WAMSI 2 - Dredging Node - Project 5.3 - Natural Dynamics [dataset]

Author Identifiers

Kathryn McMahon

ORCID: 0000-0003-4355-6247

Paul S. Lavery

ORCID: 0000-0001-5162-273X

Collection Type


Upload Date


School or Research Centre

School of Science


Mat Vanderklift: Mat.Vanderklift@csiro.au


Western Australian Marine Science Institution (WAMSI) project funded by Western Australian State Government and research partners.


The Theme 5.3 study was undertaken to improve our understanding of the spatial and temporal patterns in seagrass composition, abundance and reproductive phenology in the Pilbara region. Key environmental parameters, especially light, that influence seagrass survival and can be altered by dredging were also characterised.

From August 2013 to March 2015 (18 months), surveys of seagrass abundance were undertaken in the Exmouth Gulf region. The locations surveyed (South Muiron Island, Bundegi and Exmouth Gulf) encompassed a range in water clarity from clear to turbid. Less frequent surveys were undertaken at other locations in the Pilbara: Thevenard Island, Rosemary Island and Balla. Measurements of seagrass abundance were also obtained from monitoring conducted as part of the dredging and dredge-spoil management plan for Chevron Australia’s Wheatstone Liquefied Natural Gas (LNG) Project.

During each survey measurements were made in the field, photographs were taken or samples were collected in order to measure the following variables:

1. percentage cover of seagrass and other benthos;

2. above- and below-ground biomass, shoot density, leaf length, leaf width and number of flowers;

3. density of seagrass seeds;

4. sediment grain size;

5. stable isotope ratios (13C and 15N) of seagrass leaf tissue; and

6. water quality (light, conductivity, temperature, salinity, nutrients, suspended particulate matter and chlorophyll).

At each site the following activities were conducted:

1. Photographic transects

2. Cores

3. Stable isotope analysis;

4. Conductivity, Temperature and Depth recorder with a Licor 192SA PAR sensor

5. Water samples

Geographic bounding :

North bound: -21.60000, West bound: 114.10000, East bound: 114.40000, South bound: -22.30000

Data URLs

Access CSIRO record here

Start of data collection time period


End of data collection time period





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