About the Subprogram

What is the role of the Rock Lobster Enhancement and Aquaculture Subprogram ?

The Fisheries Research and Development Corporation established the Rock Lobster Enhancement and Aquaculture Subprogram (RLEAS) in July, 1998 following consultation with industry and scientists. The Subprogram was established with the following objective or "mission":

"To provide technology for use in Australian rock lobster enhancement and aquaculture systems so they can be internationally competitive and can operate in harmony with the wild fisheries".

What would we like to achieve through the Rock Lobster Enhancement and Aquaculture Subprogram

Delivery of technologies that facilitate the development of a viable rock lobster aquaculture industry in Australia, with adequate consideration and contingency for:

• Protection of the wild fishery in terms of economic and social viability;
• Neutral or positive impact on the wild fishery in terms of stock numbers;
• Commercial viability of closing the life cycle of rock lobsters;
• Increasing profitability and wealth for Australasia;
• Economic and marketing assessments to ensure aquaculture and wild fishery products do not compete for common markets.

What are the specific requirements and subsequent research needs to develop successful rock lobster aquaculture and enhancement systems ?

Species selection for aquaculture

• Viable rock lobster species with a short larval phase, fast growth potential at high densities, disease resistance and high market value that does not compete with existing wild capture sectors for common markets.
• Species well suited to aquaculture that is native to the wild fishing sector in the region of the aquaculture enterprise.

At present, research is focussing on dominant wild capture species, while perhaps more resources could be directed towards comparative morphology and aquaculture potential of other less common species, particularly some of the tropical species.

Puerulus collection

• Collect large numbers of puerulus from the wild for on-growing in aquaculture systems.
• Identify when surplus numbers of puerulus exist so that they can be captured and on-grown to increase survival rates.
• Minimise labour inputs for collection.
• Alternative sites for puerulus collection in conjunction with existing aquaculture enterprises.

Research in Western Australia and Tasmania has examined the development of collection methods for puerulus from the wild. Large ‘fluffy’ collectors set at different depths and in different areas off the Western Australian coast have been trialed with varying levels of success. This research has recently been extended to Tasmania where a number of different collector types on long lines are being examined. The Western Australian research has been hampered by low puerulus settlement, but has found that inshore collectors are more successful than those situated at a distance off shore. In Tasmania a survey of commercial aquaculture facilities has revealed some interesting spatial patterns of settlement on submerged structures while the research component has led to the development of suitable cost-effective collector types.

Biological neutrality

• Collect puerulus from the wild without an influence on the number of mature lobsters reproducing or the viability of the wild fishery.

Historical data on the settlement of puerulus in specific areas in Western Australia has been used to assess the potential impact of puerulus removal on subsequent wild populations of adult lobsters. Extensive statistical analysis has been employed to assess a range of scenarios. The large numbers of puerulus involved and the high mortality rates in the regions examined suggest that removal of puerulus would have a minimal impact on settlement rates in these regions.

Larval rearing/Propagation

Closure of the rock lobster life cycle to permit commercially viable culture of lobsters from eggs to adults through:

Pre-Breeding

• Ensure broodstock are collected/maintained at adequate size/condition.
• Optimise nutrition, environmental conditions for maintaining condition of broodstock.
• Know the history of individual broodstock
• Optimise health.

Breeding

• Ensure correct ratio of males:females
• Provide optimum conditions for incubation, mating
• Mate at correct time for successful fertilisation
• Maximise gamete production
• Disease control, maximise hygiene

Hatch-out stage

• Provide a system to catch/select larvae
• Provide adequate conditions for hatching out

Larval phase

• Maximise survival
• Optimise growth
• Synchronise development (eg moults)
• Minimise length of larval phase & selection to achieve high quality puerulus
• Most efficient culture system

Puerulus Phase

• Maximise moults
• Appropriate settlement conditions

Nursery/Juvenile Phase

• Optimise growth
• Maximise survival
• Grading to minimise size differences
• Transport from nursery and deliver to market or grow-out or wild
• Optimise conditions & preparation for grow-out
• Wean onto a suitable diet

Others

• Health (optimise)
• Efficiency of mass production systems (particularly larval phase)
• Optimum nutrition
• Minimise cost/unit production
• Minimise environmental impact
• Select appropriate site

Broodstock selection

• Selection of broodstock
• Maintenance for broodstock
• Initiate breeding program
• Optimise genetic strategy
• Optimise genetic integrity

Research on propagation of the southern rock lobster in Tasmania has resulted in the successful culture through 10 of it’s 11 larval stages in around 9 months. The outcomes of an International Workshop organised by the Tasmanian Aquaculture and Fisheries Institute through the Rock Lobster Enhancement and Aquaculture Subprogram suggest that the problems involved in larval rearing make it a risky proposition. However, economic and biologically feasibility on a commercial scale do appear to be achievable. Subsequent research on the rearing of rock lobster phyllosoma suggests that the nutrition of these larval stages is limiting and new techniques need to be developed for the delivery and improved utilisation of feeds. It is hypothesised that nutritional status of the phyllosoma towards the end of their larval phases has a significant influence on settlement.

Nutrition

• Multiple sources of nutrients for all growth phases.
• Robust diets that can be altered depending on the availability of raw materials while still supplying the same nutrients.
• Commercially produce a manufactured diet that is water stable, attractive, easy to handle, store and transport, shelf stable and cost-effective.
• Diets suitable to support optimum growth of all phases of the production cycle.
• Minimal impact on the surrounding water quality through nutrient loads.
• Diets that support optimum survival of juveniles during their first year of development.
• Nutritional manipulation of moult cycles.
• Nutritional enhancement of lobster product quality in live-held adults.

Nutrition research is being conducted on tropical, western and southern rock lobsters. All stages from early juveniles through to adults are being examined and cost effective manufactured diets are being evaluated. Recent work has shown that the protein content of diets for southern rock lobsters should be approximately 450 g/kg with lipid levels around 100 g/kg. The most noteworthy outcomes of nutrition experiments in all states to date are the apparent superiority of mussels over other diets and the distinct colour differences observed in lobsters fed different diets. It has been demonstrated that inclusion of approximately 100 mg/kg of carotenoids in southern rock lobster diets produces lobsters which are close to the natural colour of wild caught juveniles.

On-growing of juveniles and system requirements

• Cost effective tanks or sea-based holding cages that promote optimal growth and feed conversion performance.
• Husbandry procedures to ensure optimal growth (stocking density, water temperature, water quality, light, feeding regimes etc).

On-growing of juvenile rock lobsters takes place in tanks and the animals grow best on a diet of fresh mussels. Artificial diets are readily accepted, but the growth and survival rates are not as good as with mussels. Despite this, artificial diets do support exceptional growth of southern rock lobsters if supplemented with mussels three times per week. Hides are placed in the tanks to reduce cannibalism that can occur at the moult. Under these conditions a marketable size can be reached in 2 years (Tasmania) or a weight of 500 g in 1 year (Queensland) with very low mortality levels. System design research is defining environmental requirements of juvenile and adult tropical and southern rock lobsters as well as identifying system design criteria for on-growing of adults. A recent experiment in Tasmania has shown that a temperature of 18-22° C is optimal for growth and survival of southern rock lobsters. Further research is required to identify optimal growing conditions in South Australia. Both dry and moist manufactured feeds have been examined as cheap alternatives to fresh mussels, yet cannibalism at the moult and a disease causing blackening and necrosis of the tail sections requires further attention.

Health

• Disease-free aquaculture environment.
• Disease-monitoring to ensure disease transfer to the wild fishery is not possible.

In the absence of identifiable diseases, it is difficult to priortise health research. Linkages with existing health programs such as "AQUAVETPLAN" may provide the best opportunities to ensure the above requirements are met.

Economics and marketing

• Aquaculture reared lobsters of appropriate size and colour for premium markets that do not compete with existing lobster markets.
• Capacity to support premium markets for both aquaculture reared and wild caught lobsters.

Enhancement

• Reseeding of juvenile aquaculture reared juveniles that survive to increase wild fishery stocks and egg production levels.

As an adjunct to the above research in rock lobster aquaculture and enhancement, research underway in Tasmania is concentrating on the survival of wild caught on-grown juveniles after release back into the wild. Using electronic tagging methods released juveniles have been tracked for up to two weeks with no mortalities recorded.

Annual Operating Plan

Download the Annual Operating Plan 2005 in PDF Format.