Duckweeds as feed supplement for fish pushed

In a bid to address the global economic crisis, fishery officials in the Cagayan Valley region have introduced cost-reduction and productivity enhancement technologies.

Recognizing how fish farmers are burdened by high- input costs, particularly feeds, the Bureau of Fisheries and Aquatic Resources (BFAR) has included in its plans for 2009, the widespread promotion of duckweeds as supplemental feed for tilapia, bangus, pangasius and carp.

Duckweeds are small flowering plants with a reported crude protein content of 18 percent to 42 percent.

An earlier study made at the bureau's fish farm in Iguig, Cagayan has determined the viability of this rapidly reproducing plant as alternative diet without adverse effect on the growth of tilapia.

The study has determined an optimum feeding mixture of 50-percent fresh duckweeds and 50-percent commercial feeds. The combination achieved higher growth rate compared to fish fed with commercial feeds.

A 1,000-square-meter, semi-intensive fishpond using the duckweed feed combination easily cut farm expenses by more than P10, 000 or more than 20 bags in the 4-month to 5-month culture cycle. More than P100,000 can be cut on expenses of a hectare of fishpond.

"Considering that costs of commercial feeds have risen by less than 10 percent to 25 percent based on 2008 figures, while retail price of tilapia had remained constant, the 50-percent savings will certainly mean a lot. Duckweeds will also help us address dependence on imported corn as raw material for feeds, which is currently around 90 percent of total national requirement," Fisheries and Aquatic Resources regional director Jovita Ayson said. 

As agreed during a two-day planning workshop with local government leaders early this month in Aparri, Cagayan, the bureau has earmarked funds to establish 10 duckweed-demo sites for the region.

Other aquaculture technologies to be promoted are the polyculture and pangasius culture, she added.

Polyculture is the scientific process of raising two or more noncompeting fish species in single or common culture. It can potentially raise farmer's income through the optimum use of inputs and culture area, she said.

Polyculture projects involving the combination of ulang (Macrobrachium rosenbergii) and tilapia, carp and tilapia, and common carp and African catfish, have achieved from 58 percent to 98 percent in additional net income compared to pure semi-intensive tilapia farming.

In pangasius culture, the fast-growing and hardy fish pangasius is the feasible specie in fishpond, fish cage and organic-culture systems under the region's weather conditions.

To address the inadequate supply of fingerlings, a hatchery will be established in the fishery station in San Mateo town in Isabela.

The bureau and the Office of Provincial Agriculturist in Cagayan also proposed to the Department of Agriculture the construction of a pangasius hatchery at the agriculture facility in Bantay, Camalaniugan, Cagayan.

Other aquaculture technologies to be introduced are urban, upland and mangrove aquaculture and 45-day delayed feeding technology. The agency will also introduce a culture of high- value species such as abalone, sea urchin and mud crab.

To support its flagship fingerling production and dispersal program, Ayson bared the rationalization of six BFAR fish farms in the region to maximize area use and enhance fingerling production.

The agency has targeted to produce 12.29 million fingerlings and a million oyster spats this year as measures to increase dispersal to local government units and fish farmers in the region.

Meanwhile, the fisheries bureau will distribute environment friendly fishing gears such as fish trap, troll line, long line and gill nets in addition to the implementation of regulatory activities. The bureau will also continue the widespread distribution and installation of fish aggregating devices or payao, she said.

Ayson said the interventions will help address the ongoing economic crisis and enable the region to produce 66,400 metric tons of fish this year or 7 percent more than last year.

Fisher production in Cagayan Valley stands at 62,057.96 metric tons, which corresponds to a 56.49-percent fish sufficiency level.