Dissolved oxygen, temperature, and pH represent easily measured field parameters that are critical for most aquatic life. Water quality monitoring programs can be very expensive, time consuming and often the results are inconclusive or misleading. However, if the assessment is specifically designed to track parameters of concern, the information obtained can be used to explain biological conditions and trends. Support of food chains can be assessed by sampling fish. Freshwater fishes are an important component of wetland systems, filling different trophic levels in the food chain ranging from primary consumers of detritus, algae and vegetation, through intermediate trophic levels such as predators on crustacea and aquatic insects, to top-level carnivores such as piscivores.
Fish sampling methodologies can be selective for different species.
Dip net sampling is a qualitative method that can be used to collect Poeciliids , Cyprinodontids and Fundulids . Breder traps will yield the greatest diversity of fish species and relative densities per unit effort and they perform efficiently in both open and dense vegetation with minimal habitat disturbance. These sampling methods can be used at different times of the year to provide data to indicate fish utilization of wetlands and thus habitat and support of food chains. Provision of habitat and wildlife utilization can be measured by conducting appropriate wildlife surveys. Qualitative wildlife surveys along transects should include visual and audible observations for birds.