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Pressures affecting riverine ecosystems

Key finding

Sediment, nutrients and chemicals, and the loss of riparian forests are the major catchment pressures that broadly impact Queensland’s freshwater rivers but vary in their relative importance between regions.

Queensland

Pressures on Queensland's waterways vary between regions and are generally linked to catchment land uses.

Overall, sediment, nutrients and chemicals are the major catchment pressures that broadly impact Queensland rivers, but these also vary in their relative importance between regions.

Healthy Land and Water South East Queensland report card

The Healthy Land and Water South East Queensland (SEQ) Report Card helps us understand the pressures affecting ecosystem health in freshwater areas.

Much of the natural riverbank vegetation has been cleared for agriculture and urban development in SEQ. This is a major pressure affecting the health of region’s freshwater ecosystems. In 2017 50% of SEQ had forest cover, however clearing rates are the highest in 10 years.

  • Riparian vegetation provides shade for rivers, helping regulate temperature to support habitat for freshwater creatures.
  • Riverbank vegetation filters nutrients and sediments that pollute waterways.

Sediments and runoff from urban activities, particularly construction, and agriculture are a significant pressure, with 30,000 dump trucks worth of sediment entering rivers across SEQ in 2017 alone.

  • Sparsely vegetated riverbanks are highly sensitive to storm events, releasing large amounts of sediment to waterways.

Nutrients from sewage treatment effluent also impact waterways. A major program of sewage treatment plant upgrades and stream rehabilitation has significantly reduced the adverse role of effluent in waterways’ health over the past 15 to 20 years, and agricultural best management practice programs aim to reduce nutrient runoff.

More information:

    Great Barrier Reef report card

    Coastal freshwater wetlands have suffered a range of cumulative pressures such as increased nutrient and sediment loads, loss of connectivity and changes in hydrology. Catchment modifications have led to secondary impacts such as weed infestations, low water quality and algal blooms. For example, wetlands south of Cairns are characterised by extensive development, particularly on coastal lowlands.

    While freshwater wetlands in catchments with less intensive development are usually in better condition, they are still considered highly vulnerable due to impacts such as grazing, soil erosion, feral animals, weeds, altered fire regimes and climate change. Wetlands within the Great Barrier Reef region vary greatly among catchments, thus their response to impacts may differ. The main source of excess nutrients, fine sediments and pesticides in the Great Barrier Reef catchments is from agriculture.

    Condition (state and pressure) of freshwater wetlands was reported in the 2016 report card for the first time. Wetland pressure is assessed based on physical integrity, hydrology, connectivity and biotic integrity. The overall wetland pressure was reported as moderate. The loss of wetlands and riparian vegetation is mostly caused by clearing, often for agricultural use. Wetland modification through bunding can increase the extent of wetlands.

    More information:

      Fitzroy Basin report card

      Water quality in the Fitzroy River is heavily influenced by activities in its catchment: 28 dams and weirs regulate water flows.

      High sediment volumes and turbidity result from its highly variable flow regime, ephemeral streams in its upper reaches, large tidal volumes in the estuary and periods of extensive riverine flooding.

      Water quality varies because of natural variations in geography, geology, climate and soils as well as human activities and land use. Proposed increases in agricultural development, more mining operations and increasing coal seam gas extraction have potential to further impact water quality.

      The Fitzroy Basin is home to several rare and threatened species, and internationally significant wetlands. It has the greatest diversity of native freshwater fish in Australia and supports commercial and recreational fisheries significant to Queensland.

      Rainfall is a major influence on the annual fluctuation of report card scores.

      More information:

      Gladstone Harbour report card

      Freshwater ecosystems not analysed in report card publication.

      More information:

      Mackay-Whitsunday report card

      The Mackay–Whitsunday Healthy Rivers to Reef Partnership report card helps identify the regional pressures affecting waterway health in freshwater, estuarine and marine environments.

      Pressures in the Mackay-Whitsunday region range from those occurring on an international level such as climate change to reef-wide and localised regional pressures, among them coastal, port and agricultural development, tourism and litter.

      Activities in the catchment strongly influence waterway health scores. In a major sugarcane producing area, catchment runoff of pollutants, particularly nutrients and pesticides, present a major pressure, especially in the Pioneer and Plane river basins.

      Loss of wetlands and riparian vegetation is also a key pressure on the region’s basins and estuaries.

      Rainfall impacts water quality. The region was heavily impacted by Severe Tropical Cyclone Debbie in 2017. These impacts are being monitored and will be reported in the 2017 report card.

      More information:

      Wet Tropics report card

      Significant industries in the Wet Tropics region—which includes 2 World Heritage Areas—include tourism, agriculture, ports, aquaculture, fishing, urban and heavy industry.

      The main agricultural sectors—grazing, sugarcane, and banana growing— collectively contribute to sediment, nutrient and pesticide nutrient impacting the local rivers.

      Historic loss of wetlands and estuary habitats of riparian, mangrove and saltmarsh areas have led to poor freshwater grades and estuary and hydrology grades in the Wet Tropics Report Card 2017. Invasive weeds are another pressure impacting freshwater areas.


      More information:

        Condamine Catchment report card

        Technical reports for water, land and nature provide contextual information on pressures from which score card grades are drawn for the Condamine catchment.

        Significant pressures for water come from:

        • irrigated agriculture
        • grazing
        • coal mining
        • coal seam gas production
        • energy generation.

        Intensive agriculture is the most significant pressure identified in the Condamine catchment. The catchment has high quality agricultural soils and is one of the most cleared catchments in Queensland, which has led to reduced tree canopy cover, groundcover, reduced habitat and fragmentation of vegetation.

        Ground cover plays a pivotal role in retaining biodiversity in cleared areas and in protecting land quality in intensive agricultural areas. However, ground cover is only one of many factors influencing the quality of biodiversity habitats and land quality. Other factor include weather patterns, regional ecosystem locations, soil types, farming tillage patterns, erosion hot spots, soil conservation structures, elevation and urban development patterns.

        More information:

        QCatchment Bulloo

        Conceptual models are used to determine catchment specific condition indicators based on the relevant pressures in the catchment.

        The main threats for the Bulloo catchment were:

        • introduced aquatic fauna
        • deposited sediment
        • introduced riparian fauna.

        The overall rating for the Bulloo catchment 2012 was ‘slightly disturbed’.


        I
        ntroduced aquatic fauna such as European carp, goldfish, eastern mosquitofish and red claw crayfish pose the highest potential risk to riverine ecosystems in the Bulloo catchment, but currently represent a ‘low threat’.

        Deposited sediment (sediment settling to the bottom and filling waterholes) was identified as a high potential risk to riverine ecosystems in the Bulloo catchment, but only a ‘slight current threat’.

        Activities such as vegetation clearing and introduced animals in riparian zones (vegetation on the banks of the river) can increase the chances of sediment entering waterholes.

        Introduced riparian fauna, such as feral pigs and unfenced cattle, were identified as a ‘moderate risk’ and ‘moderate current threat’ to riverine ecosystems of the Bulloo catchment, which can cause physical damage to banks and water quality issues.

        More information:

        QCatchment Paroo

        Conceptual models are used to determine catchment specific condition indicators based on the relevant pressures in the catchment.

        The main threats for the Paroo catchment were:

        • introduced aquatic fauna
        • deposited sediment
        • introduced riparian fauna.

        The overall rating for the Paroo catchment 2012 was ‘moderately disturbed’.

        Introduced aquatic fauna such as European carp, goldfish, eastern mosquitofish and red claw crayfish pose the highest potential risk to riverine ecosystems in the Paroo catchment and currently represent a ‘moderate threat’.

        Deposited sediment (sediment settling to the bottom and filling waterholes) was identified as a ‘high potential risk’ to riverine ecosystems in the Paroo catchment but only represents a ‘slight current threat’.

        Activities such as vegetation clearing and introduced animals in riparian zones (vegetation on the banks of the river) can increase the chances of sediment entering waterholes.


        Introduced riparian fauna, such as feral pigs and unfenced cattle, were identified as a ‘moderate risk’ and ‘moderate current threat’ to riverine ecosystems of the Paroo catchment, which can cause physical damage to banks and water quality issues.

        More information:

        QCatchment Warrego

        Conceptual models are used to determine catchment specific condition indicators based on the relevant pressures in the catchment.

        Main threats to the Warrego catchment were:

        • introduced aquatic fauna
        • deposited sediment
        • introduced riparian fauna.

        The overall rating for the Warrego catchment 2012 was ‘moderately disturbed’.

        Introduced aquatic fauna such as European carp, goldfish, eastern mosquitofish and red claw crayfish pose the highest potential risk to riverine ecosystems in the Warrego catchment, but only a ‘slight current threat’.

        Deposited sediment (sediment settling to the bottom and filling waterholes) was identified as a ‘high potential risk’ and ‘moderate current threat’ to riverine ecosystems in the Warrego catchment, with activities such as vegetation clearing and introduced animals in riparian zones (vegetation on the banks of the river) increasing the chances of sediment entering waterholes.

        Introduced riparian fauna, such as feral pigs and unfenced cattle, were identified as a ‘moderate risk’ and ‘moderate current threat’ to riverine ecosystems of the Warrego catchment, which can cause physical damage to banks and water quality issues.

        More information:

        QCatchment Nebine

        Conceptual models are used to determine catchment specific condition indicators based on the relevant pressures in the catchment.

        Main threats for the Nebine catchment were:

        • introduced aquatic fauna
        • deposited sediment
        • introduced riparian fauna.

        Introduced fauna such as European carp, goldfish, eastern mosquitofish and red claw crayfish pose the highest potential risk of the risks considered and a ‘moderate current threat’ to riverine ecosystems in the Nebine catchment.

        Deposited sediment (sediment settling to the bottom and filling waterholes) was identified as a ‘high potential risk’ to riverine ecosystems in the Nebine catchment, but a ‘low current threat’.

        Activities such as vegetation clearing and introduced animals in riparian zones (vegetation on the banks of the river) can increase the chances of sediment entering waterholes.

        Introduced riparian fauna, such as feral pigs and unfenced cattle, were identified as a ‘moderate risk’ but only a represent a ‘slight current threat’ to riverine ecosystems of the Nebine catchment.

        More information:

        QCatchment Lake Eyre

        An ecological risk assessment of threats to waterways in the province identified three threats for further investigation:

        • introduced riparian fauna
        • introduced aquatic fauna
        • introduced riparian weeds.

        No overall condition score was provided for the Lake Eyre and Bulloo Province.

        Introduced riparian fauna (feral pigs and cattle) was assessed as a ‘moderate risk’, as pigs and cattle have access to the riparian zone (vegetation on the banks of the river). Slightly higher risks (in the high end of the ‘moderate’ range) were observed in the Georgina and Diamantina catchments. Overall, cattle impact was more severe than pig impact at surveyed sites across the Province.

        The province as a whole was ranked at ‘moderate risk’ from introduced aquatic fauna, based on the Georgina and Cooper being at ‘moderate risk’. However the Bulloo and Diamantina were at ‘no risk’.

        Risk to ecosystem condition from introduced riparian weeds was assessed to be ‘slight’ in the Bulloo catchment, ‘moderate’ in the Diamantina and Cooper Creek catchments and ‘high’ in the Georgina catchment. Risk overall from riparian weeds was ‘moderate’.

        The highest numbers of targeted weed species were recorded in the Cooper and Georgina catchments.

        More information:

        QCatchment Archer

        Field-collected data was used to assess identified key threats, rating the overall threat to Archer catchment’s riverine ecosystems as ‘moderate.

        Key current threats for the Archer catchment were:

        • introduced riparian fauna (e.g. feral pigs, unfenced stock)—moderate
        • introduced riparian flora (e.g. rubbervine, sicklepod)—severe
        • introduced aquatic fauna—low.

        Introduced riparian fauna, such as stock and feral pigs, accessing the riparian zone, river bank and channel pose the main threat.

        While introduced riparian flora condition was ranked as ‘minor disturbance’, the threat is severe as only 1 of 4 sites was weed-free.

        Neither cane toads nor their tadpoles were sighted at any sites but are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

        More information:

        QCatchment Coleman

        The Coleman catchment is on the western coast of Cape York, and includes several river systems including the Coleman and Edward rivers.

        Field-collected data was used to assess identified key threats, rating the overall threat to Coleman catchment’s riverine ecosystem as ‘moderate’.

        Key current threats identified for the Coleman catchment were:

        • introduced riparian fauna (e.g. feral pigs, unfenced stock)—moderate
        • introduced aquatic flora—low
        • introduced aquatic fauna—low
        • introduced riparian flora (e.g. rubbervine, sicklepod)—moderate.

        Cattle and feral pigs accessing the riparian zone, bank and channel pose the main threat to Coleman catchment riverine ecology.

        Riparian weeds were found at low levels of infestation: conditions can change rapidly, hence cause for concern.

        The potential for spread of pest fish species into the region is high, and remains a risk. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

        More information:

        QCatchment Ducie

        The Ducie catchment is on the north-west coast of Cape York, and drains to the Gulf of Carpentaria.

        Field collected data was used to assess identified key threats, rating the overall threat to Ducie catchment’s riverine ecosystem as ‘moderate.

        The QCatchments assessment identified key threats to riverine ecosystem components using field-collected data. The overall rating of threats to riverine ecosystems in the Ducie was ‘moderate’.

        Key current threats identified for the Ducie catchment were:

        • introduced riparian fauna (e.g. feral pigs, unfenced stock)—moderate
        • introduced riparian flora—low
        • introduced aquatic flora—low
        • introduced aquatic fauna—low.

        The assessment concluded that while the catchment was in good condition, feral pigs and cattle accessing the riparian zone posed the main threat to riverine ecology.

        The current threat of introduced fish species was assessed as low however potential for spread of pest fish species and cane toads is high, and therefore remains a moderate risk. Cane toads or their tadpoles were not sighted at any sites but are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

        More information:

        QCatchment Endeavour

        The Endeavour catchment is on the eastern coast of Cape York, and includes the Endeavour and Annan river systems.

        Field-collected data was used to assess key threats, rating the overall threat to Endeavour catchment’s riverine ecosystem as ‘moderate’.

        Identified key threats for the Endeavour catchment were:

        • introduced riparian fauna—moderate
        • introduced riparian flora—high
        • introduced aquatic fauna—low
        • introduced aquatic flora—low.

        Introduced riparian flora, including infestations of lantana, rubbervine and sicklepod, posed a high current threat.

        Despite the low current threat identified for aquatic fauna, introduced aquatic fauna present a high risk. Tilapia have been sampled in the Endeavour previously; confirmation of continued existence would impact on current threat and condition. Cane toads or their tadpoles were not sighted at any sites but are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

        More information:

          QCatchment Holroyd

          The Holroyd catchment is on the west coast of Cape York, and drains into the Gulf of Carpentaria.  It includes the Holroyd and Kendall river systems and many smaller creeks.

          Field-collected data was used to assess key threats, rating the overall threat to Holroyd catchment’s riverine ecosystems as ‘moderate’.

          Key threats identified for the Holroyd catchment were:

          • introduced riparian fauna (e.g. feral pigs, unfenced stock)—moderate
          • introduced riparian flora—severe
          • introduced aquatic fauna—low.

          Introduced riparian fauna and flora pose the greatest threats. Impacts from feral pigs and cattle were observed at all sites. The current threat rating for riparian flora was severe, with 2 sites having sicklepod. While introduced aquatic fauna were ranked as a low current threat, cane toads were sighted and are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

          More information:

          QCatchment Jacky Jacky

          The Jacky Jacky catchment is on the north-east coast of Cape York. It includes the Jackey Jackey and Harmer creeks, Escape River and numerous smaller coastal streams.

          Field-collected data was used to assess key threats, rating the overall threat to Jacky Jacky catchment riverine ecosystems as ‘moderate’.

          Key threats identified for the Jacky Jacky catchment were:

          • introduced riparian fauna (feral pigs)—moderate
          • introduced riparian flora—low
          • introduced aquatic fauna—low.

          Feral pigs accessing the riparian zone, river bank and channel pose the main current threat to riverine ecology in the Jacky Jacky catchment.  This assessed threat was higher than initial risk assessments. Other than moderate levels of feral pig damage, excellent scores were recorded in all other field measurements.

          While no pest fish species have been found to date, there is an ongoing risk of spread into the catchment from the north (via Torres Strait) and from catchments to the south of Cape York. Cane toads or their tadpoles were not sighted but are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

          More information:

            QCatchment Jardine

            The Jardine catchment is the northern-most catchment on the Australian mainland, at the tip of Cape York. It drains in a north-westerly direction into Torres Strait.

            Field-collected data was used to assess identified key threats, rating the overall threat for Jardine catchment’s riverine ecosystem as ‘moderate’.

            Key threats identified for the Jardine catchment were:

            • introduced riparian fauna (e.g. feral pigs)—moderate
            • introduced riparian flora—low
            • introduced aquatic fauna—low.

            With damage evident at all sites, feral pigs were deemed the main current threat to Jardine catchment riverine ecology.

            The absence of priority weed infestations at assessment sites led to a low current threat. The lack of any pest fish species in the assessment resulted in a low current threat rating however the risk is ongoing from the north (via Torres Strait) and from catchments to the south of Cape York. Cane toads or their tadpoles were not sighted but are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

            More information:

              QCatchment Jeannie

              The Jeannie catchment is on the east coast of Cape York and includes the Jeannie and Starcke river systems.

              Field-collected data was used to assess key current threats, rating the overall threat to Jeannie catchment riverine ecosystems as ‘minor’.

              Key threats identified for the Jeannie catchment were:

              • introduced riparian fauna (e.g. feral pigs)—minor
              • introduced riparian flora—low
              • introduced aquatic fauna—low

              From the single site assessed, feral pigs accessing the riparian zone, river bank and channel were deemed the main current threat to riverine ecology.

              While riparian weeds were not recorded at the assessment site, they have been identified as a risk as expanding tourism could enable weed spread via 4WD vehicles. Although no pest fish species were found, there remains an ongoing risk of spread into the catchment from the north (via Torres Strait) and from catchments to the south of Cape York. Cane toad eggs were found at the site. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

              More information:

                QCatchment Lockhart

                The Lockhart catchment is on the east coast of Cape York and includes the Lockhart, Claudie and Nesbit rivers.

                Field-collected data was used to assess current identified key threats, rating the overall threat to Lockhart catchment’s riverine ecosystems as ‘moderate’.

                Key threats identified for the Lockhart catchment were:

                • introduced riparian fauna (e.g. feral pigs)—moderate
                • introduced riparian flora—low
                • introduced aquatic fauna—low.

                Introduced riparian fauna (i.e. feral pigs and cattle) accessing the riparian zone, river bank and channel pose the main  current threat to riverine ecology in the Lockhart catchment

                While there was no evidence of priority weed species present at the assessment sites, there are known to be weeds (e.g. sicklepod, grader grass, pond apple) in the catchment.  No pest fish species were found, however an ongoing risk of spread remains from the north (via Torres Strait) and from catchments to the south of Cape York. A cane toad was sighted at one of the sites. (The presence of cane toads is not reflected in the condition scores because of their extensive presence across Cape York.).

                More information:

                  QCatchment Normanby

                  The Normanby catchment is located in the south-east of Cape York.

                  Field-collected data was used to assess identified key threats, rating the overall threat to Normanby catchment’s riverine ecosystem as ‘moderate’.

                  Key current threats identified for the Normanby catchment were:

                  • introduced riparian fauna (e.g. cattle, feral pigs)—moderate
                  • introduced riparian flora—moderate
                  • introduced aquatic flora—low
                  • introduced aquatic fauna—slight.

                  Introduced riparian flora and fauna pose the highest risk to Normanby catchment riverine ecosystems. Cattle and feral pigs are likely to be having a negative impact on waterholes by destroying habitat, increasing erosion and contributing contaminants to water. The presence of significant and widespread infestations of weeds among monitoring sites (including lantana, rubber vine and sicklepod) indicated a moderate current threat.

                  Goldfish were identified at 1 isolated site and the area is a high risk for other introductions, especially tilapia. Cane toads or their tadpoles were identified at most assessment sites. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.

                  More information:

                    QCatchment Olive-Pascoe

                    The Olive-Pascoe catchment is located on the east coast of Cape York, and includes the Olive, Pascoe and Claudie rivers.

                    Field-collected data was used to assess identified key threats to riverine ecosystem, rating the overall   threat the Olive-Pascoe catchment as ‘severe’.

                    Key threats identified for the Olive-Pascoe catchment were:

                    • introduced riparian fauna (e.g. cattle, feral pigs)—minor
                    • introduced riparian flora—severe
                    • introduced aquatic fauna—low.

                    Introduced riparian flora poses the main threat to riverine ecology in the Olive-Pascoe catchment. While weeds (including rubbervine and sicklepod) were recorded at low levels of abundance, their widespread presence implies ecosystem condition could change quickly. Tourism is expanding in Cape York, increasing the chance of weed spread via 4WD vehicles.

                    No pest fish species were found in this or previous surveys, however a risk of spread remains from the north (via Torres Strait) and from catchments to the south of Cape York. Cane toads are known to occur in the catchment. (The presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.)

                    More information:

                      QCatchment Stewart

                      The Stewart catchment is located on the east coast of Cape York.

                      Field-collected data was used to identify key current threats to riverine ecosystem components, rating the overall threat in the Stewart catchment as ‘minor’.

                      Key threats identified for the Stewart catchment were:

                      • introduced riparian fauna (e.g. cattle, feral pigs)—minor
                      • introduced riparian flora—low
                      • introduced aquatic fauna—low.

                      Based on evidence of minor impacts at sites (mainly from pigs), there is expected to be little change in instream flora and fauna community structure.  There were no infestations of priority weeds at the monitoring sites, hence a low current threat was recorded for riparian flora.

                      No pest fish species were identified in this assessment (or in previous surveys), however the threat remains and would have serious consequences to aquatic ecosystems across Cape York if they establish.  While cane toad adults were sighted in very high numbers at 1 site, the presence of cane toads is not reflected in the threat scores because of their extensive presence across Cape York.

                      The assessment also identified suspended and deposited sediments as posing a higher risk in the Stewart catchment than Cape York generally.

                      More information:

                        QCatchment Wenlock

                        The Wenlock catchment is located on the west coast of Cape York.

                        Field-collected data was used to assess identified key current threats to riverine ecosystem, rating the overall threat the Wenlock catchment as ‘severe’.

                        Key threats identified were:

                        • introduced riparian fauna (e.g. cattle, feral pigs)—minor
                        • introduced riparian flora—severe
                        • introduced aquatic flora—low
                        • introduced aquatic fauna— low.

                        Riparian weeds pose the main threat to Wenlock riverine ecology, with infestations of rubbervine and sicklepod in evidence.

                        While aquatic flora was assessed as having low threat (no introduced aquatic flora infestations at sites), there are anecdotal reports of water hyacinth in this catchment and water lettuce has been identified in adjoining catchments.

                        Aquatic fauna was considered a ‘low’ current threat with no pest fish species identified in this assessment. Potential remains for such spread into the region; exotic and translocated fish could have a devastating impact on the Wenlock, as it is one of the most diverse catchments in Australia in terms of freshwater fish.

                        Cane toads or their tadpoles were not sighted at any of the sites but are known to occur in the catchment.

                        More information:

                        Indicator: Pressures identified in report card area

                        Pressures identified in various water quality report card areas across Queensland.

                        Download data from Queensland Government data

                        Last updated 8 January 2019

                        Assessment summary

                        See an overview of gradings for freshwater wetland ecosystems in the assessment summary.