) 10. Nursery feed (40 to 100mm) 11. Nursery labour (40 to 100mm) 12. Electricity

COST/UNIT (i) Tru Blu 630,000 x40mm $0.012 $22,800

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UNIT

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ITEM

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Table 2 Production costs using Tru Blu hatchery for 630,000 x 40 mm (1 g) and 150,000 x 100 mm (12g) mulloway fingerlings. All costings in Australian dollars.

TOTAL COST $65,186 $42,137 -Production cost Per fish $0.104 $0.281 a b 6 c Peak algae demand 9,000 Litres/day; Peak rotifer demand 600 x 10 /day; Peak Artemia demand 900 x 106/day; d Peak water demand 2,300 M3/hr; e Not Applicable

Page 29 of 32

A

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B

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C

12

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11

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7

d

8

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10

1

2

17

16

14

9

15

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D

3

5 4 6

Fig. 1. Australian design prawn hatchery facility at Palmers Island, northern NSW. (A) Hatchery building (exterior). (B) 20 000-L larval rearing half barrel tank showing intensive tank aeration system (interior). (C) Algae room showing 6 000-L white tanks with overhanging high wattage lights (interior). (D) General plant schematic upper view with main indoor and outdoor areas: (1) 80 mm supply line from reservoir (2) Filtration (sand and cartridge filters) and heating (boiler with temperature control) undercover area (3) Hatching room (4) Insulated broodstock room containing 12 000-L tanks (5) Kitchenette (6) Accommodation (7) 30 000-L water storage tank (8) Roots type

Page 30 of 32

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blower bank (9) Storage and cold room (10) Laboratory/office with bench space and (11) Microalgae laboratory with laminar flow cabinet and 15- L plastic carboys for culture of Tetraselmis chuii, Skeletonema costatum and Chaetoceros sp. (12) Algae room with 6 000-L tanks for open –topped mass culture of algae (13) Hatchery supply line with indoor ultra violet (UV) steriliser (14) 20 000-L half barrel tank for larval rearing of nauplii to PL15 (15) Drainage sump (16) 3 000-L and (17) 1 000L Artemia hatching and enriching tanks.

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A

B

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C

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1

2

D

4

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3

5

7

11

11

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9

6

13

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12

d

10

Fig. 2. Taiwanese design prawn hatchery facility at Palmers Island, northern NSW. (A) Hatchery building (exterior). (B) Insulated larval rearing room showing flat concrete bottom covered with an epoxy coating and intensive aeration system (interior). (C) Algal raceway area. (D) General plant schematic upper view with main outdoor and indoor areas: (1) 80 mm main supply line from river; (2) Open sand filter (3) Closed sand filter (4) Elevated tank reservoir (5) In-line UV steriliser (6) Hatchery supply line (7) Elevated 25 000-L broodstock holding tanks with walkway (8)12 000-L hatching tanks (9)12 000-L algal raceways (10) 300-L Artemia hatching and enriching tanks (11) 20 000-L larval rearing tanks (12) Storage and laboratory (13) 30 000-L nursery tanks

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