Wood and fish residuals composting in Alaska
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Biocycle. (Apr. 2002): pages 32-34
The unique climates and industrial mix in southeast and south central Alaska are challenges being met by the region's organics recyclers. OMPOSTING wood residuals in Alaska has become increasingly important in recent years as wood processors and other industrial waste managers search for environmentally sound and profitable outlets. Traditionally, Alaska?s sawmills have had dependable markets?supplying area pulp mills with high quality chips. However, the recent closure of two major pulp facilities in southeast Alaska has greatly reduced demand for the region?s wood residuals. Further north, the Kenai Peninsula of Alaska has experienced a recent spruce bark beetle epidemic?leaving large volumes of standing dead timber. Meanwhile, the Alaskan fisheries industry also could benefit from environmentally sound methods of managing processing wastes, while creating useful by-products. Research in the area of wood and fish composting often has focused on the need for reduction of fish residuals, with wood being used primarily as a bulking agent. While typical sawmill facilities in Alaska generate close to one-half of their incoming timber volume as waste materials, fish processing wastes tend to be even more abundant. It is estimated that fish residues can account for 30 to 85 percent of the total harvest for finfish, crab and shrimp. Since there are limited uses for unamended fish residuals (especially for land application), wood residuals can be used as bulking agents to improve pile porosity and facilitate decomposition. Other benefits of composting with wood include moisture absorbency, odor filtration and desirable thermal properties. Optimal ratios of wood to fish can vary considerably, depending on the specific application. For example, ratios of about one part fish residuals to three parts wood residuals by volume, or three parts fish residuals to one part wood residuals by weight are often used for desirable carbon:nitrogen (C:N) properties. Ideally, wood residuals should include a mixture of chips and sawdust for aerabon and carbon availability. The use of aged wood is generally not a negative factor when cornposting with fish residuals, which decompose much more quickly than wood.
KeywordsFishery products; fishery by-products; fish-scrap fertilizer; wood waste utilization; compost
Nicholls, David; Richard, Thomas; Micales, Jesse A. 2002. Wood and fish residuals composting in Alaska. Biocycle. (Apr. 2002): pages 32-34