Research Product

The decision to monitor an estuary for pesticides may derive from any one or several specific needs. These needs or objectives will largely determine the character and modus operandi of the program. Obviously, two pesticide monitoring programs in the same estuary might be entirely different because of the kinds of information sought. Estuarine monitoring objectives may be for the purpose of determining: 1. Background levels of an array of persistent waterborne pesticides by randomized sampling of estuaries in a particular geographical area. 2. The escapement of pesticides in surface run-off from specific use areas in the drainage basin by sampling deltaic sediments. 3. The cause of increased faunal mortalities or lack of species diversity in an otherwise normal appearing estuary. 4. Tissue residue levels of persistent pesticides to ensure that they are within legal tolerance levels for edible fish and shell fish or their products. 5. Pesticide residues in food chain organisms to alert resource management agencies of possible mortalities resulting from trophic magnification. 6. Pesticide residues in pre-spawning gonads of commercially valuable species to identify causes of change in productivity. The choice of which physical or biological elements are to be monitored in an estuary will be determined by specific program objectives.