Spiny (Rock) Lobster Farming
In July 2004, the Australian Centre for International Agricultural Research (ACIAR) sponsored a workshop in Nha Trang, Viết Nam, as a forum to gather information on the use of lobsters in the South China Sea and the measures that should be taken for sustainable exploitation of lobster stocks in the region. At that time, the lobster aquaculture industry in Viết Nam was rapidly expanding, with an annual production of marketed lobsters in excess of 2,000 tons and a farm-gate value of around $60 million.
Viết Nam is the only country in the world where farming of lobsters is fully developed and commercially successful. The Vietnamese industry is based on natural supply of seed lobsters – the puerulus stage (the postlarva), as hatchery supply is not yet available due to the difficult technical demands of rearing spiny lobster larvae in captivity. Viết Nam currently produces around 1600 tonnes of premium grade lobsters, primarily of the species Panulirus ornatus, that are exported to China where the price is higher. Fortunately, as P. ornatus is the most valued of the various tropical species in the China market. For Viết Nam, Panulirus homarus is a secondary species, representing the remaining 10% of farm production.
Today, the industry is valued at over $US120 million. This success led to significant interest in Indonesia where a fishery for seed lobsters has become well developed, with a catch 10-20 times greater than that of Viết Nam. However, grow-out of lobster in Indonesia remains insignificant due to unfavourable government policy and lack of farmer knowledge and skills. The seed lobsters available in Indonesia are primarily Panulirus homarus, a species with excellent production characteristics like P. ornatus, although with lesser value.
Indonesia has a unique opportunity to establish the world’s largest lobster aquaculture industry, based on a significant natural resource of settling puerulus. These seed lobsters can be captured and on-grown to generate high value, consumption size lobsters. However, existing fisheries regulation forbid fishing of these seed lobsters in Indonesia. Nevertheless, seed fishing occurs widely, and the seed is smuggled into Viết Nam, where the Vietnamese gain most of the commercial benefit.
Methods for the fishing of lobster pueruli (seed) were first developed in Viết Nam in the mid-1990s. Entrepreneurial Vietnamese fishers recognised that small lobsters could be fattened to a more valuable product, as the Chinese demand and price per kilogram was greatest for lobsters larger than one kilogram.
In the earliest years, methods were developed for catching small juveniles, typically by creating habitat in which juvenile lobsters would settle. Small-diameter holes were drilled into coral rocks and timber posts, and these materials were placed in shallow waters along the coastline. Fishers would periodically dive on to these habitats and manually remove settled juveniles. This method was progressively replaced with fishing for the puerulus stage, using various nets to capture the swimming pueruli as they actively move through inshore waters seeking suitable habitat. Puerulus fishing quickly proved to be more effective than juvenile fishing, as the abundance of pueruli was often much higher. Methods evolved and catch rates increased as the canny fishers came to understand the oceanographic conditions that matched the highest abundance. These conditions were characterised by inshore areas protected from larger swells, inside embayment often with fringing islands, moderate current, against which the puerulus would swim, and often in proximity river mouths where turbidity was elevated.
Nets set across the current would effectively intercept the pueruli as they swam through the hours of darkness. Today, the most common and effective method for fishing of pueruli use a set seine (fishing net which hangs vertically in the water with floats at the top and weights at the bottom edge, the ends being drawn together to encircle the fish), deployed in a V-shape with opening facing the prevailing current, and using lights positioned near the apex to attract the pueruli. These nets are set in the hours around dusk and retrieved twice each night around midnight and again at dawn, with pueruli hand collected from the net as it is hauled aboard.
Lobster Seed Fishing
In Viết Nam the natural supply of such seed is sufficiently abundant to support industrial-scale aquaculture. Despite valid concerns that using a wild supply may not be sustainable, particularly in regard to possible impacts on existing adult lobster populations, the source of lobster seed in the country appears to be sink populations, whose abundance is unrelated to adult populations. The lobster seeds, although very small and delicate, are sufficiently robust to be transported from catching locations to areas suitable for grow-out and easily adapt to the high-density culture in sea cage systems. As naturally social species, both P. ornatus and P. homarus – the two prominent species widely available as seed, have proven to be excellent for farming, and their high value in various Asian markets provides a strong economic basis for commercial production. Relatively poor coastal communities, who have engaged in lobster farming in Vietnam, have gained great economic and social benefit from this enterprise.
In Viết Nam, the seed is typically sold by fishers to dealers, who aggregate supplies and then on-sell to nursery farmers. Nursing consists of rearing the seed lobsters in small suspended or submerged cages, with a diet of fresh seafood – crabs, mollusc and trash fish. Advanced juvenile lobsters are produced that are in turn on-sold to grow-out farmers who stock them to larger floating cages, suspended from simple floating frames. The economics involve relatively low capital and operating costs and production of a high-value product that provides significant economic and social benefit to the communities involved. Although some health and disease issues have impacted spiny lobster farming, they can be effectively managed through good nutrition and husbandry.
The primary market for farmed tropical lobster is China, with Taiwan a valuable secondary market. Farmed P. ornatus and P. homarus from Viết Nam are nearly all sold to these markets as the live lobster. In regard to tropical lobster species, the Chinese market displays a clear preference for P. ornatus at 1kg size and alive. Nevertheless, there is increasing acceptance of other species and price is trending upwards for all species. P. homarus is increasingly accepted as a substitute for P. ornatus. The wholesale price in China fluctuates around cultural events when lobsters are traditionally sought or avoided, e.g. Chinese New Year vs The Qingming festival.
Marine spiny lobsters are a premium seafood product representing esteem, wealth and fine dining. Farming of lobsters is not for the production of protein to feed hungry people, it is rather to supply prestige to a specific market motivated to boast and impress for social eminence. Much of the farmed lobster from Viết Nam is supplied to Hong Kong live seafood markets, from where it is trans-shipped to other mainland Chinese cities.
Viết Nam is advantaged by having free trade agreements with China by virtue of their ASEAN (Association of South-East Asian Nations) membership that precludes any import tariffs. Nevertheless, importation via Hong Kong still attracts significant costs in other taxes and duties which has prompted Viết Nam to bypass Hong Kong for the importation of live lobster by using road transport overland via Hà Nội. Whereas, for example, Australia does not have a free trade agreement with China, and consequently attracts a 40% import tariff on imported live lobster coming from the fishery in north Queensland and the Torres Strait. This is to the advantage of Vietnam as they do not have such a tariff added to the cost of their lobster product.
Some health and disease issues impact lobster farming and constrain production. The most common are red-body disease, milky disease, black gill disease, big head syndrome and separate head syndrome.
The proportion of lobster farm impacted by the milky disease in 2007 in the farming areas of Ninh Thuận, Bình Thuận, Phú Yên, and Khánh Hòa, provinces was 61%, 71%, 36% and 31% respectively. Approximately 50% of total production was lost due to milky disease from 2007 to 2009.; equating to approximately US$90 million lost and affecting more than 5,000 households. Before 2001, the typical survival rate through the grow-out phase was 70%.
The mortality of the captured lobster seed prior to stocking for grow-out is between 40 and 60%. This mortality can be attributed to a variety of factors, including capture technique, handling, transport, and during the nursery phase to nutrition, husbandry issues. If lobster losses during the capture through nursery phase could be reduced to only 10%, Vietnam’s total annual lobster production could be doubled without any increase in the catch.
Lobster farming in Viết Nam is also constrained by the availability of suitable sea-cage sites. Due to competing demands on marine areas, particularly for increasing tourism, many established lobster sea-cage sites have been closed to farming, forcing farmers to relocate or stop farming.
Although the China market is the primary market for farmed lobsters and offers the highest price, driven by strong demand that exceeds supply, there is some risk in complete reliance on this market. Decrees from the Chinese central government to reduce or avoid celebratory corporate events and 143 dinings can have a dramatic effect on demand for some products. In the past, this has significantly affected abalone and grouper sales, as these products were specifically mentioned in the government pronouncements. Some diversification in the marketing of farmed lobster is prudent to reduce such risk.
Hatchery technology for the tropical spiny lobster P. ornatus reached proof of concept in 2006 when the first puerulus were produced in a hatchery setting. Despite ongoing research efforts at four laboratories in Australia, commercial technology has not yet been achieved.
The approximately 8 months required for the hatched eggs to progress through its planktonic forms (phyllosoma) to the juvenile lobster form is the longest of any marine invertebrate. The local government agencies need to provide a site for further research into improved husbandry and propagation techniques for contained for open water hatcheries as well as willing to think long-term plan to construct a commercial-scale hatchery that will be capable of supplying spiny lobster aquaculture operations.
The objective is to develop and refine a spiny lobster production hatchery structure and methodology that can be reproduced at an affordable cost using materials and technologies appropriate for developing countries. If achieved, this spiny lobster aquaculture plus hatchery model could be replicated throughout the world in any impoverished or overfished region for the benefit of the local fishermen and their families.
Government of Viết Nam need to partner with universities around the world, to provide educational opportunities for students in Marine Biology and related fields. These students would be expected to contribute to the scientific support of both hatchery and aquaculture operations.