History proves that seafood — either a lack thereof or overabundance — has affected global politics, influenced world exploration, caused territorial disputes and led to international agreements. Battles have been fought to gain or stop access to supplies of cod, herring, salmon, sharks, whales and even oysters, and trade disputes are ongoing today.
What we may not expect in “civilized” times is organized poaching gangs and smuggling rings over a glorified limpet — the abalone. Over the past 10 years there have been shootouts and deaths in South Africa attributed to turf battles for wild abalone, and stiff prison sentences dished out to poachers and smugglers in Australia and New Zealand. In the Channel Islands (English Channel) in 2005, a policeman in full diving gear made the world’s first recorded underwater arrest of an abalone poacher.
But why so much fuss over a primitive gastropod mollusk? The answer is that abalone is one of the world’s most highly prized, highly priced gourmet delicacies, particularly popular in the Japanese market.
Known variously as ormer, paua and perlemoen, abalone belong to the genus Haliotis, and more than 100 different species exist. Their shells have a pearlescent, nacreous lining in demand for jewelry and ornaments. Slow to move, slow to grow and easy to collect, they suffer from over-exploitation and, sometimes, complete destruction of populations.
According to Food and Agriculture Organization figures, in 2009 the global catch of wild abalone totaled around 9,000 tons, down from a peak of 18,000 tons in the mid-1980s. However, it is acknowledged that illegal, unregulated and unrecorded landings are a major problem, making it impossible to gauge the real figure. More than half of the world’s reported wild landings come from Australia, while New Zealand, Mexico and Japan provide the bulk of the remainder.
Cultivation of abalone takes place in South Africa, Australia, the United States, Chile, Namibia, Korea and most notably China, where production has risen from around 1,000 tons to 42,000 tons in the past 10 years. Abalone cultivation is in its early stages in France, Spain, Ireland and the United Kingdom, and the quantities produced will not make a noticeable impact on world markets in the short term. However, expectations are high.
A number of European partners recently gained funding for a project that will tackle the technical, scientific and financial hurdles to successful production. It will also look at whether the formation of a producer’s organization would help to ensure that the European industry remained market-driven, not production-led, avoiding the boom-and-bust cycle seen in other aquaculture sectors.
Abalone are grown in high-tech onshore recirculation systems and in offshore farms using seabed cages or longline barrels. One of the major hurdles to production is feeding, which must mimic the natural process. In the wild, juveniles graze on algal turf growing on sub-tidal rocks. As they grow larger, they trap and eat broken fronds carried on the current.
Seaweed is gathered or grown to feed the animals, but they are fussy eaters, and with conversion ratios as high as 10:1, it can be a lengthy and laborious business. Artificial feeds have been developed, but are a long way from being perfected.
Integrated multi-trophic aquaculture systems may provide the answer for abalone aquaculture in the future. High-tech pump-ashore finfish recirculation systems may remove excess nutrients with macro algae, and research has shown that seaweed grown in this way has elevated protein levels. Fed to abalone, it would in turn lead to enhanced growth rates.
Abalone may also add value to extensive integrated systems that cultivate seaweed and bivalve filter feeders around offshore fish cages to mop up waste nutrients. Such a system could grow species of seaweed preferred by local abalone, thus negating the need to harvest it from the wild.
Whichever way the abalone industry develops in Europe, it is unlikely to become a candidate for feeding the masses. It could, however, become a significant, financially valuable sector, with benefits all round.
