February 15-18, 2009 Washington State Convention Center Seattle ...

EVALUATING POND AQUACULTURE EFFLUENTS THROUGH BIOLOGICAL
ASSESSMENT OF FISH AND BENTHIC MACROINVERTEBRATE ASSEMBLAGES IN
RECEIVING STREAMS
Emmanuel A. Frimpong* and Steve Amisah
Department of Fisheries and Wildlife Sciences (0321)
Virginia Polytechnic Institute and State University
156 Cheatham Hall
Blacksburg, VA 24061 USA
frimp@vt.edu
Aquaculture is a promising alternative to capture fisheries, especially in developing countries where most capture fisheries are
already over-exploited and the value of small streams and headwaters as prime protection for large, downstream productive
rivers is often threatened by unsustainable agricultural practices. Some of the most intimate relationships between farmers and
streams are found in the use of streams as a source of clean water for filling earthen ponds and as conduits of effluents from
ponds. As a supporting system for pond aquaculture, streams are vital to the sustainability of aquaculture industries, but are also
directly threatened by harmful effluents in the absence of best management practices.
Developing countries need to develop inexpensive methods for monitoring pond effluent impacts on receiving waters and adopt
management practices that maintain the quality of streams to support aquaculture development. This study gives an overview
of ongoing research work in Ghana in partnership with Virginia Polytechnic Institute and State University and the Aquaculture
and Fisheries Collaborative Research Support Project to develop ecologically-based effluent monitoring protocols for aquaculture.
A vital first step in the development of a biological monitoring protocol is standardization of sampling techniques to collect
representative samples of biota. While standardized stream fish and macroinvertebrate sampling is now routinely done is temperate
and developed regions (for example, in the United States), tropical streams present unique sampling challenges for biological
assessment and little is known about the best way to collect representative samples of tropical stream biota. We present
preliminary results of the performance of different configurations of seining and kick-sampling and benthic cores as standard
methods for fish and macroinvertebrate sampling, respectively, in tropical streams. Methods for developing assessment metrics
based on the two types of biological assemblages will also be discussed. Biological assessment and best management practices
provide a viable, low-cost balance to the growth of aquaculture in developing countries.
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