Port Phillip Bay Nutrient Distributions During High and Low Runoff

Nutrient and chlorophyll a distributions were measured monthly for two years as part of the Port Phillip Bay Environmental Study. The dataset focuses on spatial patterns during high runoff in September 1993 and low runoff in January 1995, collected via continuous profiling from a ship.

Use Cases

• Analyze ammonium, nitrate, nitrite, phosphate, and silicate concentration variations between high and low runoff periods to identify pollution sources.
• Model nutrient-salinity relationships, such as ammonium/salinity and silicate/salinity, to distinguish inputs from the Yarra/Maribyrnong River versus Werribee sources.
• Investigate chlorophyll a concentration (1-6 mg L-1) correlation with freshwater and nutrient inputs during high flow versus internal recycling during low flow.
• Map spatial variability of oxidised N (nitrate + nitrite) and phosphate concentrations across the northern and western perimeters of the bay.

Strengths

• Data collected via continuous profiling technique with measurements every 10 seconds, resolving features over scales of about 200 meters.
• Surveys cover the entire Port Phillip Bay, an area of approximately 2000 km2, completed within 3-day campaigns.
• Includes simultaneous hydrographic and chlorophyll a data alongside nutrient measurements for integrated analysis.

Limitations

• Limited temporal coverage, focusing on two specific periods (September 1993 and January 1995) rather than a continuous time series.
• Precise row count, column structure, and sample data are unavailable, hindering immediate assessment of dataset scale and format.
• Data is presented in HTML and PDF formats, which may require extraction and structuring for quantitative analysis.

Provenance

Source

Geoscience Australia Data

Collection Method

Nutrients measured by flow-segmented colorimetric analysis on filtered seawater pumped into a mobile laboratory aboard ship.

Time Range

Monthly measurements over two years, with detailed focus on September 1993 (high runoff) and January 1995 (low runoff).

Freshness

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Geography

Northern Port Phillip Bay, Victoria, Australia.