Estuarine high ecological values (HEV)

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High ecological value (HEV) condition is defined by ANZECC 2000 as “ effectively unmodified or other highly valued systems, typically (but not always) occurring in national parks, conservation reserves or in remote and/or inaccessible locations. While there are no aquatic ecosystems in Australia and New Zealand that are entirely without some human influence, the ecological integrity of high conservation/ecological value systems is regarded as intact.” (ANZECC 2000; Chapter 3).

HEV "default" estuarine ecosystems

Estuarine locations (e.g. mapped as ‘Estuarine Wetland’ in the Qld EPA Wetland mapping) that are classified as:

  • State Marine Park (QLD)
  • Marine National Park
  • Preservation Zones
  • Scientific Research
  • Buffer Zones
  • Fish Habitat Areas (A)
  • National Park, NP Scientific

Management intent for HEV "default" estuarine ecosystems

Protect natural condition/values (including biotic, physical form, riparian vegetation, flow and physical-chemical water quality attributes)

No change to natural condition/values beyond natural variability:

(ANZECC, 2000; p3.1-10: “the recommend level of protection would be no change beyond natural variability”).

(ANZECC, 2000: p3.3-1: “ For ecosystems requiring the highest level of protection, the objective for water quality management is to ensure there is no detectable change (beyond natural variability) in the physical and chemical stressors”).

Water quality guidelines to protect HEV "default" estuarine ecosystems

  • Toxicants in water: No change to natural – interpreted as 99% spp protected with 50% certainty (ANZECC, 2000; Table 3.4.1, 3.4.2)
  • Toxicants in sediments: No change to natural – interpreted as no detectable chemicals from human activities, and naturally occurring toxicants not to exceed background concentrations (ANZECC, 2000; p3.5-1)
  • Physico-chemical: No change to natural – interpreted by QWQG (2006; Appendix D) as maintaining the natural distribution of water quality using 20th, 50th and 80th percentiles of good quality “natural” reference sites as a basis for maintaining natural variability
  • Biological: No change to natural biodiversity– interpreted by maintenance of biological indicators relative to suitable reference condition (ANZECC, 2000; Table 3.1.2)

HEV "technical" estuarine ecosystems

  • HEV (a). Estuarine locations (e.g. mapped as ‘Estuarine Wetland’ in the Qld EPA Wetland mapping) identified by technical panel or other information sources as highly valued systems with indiscernible disturbance from natural. HEV (a) systems have little or no human influence.
  • HEV (b). Estuarine locations (e.g. mapped as ‘Estuarine Wetland’ in the Qld EPA Wetland mapping) identified by technical panel or other information sources as highly valued systems with indiscernible disturbance from natural. HEV (b) systems may include waters with some human influence (e.g. due to their downstream location) but must have intact conservation/ecological values. In this case the human influence is seen as a threat to ecological values but the threat has not been realised into ecological impacts. If minor ecological impacts are suspected the system should be categorised as SD .

Management intent for HEV "technical" estuarine ecosystems

  • HEV (a)

Protect natural condition/values (including biotic, physical form, riparian vegetation, flow and physical-chemical water quality attributes). No change to natural condition/values beyond natural variability.

  • HEV (b)

Protect natural condition/values (including biotic, physical form, riparian vegetation, flow and physical-chemical water quality attributes). No change to natural condition/values beyond natural variability.

Interpretation as for HEV (a), with caution given the identified human influence and threat of disturbance.

Caution should be used if using HEV (b) waters as “natural” reference sites.

Water quality guidelines to protect HEV "technical" estuarine ecosystems

Same as for HEV "default" estuarine ecosystems.

References

Estuarine Wetland &copy NQ Dry Tropics
Estuarine Wetland © NQ Dry Tropics

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