Rivers and Streams

Why survey?

Conservation assessment of a watercourse to establish baseline conditions.

Evaluate impacts of, or monitor recovery from, nutrient enrichment, chemical or metal contamination, acidification or sediment deposition.

Assess flow requirements of the aquatic faunal assemblage and potential impacts from alterations to the hydrological regime of a watercourse, such as for a hydro-electric scheme.

Assess the potential resilience of faunal assemblage to diminished flows, such as from water abstraction.

Characterise habitat structure, and enhancement or restoration potential, of a watercourse and riparian zone.

To provide advice on river and riparian habitat creation, enhancement and restoration.

Techniques employed

Survey design is customised to suit the needs of each project. Surveys utilise techniques monitoring benthic, pelagic and emergent macroinvertebrate communities in aquatic habitats.

Streams and rivers can be surveyed using established protocols (Environment Agency RIVPACS guidelines), or using tailored quantitative, experimentation or biomanipulation techniques, as appropriate.

Waterbodies may be surveyed using any or any combination of kick, sweep, dredge or drift netting, Surber or grab sampling, or using artificial substrates.  Surveys are undertaken by wading or by Canadian canoe.

Macrophyte-epiphyte dynamics and biomass studies can be used to investigate the relationship between flow and organic enrichment in a river or stream.

 

Interpretive Metrics

The conservation value of a waterbody can be assessed using a combination of metrics; species richness and diversity indices and the Community Conservation Index (CCI).

Biological water quality of a river or stream is evaluated using the bioassessment tools RIVPACS (River InVertebrate Prediction And Classification) and RICT (River Invertebrate Classification Tool).

Where alterations to the flow regime of a watercourse are proposed, the relationship between the aquatic faunal community and hydrological regime can be investigated using the Lotic-invertebrate Index for Flow Evaluation (LIFE).

River Habitat Survey (RHS) methodology can be used to characterise the physical structure, habitat and enhancement potential of a watercourse.

Riverbed sediment deposition can be assessed using the Proportion of Sediment-sensitive Invertebrates (PSI) metric.