Location: Warmwater Aquaculture Research Unit
Title: DISPOSAL OF SMALL-SCALE FISH PROCESSING WASTE THROUGH COMPOSTING Author
Submitted to: Aquaculture
Publication Type: Abstract Only
Publication Acceptance Date: August 2, 2005
Publication Date: February 13, 2006
Citation: Torrans, E.L. 2006. DISPOSAL OF SMALL-SCALE FISH PROCESSING WASTE THROUGH COMPOSTING [Abstract]. In: Book of Abstracts. Aquaculture America, February 13-16, 2006, Las Vegas, Nevada. p. 330. Technical Abstract: Large catfish processors in the U.S. typically recycle fish waste into fish meal. For small-scale processors or aquaculture research facilities, fish waste disposal can be problematic. We adapted a design developed for composting wastes from Minnesota fishing lodges and tested it for suitability for catfish waste disposal from our research ponds and processing facility. The composter was 60 in tall, 5 ft wide (I.D.) and 15 ft long. It was constructed from 2 in X 6 in and 4 in X 4 in treated pine. The 4 in X 4 in X 8 ft posts were buried 3 ft in the ground; the 2 in X 6 in boards were attached to the inside with #8 X 3 in screws, leaving a gap for aeration between boards. Six pieces of 4 in dia. perforated drain field pipe were spaced across the bottom to increase aeration. Total materials cost was $443.00. The unit was filled with gravel to the bottom of the pipe for drainage and support, and then a layer of wood chips was added to cover the pipes. The unit was divided into three sections with 1 in poultry netting, and filled one section at a time with alternating 6 in layers of fish and sawdust. A 6 in band of wood chips was added around the periphery as the unit was filled. The wood chips were obtained from the Mississippi State Highway Department and the sawdust from a local wood pallet manufacturer, all free of charge. A total of 6951 lbs of fish and fish waste were available for the trial. It was estimated that the total capacity of the unit is approximately 10,000 lbs. An internal temperature of 140-150 F was achieved. The unit did not create an odor problem. Two or more units should be constructed (depending on waste volume generated), allowing filled unit(s) to compost while the next unit is being filled. For large scale use, internal width should allow for loading and removal of material with a front-end loader. While the permanent wood unit tested was attractive, a two-bin portable structure made from five cattle catch-pen panels would be cheaper.