Marine Water Clarity Measurements at Nine Australian Reference Stations

Monthly and quarterly Secchi Depth and Total Suspended Solids measurements began between September 2008 and November 2010 at nine Australian coastal sites, with sampling ongoing at seven stations. The dataset includes historical data from CSIRO coastal monitoring programs for three sites, extending records back to 1944. Data collection is conducted by the IMOS National Reference Station Biogeochemical project.

Use Cases

• Analyze Secchi Depth trends over time to assess long-term water clarity changes at specific stations like Maria Island or Port Hacking.
• Correlate Total Suspended Solids (inorganic and organic) measurements with seasonal or geographic factors across the nine NRS sites.
• Compare historical CSIRO coastal monitoring data (e.g., from 1944-2008) with IMOS NRS data to study decadal changes in marine biogeochemistry.
• Model the relationship between Secchi Depth and Total Suspended Solids components to develop regional water quality indicators.

Strengths

• Long-term temporal coverage, with data collection ongoing since 2008-2010 and historical records extending back to 1944 for three sites.
• Spatial coverage includes nine distinct National Reference Station sites around Australia's coastline, from Tasmania to Western Australia.
• Standardized collection following the documented 'IMOS National Reference Stations Biogeochemical Operations Manual'.
• Planned interoperability with other national and international marine observation programs through IMOS infrastructure.

Limitations

• Sampling ceased at two sites (Ningaloo and Esperance) in 2013, creating incomplete temporal series for all nine original locations.
• Primary data is available in document formats (PDF, HTML), which may require extraction and parsing for quantitative analysis.
• The dataset has been superseded by a newer combined collection, indicating it may not be the most current version available.

Provenance

Source

Integrated Marine Observing System (IMOS) National Mooring Network - National Reference Station (NRS) field sampling.

Collection Method

Monthly (and previously quarterly) sample collection from small vessels, with analysis for Secchi Depth and Total Suspended Solids.

Time Range

Sampling began 2008-2010 and is ongoing; includes historical CSIRO data from 1944-2010 for three sites.

Freshness

Data collection is described as ongoing for seven sites; the metadata record was last updated in March 2026.

Geography

Nine coastal sites around Australia: Maria Island (TAS), Kangaroo Island (SA), Esperance (WA), Rottnest Island (WA), Ningaloo (WA), Darwin (NT), Yongala (QLD), North Stradbroke Island (QLD), Port Hacking (NSW).