Expert Commentary A - Tropical Spiny Lobsters Aquaculture: How far from Success? (Prospect for the Caribbean)(pp. 1-5)
Authors: (Erick Perera, Center for Marine Research, University of Havana, Cuba)
Abstract: Word fisheries landings have been declining slowly since the late 1980s, by about 0.7
millions tones per year (Pauly et al., 2002). Spiny lobsters support some of these fisheries all
around the world being the most important marine resource for many countries. As for other
aquatic animals, the idea of meeting growing demand for spiny lobsters through aquaculture
is actually old but it is now enhanced by the fact that most fisheries are exploited at or above
sustainable levels. Spiny lobsters hold excellent market price and many biological features
that make them suitable candidates for aquaculture (Booth and Kittaka, 2000) but other ones
so far impair a world-wide expansion of such an industry such as extended larval period and
low survival rates through larval culture. After many years of research, some important
progress has been made on larval culture of different species, mostly in Japan, Australia and
New Zealand. However, rearing larva is still very difficult even at experimental scale for most
species preventing the development of lobster aquaculture in a conventional way, at least in
the nearest future. Culture of P. argus throughout all larval stage was recently accomplished
in Florida but survivals to low.
Given that to date there is no technology for providing sufficient spiny lobster seed from
hatcheries, commercial interest is now focused on the growout of wild caught post-larvae to
market size. This phenomenon is not surprising since many costal aquaculture productions
still rely on wild-caught seed due to the lack of propagation techniques or because the scale of
wild collection often is too superior to hatchery production (see Hair et al., 2002). Although
land-based systems, whatever flow-through or recirculated, have been successfully used to
hold spiny lobsters, less capital intensive sea cages or sea enclosures have proven to be more
profitable specially in tropical areas with high sea temperature all year round. Tropical
lobsters (e.g. Panulirus ornatus in SE Asia and Panulirus argus in the Caribbean) have
shown the highest potential for aquaculture due to high growth rates (Jeffs and Davis, 2003).
At present, the commercial growout of tropical spiny lobsters in Vietnam with fresh food
have shown to be profitable (Thuy, 2004), supporting now 100 US millions/year industry.
However, there is evidence of detrimental effects on coastal environments thus proving to be
an unsustainable venture based on current practices. This is partially due to management
strategies that skip the many lacks in knowledge about nutritional and culture requirements of
tropical lobsters. The diminishing supply and increasing cost of by-catch are also of concern.
Combining fresh and shrimp pellet have produced encouraged results for some species and
could be a short-term strategy to mitigate pollution by the partial replacement of fresh food.
The development of cost-effective pellets as an environmentally more sustainable
alternative to fresh food has been recognised as the main obstacle for sustainability. Despite
impressive advances during the last decade have been obtained (see Williams, 2006, 2007, for
reviews), information on the nutritional requirements for spiny lobsters is still insufficient.
Unfortunatelly, little information is available on digestibility of feed ingredients and results,
in some cases, are contradictories (e. g. squid meal). Temperate lobsters historically have
received more research attention and results are not always pertinent for tropical species.
Intense research is now ongoing in Australia to improve feed technology for tropical P.
ornatus. Studies in Florida and the Caribbean are providing information on culture
requirements for P. argus at different scales including diet development. We have
demonstrated that gastropod, pelecypoda and crustacean provide the most efficient use of
dietary proteins (Díaz-Iglesias et al., 2002). None of these items are, however, available in the
amounts needed for sustaining large scale growout of P. argus. Preliminary studies based on
local fish meal dry pellets did not yield satisfactory growth, but we further obtained
encouraging results when partially replace local fish meal by squid meal or high quality fish
meal (Perera et al. 2005). Digestive enzymes of P. argus are also under investigation in our
In addition, pellets tested are much less attractive for P. argus than fresh food (Perera and
Díaz-Iglesias, 2004) and similar results have been regularly obtained for other lobsters. The
tropical P. argus has been an organism of choice in several neurobiological studies of the
chemical sense and as a result, much is known about the sensory basis of their feeding
behaviour (see Derby et al., 2001). The use of this information to increase feed intake is an
exciting area for research in terms of both increase growth rates and reduce pollution but very
little has been really done to date. A study on P. ornatus has suggested that including protein
hydrolysates and free amino acid-rich ingredients in diet might prolong the attractiveness of
pelleted feeds (Williams et al., 2005).
Once nutritional inconveniences are overcome for particular specie, further expansion of
lobster aquaculture is being limited only by the availability of wild seed. The case of P. argus
appears complex since it has among spiny lobsters the widest distribution range from North
Carolina to Brazil as well as the Caribbean (Lellis, 1991). In Florida and the Caribbean (e.g.
Cuba, Antigua, Puerto Rico, Jamaica, Mexico) high amount of post-larvae can be easily
collected, but it is unlikely that this can be done in all areas throughout the distribution range
of the specie. The impact of post-larvae removals on the subsequent catch was estimated to be
slight in Australia (Phillips et al., 2003) but such an assessment is yet to be produced for P.
argus. There is a great amount of knowledge about P. argus ecology including natural
mortality rates, so I guess this information is coming soon.
Recruitment process is complex and number of post-larvae collected will often very
markedly even at the same location. Therefore, it should be evaluated before any project
comprising the removal of recruited post-larvae started. This is of a particular importance for
countries where a sustained reduction in catches has been observed in last years due to either
environmental factors or overexploitation. Insufficient seed supply could cause this activity to
Although restricted gene flow among P. argus populations it was suggested in
preliminary studies using protein isozyme electrophoresis (Menzies, 1980), more recent
studies based on mitochondrial DNA support the hypothesis that P. argus is genetically
homogeneous throughout the Caribbean (Silberman et al., 1994) but distinct to Brazilian
population (Sarver et al., 1998). To my knowledge, there are current attempts to differentiate
P. argus populations with more variable genetic markers but due to the extended larval stage
and complex oceanic currents, I do not think the scenario will change at least for the
Caribbean. Although definite studies are necessary, it seems that post-larvae could be moved
out from the place of capture to pay off the shortest of seed in related areas. This is now of a
minor importance given the scale of present industry but could be relevant in the future.
Two strategies have been proposed for sustainability in post-larvae lobster collection.
One is the release into the wild of a percent of artificially grown lobsters for stock
enhancement. The other one is the retirement of units of fishery quota to compensate for the
removal of post-larvae. The reseeding option would be better for the Caribbean, since avoids
the impact on fisherman incomes, especially in low productive areas. Different to clawed
lobsters, restocking of spiny lobsters have received little attention. Recent results on survival
of released Jasus edwardsii are encouraging for the potential of enhancement of wild
populations (Mills et al., 2005).
Diseases are not common in wild lobsters and molt death syndrome due to poor nutrition
was found to be the major health problem of captive lobsters since early studies. Today,
nevertheless, unsuitable culture conditions have lead to massive mortalities in Vietnam
probably due to fungal or bacterial infections. A recently identified virus (Shields and
Behringer 2004) also cause massive mortalities in cultured P. argus (Staine and Dahlgren,
2005). Research in Florida has demonstrated that the effect of this virus can be nearly
eliminated by ultraviolet irradiation of sea water but it is obvious that this treatment can not
be used to protect sea caged lobsters from infection. We know virtually nothing about the
immune system of spiny lobsters. Our group is now providing basic information on P. argus
immune system (Perdomo-Morales et al., 2007, 2008) and studies go on towards the
understanding of main defence mechanisms. The impact of environmental conditions on
lobster immunity remains almost unexplored and such knowledge would be pertinent in the
future if lobster aquaculture continue to expand.
It is noteworthy that most countries where P. argus aquaculture could be developed in a
near future belong to the so called developing countries, where very few can afford lobster for
dinner. This type of aquaculture has demonstrated to increase economic opportunities of
costal communities in Asian countries (Hambrey et al., 2001) as it is ideal for subsistence
farming. Moreover, collection and sale of post-larvae to growout enterprises can provide
income for sectors of the population otherwise excluded from aquaculture operations (Hair et
al., 2002). Looking into the future, I think that encouraging independent small-scale
aquaculturist in the Caribbean, rather than large enterprises, to spiny lobster growout, could
ensure costal communities to obtain the benefits of this new aquaculture venture. In any case,
scaling-up to more intensive forms of production based on fresh feeding and uncontrolled
removal of post-larvae can lead to deleterious effects on both environment and society.
Herein, I have provided a brief overview of recent trends and research on spiny lobster
aquaculture with emphasis in tropical P. argus. Despite most of the above exposed is my
personal view, everybody most agree that there are still many constrains to a sustainable
industry and that many questions need to be answered so far. Studies are in progress and
results under way.