Spiny lobster Production:Of the various tropical spiny lobster species in the Indo-West Pacific region, Panulirus ornatus and P. homarus are emerging as the favoured species for aquaculture. This is based on a number of factors including market demand and pricing, availability of naturally settling seed (for on-growing), development of hatchery technology, suitability for captive grow-out and adaptability to a variety of production systems. Production to date is based only on naturally settled pueruli, which in some areas of Vietnam and Indonesia are particularly abundant and easily caught. In Vietnam, more than 1 500 tonnes of P. ornatus are farmed each year in sea cages, while in Indonesia lobster farming has begun in Lombok, where large numbers of P. homarus seed settle each year. Further seed resources are likely to be identified elsewhere in the archipelago. In Australia, exploitation of wild pueruli is uneconomic and the focus has been on hatchery technology which is now poised for commercialisation. Aquaculture production of lobsters is an attractive proposition worldwide, as the species are generally of high value and in great demand, and fishery production cannot be increased. Active research and development programmes throughout the world have sought to develop this sector, but to date none have been successful, beyond the developments referred to in this fact sheet. Tropical species of spiny lobsters are likely to remain at the forefront of aquaculture production development because of the availability of wild seed, the development of commercially viable hatcheries, and their highly economic grow-out characteristics. The development of spiny lobster culture has been actively pursued for many decades, although advances have been slow to realise because of the protracted larval phase. To date the only significant established lobster aquaculture industry is that of Vietnam, based on the grow-out of wild caught juveniles. Its development was entirely market driven and dates back to the late 1970s and early 1980s, when demand for lobsters from China grew rapidly. Prior to that a small lobster fishery of less than a hundred tonnes of annual catch operated along the coast of Vietnam, operated by divers and supplying a local market only. Panulirus ornatus was part of the supply but demand was only moderate as this species was of less value than others because its eating quality was less revered. However, Chinese consumers were specifically interested in P. ornatus as a sashimi product, served as a centrepiece for celebratory banquet dining. Only P. ornatus, with its colourful shell satisfied the visual appeal, was large enough (>1 kg) for such presentation and possessed the flesh characteristics (pearly lustre, sweet taste and firm texture) required for sashimi. Increasing demand from China heralded increased fishing effort throughout the South China Sea and beyond. In Vietnam, fishing effort increased through the use of larger vessels equipped with trawl nets that could operate further offshore and spiny lobster yields increased to >700 tonnes. For several years much of the catch was of large lobsters, namely P. ornatus of up to 5 kg per individual, P. homarus of over 1 kg per lobster and P. longipes and P. stimpsoni of up to 1 kg each. By the 1990s, fishing pressure and lack of any regulatory management led to decreasing catch and diminishing mean size. For P. ornatus, the Chinese demand was for larger lobsters, and the price paid for those less than 1 kg was lower. Vietnamese fishers were adaptive and inventive and soon began holding the smaller lobsters to fatten them to the preferred market size. Although the initial methods and equipment to do this was necessarily rudimentary, P. ornatus in particular demonstrated to them it was well suited to captivity. Growth rates and survival of lobsters held in simple enclosures staked into the seafloor in shallow waters off the beach and fed low value trash fish were excellent and the practice proved to be very profitable. By 2004 over 30 000 net cages had been established along the south central coastline producing more than 2 000 tonnes of farmed lobsters, primarily P. ornatus. In less than a decade a small but valuable fishery for market sized lobsters in Vietnam had been decimated. The catch of smaller lobsters destined for fattening farms decreased in volume but increased numerically as the mean size of lobsters caught continued to drop. By the mid 1990s Vietnamese fishers had developed techniques and identified locations to capture lobsters at the swimming (puerulus) stage; since 1996 the bulk of lobsters marketed from Vietnam have been farmed from an initial capture size of less than 5 g.
Posted on: Thu, 20 Nov 2014 03:02:10 +0000
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