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Macroinvertebrates Report Card

Aquatic Plants

B

Aquatic Plants

Macroinvertebrates

B

Black Bream

A

Waterbirds

C

Fish Kills

A

Water Quality

A

Macroinvertebrate are an important food source for fish and waterbirds and provide critical ecological functions including decomposition of organic matter and recycling of nutrients.  Benthic macroinvertebrate including worms, shrimps, and snails were monitored in spring across four regions in the wetlands.  Seven metrics including community dominance and diversity were used to calculate macroinvertebrate indicators for each region following methodology developed by Murdoch University.

Macroinvertebrates Summary 2022 Across Regions

Upper Vasse

B

Lower Vasse

B

Lower Wonnerup

B

Upper Wonnerup

B

ANNELIDA

HEXAPODA (CLASS INSECTA)

MOLLUSCA(CLASS GASTROPODA)

CRUSTACEA

Density (per phyla)

1 invertebrate = 10-50 per 225m²

2 invertebrates = 50-100 per 225m²

3 invertebrates = 100-200 per 225m²

4 invertebrates = 200+ per 225m²

Densities of under 10 were excluded

Key Findings

  • The average total density of invertebrates was 191 individuals per grab sample across both seasons in 2022, with the highest abundances of invertebrates encountered in the Upper and Lower Wonnerup.
  • The greater abundance of invertebrates in the Wonnerup are due to the polychaete worms Capitella ‘capitata’ and Polydora sp.
  • In spring 2022, benthic ecological health of the Vasse-Wonnerup was ‘Very Good’
  • Benthic ecological health was worse in January 2022, with the estuary having an average grade D, ‘Poor’. This seasonal decline is as expected due to a range of seasonal stressors like higher temperatures and salinities.
  • Since biannual monitoring began in November 2020, grades have remained relatively similar within each region.

Macroinvertebrates Grades Over Time

SpringUpper VasseLower VasseLower WonnerupUpper WonnerupDownload Reports
2022BBBBDownload Report
2021BBAADownload Report
2020BBCB
2019DCBB
2018BBAB
2017BBAA

Grades

A

Excellent

B

Very Good

C

Fair

D

Poor

E

Very Poor

View other report cards

Aquatic Vegetation

B

Aquatic Plants

Black Bream

A

Waterbirds

C

Fish Kills

A

Water Quality

A