Freshwater high ecological values (HEV)

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High Ecological Value (HEV) condition of freshwater systems 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” freshwater ecosystems

Freshwater wetland locations (e.g. mapped as ‘Riverine’, ‘Lacustrine’ or ‘Palustrine’ Wetland in the Qld EPA Wetland mapping) that are classified as:

  • World Heritage Area (zone A/B)
  • Protected estate
  • National Park
  • National Park Scientific
  • Wild Rivers – High preservation areas
  • Fish Habitat Areas –management type “a”

Management intent for HEV “default” freshwater 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 recommended 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)

WQ guidelines to protect HEV “default” freshwater ecosystem values

  • 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” freshwater ecosystems

HEV (a) Freshwater wetland locations (e.g. mapped as ‘Riverine’, ‘Lacustrine’ or ‘Palustrine’ 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) Freshwater wetland locations (e.g. mapped as ‘Riverine’, ‘Lacustrine’ or ‘Palustrine’ 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 SMD.

Management intent for HEV “technical” freshwater 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.

WQ guidelines to protect HEV “technical” freshwater ecosystem values

Same as for HEV “default” freshwater ecosystems.

References

Running River © NQ Dry Tropics 2014
Running River © NQ Dry Tropics 2014

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