MS Excel Format (447KB).Rainfall data presented on this CD-ROM has been collected by Bureau of Meteorology
as part of their routine weather monitoring programme. It can be viewed here
in
MS Excel Format (447KB).
Water quality has been monitored on a weekly to monthly basis at three sites
in Peel Inlet and central site in Harvey Estuary from August 1977 and another
two in Harvey from March 1979 (Figure 1). The
raw data can be view here in
MS Excel Format (2.42MB).
The field parameters measured were: Secchi depth and total depth; surface and bottom pH (± 0.1Ph unit, Hanna HI 8424), salinity (± 0.1ppt, Hamon Salinity-Temperature Bridge, Model 602), temperature (± 0.1°C, Hamon Salinity-Temperature Bridge, Model 602) and dissolved oxygen (± 0.2 mg L-1, Yeo-Kal Dissolved Oxygen-Temperature Meter, Model 603). Light attenuation coefficients were calculated from the regression of the logarithm of irradiance values against depth. Irradiance was measured in the water column using a Licor Quantum Meter, with submersible probe, together with Secchi depth.
Surface and bottom water samples were taken for total nitrogen (± 200 µg N L-1) and total phosphorus (± 10 µg P L-1). Water was filtered through GF/C filter paper (pore size 1.2 µm, Whatman Ltd, England) to determine chlorophyll a (± 0.1 µg L-1) and phaeophytin (± 0.1 µg L-1) and then 0.45 µm cellulose nitrate filter paper for ammonium (± 4 µg L-1), nitrate-nitrite (± 2 µg L-1), filterable reactive phosphate (± 2 µg L-1) and silicate (± 10 µg L-1). Samples were kept in ‘Whirlpaks’ on ice in the field and stored frozen in the laboratory until analysis. Chlorophyll a is a measure of phytoplankton abundance and phaeophytin is a degradation product of chlorophyll, and a sign of recently collapsed blooms.
All analyses were carried out by the Marine and Freshwater Research Laboratory,
Murdoch University (previously the Nutrient Analyses Laboratory, University
of Western Australia). Chlorophyll a and phaeophytin were extracted from
the GF/C filter papers by grinding in 90% acetone and storing for 24 hours in
the dark at 4°C. The chlorophyll a and phaeophytin concentrations
were then measured spectrophotometrically (Varian DMS 90 Spectrophotometer,
Varian Techron Pty Ltd, Springvale, Australia) according to the method of Strickland
and Parsons (1968). Filterable reactive phosphate was analysed by the single
solution method (MAFRL, 1998); nitrate plus nitrite after
copper-cadmium reduction with a Technicon Autoanalyser II (Technicon
Industrial Systems, 1975); an ammonia plus ammonium by the phenol-prusside
method (Dal Pont et al., 1974). Total nitrogen
and phosphorus were determined from sulphuric and perchloric acid digests respectively;
followed by analysis for ammonium and phosphate by the above methods. Total
N was computed as a sum of nitrate-nitrite, organic nitrogen and ammonia. Total
phosphorus was calculated as the sum of organic phosphorus and orthophosphate
and inorganically bound phosphorus.
Macroalgal biomass and species compositions were measured at 30-42 sites at least once a year between 1978 and 1994, except from 1980 to 1983. After the opening of the Dawesville Channel, seasonal (spring, summer and autumn) sampling of macroalgal biomass and species composition took place at 42 sites (Figure 2).
Stratified macrophyte sampling was conducted at sites selected to best represent the environments in the System. At each site, five replicate cores were collected by divers using Perspex corers (9 cm diameter x 50 cm length, total area = 64 cm2). The cores were pushed into the sediment surface over the benthic macrophytes and sealed. Plant material was sieved to remove excess sediment and bagged for transport. At the laboratory each sample was sorted into species, oven dried at 70°C to constant weight. Dry weights were determined to 2 significant figures and biomass converted to grams per unit area gm-2. Estimates for species biomass are the means of five replicates. Total macrophyte biomass for an individual site could vary significantly; standard errors for particular sites were generally between 25 and 50% of the mean.
The total biomass, along with the total macrophyte biomass in the Peel Inlet, of each macrophyte component, was estimated using a computer mapping system (‘SYMAP’, Dougenik and Sheehan, 1977) which provided contours comprising different quantities of the biomass of a particular component. The method for estimating the biomass for the Inlet is therefore subject to the limitations of the SYMAP method. As there were relatively few sites sampled for such a large water body, this may lead to overestimates of biomass. Adherence to the same sampling sites and methods produced a valid representation of trends in biomass.
To increase the accuracy of biomass estimates for Harvey Estuary, from 1994
onwards, visual transects were used to determine the extent of macroalgal and
seagrass growth. These areas were multiplied by the macroalgal biomass at each
site, then summed to give a figure for macroalgal biomass for the total area.
This method was adopted because macroalgal populations in Harvey Estuary are
of a far lesser magnitude and are more evenly distributed than in Peel Inlet.
Areas of sites were determined by digitising a map of Harvey Estuary into a
computer program, CanvasTM, to determine site areas. The one metre contour was
used to divide the sites, as very little macroalgae is found beyond this depth.
Two sets of saltmarsh data are presented in this CD-ROM. The first is presented
in a report format, the second as raw data. "The
Samphire Marshes of the Peel-Harvey Estuarine System, Western Australia"
was a report on the saltmarshes of the Peel-Harvey Estuary and Serpentine River,
carried out before the opening of the Dawesville Channel. The report can be
viewed as a single Adobe
Acrobat file (
PDF - 4.72MB) or downloaded as multiple files (
Part 1 - 2.77MB)(
Part 2 - 703KB)(
Part 3 - 1.27MB) for web users. This study focused on the use of aerial
photographs combined with ground truthing to document changes in saltmarsh area
and continuity of cover from 1957 to 1994. Ten sites around the estuary were
also selected for detailed studies on zonation of saltmarsh communities.
The second set of data was collected after the Channel opened. Twelve transects,
two per site, were established on CALM reserves around the Peel-Harvey (Figure
3) during October and December 1994, and revisited at the same time each
year. For each transect, heights above temporary datum along the first seaward
twenty meters were determined, along with plant species composition every ten
centimetres of the transect.
A study was undertaken in 1995 using airborne Digital Multi-Spectral Video (DMSV) to map the peripheral vegetation on the Peel-Harvey Estuary, Serpentine and Murray Rivers. The data from the study are present on this CD as a report entitled "An evaluation of Digital Multi-Spectral Video for Classification of Peripheral Vegetation of the Peel-Harvey Estuary and the Serpentine, Murray River Systems".
Dal Pont, G; Hogan, M and Newell, B. 1974. Laboratory techniques in marine chemistry. II Determination of ammonia in seawater and the preservation of samples for nitrate analysis. CSIRO Division of fisheries and Oceanography Report No. 55: pp 1-5.
MAFRL (Marine and Freshwater Research Laboratory), 1998. Test Methods Manual, Method: 4100A, Murdoch University, Perth WA, pp1-7.
Strickland, J.D.H. and Parsons, T.R. 1968. A Practical Handbook of Seawater Analysis. (Fisheries Research Board of Canada, Ottawa.)
Dougenik, J. A. and Sheehan, P. E., 1977, Symap Users Reference Manual, 5th edition, Laboratory for Computer Graphics and Spatial Analysis, Harvard University, Cambridge Mass.
Technicon Industrial Systems 1975. Operation Manual for the Autoanalyser II Systems. (Technicon Industrial Systems: Tarrytown, New York).