Nutrient Patterns in Port Phillip Bay During High and Low Runoff Periods

Monthly nutrient and chlorophyll a distributions were measured across Port Phillip Bay for two years as part of the Port Phillip Bay Environmental Study. Reported data focus on the northern bay during high runoff in September 1993 and low runoff in January 1995, collected via continuous profiling from a ship. The study distinguishes nutrient sources from the Yarra/Maribyrnong and Werribee river systems.

Use Cases

• Modeling nutrient source attribution based on ammonium/salinity and silicate/salinity relationships described in the study.
• Analyzing spatial variability of phosphate and silicate concentrations during high-flow events.
• Studying the link between freshwater runoff and phytoplankton biomass (chlorophyll a) in a semi-enclosed bay.
• Comparing internal nutrient recycling versus riverine inputs during periods of low runoff.

Strengths

• High spatial resolution with measurements resolved over scales of about 200 meters.
• Specific concentration ranges provided for ammonium (<0.5-40 mM), oxidised N (<0.2-20 mM), phosphate (<1-8 mM), and silicate (<1-80 mM).
• Data collected during contrasting hydrological conditions (high runoff September 1993, low runoff January 1995) enabling comparative analysis.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is from a specific study period (1993-1995); current conditions may differ.

Provenance

Source

Geoscience Australia Data

Collection Method

Continuous profiling technique with seawater pumped into a shipboard lab, filtered, and measured by flow-segmented colorimetric analysis.

Time Range

Primary focus on September 1993 and January 1995, with broader monthly sampling over two years.

Freshness

Last updated 2026-05-14 09:18:14.531786; freshness should be verified.

Geography

Northern Port Phillip Bay, Victoria, Australia, with references to the Yarra/Maribyrnong and Werribee river sources.