Developing Developing Nutrient Criteria Nutrient Criteria for Reservoirs: for Reservoirs:

How it May Impact How it May Impact You You

J. Warren Schlechte and John B. Taylor - Inland Fisheries

Patricia L. Radloff – Coastal FisheriesTexas Parks and Wildlife Department

OutlineOutline

Background/History Current Approaches

in TX Current Approaches

across the South Future

BackgroundBackground

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

BackgroundBackground

Ecology of Cultural Eutrophication Results

Increased productivity Shifts in species composition Low DO and death

www.saltonsea.ca.gov/ltnav/current.html

BackgroundBackground

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

BackgroundBackground

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

BackgroundBackground

EPA Requirements Nutrient over-enrichment

Nitrogen and Phosphorous are causal agents Chlorophyll-a is measurable response

variable

Divide US in 14 ecoregions

BackgroundBackground EPA Approach

75th percentile of pristine waters 25th percentile of all waters

E P A S u g g e s t e d M e t r i c s

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T o t a l P h o s p h o r o u s ( u g / L )

Lik

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ho

od

Current - TXCurrent - TX

Three approaches Use-based Anti-degradation Approach

Parametric, based on all historic data Nonparametric, based on recent historic

data

Current - TXCurrent - TX

Use-based Proposal

Visit reservoirs in summer Survey users (min. 7) Collect WQ data concurrently Correlate user survey with WQ

Current - TXCurrent - 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)

Current - TXCurrent - 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

Current - TXCurrent - 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

Current - TXCurrent - 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

Current - TXCurrent - 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

Current – Other StatesCurrent – 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

Current – Other StatesCurrent – 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

Ramifications for Ramifications for FisheriesFisheries

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

Next StepsNext Steps

Rivers and Streams in ???? Estuaries in ????

Get Involved

AcknowledgmentsAcknowledgments

Texas Parks and Wildlife – Inland Fisheries

Sportfish Restoration