Conclusions
- Low dissolved oxygen (DO) levels likely have the biggest impact on species' health. Low DO can be caused by increased nutrient loading into waterways, increased algal decomposition, decreased flushing, and increased stratification. Warmer weather can also exacerbate low DO in the summer months.
- Tributaries and bottom layers had the most unsuitable conditions for species considered. This could have greater effects on benthic organisms, like crabs and shellfish, and the early life stages of fish and other species that use tributaries as nurseries. Poor water quality in tributaries and bottom layers could be attributed to pollutants from stormwater runoff which can cause eutrophication and can also exacerbate stratification in the water column.
- Submerged Aquatic Vegetation (SAV) is likely most impacted by impairments to light availability due to elevated turbidity levels and elevated chlorophyll-a levels measured in the water column. High levels of turbidity and algal blooms limit light availability to the bottom, thus impacting photosynthesis. Decreased SAV can affect presence of other animals since it provides important nursery habitat for many species. In addition, turbidity may further increase with decrease of SAV, since SAV root systems help stabilize the sediment and prevent erosion.
- Fecal coliform levels were significantly higher at tributary stations than at bay stations. This reflects the presence of fecal matter inputs from land sources and could include failing on-site septic systems, illicit discharges, or overflow pipes directed from on-site septic systems, pet waste, and waterfowl or other wildlife waste.
- Shellfish were ranked using the average of all four species: eastern oyster, hard clam, blue mussel, and ribbed mussel. While shellfish were generally ranked as fair or good, mussel species are more tolerant than oysters and clams and improve the ranking of the group. All shellfish are important for water quality since they filter the water when they feed and improve water quality, but mussels may be more prevalent than other species in the Patchogue region.
Conclusions are based on preliminary data and only consider the parameters measured in this study. Other factors such as pollutants, habitat, and prey availability, among others, also determine species presence in Patchogue waterways.