The Biological Condition Gradient and Tiered Aquatic Life
The Biological Condition Gradient and Tiered Aquatic Life Uses: With Applications in the State of Maine United States Environmental Protection Agency Tiered Aquatic Life Uses Working Group Susan P. Davies Maine Department of Environmental Protection
TALU: Tiered Aquatic Life Uses Bio Condition Gradient Class A/AA “as naturally occurs” Class B “support all indigenous species; no detrimental change” Class C “support indigenous fish (salmonids); maintain structure and function” Stressor Gradient A Scientific Model A Water Quality Standards framework
Aquatic Life Use Workgroup: Conceptual Model Natural (from Cairns 1993) Ecological Condition --- Historical --- 1 2 recorded condition 3 4 5 existing condition (hypothetical) Degraded - - No disturbance - - Increasing human disturbance 6 - - Severe disturbance - -
TALU: Bio Condition Gradient Tiered Aquatic Life Uses The Scientific Model. Stressor: Response Concepts Stressor Gradient A Scientific Model
Biological Responses Across the Stressor Gradient HIGH e (fish) tiv RESPONSE MEASURE Na xa Ta DELT A Int noma lies ly t h g ran i H le xa To Ta ole ra nt Ta xa LOW Stressor Gradient [Effect of Human Activity] HIGH Courtesy of Chris Yoder, CABB
from Stevenson high Biological Condition Biointegrity Criterion Biointegrity Indicators Stressor Criterion low Stressor Gradient high
TALU : A Scientific Model Concept #1 The Biological Condition Gradient
Native or natural condition 1 Biological Condition Natural 2 Minimal loss of species; some density changes may occur Some replacement of sensitive-rare species; functions fully maintained 3 4 Some sensitive species maintained; altered distributions; functions largely maintained Tolerant species show increasing dominance; 5 sensitive species are rare; functions altered Severe alteration of Degraded structure and function Low Increasing Effect of Disturbance [Stressor gradient] 6 High
Overview of 10 Attributes · Taxonomic composition and tolerance · Attributes I-V · Sensitive-Endemic through Tolerant · Non-native taxa · Attribute VI · Organism condition · Attribute VII · Ecosystem function · Attribute VIII · Physical-biotic interactions · Attributes IX-X
TALU : A Scientific Model Concept #2 The Generalized Stressor Gradient
The Linkage From Stressor Effects to Ecosystem Response Habitat Structure Flow Regime Stressor Agent(s) Water Quality & Toxicity Biological Response Energy Source This model is an explicit statement of multiple causation Biotic Interactions Biological Index or metric Stressor Metric STRESSORS STRESS/EXPOSURE RESPONSE
Relationship Land Classes and Stream Macroinvertebrates in Maine preliminary results based on 424 samples Number of Mayfly, Stonefly, and Caddisfly Genera n=57 n=150 n=119 n=98
Summary BCG-GSG Framework • A conceptually simple framework for holding enormous, user-defined complexity • Organizes and prioritizes research needs • Enhances communication
TALU: Tiered Aquatic Life Uses Bio Condition Gradient Class A/AA “as naturally occurs” Class B “support all indigenous species; no detrimental change” Class C “support indigenous fish (salmonids); maintain structure and function” Stressor Gradient A Scientific Model A Water Quality Standards framework
Pass-Fail Aquatic Life Use Scenarios for a Hypothetical State --- Historical --- Ecological Condition Natural 1 2 PASS 3 4 FAIL 5 One 303 d Listing Threshold? 6 Degraded --- Severely Altered --- - - No disturbance - - Increasing human disturbance - - Severe disturbance - -
MAINE TALU Native or natural condition 1 Biological Condition Natural 2 Minimal loss of species; some density changes may occur Some replacement of sensitive-rare species; functions fully maintained 3 4 AA A Some sensitive species maintained; altered distributions; functions largely maintained B C Tolerant species show increasing dominance; 5 sensitive species are rare; functions altered Severe alteration of Degraded structure and function Low Increasing Effect of Disturbance [Stressor gradient] NA 6 High
Data Analysis and Use Attainment • Biological data put into statistical model (30 variable linear discriminant model) • Model output is an estimation of strength of association of a sample to four water quality classes Class A Class B Class C NA Biological community: Natural Degraded
Designated Aquatic Life Uses in Maine % OF LINEAR MILES Class AA = 6% Class A = 45% Class B = 47% Class C = 2% Since 1990 Miles of upgrades= 1, 440 Miles of downgrades= 5
Reducing Discharges from Lincoln Pulp and Paper Company into Penobscot River BOD 5 load kg/day Biological Outcome A B 1, 600 C 2, 700 NA 13, 600 Secondary wastewater treatment in place Year
Relationship Between Impervious Surfaces and Water Quality Attainment in Maine preliminary results based on 424 samples Impervious Surfaces (Portion of Drainage) ~ 12% ~ 5% Aquatic Life Use Attainment
Maine TMDL Target Values for % Impervious Cover Class %ICdemonstrated attainment C <15% TMDL WLA MOS n i n o i t r AA c e Does u not t apply a d <6% e w r m d r e <6%to <5% 1% r A e fs e n o i g s t 7 -10% 6 -9% 1% n B E <8% c e f ef 10 -15% 8 -13% 2%
Maine Classification Attainment
Maine Extensions of TALU: Other Waterbody and Criteria Types • Wetland BCG- TALU – Targeted Stream/Wetland monitoring • Marine-estuarine – tiered aquatic life standards applied in aquaculture permitting • Tiered Nutrient Criteria – Conceptual model: – tiered chemical limits PLUS tiered biological response limits – algae, macroinvertebrates
BCG Tiers Communicate Condition a Natural 1 b 2 c 3 d 4 e 5 f 6 Degraded Susan P. Davies, MDEP
Acknowledgments Maine DEP Biological Monitoring Program Leon Tsomides, Jeanne Di. Franco Tom Danielson, David Courtemanch National TALU Work Group and Steering Committee (including 23 States and Tribes) Susan K. Jackson, USEPA-HECD, Washington, DC
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