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The Parks and Wildlife Service at the Department of Biodiversity, Conservation and Attractions (DBCA) has a key role in monitoring, evaluating and reporting on the environmental health and community benefit of the Swan Canning Estuary and its catchment. Environmental monitoring is focused on water quality, foreshore condition, biological indicators including fish and seagrasses, and community benefit including visitor satisfaction and community use.

The main objectives of the evaluation and reporting program are to track trends, measure compliance against management targets, monitor the extent and severity of low oxygen and algal blooms, report changing conditions to the community, inform catchment models, guide management decisions and incident response, and determine the effectiveness of catchment and estuary management measures.

On these pages, you will find information on:

River Protection Strategy Community Update 2015

This community update is designed to tell the public how the department is tracking with managing the Swan Canning Riverpark and the complex web of ecological pressures impacting our rivers. We all have a role in protecting our waterways and this document builds a shared understanding of the key issues and achievements during 2014-15 for the Swan and Canning rivers.


Estuary water quality

The Parks and Wildlife Service, in collaboration with the Department of Water and Environmental Regulation, conducts weekly water quality monitoring at 40 sites throughout the Swan Canning estuary. Data from these monitoring programs is reported in a number formats including water quality data plots for the Swan and Canning rivers, microalgae activity reports and quarterly estuarine data reports.

Weekly water quality plots

Each week the Parks and Wildlife Service and Department of Water and Environmental Regulation (DWER) conduct extensive water quality sampling, from Bicton to West Swan in the Swan River and Mount Pleasant to Langford in the Canning River.

This information is presented in weekly water quality plots featuring key parameters - salinity, oxygen content (mg/L and percentage saturation) and water temperature.

This data used in these plots is available to the general public from the DWER website or by emailing This email address is being protected from spambots. You need JavaScript enabled to view it..

Microalgae Activity Report

The Microalgae Activity Report (MAR) is a weekly report which informs the public on microalgae levels and the probability of discolouration and/or scum formation at sites throughout the Swan Canning estuary. The MAR is updated on the website on Friday and in the weather page of The West Australian newspaper the following Monday.

Officers from Parks and Wildlife Service and DWER monitor the Swan and Canning rivers on Monday and Tuesday at 20 routine monitoring sites, unless delayed by a public holiday. Samples for microalgae analysis are collected, with processing and reporting taking up to 48 hours.

Concentrations of chlorophyll-a, a plant pigment, are used to estimate microalgal activity. This is presented by the use of low, medium and high activity categories. An alert category may also be used and is based on the types of algal species present and their cell concentrations rather than chlorophyll-a. The alert may be used where an algal species occurs at concentrations that may be harmful to aquatic life or human health and requires public advice.

Key
 LowMediumHighAlert
  Low levels of microalgae with no likely visible impact Possibility of discolouration and/or scum formation High probability of discolouration and/or scum formation Presence of species potentially harmful to aquatic life, OR human health requiring public advice
Chlorophyll-a (µg/L)
< 4 4 - 10 > 10 N/A

This week's Microalgae Activity Report

Week starting: Monday 3 December 2018

  • Microalgae activity was high in the middle Swan and between Shelley and Cannington in the Canning this week.
  • Help keep our rivers healthy by maintaining your boat and prevent oils, fuels and cleaning chemicals from entering the water.
  • Help protect riverbanks – minimise boat wash and observe speed restrictions.
Use the map below to view this week's microalgae levels. Select the map icons for more information.
Note: Levels are published each friday. Trouble viewing the map below? view in a new window..

Map legend - Microalgae Activity Report


 Quarterly estuary water quality reports

Data collected weekly as part of the estuary water quality monitoring program is summarised each quarter in a report produced by the Department of Water. and Environmental Regulation This quarterly data report presents background and current data collected from 20 sites in the Swan and Canning rivers (see map below), representing six ecological management zones:

  • Lower Swan Estuary: BLA, HEA, ARM and NAR
  • Middle Swan Estuary: NIL, STJ, MAY and RON
  • Upper Swan Estuary: KIN, SUC, WMP and MSB
  • Swan River: JBC and POL
  • Canning Estuary: SCB, SAL, RIV and CASMID
  • Lower Canning River: KEN, BAC, NIC and ELL

Within each report, data is presented in graphical and tabular form for 13 key water quality parameters:

  • Total nitrogen
  • Ammonium nitrogen
  • Total oxidised nitrogen
  • Dissolved organic nitrogen
  • Total phosphorus
  • Soluble reactive phosphorus
  • Silica
  • Dissolved organic carbon
  • Total suspended solids
  • Alkalinity
  • Chlorophyll-a
  • Secchi depth
  • Phytoplankton

Annual reporting against estuary targets

The Parks and Wildlife Service's key performance indicators of water quality for the estuary and its catchment, reported in the annual report each year, are:

  • total nitrogen and total phosphorus concentrations in 15 priority sub-catchments
  • chlorophyll-a concentration and dissolved oxygen saturation in surface waters of the estuary

Targets for estuary basins

The surface waters of the estuary are divided into four estuary basins – upper Swan, middle Swan, Canning and lower Swan Canning – and annual targets have been developed for each. These are based on ANZECC 2000 trigger values and statistical principles, to detect the smallest change in water quality.  The targets for the estuary basins relate to chlorophyll-a concentration (a measure of algal biomass) and dissolved oxygen saturation in surface waters.

Estuary Basin

Chlorophyll-a (µgL-1) target

DO Saturation (%) target

Upper Swan

19.98

81.2

Middle Swan

8.75

75.1

Canning

11.67

49.1

Lower Swan Canning

3.55

82.1



Catchment water quality

The Parks and Wildlife Service, in collaboration with the Department of Water and Environmental Regulation (DWER), conducts fortnightly monitoring at 32 sites within 27 of the 31 Swan Canning sub-catchments. Data from these monitoring programs is reported in a number formats including quarterly catchment data reports and sub-catchment nutrient reports.

Quarterly catchment water quality data reports

Data collected fortnightly as part of the catchment water quality monitoring program is summarised each quarter in a report produced by DWER. This quarterly data report presents background and current data representing 27 of the 31 sub-catchments of the Swan Canning river system.

Reports up to 2015 have focused on 15 priority catchments, however data collected from a further 12 sub-catchments will be presented in reports from 2016, depending on data availability.

Data is presented in graphical and tabular format on a catchment-by-catchment basis for each of ten key water quality parameters:

  • Total nitrogen
  • Ammonium nitrogen
  • Total oxidised nitrogen
  • Dissolved organic nitrogen
  • Total phosphorus
  • Soluble reactive phosphorus,
  • Dissolved organic carbon,
  • Total suspended solids,
  • Dissolved oxygen
  • Specific conductivity

Annual reporting against catchment targets

The Parks and Wildlife Service's key performance indicators of water quality for the estuary and its catchment are:

  • total nitrogen and total phosphorus concentrations in 15 priority sub-catchments
  • chlorophyll-a concentration and dissolved oxygen saturation in surface waters of the estuary

Targets for catchments

Median total nitrogen and total phosphorus targets have been developed for catchment tributaries of the Swan Canning river system. In recognition of the long timeframes required for catchment management to affect nutrient levels in tributaries, both short term and long-term targets have been developed.  The long-term targets are based on Australian and New Zealand Environment and Conservation Council (2000) trigger values for near pristine rivers while the short-term targets are double the ANZECC recommendations.

Target Total nitrogen (mgL-1) target Total phosphorus (mgL-1) target
Short-term 2.0 0.2
Long-term 1.0 0.1

Long-term (over 25-40 years) load reduction targets for nitrogen and phosphorus have been established through the Swan Canning Water Quality Improvement Plan.  Although performance against these nutrient load reduction targets is not reported on annually, sub-catchment nutrient reports regularly provide information on nutrient loads from monitored sub-catchments. The nutrient load reduction targets guide long-term investment to improve water quality in those catchments contributing the greatest nutrient loads to the rivers.

Sub-catchment nutrient reports

Data that is collected fortnightly as part of the catchment water quality monitoring program is used to determine the nutrient concentrations and loads entering the Swan and Canning rivers. Long-term trends in this nutrient data are calculated every five years. However, annual calculations of total nitrogen (TN) and total phosphorus (TP) loads are used to report against catchment nutrient targets.

Five-yearly reporting

Nutrient data collected from 15 priority sub-catchments is compiled into 'catchment nutrient reports', which are produced every five years. In these reports, long-term (since 1999) trends in total nitrogen (TN) and total phosphorus (TP) concentrations are calculated and used as a basis for comparison to determine if the nutrient management actions put in place by the Parks and Wildlife Service are having a positive impact. These reports also include:

  • Brief descriptions and maps of each catchment, including size, land use, climate data and annual flows (where available)
  • Analysis of nutrient speciation (e.g. ammonium, oxidised and organic nitrogen as components of total nitrogen)
  • Examination of seasonal variation in nutrient concentrations
  • Exploration of nutrient reduction strategies targeted to each individual catchment
  • Calculation of annual concentrations and loads of TN and TP to assess catchment-by-catchment progress against nutrient targets

The most recent five-yearly nutrient reporting for 15 individual priority sub-catchments was undertaken in 2011, and another 12 in 2014.

The next five-year trend calculation, incorporating all data collected up to (and including) the 2016 calendar year will be available in the second half of 2017. 

Annual reporting

The annual re-calculation of nutrient trends for each catchment is not appropriate because of the high inter-annual variability in nutrient concentrations/loads (which is very dependent on rainfall patterns). However, reporting of annual nutrient concentrations and loads from each catchment is calculated each year to track progress against targets. As a result, the front page of each five-year catchment report is updated annually to provide a catchment-by-catchment measure of annual TN and TP concentrations and loads entering the Swan and Canning rivers.

The most recent annual updates of the nutrient reports use data collected in 2014.



Ecological health

Measures of ecological health complement water quality monitoring and reporting and provide more information about the overall health of the waterway.

The Parks and Wildlife Service is also working with project partners at Murdoch University and the DWER to monitor and evaluate the condition of fish and seagrass communities as indicators of waterway condition.

In addition, some iconic species including the bottlenose dolphins and the western school prawn are being investigated in more detail to understand their populations and factors affecting them.

Monitoring and evaluating fish communities

The Parks and Wildlife Service continues to partner with Murdoch University to annually sample and report on fish communities as an indicator of condition in the Swan Canning Riverpark, with contractual arrangements extending until 2018.

Murdoch University developed the Fish Community Index over five years (2007-12) in collaboration with the State Government. The index uses a suite of fish metrics, including diversity and the number of species, to characterise the fish community and its response to estuarine condition. The index does not focus on individual species or measure biological performance or health of any individual fish species.

The primary purpose of the Fish Community Index is to provide an ecological indicator of estuary condition that complements existing water quality monitoring and evaluation. The index is applied annually as part of an on-going monitoring and reporting framework.

Since 2012, fish communities have been monitored in summer and autumn at six nearshore and six offshore sites in the upper, middle and lower Swan, as well as in the lower Canning.

The 2017 report continues a series of yearly reports and shows that across the estuary the nearshore waters were assessed as fair-good (C/B), while that of the offshore waters of the system was assessed as fair (C), based on fish communities. These results indicate slightly poorer ecological condition in 2017 compared with 2016 and reflect the impact of the flood event that occurred in February 2017.

Unusually high river flows were experienced and resulted in markedly decreased salinities through much of the system. As flows subsided widespread areas were affected by stratified conditions and low dissolved oxygen that persisted into Autumn.

The ecological consequences of these changes were most evident in offshore waters of the Middle Swan Estuary where condition decreased from good (B) in summer to poor (D) in Autumn. Overall, fewer species were caught in 2017, compared with the previous year, as conditions were less favourable for a large number of the marine-associated and estuarine species.

Fish Community Index Report 2017

Seagrass health and distribution

Seagrasses are some of the most productive organisms in the world with productivity rates that can be twice that of forests. They play a role in maintaining oxygen levels at the sediment/water interface, support diverse and productive faunal assemblages and are an important food source for animals such as WA’s iconic black swan.

In the Swan Canning Riverpark there are three main species of seagrass, with paddleweed (Halophila ovalis) the dominant species.

The Parks and Wildlife Service has worked with DWER to develop a robust and easily repeatable method of surveying seagrass species composition and percentage coverage at sites in the lower Swan and Canning estuaries. This is coupled with monitoring of seagrass response to environmental pressures. Insights into seagrass health and distribution provided by this monitoring and evaluation program provide a useful complement to existing water quality reporting and will allow management policies to be specifically targeted at improving the resilience of seagrass in the Swan and Canning estuaries.

Two reports have been released describing the projects and their results to-date.

Dolphin population and health

Bottlenose dolphins (Tursiops aduncus) are a much loved feature of the Swan Canning Riverpark. The Parks and Wildlife Service has a keen interest in the Riverpark’s resident dolphins and works to engage the public in Dolphin Watch, a community-based citizen science dolphin monitoring program, and support research by Murdoch and Curtin universities.

Murdoch University researchers have surveyed the dolphin population in the Swan Canning Riverpark since 2011 and have recorded 52 individual dolphins (including 13 calves) using the waterway during that time. Of those, at least 22 dolphins (excluding calves) are considered resident in the Riverpark.

The dolphins are a natural part of the coastal environment and the Swan Canning Riverpark and are subject to a range of factors that can affect their survival, with an estimated 50% mortality rate in the first five years of life. It is not unusual for at least one dolphin death to occur in the Riverpark in any year. In 2009, six deceased dolphins were collected from the Swan Canning Riverpark over a period of five months, causing serious alarm. A range of factors influenced the mortality event. Morbillivirus was found to be present in the population and is thought to be the underlying factor in the dolphin deaths.

Murdoch University works in partnership with the Parks and Wildlife Service to investigate dolphin deaths in the Riverpark, through necropsy and pathology testing. The university is also researching dolphin health in more detail by taking skin biopsies from live dolphins and evaluating any markers of chronic stress. 

Factors affecting prawn populations

Scientists are using a restocking program to investigate factors that limit the natural recruitment of western school prawns in the Riverpark.

The project, a partnership between Murdoch University and the Parks and Wildlife Service, the Australian Centre for Applied Aquaculture Research (ACAAR) and the Fisheries Research and Development Foundation, is underpinned by a restocking program. The restocking program was made possible by the Recreational Fishing Initiatives Fund and supported by Recfishwest and the Fisheries Division of the WA Department of Primary Industries and Regional Development.

Since the project began in 2012, more than 2400 otter and hand trawl samples have been taken to evaluate stock status and distribution relative to an array of environmental factors. Laboratory and field investigations have examined temperature, salinity and sediment preferences.

This work, along with predation investigations, is complemented by ACAAR's culture and release of 4.5 million prawns and community engagement through the Parks and Wildlife Service's Prawn Watch initiative.

More information on Prawn Watch is available on the River Guardians website.

Foreshore condition

Rivers and estuaries are constantly changing their form in response to natural geomorphic processes, shifts in natural conditions in the surrounding catchment, and human impacts. The foreshore is a dynamic boundary that responds to relative movements in land and water.

Foreshores in the Swan Canning Riverpark comprise two main types:

  • Non-built foreshores: natural shorelines without engineered erosion protection systems, which can be further divided into rocky, vegetated and sedimentary shores. Each of these has different sensitivity to change.
  • Built foreshores: hard-engineering approaches to shore stabilisation that reduce the response of the foreshore to various environmental conditions. These artificial shorelines can be further divided into groyne fields, revetments and walled foreshores.

An assessment of Swan Canning Riverpark foreshores in 2008 reported on the condition of built and natural assets.

The strategy is divided into two parts - the findings of the foreshore assessment describing foreshores, their pressures and condition, and a management strategy summarising foreshore issues, defining management responses and identifying priorities for action.

The assessments, completed in 2008, are currently being reviewed.


Downloads

Fish communities

Seagrass health and distribution

 Dolphin population and health

Foreshore condition

 


Community benefit

The Riverpark is highly valued by the Perth community as an important feature of Perth’s landscape and to the lives of Western Australians. The Riverpark is widely used by the community for a variety of recreational pursuits including fishing, swimming, boating, picnicking, walking and cycling. It also provides a place for contemplation and connection with nature. Economic benefits flow from the Riverpark to those living in its proximity and to business deriving revenue from commercial transport, tourism and hospitality operations.

Community connection and use

People enjoy a connection to the rivers related to their beliefs, traditions and memories and commitment to looking after it. Connection to the Riverpark is developed through visual appeal of the natural elements and overall appearance of each location. Emotional attachment to places within the Riverpark is fostered through spiritual, cultural and historical features of locations.

Indicators of the level of community connection to the Riverpark are grouped under two themes:

  • Aesthetics - reflected by natural appeal and site condition
  • Attachment - reflected in visitation and involvement and sense of place

Use of the Riverpark is enabled through ease of access, having amenable and safe places for relaxation, reflection and socialisation. Maintaining activity infrastructure enables people to engage in physical activity, recreational pastimes and a range of social and community events.

Indicators of use of the Riverpark are grouped under three themes:

  • Activity infrastructure - reflected by activity spectrum, comfort and safety
  • Activity amenity - relaxation and reflection, social interaction
  • Access - land and water

A Useability Index (UI) has been developed to measure these indicators of connection and use. Surveys of Riverpark users and locations are undertaken at selected foreshore reserves and parks.

Visitor/user satisfaction with facilities, activities and management of the Riverpark is measured through interviews with users conducted annually at 35 sites around the foreshore – the same sites as surveyed by UI.

Swimming in the river is a favourite recreational activity. The Department of Health provides information about beach grades and tips for healthy swimming.

Economic Benefit

Economic benefit is the additional financial benefit of commercial and residential development and tourism opportunities gained from the Riverpark.

Indicators of direct and indirect economic benefit include residential property amenity premiums, direct revenue from commercial operations and boat asset value.

Assessment of economic benefit is undertaken every 5-10 years through an independent analysis of available data from government and private sector sources.