2021 State of the Environment Report Marine Chapter – Expert Assessment – State and Trend – Microbial communities and processes

The Marine chapter of the 2021 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "State and Trend of microbial communities and processes". A PDF of the full Expert Assessment, including figures and tables (where provided) is downloadable in the "On-line Resources" section of this record as "EXPERT ASSESSMENT 2021 - microbial communities and processes"

DESCRIPTION OF SPECIES/HABITAT/COMMUNITY/PROCESS FOR EXPERT ASSESSMENT Australian marine waters typically contain 10^5-10^7 microbial (bacteria, archaea and unicellular algae) cells/ml, belonging to tens of thousands of different species (Brown et al 2018). This highly diverse and abundant community sensitively and rapidly responds to changes in environmental conditions and is hence a valuable indicator of ecosystem status and health. Microbes also shape the marine environment by playing a central role in biogeochemical cycles, supporting phytoplankton primary productivity, contributing to the ocean carbon pump, and removing a wide range of chemical pollutants.

DATA STREAM(S) USED IN EXPERT ASSESSMENT The assessment is based on >5000 pelagic water samples, collected during marine voyages (sparsely covering most of Australia’s coastal waters) and at the 7 IMOS National Reference Stations (3 of which have been sampled since July 2012; the other 4 since July 2015).

2021 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]

• 2021 • Assessment grade: Good Assessment trend: Deteriorating Confidence grade: Limited Confidence trend: Limited Comparability: Not assessed in 2016 • 2016 • Assessment grade: Unclear Assessment trend: Unclear Confidence grade: Evidence and consensus too low to make an assessment Confidence trend: Evidence and consensus too low to make an assessment Comparability: Grade and trend are not comparable to the 2011 assessment • 2011 • Assessment grade: Very good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus

CHANGES SINCE 2016 SOE ASSESSMENT Not applicable

Data and Resources

Additional Information

Field Value
Published (Metadata Record) 04/03/2026
Last updated 04/03/2026
Organisation Australian Federal Government
License License Not Specified
Update Frequency Unknown