Developing Nutrient Criteria for Reservoirs: How it May Impact You

1. Developing Nutrient Criteria for Reservoirs: How it May Impact You J. Warren Schlechte and John B. Taylor - Inland Fisheries Patricia L. Radloff – Coastal Fisheries Texas Parks and Wildlife Department

2. Outline • Background/History • Current Approaches in TX • Current Approaches across the South • Future

3. Background • Ecology of Cultural Eutrophication • Nutrients Introduced into System • Point source and Non-point source • Flow important Source: http://www.unep.or.jp/ietc/publications/short_series/lakereservoirs-3

4. Background • Ecology of Cultural Eutrophication • Results • Increased productivity • Shifts in species composition • Low DO and death www.saltonsea.ca.gov/ltnav/current.html

5. Background • Clean Water Act (1972) • Cornerstone of surface water quality/integrity • Aims to reduce pollutants into our waterways • State must catalog waters and designate uses • Establish WQ standards • If states fail to do soEPA steps in

6. Background • Current Parties Involved • Drinking water purveyors (surface water) • Wastewater dischargers • Lakeside homeowners, recreationalists, environmentalists • Fish and aquatic inhabitants • Why Should You Care? • If you don’t participate, your views ignored

7. Background • EPA Requirements • Nutrient over-enrichment • Nitrogen and Phosphorous are causal agents • Chlorophyll-a is measurable response variable • Divide US in 14 ecoregions

8. Background • EPA Approach • 75th percentile of pristine waters • 25th percentile of all waters

9. Current - TX • Three approaches • Use-based • Anti-degradation Approach • Parametric, based on all historic data • Nonparametric, based on recent historic data

10. Current - TX • Use-based • Proposal • Visit reservoirs in summer • Survey users (min. 7) • Collect WQ data concurrently • Correlate user survey with WQ

11. Current - TX • Use-based • Pros • Familiar • Specifically addresses the recreational uses for the water and seeks to protect those uses • Cons • Typically, data vague or non-existent • Metrics coarse • Weight uses (recreational, drinking, aquatic)

12. Current - TX Anti-degradation Approach • Parametric • Proposal • Look at Chlorophyll-a • Uses all historic data, outliers eliminated • Focuses on “reference reservoirs” • Uses 99th percentile of CI of mean

13. Current - TX • Parametric • Pros • Numerical data exist and criteria measurable • Cons • Assumed distribution may not fit • Only looking at chlorophyll-a • Only focusing on subset of reservoirs • No plan for reservoirs without data

14. Current - TX Anti-degradation Approach • Nonparametric • Proposal • Look at Ortho-P, Nitrite/Nitrate and Chlorophyll-a, • Uses last 10 years historic data for non-degraded reservoirs • Uses 90th percentile of raw data • For degraded reservoirs • Similar reservoirs • Historic record when not degraded • Statewide 85th percentile

15. Current - TX • Nonparametric • Pros • Uses actual data • Criteria definable and measurable • Deals with lack of data and degraded issues • Causal and Response Variables • Cons • Single threshold, and in tail region • Tends to pick up acute changes in nutrients

16. Current – Other States • Tennessee • Site specific, Nitrate/Nitrite and Total Phosphorous • Arkansas • ??, Chlorophyll-a, possibly others • Alabama • Site specific, Chlorophyll-a • Mississippi • Reference condition, chlorophyll-a

17. Current – Other States • Florida • Regional, Combination causal and response • Georgia • Site specific, Combination causal and response • New Mexico • Ecoregions, systems, TN, TP, Chlorophyll-a • Oklahoma • Site specific, Chlorophyll-a, P and/or N

18. Ramifications for Fisheries • Excessive Nutrients • Excessive Macrophytes • Golden and Blue-green Algae • Anoxia and pH Shifts • Stress and Disease • Invasive Species • Limited ability to fertilize • Anglers are not only user group

19. Next Steps • Rivers and Streams in ???? • Estuaries in ???? • Get Involved

20. Acknowledgments • Texas Parks and Wildlife – Inland Fisheries • Sportfish Restoration