9,000-Year Marine Diatom Assemblage Reconstruction from Eastern Tasmania

Eastern Tasmanian waters have experienced rapid warming over the past fifty years. This dataset reconstructs diatom communities from a sediment core spanning 9,000 years before present, using microfossil analysis and molecular techniques like sedimentary ancient DNA. The data was contributed by the Australian Ocean Data Network and last updated in July 2026.

Use Cases

• Analyze shifts in diatom community composition over millennia based on the 9,000-year sediment core record.
• Compare detection efficacy of microfossil versus molecular methods based on the described taxonomic differences.
• Study the transition from coastal to shelf ecosystems based on the observed shift in Paralia sulcata cell size around 6,000 years BP.
• Investigate preservation biases in sediment records based on the underrepresentation of lightly silicified planktonic diatoms in microfossil data.

Strengths

• Covers a 9,000-year temporal span, providing a long-term ecological perspective.
• Combines two methodological approaches: microfossil analysis and molecular techniques (sedaDNA and 18S rRNA).
• Molecular methods detected higher diatom diversity, with lightly silicified planktonic genera comprising 73% of sedaDNA and 88% of 18S rRNA records.

Limitations

• Up to 50% of sedaDNA reads remained unclassified due to reference library limitations.
• Microfossil analysis underrepresented lightly silicified planktonic diatoms due to preservation biases.
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

Australian Ocean Data Network

Collection Method

Reconstruction from a sediment core using microfossil analysis, sedimentary ancient DNA (sedaDNA), and 18S rRNA from a water column archive.

Time Range

9,000 years before present

Freshness

Last updated 2026-07-16 03:16:39.908713; freshness should be verified

Geography

Eastern Tasmania, Australia, specifically near the Maria Island IMOS NRS mooring