Science

Feeding fishes right

FOR Filipinos fish and fishery products are the primary source of protein. Rightly so because the Philippines with its vast and rich fishery resources- over 2,000 fish specie, 17,460 km of coastline, 288,000 sq. km of coastal waters, 2.3 million sq. km. marine waters in the exclusive economic zone – ranked 6th among top fishery producing countries in the world, and ranked 9th in aquaculture production in 2008.

The fishery sector plays a major role in building the economy of the country: it helps ensure food security, generates jobs and employment, and contributes to the growth of the country’s gross domestic product. In 2009, the fishing industry contributed 4.4% at constant prices to Philippine GDP. In the same year, aquaculture contributed 48,22% to the country’s fishery production.

However, even if it enjoys the status of being the biggest contributor to the fishery sector, the aquaculture industry has suffered some setbacks from natural and man-made causes. Example is the Taal Lake which has already experienced several fish kill occurrences. A 2006 study of environment scientist Dr. Macrina Zafaralla found that the water condition of the lake has transformed from “a mesotrophic to oligotrophic state to eutrophic state” due to nutrient loading from fish feeding in fish cages and fish pens. Similarly, a report of the Bureau of Fisheries and Aquatic Resources said that in one rearing period, a total of 2,500 metric tons of feeds valued at P40M were uneaten. representing 50% of the total volume of feeds per day per cage. These were deposited at the bottom of the lake, but when there is upwelling, the uneaten feeds are brought up to the surface, emitting toxic substances which eventually cause fish kill.

In 2010, the worsening condition of Taal Lake called the attention of no less than the Representative of the Science and Technology Sector in the 15th Congress, Cong. Angelo B. Palmones, who delivered privilege speeches and filed resolutions to address this concern. His move led to the clean-up and the formulation of a three year rehabilitation plan to save the lake with support from both national and local agencies of government.

Earlier however, the country’s researchers have been studying how to help solve water pollution. One of these is an efficient fish feeding management, which is considered critical to avoid polluting aquaculture water environment, and save several thousands of pesos due to wasted feeds. Fortunately, there is such a device, called Kinetic Feeder (KF): A Breakthrough in Fish Feeding Management, developed by Engr. Philip S. Cruz of Bacolod City since late 90’s. This R & D project is one of the early awardees of then Regional and National S & T Fora and Competitions in Industry and Energy Research conducted by then Philippine Council for Industry and Energy Research and Development (PCIERD).

Engr. Cruz said in his paper said that eutrophication of the environment threatens sustainability of several fish farming centers such as Sampaloc Lake, Lake Sebu and Pansipit River because of poor feeding management. Eutrophication happens when a body of water gets excess nutrients that promote excessive plant growth which affects healthy balance of the water. At the time of his study, fish feeding practices include hand feeding which is labor intensive and not cost effective. Another is feeding tray and feeding ring which has long exposure time of feeds in the water resulting in wastage and pollution because of “physical disintegration and nutrient leaching”. Then there are electric feeders but have very limited application in the country’s fishing industry.

Thus the Kinetic Feeder, which aims to provide an alternative feeding method that addresses the problems and limitations of existing feeding practices, is a patented “demand feeding” device. Engr. Cruz said the demand feeding technology has long been used in western countries, but “no such valuable feeding device has been developed for the local aquaculture industry”.

The KF generally employs a basic feeding design being used by other countries which consists of a hopper, an actuator rod, a valve, and a valve adjusting mechanism. Engr. Cruz gradually improved the feeding design until he found the most efficient design for feeding fish. With the Kinetic Feeder, uniform sizes of fish harvests can be ensured, avoid water pollution due to feeds wasted and provide greater income for fish farmers.

For more information on the Kinetic Feeder, Engr. Philip Cruz can be reached at the Kinetic Feeding Systems Incorporation, 158-C Sincang, Bacolod City with telephone # (034) 4350021 to 23 or thru his email cruzcorp@mozcom.com. (PSciJourn/Vicky B. Bartilet)

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