Many developing countries are lacking protein in the diets of their population. Aquatic systems are good sources of protein in many areas with fish and shellfish as the main sources. The misuse of agrochemicals can directly or indirectly affect the use and suitability of these protein sources as food. Problems are found in three main areas: eutrophication which changes species production, direct toxicity to aquatic species and bioconcentration of various materials to excessive amounts. The best solution is judicious purchase and use of agrochemicals. Lacking this, testing is necessary to predict and prevent problems and several methods will be enumerated. Particular emphasis will be placed on testing facilities and personnel. A substantial bibliography will be included.