aquaculture

I was trying to verify the USA tilapia importation figures as quoted in an earlier posting. In the Electronic Outlook Report from the Economic Research Service (Aquaculture Outlook), I discovered:

U.S. tilapia imports surged to over 297 million pounds in 2005, up 19 percent from 2004 and 233 percent higher than in 2000. The value of tilapia imports rose even faster, climbing to $393 million in 2005, 32 percent higher than the previous year and 288 percent higher than in 2000.

One short ton = 2,000 pounds, therefore 297 million pounds = 148,500 short tons; according to Google.

If you are considering exporting aquacultural and related products to the USA, this report represents critical business information. You can subscribe to the Aquaculture Outlook (for free). Outlook examines the U.S. aquaculture industry, including production, inventory, sales, prices, inputs, and trade of catfish, trout, tilapia, salmon, mollusks, crawfish, shrimp, ornamental fish and new species.

Richard Bailey and Brian Cole (Aquaculture Extension Agents, Sea Grant Extension Service, School of Ocean and Earth Science and Technology, University of Hawaii) have published a report documenting techniques for spawning the tinfoil barb. The report is available as a free download (.pdf) from the Center for Tropical and Subtropical Aquaculture. It is entitled: CTSA #136. Bailey, R. and B. Cole. 1999. Spawning the Tinfoil Barb, Barbodes schwanenfeldi, in Hawaii. 8 pp.

From the report:

The tinfoil barb, Barbodes schwanenfeldi, is a common fish found in the international aquarium trade and food markets in Southeast Asia. Tinfoil barbs are a peaceful fish that can reach a length greater than 40 centimeters or 16 inches, and like other, larger barbs, can often live more than 10 years in captivity. In nature, tinfoil barbs are primarily macrophages; that is, they feed on vascular aquatic plants. However, they will eat most commercially prepared diets consisting of vegetable and fish meal proteins.

Mat Couchman’s honours project for his degree from the University of Plymouth was an investigation into the feeding interactions among crucian and common carp species within a small reservoir within the university grounds.

The full manuscript (10,000 words) is available from Mat by e-mail request.

Abstract:

The food choice of crucian carp (Carassius carassius) in Drakes reservoir and the influences upon on this by the aquatic environment were investigated.

Thirty-five fish stomachs were observed and it was found that the feeding preference of the crucians revolved around chironomid larvae (Chironomus), small bodied pelagic cladocera (C. ovalis), benthic cladocera (A. affinis) and one species of ostracoda (Cypridopsis). The chironomid larvae and benthic cladocera became more important as the fish increased in length. Rotifers and phytoplankton were not an important part of the diet; Arcella were utilised, but in unknown proportions.

It is suggested that heavy macrophyte growth was the main organism responsible for many interactions and influences upon the fishes’ diet and species diversity in the reservoir.

This population of crucian carp is omnivorous, relying upon more benthic organisms as they increase in length. Stunted growth suggests that intraspecific competition is prevalent in the reservoir. Interspecific competition with common carp (Cyprinus carpio) is suggested. It is believed the crucian carp have reverted to a more cladoceran-based diet to combat this competition with the common carp; this indicates a predominately benthic niche overlap between species.