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Farming the world’s largest fish – an alternative to deforestation

Farming the world’s largest freshwater fish – an alternative to deforestation

Farming the world’s largest freshwater fish – an alternative to deforestation
Declining fisheries force Amazonians into fish farming
May 19, 2005

The Arapaima (Arapaima gigas), also known as the Pirarucú or Paiche, is the world’s largest freshwater fish. It can reach lengths of up to 14.75 feet (4.5 m) and weigh up to 440 lbs (200 kg). Because of it’s size and tastey meat — the Arapaima has a mild sweet flavor — the Arapaima is one of the most sought after fish species in the Amazon. Today it is rare to find large Arapaima. At 1.3 meters (4 feet), the average length of individuals havested from the wild is below the average length of sexual mature fish (1.5 meters – 5 feet).

Today Arapaima are increasingly raised on fish-farms as part of integrated conservation and development projects or stand alone commerical operations. According to Dr. Marco Lima of the INPA Amazon Research Institute Manaus, about 15% of the 50-60 tons of Pirarucú consumed monthly in the Brazilian Amazon city of Manaus comes from local fish farms.

“These farms offer fresh fish at lower prices,” says Dr. Lima. “One kilo costs around $5.”

The Arapaima offers a number of characteristics that make it a valuable species for integrated aquaculture. According to the National Fisheries Institute of the Amazon, the Arapaima:
  1. does well in fish ponds
  2. is resistant to diseases
  3. survives under low oxygen conditions with its ability to breathe atmospheric oxygen
  4. gains 10 kilograms in weight per year
  5. eats foods of low commercial value
  6. high demand and commercial value
  7. yields value added by-products (scales, head, tounge and skin)
  8. offers potential for international commercialization
  9. has potential to be used in sport fishing and the ornamental aquarium/pet trade

The Arapaima is just one of several species that, through fish-farming, can provide protein and economic opportunities for rural poor in the Amazon region. While fish-farming, or aquaculture, has long been practiced in the region, many colonists and recent settlers in the Amazon fail to take advantage of its potential. Recent observations in northeast Bolivia suggest that native forest dwellers developed extensive systems for managing fish populations through small artificial ponds and fish weirs, fences made of wood, woven material, or stones used to trap migrating fish.

Increasingly, development organizations are encouraging aquaculture as a means for local people to earn a living while minimizing their impact on the Amazon ecosystem. Unlike subsistence agriculture and cattle grazing which require forest clearing and usually generate little revenue for poor farmers, aquaculture offers a sustainable income with low start up costs. And, by using native species, there is no risk of introducing non-native fish species into local river systems while helping to maintain native Amazonian fish populations. Further, there is a reduced need for farmers to clear additional rainforest for farming purposes.

The Arapaima.

Integrated aquaculture — a form of aquaculture in which food for fish ponds comes from other agricultural activities on the same farm and in which the pond’s output is used on the same farm as well (for example, as fertilizer) — minimize operating costs for local fish farmers. Thus waste from pigs and chickens can be used to support plankton populations which, along with naturally occurring insects and plant matter, provide sustenance to fish.

The annual yield from such techniques can be quite high. Studies show that a single hectare (2.5 acres) pond can generate 500-600 kg (11,000 to 13,000 pounds) of fish per year. The ongoing nature of aquaculture means that fish farmers can count on this food and income source year round — a critical feature in an environment where natural fish populations become widely dispersed during the high water season.

Integrated aquaculture offers great potential for sustainable poverty allievation in the Amazon region. It reduces the need to clear land for subsistence agriculture while generating significant economic and nutritional benefits for poor Amazonian colonists. As such, fish like the giant Pirarucú may be the best hope for the Amazon’s settlers and its rain forests.