Collie River - Coolangatta Gauging Station Upstream

River condition at the Coolangatta Gauging Station Upstream site on the Collie River (site code: CR412COLL3, site reference: 6124037) has been assessed on several occasions as part of the Healthy Rivers program. The most recent survey was undertaken in March 2022.

Healthy Rivers assessments are conducted using standard methods from the South West Index of River Condition (SWIRC), which incorporates field and desktop data from the site and from the broader catchment. Field data collected included the following indictors, assessed over about a 100 m length of stream:

• Aquatic biota: fish and crayfish community information (abundance of native and exotic species across size classes, general reproductive and physical condition)
• Water quality: dissolved oxygen, temperature, specific conductivity, and pH (logged in situ over 24 hours), as well as laboratory samples for colour, alkalinity, turbidity, and nutrients
• Aquatic habitat: e.g. water depth, substrate type, presence of woody debris and detritus, type and cover of macrophytes and draping vegetation
• Physical form: channel morphology, bank slope and shape, bioconnectivity (barriers to migration of aquatic species), erosion and sedimentation
• Fringing zone: width and length of vegetation cover within the river corridor and lands immediately adjacent, structural intactness of riparian and streamside vegetation
• Hydrology: measures of flow (velocity) at representative locations (compared against data from stream gauging stations within the system)
• Local land use: descriptions of local land use types and activities (compared against land use mapping information for the catchment)

All the Healthy Rivers assessments are listed below.

• 2022 summer (28 February–1 March): Healthy Rivers
• 2018 summer (February 19–20): Healthy Rivers

For a subset of the assessments above, water quality loggers were deployed for extended periods (see below). This enabled assessment of water quality responses to changes in climate, streamflow, and factors such as the intactness of vegetation within the river corridor. Amongst other things, this allows detection of sub-optimal water quality conditions which can be missed during the standard 24-hour assessment.

• 2019–20 summer (December to April)
• 2018–19 summer (November to May)
• 2017–18 summer (December to May)

Other departmental data: The Coolangatta Farm Gauging Station (site reference: 612001) is 250 m downstream of the Coolangatta Gauging Station Upstream site. The gauging station is owned by the Department of Water and Environmental Regulation (the department) and has been in operation since 1968.

Search the site code or site reference in the department’s Water Information Reporting (WIR) system to find data for this site and nearby sampling points (flows, surface water quality, groundwater monitoring, department’s meteorological data). See also the Bureau of Meteorology website for additional meteorological data for the area.

The species captured during each of the sampling events are provided in Table 1. The table includes a list of all species previously reported in the subcatchment, which provides an indication of species that may occur at the assessment site. This list is only indicative as differences in habitat within a subcatchment naturally influence species distributions, and variability in methods between sampling programs can affect the species caught.

Seven species of fish and crayfish were captured in the March 2022 sampling event. This includes two endemic freshwater fish (western minnow and freshwater cobbler), two non-native freshwater fish (eastern gambusia and redfin perch) and three endemic freshwater crustaceans (smooth marron, gilgie and south-west glass shrimp).

Nightfish, western pygmy perch and blue-spot goby were absent from the February 2018 and March 2022 assessments. The absence of these species during the low-flow period is not considered to be of immediate concern as they were present at nearby sites upstream and downstream in March 2022 and healthy populations of other endemic freshwater species were present (i.e. the site retains good water and habitat quality). Nightfish were detected immediately downstream at the Coolangatta Gauging Station Downstream site, and nightfish, pygmy perch and blue-spot goby were recorded further upstream at the Quinns Road 2 site in March 2022. The lack of detection of other species at the site is expected to be related to low sampling effort (i.e. species are present but were not detected, or species had migrated away from the site temporarily); however, this will be closely monitored in future.

The photos of fauna provided are linked to more information about the species, including maps of where each species is expected across the South West.

Note: collection of fauna from inland aquatic ecosystems across Western Australia requires a licence from the Department of Primary Industries and Regional Development (DPIRD) and the Department of Biodiversity, Conservation and Attractions (DBCA). All species collected must be reported to these agencies as part of licence conditions.