Passport


(June 19, 1997, Gazette)

Improving shrimp culture in Brazil

By Alberto Campos
After spending my first Newfoundland winter attending classes at the Marine Institute and the Ocean Sciences Centre, I went back to my home country of Brazil in April to proceed with the fieldwork involved in my research.

There, having left the snow behind, I found myself surrounded by piles of salt -- my work was conducted in one of the largest salt producing areas in the world, the northeastern Brazilian coast and its estuaries. The principle of marine salt production, although a fairly mechanized process during harvest and processing (washing, drying, pulverizing), is still the same as it was centuries ago: salt water is basically trapped in ponds or "pans" and is left to evaporate until the salts precipitate to the bottom.

In this salt-producing region of Brazil there is a large area of abandoned salt ponds (estimated at about 2,000 hectares), mainly small units close to local communities which can't afford mechanization, and thus competition with the larger operations. My research involves the utilization of these existing ponds to harvest a much more valuable product: the brine shrimp.

Brine shrimp of the genus Artemia are tiny crustaceans (about one centimetre in length) which occur naturally in hypersaline environments like coastal lagoons, inland salt lakes and saltworks. Because they are much appreciated by fish and other predators, brine shrimp are the most widely used live food animal in finfish and shrimp aquaculture worldwide. Their small size when newly hatched (less than half a millimetre) makes them a good prey size for larval and juvenile cultured species. Their nutritional deficiencies can be easily supplemented by enrichment with prepared emulsions, taking advantage of their non-selective filtering behavior, which means they are continuously and indiscriminately filtering the water column. They produce resistant eggs, or cysts, that can be stored dried for more than a year, making them a convenient (and inexpensive) off-the-shelf produce for fish and shrimp larvicultures.

If you remember the brownish powder that was advertised a few years ago as "Sea Monkeys" -- which would magically produce a myriad of frantically swimming little things when left overnight in a container with water and salt -- then you'd know what cysts and baby brine shrimp look like.

As part of a Canadian International Development Agency (CIDA) funded linkage between Memorial University and the Federal University of Ceará in Brazil -- implemented via Memorial's Canadian Centre for International Fisheries Training and Development -- I spent the dry season in Brazil looking for alternative feeds, mainly residues and/or byproducts of local industries, and testing low tech semi-intensive methods to turn abandoned saltworks into brine shrimp farms. The results -- which were very favorable and which are now being written into my thesis -- should provide valuable background information to the extension and training programs that will be put in practice by other CIDA projects planned for the area.

As five kilos of brine shrimp are worth as much as one ton of salt, local communities were excited about the possibility for making better use of their land and increasing their income. They recognize aquaculture as weapon against the rural exodus that afflicts the region. Dr. Steve Goddard of the Marine Institute's Aquaculture Unit has been actively involved in shrimp aquaculture activities in Brazil, which provided a basis for my research.

Alberto Campos is an M.Sc. student in aquaculture supported by a CIDA Marine Science Scholarship.