Standard List of Candidate Causes Used in Mississippi
| Candidate Cause | Available Indicators |
|---|---|
| Oxygen concentration and oxygen demand | Alteration to photosynthesis/respiration balance Decrease in oxygen and increase in oxygen demand Temperature alteration Alteration to natural flow regime Increase in organic enrichment Disruption of nutrient cycles |
| Organic carbon | Increase in organic enrichment Change in food source Alteration to photosynthesis/respiration balance characteristics Decrease in oxygen and increase in oxygen demand |
| Nutrients | Disruption of nutrient cycles Alteration to photosynthesis/respiration balance characteristics Decrease in oxygen and increase in oxygen demand Change in food source characteristics |
| Temperature | Alteration to thermal regulation Alteration to photosynthesis/respiration balance characteristics Decrease in oxygen and increase in oxygen demand |
| Turbidity | Increase in amount and duration of suspended sediment Alteration to natural flow regime Decrease in suitable in-stream habitat Alteration to channel morphology Decrease in riparian vegetation |
| Sediment particle size | Increase in deposited sediment Alteration to natural flow regime Decrease in suitable in-stream habitat Alteration to channel morphology |
| Habitat | Alteration to natural flow regime Decrease in suitable in-stream habitat Decrease in riparian vegetation Alteration to channel morphology Increase in suspended and deposited sediment Change in food source characteristics Decrease in suitable floodplain habitat Temperature alteration Alteration to groundwater interaction |
| Conductivity, total dissolved solids (TDS) and chloride | Increase ion concentrations Alteration to natural freshwater/saltwater interaction |
| pH | Increase in alkalinity or decrease in hydrogen ion activity Increase in acidity or hydrogen ion activity |
| Toxic Substances | Increase in toxic substance concentrations |
Source: Adapted from Mississippi DEQ (2005)