Keeeping it sustainable and profitable






 In many places an environmental cost from past introductions of tilapia has already been paid. How best can Pacific Islands obtain the expected social benefits?
  This emerged as the main theme of a regional meeting hosted by the Secretariat of the Pacific Community (SPC) in Noumea, New Caledonia, in December.
  On the one hand, farming of tilapia is one of the readiest available responses to regional food security concerns. On the other hand, tilapia is an introduced species that raises concerns about impacts on indigenous freshwater fish biodiversity.  
  The Pacific Islands will face an increasing shortfall in availability of fish for domestic consumption. SPC analyses show that an additional 100,000 tonnes of fish will be needed by 2030 if present dietary levels are to be maintained.
  Even assuming good management and no impacts on coral reefs by climate change, the region’s coastal fisheries will not be able to supply the fish needed.
  Two main options exist—allocating more of the region’s tuna catch to domestic food security needs and developing small-pond aquaculture. 
 
  Tilapia—an obvious choice
  Small-scale fish farming requires a fish that is simple to breed and simple to feed. There are no obvious candidates among the indigenous freshwater fishes in this region. To research local possibilities could take several years.
  Tilapia is an introduced fish already present in much of the region since the 1950s and 1960s. It is one of just a handful of species available worldwide that meets all the requirements for successful low-cost farming—it is hardy, easy to breed and grow, and versatile in what it can eat, and no high technology is needed to farm it.
  Tilapia is a fish now so domesticated for farming in Asia and the Americas that it has been dubbed the ‘aquatic chicken’.
  Internationally, farmed tilapia has entered the mainstream. US Tilapia Association past-president Professor Kevin Fitzsimmons says tilapia has become one of the top five of seafoods sold in the USA, overtaking salmon for the first time during 2009 and expected to be worth US$5 billion in 2010.
  Secretary-General of the Network of Aquaculture Centres in Asia and the Pacific (NACA), Professor Sena De Silva states: “If we ask whether this introduced alien species in Asia is a “friend” or a “foe”, the answer is overwhelmingly that tilapia is now a “friend” to millions of our people”. 
  Farming tilapia for food security is not a new idea in the Pacific. Fiji Islands and Papua New Guinea (PNG) both have long-standing policies of government support for tilapia farming in rural areas.
  PNG’s representative at the meeting, Peter Minimulu (National Fisheries Authority), reported that roughly 20,000 household-scale tilapia farms now exist, making PNG the Pacific region’s leader in tilapia farming.
  Government support, aimed at helping ‘the poorest of the poor’ in isolated rural areas, is usually needed to keep projects going.
  But now, medium-scale enterprises are emerging, with economies of scale to support infrastructure like fish hatcheries or feed mills. The smaller-scale operators can also access these services. Most importantly, jobs are created on the farms themselves and in supporting industries. Vanuatu can boast one such medium-scale enterprise.
  Vate Ocean Gardens, operated by Paul Ryan in Lake Manuro on Efate, uses floating cages to culture an attractive red variety of hybrid tilapia.
  “It’s a nice little business,” says Ryan, whose regular harvests usually sell out in Port Vila within two hours.
 
  The Pacific got
  the ‘wrong’ tilapia
  Mozambique tilapia, introduced to this region in the 1950s and 1960s, is genetically a poor variety and not very farmable. Ninety percent of the tilapia farmed globally nowadays is Nile tilapia.
  “To make it even worse,” stated geneticist Professor Peter Mather of Queensland University of Technology, “the particular Mozambique tilapia distributed throughout the Pacific came from less than a dozen fish; these are so lacking in genetic variation that improvement by selective breeding will be almost impossible.”
  For Nile tilapia, improved varieties are now available, domesticated for pond conditions. Some countries like Fiji Islands and PNG are already farming these. Other countries in the region that want their own successful tilapia farms should ignore the feral Mozambique tilapia already present in their rivers and instead use a domesticated variety of Nile tilapia.
 
  Managing environmental
  risks of tilapia   
  Dr Aaron Jenkins of Wetlands International includes feral tilapia among several threats to indigenous river fish biodiversity, of which deforestation along riverbanks and clear waters turning muddy are chief offenders.
  “In Fijian streams, we’ve found that presence of tilapia along with deforestation is associated with the absence of as many as 10 of the indigenous fish species.”
  They are more vulnerable to these multiple threats than fishes of Australia or Asia, he says, because more have young that spend time in the ocean—thus they cross several habitats during their lives.
  De Silva commented on Asia’s experience that tilapia do not easily invade pristine clear-running forested streams, but prefer slower-moving muddy rivers in open sun-lit countryside.
  “If deforestation occurs, tilapia will move in. They can often be found at the scene of the crime, but are not necessarily the criminal.”
  Jenkins counters that the unusually high level of connectivity between Pacific river habitats demands that ecosystem-based approaches be used.
  “It’s increasingly important to protect the invasive-free status of those river catchments that are still pristine.”