Estuary Desktop EcoClassification & identification of hotspots

1. Estuary Desktop EcoClassification & identification of hotspots PRESSURES, PRESENT ECOLOGICAL STATUS, ECOLOGICAL IMPORTANCE, HOTSPOTS 1

2. Outline • Geographical Boundaries • Evaluate pressures • Define Present Ecological Status • Importance (national and regional) • Determining the Recommended Ecological Category • Hotspot identification • Monitoring requirements

3. Geographical boundaries • 5 m mean sea level contour from Survey General • Modify with KNZ database (Boyd Escott) & Forbes & Demetriades 2009 • Confirmed at workshop by regional experts Mdloti Estuary boundaries

4. EstuarineHealthIndex… Estuarine Health 50 50 Biotic health Abiotic health 25 25 20 20 20 20 20 25 25 Microalgae Macrophytes Invertebrates Fish Birds Hydrology Mouth Condition Water Quality Physical habitat

5. Estuarine Health Index to compare similarity between Reference Condition and Present State Variable Score Weight Hydrology 25 Hydrodynamics/Mouth condition 20 Water Quality 20 Physical habitat 20 Non-flow related 20 50 HABITAT HEALTH SCORE Micro algae 20 Macrophytes 20 Invertebrates 20 Fish 20 Birds 20 ESTUARINE HEALTH SCORE BIOLOGICAL HEALTH SCORE 50

6. Estuarine Health Index scores to compare similarity between Reference Condition and Present State Variable Score Weight Hydrology 78 25 Hydrodynamics/Mouth condition 70 20 Water Quality 30 20 Physical habitat 68 20 Non-flow related 18 20 50 62 HABITAT HEALTH SCORE Micro algae 17 20 Macrophytes 25 20 Invertebrates 17 20 Fish 25 20 Birds 20 20 BIOLOGICAL HEALTH SCORE 21 50 ESTUARINE HEALTH SCORE 41 D

7. Define Present Status Category 91 - 100 A Unmodified, natural Present Status Category EHI Score 76 - 90 General Description B Largely natural, few modifications 61 - 75 C Moderately modified 41 - 60 D Largely modified 21 - 40 E Highly degraded 0 - 20 Extremely degraded F

8. EstuarineImportance Estuarine Importance 25 15 10 25 Size Zonal Type Rarity Habitat diversity Biodiversity 25 25 25 25 • National scale: DWA (2008) ranked 1 – 5 • Regional scale: Experts ranked plants, fish and birds. • No regional scale data available for inverts on all systems. Experts lifted out some NB systems. • Used maximum of national or regional importance Plants Invertebrates Fish Birds

9. Recommended Ecological Reserve Category PROTECTION STATUS/ IMPORTANCE ECOLIGICAL RESERVE CATEGORY Protected Area A or Best Attainable Status (BAS) Desired Protected Area A or Best Attainable Status Highly important (rated = 5) Present Status Category +1, min B, or BAS Important (rated = 4) Present Status Category +1, min C, or BAS Low to average importance (≤ 3) Present Status Category, min D • ‘Present Status Category = ‘B’ & ‘Highly important – 86’ • ERC should be ‘A’. • However, not likely to attain ‘A’, thus go for BAS = ‘B’

10. Hydrology • Reference flow scenario • Present flow scenarios • WWTW, forestry, stormwater

11. Example of Desktop HealthAssessment

12. Summary of Desktop HealthAssessment Results • While more than 80% of estuaries are in a B or C, nearly 50% of estuarine area is in a E catogory

13. EstuaryHotspots DWAF (2008) Water Resource Protection and Assessment Policy Implementation Process. Resource Directed Measures for protection of water resources: Methodology for the Determination of the Ecological Water Requirements for Estuaries. Version 2. Pretoria.

14. Recommend for further work: DWAF (2008) Water Resource Protection and Assessment Policy Implementation Process. Resource Directed Measures for protection of water resources: Methodology for the Determination of the Ecological Water Requirements for Estuaries. Version 2. Pretoria.