Assessment of River and Estuarine Condition

Transcription

1 Bellinger-Kalang Rivers Ecohealth Project Assessment of River and Estuarine Condition Final Technical Report to the Bellingen Shire Council Darren Ryder, Rob Veal, Carla Sbrocchi & John Schmidt

2 Cover Photo: Bellinger River catchment from Dorrigo National Park. Photo by D.Ryder 2010.

3 Bellinger-Kalang Rivers Ecohealth Project Assessment of River and Estuarine Condition Final Technical Report to the Bellingen Shire Council. March Darren Ryder and Rob Veal. School of Environmental and Rural Science, University of New England, Armidale, NSW Carla Sbrocchi. Northern Rivers Catchment Management Authority, 41 Belgrave St Kempsey, NSW John Schmidt. NSW Department of Environment, Climate Change and Water, 41 Belgrave St Kempsey, NSW 2440.

4 Acknowledgements This project was funded by the Bellingen Shire Council with supporting funds from the NSW Department of Environment, Climate Change and Water. Special thanks to the Ecohealth Technical Reference Group for providing valuable information and for their ability to help overcome hurdles. The people below provided significant support for the proct, our thanks to each of them. Ian Turnbull and Andrew Rickert: Bellingen Shire Council. Michael Healey and Tod Lockridge: NSW Office of Water Tony Broderick, Nigel Blake and Max Osborne: NRCMA Maxine Rowley, Geoff Code and Yoshi Kobayashi: NSW DECCW Thor Aaso: Port Macquarie Hastings Council Hamish Malcolm: Solitary Island Marine Parks Authority Malcolm Robertson: Coffs Harbour Council Marion Costigan, Adrienne Burns, Morag Stewart, Jake Chandler and Peter Berney: University of New England This report should be cited as: Ryder, D, Veal, R, Sbrocchi, C and Schmidt, J (2011). Bellinger-Kalang Rivers Ecohealth Project: Assessment of River and Estuarine Condition Final Technical Report to the Bellingen Shire Council. University of New England, Armidale 75pp. Project Contact Dr Darren Ryder School of Environmental and Rural Science University of New England, Armidale, NSW darren.ryder@une.edu.au Ph i

5 Table of contents Summary i 1. Background 1 2. Scope 1 3. Project Objectives 2 4. Report Structure 3 PART 1. Study Area, Design and Site Descriptions 5. Study Area and Design 4 6. Study Sites 8 PART 2. Ecological Indicators: Water Quality, Macroinvertebrates and Riparian Condition 7. Water Quality Indicators 7.1 Background Field and Laboratory Methods Results Summary of Findings 52 8 Macroinvertebrates 8.1 Background Field and Laboratory Methods Data Analyses Results Summary of Findings 58 9 Riparian Condition 9.1 Background Development of a Sub-tropical Rapid Assessment of Riparian Condition Field methods Results Summary of Findings 65 PART 3. Management Recommendations and Future Monitoring Water Quality 66 Macroinvertebrates 68 Riparian Condition 68 References 70 Appendices 71 ii

6 Summary The development of a standardised means of collecting, analysing and presenting riverine, coastal and estuarine assessments of ecological condition has been identified as a key need for coastal Catchment Management Authorities and Local Councils who are required to monitor natural resource condition, and water quality and quantity in these systems. This project was conducted over a 12 month period in the Bellinger and Kalang Rivers to contribute to the assessment of the ecological condition of the catchment. The project aimed to assess the health of coastal catchments using standardised indicators and reporting for estuaries, and upland and lowland river reaches using hydrology, water quality, riparian vegetation and habitat quality, and macroinvertebrates assemblages as indicators of ecosystem health in the Bellinger/Kalang system, contribute scientific information to the development of a report card system for communicating the health of the estuarine and freshwater systems in the Bellingen Shire. Hydrology Indicative discharge for the region was calculated from mean daily discharge at the Thora Gauge on the Bellinger River. Peak discharge during the study period of October 2009 to September 2010 was 5157 ML/day recorded on November 8 th The minimum discharge recorded was 68 ML/day on September 14 th Mean monthly discharge ranged from 98.2 ± 38.5 ML/day in September 2010 to ± ML/day in March 2010 (Figure 2). The absence of high flow events during the study period must be considered when interpreting the results from the water quality monitoring. Water Quality Water chemistry variables; ph, conductivity and salinity, dissolved oxygen (DO), temperature and turbidity were measured in situ from 22 sites (10 freshwater, 12 estuarine) each month in the Bellinger and Kalang Rivers from October 2009 to September Samples for TN, TP, SRP and NOx were also sampled from each site. ANZECC trigger values for ph, dissolved oxygen, nitrogen and phosphorus, and turbidity were exceeded in some months at sites within both river systems. Spicketts Creek in the Kalang catchment was particularly noteworthy as a freshwater site that exceeded the trigger values for nitrogen, phosphorus, DO and turbidity. Tributaries in both catchments had higher turbidity than the main stem of each river, suggesting these systems may be a source of suspended material. Calculation of nutrient loads entering the estuary of each river system revealed the Bellinger River supplies a disproportionate amount of N (460 tonnes/year), P (86 tonnes/year) and iii

7 suspended solids (4320 tonnes/year) compared to the inputs from the Kalang River. These differences arise from the higher discharge in the Bellinger River rather than higher concentrations. The highest loads of N, P and suspended sediment were associated with high discharge levels, suggesting flood flows contribute substantial volumes of sediments to downstream reaches. Macroinvertebrates Macroinvertebrates were collected from 10 freshwater sites in Spring 2009 and Autumn This included five sites in the Kalang catchment (including one on Spicketts Creek as major tributary) and 5 sites in the Bellinger catchment (including one in Rosewood River and one in Never Never River as major tributaries). In Autumn, a total of 2003 individual macroinvertebrates from 22 families were collected from the Bellinger River, while abundance was lower in the Kalang River with 826 individuals collected from 23 families. In Spring, the pattern in abundance was reversed with a total of 1330 individuals collected in the Kalang River from 22 families, with 747 individuals from 21 families collected from the Bellinger River. SIGNAL grades for macroinvertebrate Families ranged from 2 to 10 in main stem reaches on the Bellinger and Kalang Rivers, with a median score of 5 to 6 for both rivers and seasons. Tributaries generally ranged from 2-8, with Spicketts Creek displaying a consistently low SIGNAL score, reinforcing the poor water quality and habitat condition documented in this study. Riparian Condition An assessment of the riparian condition was undertaken from 10 freshwater sites in This included five sites in the Kalang catchment (including one on Spicketts Creek as major tributary) and 5 sites in the Bellinger catchment (including the Rosewood and Never Never Rivers as major tributaries). The Bellinger catchment had an average riparian condition score of 7.14/10, ranging from 6.75 to Sites in the Kalang catchment had an average riparian condition score of 5.27/10 ranging from 3.89 to The most upstream sites in each river consistently had the best condition score. Sub-index scores revealed that the Bank Condition indicator contributed most to a positive riparian condition score in the Bellinger catchment sites. In the Kalang catchment, riparian condition scores were consistently low across all indicators. Major disturbances to the riparian zone identified by this study that have reduced the riparian condition score are weeds, reduced number of vertical strata leading to simplified canopy structure, and minimal riparian habitat in the form of organic litter and woody debris. Poor bank condition as evidenced by undercutting and bank slumping were consistent issues in all iv

8 tributaries, and may provide a link to increased suspended sediment loads recorded from these systems. Recommendations Interpreting water quality variables relies on trigger values generic to a broad range of systems. Recommend the development of regional-scale or system-specific trigger values for water quality indicators relevant to current or predicted water quality issues in the catchment. Determination of estuarine health is currently limited to water quality variables. Recommend the development of biotic indicators for estuarine environments to compliment water quality indicators. Biota provide a temporally-integrative indicator of change as they have a longer residence time in any location that a parcel of water. Broaden future monitoring to incorporate an increased number of tributaries in each catchment to help identify sub-catchment level sources of poor water quality. Continue to monitor water quality in reaches approximate to the limit of tidal influence for water quality as the impacts on these reaches are more pronounced. Develop long-term water quality sample sites at locations with active discharge measurements to determine load-based nutrient and sediment inputs to estuarine environments. This project was conducted during a period of consistently low discharge and an absence of flood flows. Recommend developing a flood-based monitoring program to sample high flows of various magnitudes to develop load-based calculation for different flow events. Continue to collect samples for macroinvertebrate community composition in Autumn and Spring on an annual basis. In addition it is recommended to incorporate macroinvertebrate sampling into the recommended flood-based sampling protocol as measures of resilience and recovery post flood disturbance. Priority actions for riparian zones in all reaches should focus on weed management, increasing structural complexity of canopy such as native vines, improving riparian habitat in the form of organic litter and woody debris, and addressing undercutting, exposed roots and slumping of channel banks. Priority areas for riparian restoration are Spicketts Creek, Kalang Scotchman, Kalang Brierfield, and Never Never River. v

9 1. Background The NSW Natural Resources Monitoring Evaluation and Reporting (MER) Strategy was prepared by the Natural Resources and Environment CEO Cluster of the NSW Government in response to the Natural Resources Commission standard and targets and was adopted in August The purpose of the Strategy is to refocus the resources of NSW natural resource and environment agencies and coordinate their efforts with CMAs, Local Governments, landholders and other natural resource managers to establish a system of monitoring, evaluation and reporting on natural resource condition. At this time there was no consistent monitoring of estuarine ecological condition in NSW. Working groups were formed to consider the most appropriate indicators and sampling designs to enable a statewide assessment of the ecological condition of rivers and estuaries. This report outlines the approach taken by stakeholders in the Bellinger LGA to supplement the MER monitoring and is aligned with the objectives of the Bellinger River Health Plan Scope Estuarine and coastal lagoon systems are focal points for the cumulative impacts of changed catchment land-use, and increasing urbanisation and development in coastal zones (Davis and Koop 2006). As a result, these ecosystems have become sensitive to nutrient enrichment and pollution, and degraded through habitat destruction and changes in biodiversity. The development of a standardised means of collecting, analysing and presenting riverine, coastal and estuarine assessments of ecological condition has been identified as a key need for coastal Catchment Management Authorities and Local Councils who are required to monitor natural resource condition, and water quality and quantity in these systems. This project will review and integrate information from the following sources to develop an Ecohealth framework: The NSW Monitoring, Evaluation and Reporting (MER) Program currently monitoring NSW estuaries on a bi- or tri-annual basis; NSW State of Environment (SoE) and proposed State of Catchments (SoC) reports, EHMP Healthy Waterways program; proposed estuary report cards from the NLWRA (through WA D of Water), NSW Estuary Management Policy and Coastal Zone Management Manual and relevant Estuary Management Plans, sampling protocols developed by the CRC for Coastal Zone, Estuary and Waterway Management. The Ecohealth Waterways Monitoring Program outlines a framework for the development of a catchment-based aquatic health monitoring program for rivers and estuaries in the Northern 1

10 Rivers CMA with the aim of providing consistency in monitoring and reporting, and establish the partnerships required for local and regional dissemination of outcomes. This project brings together major stakeholders in the coastal management of Northern NSW; State agencies (NRCMA, DECCW, DII Fisheries), Local Council (Bellingen) and University Researchers (UNE) to develop, refine, report and promote a standardised estuarine health assessment tool for the Bellinger/Kalang system. This project is a pilot program to trial designs, methods and variables that may contribute to the Ecohealth framework. The main output will be specific monitoring and management plans for the study areas, with a generic framework outlining a standardised (and trialled) set of partnership, monitoring, data management and reporting protocols for implementation in coastal catchments throughout NSW. This framework will facilitate an effective reporting mechanism to communicate water quality and resource condition information to the general public stakeholders and managers through a simple report card system to be developed by the NRCMA. 3. Project Objectives to assess the health of coastal catchments using standardised indicators and reporting for estuaries, and upland and lowland river reaches using hydrology, water quality, riparian vegetation and habitat quality, and macroinvertebrates assemblages as indicators of ecosystem health in the Bellinger/Kalang system, to contribute scientific information for the development of a report card system for communicating the health of the estuarine and freshwater systems. 2

11 4. Report Structure Part 1 of the report outlines the catchment characteristics of the Bellinger and Kalang Rivers as context of the need for river and estuarine monitoring, and to provide the background to study design and site selection processes. 5. Study Area and Study Design provides information on the catchment characteristics of the Bellinger and Kalang Rivers such as area, hydrology and land-uses. A detailed description of the study design and protocols developed for site selection are provided. 6. Study Sites section provides a detailed site description for the 22 study sites, including the range of water quality conditions measured, physical measures of channel and bank characteristics, riparian features and local disturbance issues. Part 2 of the report provides a detailed report on the monthly water chemistry and biophysical data collected from October 2009 to September Results from the three groups of indicators used are reported at spatial scales of river and site, and temporal scales of year, season and month. 7. Water Quality section identifies trends in nutrient (nitrogen and phosphorus), chlorophyll a and suspended solids values, as well as static variables such as ph, salinity, dissolved oxygen and temperature. Sites that exceed NSW MER or ANZECC guideline thresholds are identified. 8. Macroinvertebrate assemblages collected from 10 freshwater sites in Spring 2009 and Autumn 2010 are used to assess long-term condition of in channel habitats. The taxonomic richness, abundance and diversity are reported, as well as health indicators using SIGNAL2 scores and percent EPT. 9. Riparian Condition assessment provides information for the 10 freshwater sites on the cover, structure and habitat as indicators of a health riparian ecosystem at each site, as well as an identification of local-scale disturbances to riparian zones. Part 3 provides management recommendations for the future management of the instream and riparian condition in the Bellinger and Kalang Rivers, and identifies priorities for future monitoring within the Ecohealth framework. 3

12 5. Study Area and design Study Area PART 1 STUDY AREA, DESIGN AND SITE DESCRIPTIONS The Bellinger catchment is situated on the Mid North Coast of NSW encompassing approximately 1,110 km 2 (Figure 1). The two main rivers in the catchment are the Kalang River (330 km 2 ) to the south and the Bellinger River (780 km 2 ) to the north. The catchment is approximately 70km long and 20km wide. Most of the catchment is mountainous with limited areas of flat land associated with river and creek valleys and the coastline. Major tributaries of the Bellinger River are the Never Never and Rosewood Rivers, and Spicketts Creek and Pickett Hill Creek in the Kalang River. The Bellinger-Kalang estuary covers an area of approximately 160 km 2, with the rivers sharing a common entrance to the Pacific Ocean at Urunga. The regional climate is sub-tropical with warm, wet humid summers and mild, dry winters. Annual average rainfall for the area is 1526 mm with the majority of rainfall occurring in the summer period of December to April with average monthly rainfalls of mm (BoM 2010). The upper catchment of the Bellinger/Kalang Rivers is predominantly forested. More than half the catchment area is contained within State Forest, National Parks and Nature Reserve boundaries (Lawson and Treloar 2003). Logged native forests are a next major land use type, with agricultural use of the floodplain for beef cattle, dairy cattle, small fruit, vegetable and nut operations. Urban areas within the catchment are dominated by the towns of Bellingen and Urunga, and a number of small settlements throughout the catchments. The long-term flow record for the catchment is limited to gauges at Thora (205002) and a new gauge upstream of Bellingen (Fosters) on the Bellinger River, as well as rainfall-runoff models that estimate mean annual runoff is approximately 1,482,000 ML/yr (BoM 2010). Discharge data are available for additional sites and tributaries relevant to this study but the BoM would not release data due to unreliable cusum curves for these sites. Long-term flow modeling is available in Telfer and Cohen (2010). Indicative discharge for the region was calculated from mean daily discharge at the Thora Gauge on the Bellinger River. Discharge during the study period of October 2009 to September 2010 did not include any major flooding, with a peak discharge of 5157 ML/day recorded on November 8 th The minimum discharge recorded was 68 ML/day on September 14 th Mean monthly discharge ranged from 98.2 ± 38.5 ML/day in September 2010 to ± ML/day in March 2010 (Figure 2). Variability in discharge was highest from October 2009 to March 2010 with the standard deviation of discharge ranging from 0.8 to 2.2 times the mean indicating highly variable (but low magnitude) flow regimes during this period. From April to September 2010 a standard deviation of 0.17 to 0.4 of the mean discharge was recorded indicating a period of relatively stable discharge. 4

13 Figure 1: Bellinger and Kelang Catchments (Source Northern Rivers Catchment management Authority, 2011) 5

14 Mean Daily Discharge ML/day Figure 2: Mean daily discharge ± standard deviation at Thora gauge (205002) on the Bellinger River from October 2009 to September Study Design The design of the Ecohealth freshwater/estuarine monitoring program for the Bellinger and Kalang Rivers is based on the NSW Monitoring, Evaluation, Reporting (MER) protocols for Rivers and Estuaries, and aligned for reporting outcomes used in the South-East Queensland Ecosystem Health Monitoring program (EHMP) methodologies, as well as previous ecosystem health assessments undertaken within the local region. The number and location of sample sites has been designed to be statistically robust, and as such, will provide a data set that can be used to assess spatial and temporal variability of the system, and in time, further refine the monitoring program. Constraints on study design from available budgets limited the project to 22 sample locations and monthly sampling for water quality. The location of the 10 freshwater monitoring sites (5 sites on each river) was based on selection criteria to: identify longitudinal change within the main stem of each river system, represent major tributaries of each river system or were identified by stakeholders as tributaries of interest for management; compare River Styles and elevations within and across catchments, locate ecological changes at the point of the tidal limit. 6

15 The location of the 12 estuarine monitoring sites (5 on the Bellinger River and 7 on the Kalang River) was based on selection criteria to: identify longitudinal change within the main stem of each river system, represent paired sites within salinity categories of; 0-15ppt, 15-30ppt and 30+ppt; compare River Styles and elevations within and across catchments, locate ecological changes at the point of the tidal limit. Sampling schedule Monthly sampling for water chemistry, bi-annual sampling for freshwater macroinvertebrates, and a once-off assessment of riparian condition were undertaken from October 2009 to September 2010 (Table 1). Each water chemistry sampling event was undertaken over a 3-day period to ensure consistency in sampling with tidal regime. The estuarine sites on the Bellinger and Kalang Rivers were sampled consistently on an incoming high tide to maximize access to all sites via boat. The average 40 minute difference in mean high tide on consecutive days facilitates comparable data collection, and required adjusted start times for each sampling event. Sites BR4 to BR8 on the Bellinger River, and KR 5 KR11 on the Kalang River were sampled using a boat supplied by DECCW. All other sites were sampled via road access and vehicles. Table 1: Sampling regime for field collection of water quality and biota. Event Date Variables from freshwater sites Variables from estuary sites 1 Oct Water Quality, Invertebrates Water Quality 2 Nov Water Quality Water Quality 3 Dec Water Quality Water Quality 4 Jan Water Quality Water Quality 5 Feb Water Quality Water Quality 6 March Water Quality Water Quality 7 April Water Quality, Invertebrates Water Quality 8 May Water Quality Water Quality 9 June Water Quality Water Quality 10 July Water Quality Water Quality 11 August Water Quality Water Quality 12 Sept Water Quality Water Quality 7

16 6. Study Sites Twenty two sites were selected on the Bellinger and Kalang Rivers that conform to the selection criteria outlined above (Table 2, Figure 3). Estuarine sites are consistent with tidal river River Styles, and we have followed the MER approach of duplicating sites within known salinity zones (0-15ppt, ppt, and 30+ppt), and are consistent with those salinity zones used by the MER process (Figure 3). Freshwater sites are representative of mountainous headwater stream, confined bedrock river with discontinuous floodplain, and alluvial meandering gravel river bed, and are consistent with the elevation zones used by the MER process (Figure 4). Detailed site descriptions identifying the range of water quality conditions measured, physical measures of channel and bank characteristics, riparian features and local disturbance issues are provided to provide context for the ecological results. 8

17 Table 3. Names and locations of field sampling sites in the Bellinger and Kalang Rivers. ID Location Decimal Degrees UTM 56J Elevation (m) Latitude Longitude Easting (E) Northing (S) BR1 86 Richardsons Bridge Crossing Bellinger River BR2 41 Darkwood Bridge crossing RW1 54 Rosewood River, Summersville Rd Crossing BR3 20 Gordonville Cutting (0-15ppt) NN1 42 Never Never River, Keoghs Reserve BR4 7 Marx Hill (0-15ppt) BR5 3 Fernmount (15-30ppt) BR6 3 Pacific Hwy Bridge (15-30ppt) BR7 1 Repton (30 + ppt) BR8 0 Mylestom (30+ ppt) Kalang River KR1 76 Kalang Rd Kalang KR2 40 Pearns Bridge, Kalang Rd KR3 22 Sunny Corner Rd SC1 16 Spicketts Creek, Bowraville Rd KR4 14 Brierfield Bridge, Bowraville Rd (0-15ppt) KR5 13 South Arm Rd (0-15ppt) KR6 12 Pine Creek Bend (15-30ppt) KR7 11 Tarkeeth (15-30ppt) KR8 5 Upstream Newry Island (30+ ppt) KR9 4 North channel Newry Island (30+ppt) KR10 2 South Channel Newry Island (30+ppt) KR11 0 Urunga Boat ramp (30+ ppt)

18 NN1 BR1 KR1 BR2 RW1 BR3 BR4 BR5 BR6 KR2 KR11 KR3 KR9 KR7 SC1 KR5 KR8 KR4 KR6 KR10 BR7 BR8 Figure 3. Location of the 22 monitoring sites in the Bellinger and Kalang Rivers. 10

19 Figure 4. Location of estuarine monitoring sites and salinity zones on the Bellinger and Kalang Rivers.. 11

20 Bellinger River: SITE ID: BR1 Freshwater. Confined bedrock river with discontinuous floodplain Location: Most upstream site at Richardsons Bridge Crossing Downstream Reach Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape assymetrical floodplain Channel Shape two stage Bar Types side/point bars UNVEGETATED Dominant Particle Size on Bars gravel Bank Shape convex concave Bank Slope ( ) low (10-30 ) low (10-30 ) Bedform features Bed Compaction packed, unarmoured Sediment Matrix matrix filled contact framework Vegetation left bank right bank Riparian Average Cover (%) Continuity isolated/scattered continuous Woody Debris 5 logs Native v Exotic 25n/75e Machrophyte Cover (%) <5 Disturbance left bank right bank Local Impacts/Landuse native forest native forest Channel Midofications no modifications Bed Stability Rating bed stable Vegetation Disturbance Rating moderate disturbance 12

21 Bellinger River: SITE ID: BR2 Freshwater. Confined bedrock river with discontinuous floodplain Location: Leans Bridge Crossing Downstream Upstream Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape assymetrical floodplain Channel Shape flat u-shape Bar Types bars absent Dominant Particle Size on Bars - Bank Shape concave convex Bank Slope ( ) low (10-30 ) steep (60-80 ) Bedform features Bed Compaction moderate compaction Sediment Matrix framework dilated Vegetation left bank right bank Riparian Average Cover (%) Continuity occasional clumps continuous Woody Debris 5 logs Native v Exotic 25n/75e Machrophyte Cover (%) <5 Disturbance left bank right bank Local Impacts/Landuse grazing native forest Channel Midofications no modifications Bed Stability Rating bed stable Vegetation Disturbance Rating moderate disturbance 13

22 Rosewood River SITE ID: RW1 Freshwater. Confined bedrock river with discontinuous floodplain Location: Rosewood River, Summersville Rd Crossing Downstream Upstream Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape shallow valley Channel Shape flat U shaped Bar Types side point bars VEGETATED Dominant Particle Size on Bars boulder/cobble Bank Shape concave concave Bank Slope ( ) moderate (30-60) low (10-30) Bedform features Bed Compaction moderate compaction Sediment Matrix open framework Vegetation left bank right bank Riparian Average Cover (%) >85 75 Continuity continuous continuous Woody Debris 2 logs Native v Exotic 75n/25e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse native forest native forest Channel Midofications no modifications Bed Stability Rating bed stable Vegetation Disturbance Rating very low disturbance 14

23 Bellinger River SITE ID: BR3 Freshwater Limit of Tidal influence. Alluvial meandering gravel bed river Location: Gordonville Cutting Downstream Upstream Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) 0 10 DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape symmetrical floodplain Channel Shape U shaped Bar Types side/point bars VEGETATED Dominant Particle Size on Bars boulder/cobble Bank Shape undercut convex Bank Slope ( ) vertical (80-90) low (10-30) Bedform features Bed Compaction tightly packed, armoured Sediment Matrix framework dilated Vegetation left bank right bank Riparian Average Cover (%) Continuity none semicontinuous Woody Debris 0 Native v Exotic 25n/75e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse grazing grazing Channel Midofications no modifications (flood damage) Bed Stability Rating severe erosion Vegetation Disturbance Rating very high disturbance 15

24 Never Never River SITE ID: NN1 Freshwater. Alluvial meandering gravel bed river Location: Never Never River, Keoghs Reserve Downstream Upstream Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape symmetrical floodplain Channel Shape U shaped Bar Types side/point bars VEGETATED Dominant Particle Size on Bars boulder/cobble Bank Shape convex concave Bank Slope ( ) low (10-30) low (10-30) Bedform features Bed Compaction tightly packed, armoured Sediment Matrix framework dilated Vegetation left bank right bank Riparian Average Cover (%) Continuity continuous continuous Woody Debris 2 Native v Exotic 25n/75e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse grazing grazing Channel Midofications no modifications Bed Stability Rating moderate erosion Vegetation Disturbance Rating high disturbance 16

25 Bellinger River SITE ID: BR4 Estuarine 0-15ppt. Tidal River Location: Marx Hill Upstream view Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 17

26 Bellinger River SITE ID: BR5 Estuarine 15-30ppt. Tidal River Location: Fernmount Downstream Reach Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 18

27 Bellinger River SITE ID: BR6 Estuarine 15-30ppt. Tidal River Location: Pacific Hwy Bridge Downstream Reach Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 19

28 Bellinger River SITE ID: BR7 Estuarine 30+ppt. Tidal River Location: Repton Right Bank Left Bank Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 20

29 Bellinger River SITE ID: BR8 Estuarine 30+ ppt. Tidal River Location: Mylestom Downstream Reach Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 21

30 Kalang River SITE ID: KR1 Freshwater. Confined bedrock river with discontinuous floodplain Location: Most upstream site Kalang Rd Kalang Downstream Upstream Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) 0 3 DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape assymetrical floodplain Channel Shape U shaped Bar Types bars absent Dominant Particle Size on Bars gravel Bank Shape concave concave Bank Slope ( ) moderate (30-60) steep (60-80) Bedform features Bed Compaction low compaction Sediment Matrix matrix dominated Vegetation left bank right bank Riparian Average Cover (%) Continuity continuous continuous Woody Debris 4 logs Native v Exotic 60n/40e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse grazing urban residential recreation recreation irrigation pumps irrigation pumps Channel Midofications no modifications Bed Stability Rating bed stable Vegetation Disturbance Rating low disturbance 22

31 Kalang River SITE ID: KR2 Freshwater: Confined bedrock river with discontinuous floodplain Location: Pearns Bridge, Kalang Rd Riffle site at Bridge Pool downstream of Bridge Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx (mg/l) Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape assymetrical floodplain Channel Shape two stage side/point + mid-channel Bar Types VEGETATED Dominant Particle Size on Bars gravel Bank Shape concave convex Bank Slope ( ) steep (60-80) low (10-30) Bedform features Bed Compaction low compaction Sediment Matrix matrix dominated Vegetation left bank right bank Riparian Average Cover (%) Continuity continuous occassional clumps Woody Debris 8 logs Native v Exotic 60n/40e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse native forest grazing Channel Midofications no modifications Bed Stability Rating bed stable Vegetation Disturbance Rating moderate disturbances 23

32 Kalang River SITE ID: KR3 Freshwater. Confined bedrock river with discontinuous floodplain Location: Sunny Corner Rd Downstream riffle Upstream pool Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape asymmetrical floodplain Channel Shape flat U shaped Bar Types bars absent Dominant Particle Size on Bars gravel Bank Shape undercut undercut Bank Slope ( ) vertical (80-90) vertical (80-90) Bedform features Bed Compaction low compaction Sediment Matrix matrix dominated Vegetation left bank right bank Riparian Average Cover (%) Continuity occassional clumps occassional clumps Woody Debris 1 log Native v Exotic 20n/80e Machrophyte Cover (%) <5 Disturbance left bank right bank Local Impacts/Landuse grazing grazing Channel Midofications no modification (flood damage) Bed Stability Rating severe erosion Vegetation Disturbance Rating very high disturbance 24

33 Spicketts Creek SITE ID: SC1 Freshwater tributary. Confined bedrock river with discontinuous floodplain Location: Spicketts Creek, Bowraville Rd Downstream reach Upstream reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) 0 72 DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape symmetrical floodplain Channel Shape deepened U shape Bar Types bars absent Dominant Particle Size on Bars - Bank Shape convex undercut Bank Slope ( ) low (10-30) steep (60-80) Bedform features Bed Compaction low compaction Sediment Matrix matrix filled contact framework Vegetation left bank right bank Riparian Average Cover (%) occasional clumps semicontinuous Continuity Woody Debris 1 log Native v Exotic 60n/40e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse grazing grazing Channel Midofications Bed Stability Rating Vegetation Disturbance Rating no modifications severe erosion very high disturbance 25

34 Kalang River SITE ID: KR4 Limit of Tidal influence Location: Brierfield Bridge, Bowraville Rd Downstream reach Upstream reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape shallow valley Channel Shape flat U shaped Bar Types side/point bars VEGETATED Dominant Particle Size on Bars boulder/cobble Bank Shape undercut undercut Bank Slope ( ) vertical (80-90) vertical (80-90) Bedform features Bed Compaction moderate compaction Sediment Matrix open framework Vegetation left bank right bank Riparian Average Cover (%) Continuity occassional clumps continuous Woody Debris 2 logs Native v Exotic 60n/40e Machrophyte Cover (%) 0 Disturbance left bank right bank Local Impacts/Landuse grazing grazing Channel Midofications no modifications Bed Stability Rating severe erosion Vegetation Disturbance Rating very high disturbance 26

35 Kalang River SITE ID: KR5 Estuarine 0-15ppt Location: South Arm Rd Right Bank Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 27

36 Kalang River SITE ID: KR6 Estuarine 15-30ppt Location: Pine Creek Bend Downstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 28

37 Kalang River SITE ID: KR7 Estuarine 15-30ppt Location: Tarkeeth Downstream Reach Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 29

38 Kalang River SITE ID: KR8 Estuarine 15-30ppt Location: Upstream Newry Island Downstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 30

39 Kalang River SITE ID: KR9 Estuarine 15-30ppt Location: North Channel Newry Island Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 31

40 Kalang River SITE ID: KR10 Estuarine 30+ppt Location: South Channel Newry Island Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 32

41 Kalang River SITE ID: KR11 Estuarine 30+ ppt Location: Urunga Boat Ramp Left Bank Upstream Reach Water Chemistry min max ph EC (ms/cm) Turbidity (NTU) DO (mg/l) Water Temperature ( C) Salinity (%) Chlorophyll a (µg/l) NOx Reactive Phosphorus (mg/l) TN (mg/l) TP (mg/l) TSS (mg/l) Physical left bank right bank Valley Shape Channel Shape Bar Types Dominant Particle Size on Bars Bank Shape To be assessed Bank Slope ( ) Bedform features Bed Compaction Sediment Matrix Vegetation left bank right bank Riparian Average Cover (%) Continuity Woody Debris To be assessed Native v Exotic Machrophyte Cover (%) Disturbance left bank right bank Local Impacts/Landuse Channel Midofications Bed Stability Rating To be assessed Vegetation Disturbance Rating 33

42 PART 2 ECOLOGICAL INDICATORS: WATER QUALITY, MACROINVERTEBRATES AND RIPARAIN CONDITION The indicators chosen focus on the condition of the system to best identify the stressors and pressures that cause change in ecological condition. The selection of indicators (and groupings of indicators) represents elements of the structure, function and composition of riverine and estuarine ecosystems. 7. Water Quality Indicators 7.1 Background Assessing the impacts of land-use change on the ecological health of rivers and streams is an important issue for the management of water resources in Australia. Traditionally, these assessments have been dominated by the measurement of patterns in species distribution and abundance which contribute important information such as the status of threatened species and their habitat requirements. However, many goals of river management refer to concepts of sustainability, viability and resilience that require an implicit knowledge of ecosystem or landscape-level interactions and processes influencing these organisms or populations The water chemistry of rivers and estuaries can be an ideal measure of their ecological condition by providing an integrated response to a broad range of catchment disturbances. Nutrients such as nitrogen, phosphorus, and carbon can play an integral role in regulating rates of primary production these systems. However, anthropogenic changes to catchment land-use have led to increased supply of nutrients from diffuse or point sources, and altered light and turbidity regimes through increased suspended sediment loads and loss of riparian vegetation. These landscape-level processes define the supply of contaminants to a stream and provide the framework within which other processes operate at smaller spatial scales and shorter temporal scales to regulate their supply and availability. Table 4. Water quality measurements taken each month from all sites. In situ measurements Water quality samples for laboratory analysis Water depth Total nutrients (nitrogen and phosphorus) ph Dissolved nutrients (nitrate, nitrite, and phosphate) Temperature Chlorophyll a Salinity Total Suspended Solids (TSS) Dissolved oxygen Turbidity 34

43 7.2 Field and laboratory methods At each sampling site, insitu water quality measurements were measured with the use of a Horiba water quality multi-probe or Hydrolab Quanta multi-probe (ph, Conductivity, Dissolved Oxygen (DO), Temperature, Turbidity). The following procedural steps are outlined to standardise the collection of these data and to identify quality control. Water Quality Probe Calibration and Use The water quality probe(s) were calibrated each day prior to use in the field. At each sample site, field measurements for the water column profile was taken at near surface (approx. 0.2m below surface), and at 1 m intervals through the water column to a depth of 0.5m from the bottom (epibenthic). Measurements for each water quality parameter using the multiprobe were recorded at each interval. In freshwater sites that were less than 1 meter in depth, surface and epibenthic measurements were taken and maximum sampling depths noted. Data were recorded on proforma data recording sheets (Appendix 1). Water Quality Sampling Water samples were collected at each site for the determination of Chlorophyll a, total and dissolved nutrients, and total suspended solids. Samples were collected at near surface (<0.2m) and obtained with the use of a hand held sampling device to ensure sample is taken at least 1.5m from the edge of the boat or riverbank. Samples were transferred to acid-washed and rinsed (3x rinsed with sample water) 125mL containers. Duplicate samples for each parameter were taken from each site, and a third sample of each parameter was collected from a random subset of sites for quality assurance (QA) processing at an independent laboratory. The following procedures for sample collection and treatment are provided for each determination. Chlorophyll a Water column chlorophyll a is a measure of the photosynthetic biomass of algae/phytoplankton. These organisms are central to important nutrient and biogeochemical processes, and as such may respond to disturbance before effects on higher organisms are detected. This is because the higher organisms depend on processes mediated by algal communities. Consequently, they form the base of food webs supporting zooplankton, grazers such as crustaceans, insects, molluscs and some fish. The short generation time, responsiveness to environmental condition and the availability of sound, quantitative methodologies such as chlorophyll a make these measures of phytoplankton ideally suited as indicators of disturbance in aquatic systems. Information can be collected, processed and analysed at time scales relevant to both scientific and management interests. 35

44 In the field, a 1 litre bottle of water from a 0.5m depth was collected using the hand held sampling device at each site, labelled, and placed on ice in an esky for transport to the laboratory. Sample processing was carried out within 48 hours of collection. After filtration, samples were stored at below minus 4 degrees C and protected from the light. a) Place a GF/F filter, using forceps, textured side up into the filtration apparatus just prior to filtration. b) Filter a sufficient amount of sample (100-1,000ml measured with a graduated cylinder), to produce a green colour on the filter paper, or until the flow through the filter paper at ½ atmosphere pressure (approx. 7PSI) is reduced to a trickle. When approximately 10-15mL of sample remains on the filter, add 5-10 drops of the MgCO 3 powder to preserve the chlorophyll. Thoroughly rinse the filter apparatus and graduated cylinder, using a squirt bottle with deionised water. Drain the filter thoroughly to remove all signs of moisture. c) Record the sample volume filtered on the field data sheet. The amount of water filtered is subject to the level of turbidity at the sampling site. d) Using forceps, fold and remove the filter and carefully place into the bottom portion of the prelabled culture tube and close tightly, wrap in aluminium foil, place into a labelled ziplock bag and immediately freeze. e) The concentration of chlorophyll-a was measured by filtering 1 L of unfiltered sample water was through 934-AH RTU Glass Microfiber filter paper using an EYELA Tokyo Rakahikai Coorperation Aspirator A-35. The filter paper was then placed in 10 ml of 90% ethanol. The solution was then refrigerated for 24 hours. The samples were then centrifuged. The absorption spectra were recorded using a UV-1700 Pharmaspec UV-visible spectrometer at 666 nm and 750 nm. Total Suspended Solids Total suspended solids is a direct measure of turbidity of the water In the field, collect a 1 litre bottle of water from a 0.5m depth at each site using the hand held sampling device, label, and place in a cool dark esky. a) Place a pre-weighed GF/F filter, using forceps, textured side up into the filtration apparatus just prior to filtration. b) Filter a sufficient amount of sample (100-1,000ml measured with a graduated cylinder), to produce a colour on the filter paper, or until the flow through the filter paper at ½ atmosphere pressure (approx. 7PSI) is reduced to a trickle. Thoroughly rinse the filter apparatus and graduated cylinder, using a squirt bottle with deionised water. Drain the filter thoroughly to remove all signs of moisture. c) Using forceps, fold and remove the filter and carefully place into the bottom portion of the prelabled culture tube and close tightly, wrap in aluminium foil, place into a labelled ziplock bag and immediately freeze. 36

45 d) TSS were measured by filtering 1L of sample water through a 934-AH RTU Glass Microfiber filter paper, with a known weight, using a EYELA Tokyo Rakahikai Coorperation Aspirator A-35. The filter paper with retained material was then placed into a foil envelope and dried in an oven at 50ºC. They were reweighed after they dried to gain a measure of the weight of the TSS on each sample. The organic content of the TSS was then analysed by placing the filter paper into the furnace for 4 hours at 500ºC. The filter paper was then reweighed and the organic content calculated. Inorganic Nutrients For inorganic nutrients, we collected 3 x 125mL bottles of water from a 0.2m depth at each site using the hand held sampling device. Samples for total nitrogen and total phosphorus remain as separate unfiltered samples. Water is transferred into a pre-rinsed, pre-labelled, clean 125mL sample container and immediately placed in a cool dark esky. Samples remained frozen until time of analysis. Duplicate samples for quality assurance processing at an independent laboratory remained frozen until analyzed. For organic nutrients, we collected 3 x 125ml bottle of water from a 0.5m depth at each site using the hand held sampling device. Approximately 125mL of water is passed through a GF/C filter paper (effective pore size 0.7µm) in the field and collected into a pre-rinsed, pre-labelled, clean sample container and immediately placed in a cool dark esky. Samples remained frozen until time of analysis. Duplicate samples for quality assurance processing at an independent laboratory remained frozen until analyzed. Nitrogen was measured by digesting an unfiltered water sample in a digestion tube with 10 ml of digestion mixture. This contained 40 g of di-potassium-peroxodisulfate (K 2 S 2 O 8 ) and 9 g of sodium hydroxide (NaOH) in 1000 ml of Milli Q water. This sample was then digested in the autoclave for 20 minutes. 5 ml of the sample was then placed into a 50 ml acid washed measuring cylinder and diluted to 50 ml (Hosomi & Sudo 1986). 5 ml of buffer solution was added; 100 g of NH 4 Cl, 20 g sodium tetra borate and 1 g EDTA to 1 L with Milli Q water. 50 ml of each sample was measured into a numbered jar. The samples were then filtered. Firstly, the cadmium reduction column was rinsed with 10% buffer solution, making sure the cadmium granules remained covered at all times by either the 10% buffer of the sample. The column was drained to 5 mm above the cadmium granules, and 25 ml of the first sample added. This was collected in a separate beaker for wastes as it drained through to rinse the column and discarded. The column was then filled with the sample and 20 ml was collected in the same sample jar. 1 ml of sulfanilamide solution was added and mixed thoroughly. After 2 minutes 1 ml of dihydrochloride solution was added and mixed. This was repeated for all water samples. After 10 minutes, the absorbance of each sample was measured using a UV-1700 Pharmaspec UV-visible spectrometer at 543 nm. This colormetric determination of nitrogen can be used when nitrogen is in the range to 2.25 g/ml. Samples must also be prepared before analyzing the samples 37

46 to calculate linear regression at 0 g/ml, 0.05 g/ml, 0.2 g/ml, 0.5 g/ml, 1 g/ml, 2 g/ml and 5 g/ml of known nitrogen concentration. Phosphorus was measured by digesting an unfiltered water sample in a digestion tube with 10 ml of digestion mixture. This contained 40 g of di-potassium-peroxodisulfate (K 2 S 2 O 8 ) and 9 g of sodium hydroxide (NaOH) in 1000 ml of Milli Q water. This sample was then digested in the autoclave for 20 minutes. 20 ml of sample was then added to a plastic SRP tube with 2 ml of colour reagent; 20 ml of ascorbic acid solution with 50 ml of molybdate antimony solution. This was repeated for all water samples. After 8 minutes, the absorbance of each sample was measured using a UV-1700 Pharmaspec UV-visible spectrometer at 705 nm. Samples must also be prepared before analyzing the samples to calculate linear regression at 0 g/ml, 0.05 g/ml, 0.2 g/ml, 0.5 g/ml, 1 g/ml, 2 g/ml and 5 g/ml of known nitrogen concentration. Laboratory QA/QC Quality control was maintained with the laboratory by the use of standard analytical methods, analysis of QA/QC samples at the DECCW Lidcombe Laboratories, and the regular calibration and maintenance of laboratory instrumentation. An additional water chemistry sample was collected (via random number generator) from selected sites on each sample occasion and sent to an independent laboratory for analysis. These QA samples represented 5% of the total number of samples collected. Results confirmed no significant difference between results for N and P between laboratories. ANZECC and MER water quality guidelines The ANZECC Water Quality Guidelines (the guidelines) established in 1992 under the Commonwealth s National Water Quality Management Strategy (NWQMS), provide a scientifically informed framework for the water quality objectives required to maintain current and future water resources and environmental values (ANZECC, 2000b). The ANZECC guidelines were created in response to growing understanding of the potential for water quality to be a limiting factor to social and economic growth. The guidelines were derived from reviewing water quality guidelines developed overseas. However; Australian guidelines were also incorporated where available (ANZECC, 1994b). The ANZECC Australian Water Quality Guidelines for Fresh and Marine Waters was released in 1992, and developed using two approaches: 1. an empirical approach which used the Precautionary Principle to create conservative trigger values from all available and acceptable national and international data. This method implemented data from only the most sensitive taxa in order to ensure the protection of these species. 38

47 2. the modeling of all available and acceptable national and international data into a statistical distribution with the confidence intervals of 90% and 50%. Trigger values are conservative thresholds or desired concentration levels for different water quality indicators. When an indicator is below the trigger value there is a low risk present to the protection of that environment. However, when an indicator is above the trigger value there is a risk that the ecosystem will not be protected. In cases where the trigger value is exceeded further research and remediation of the risk identified should be conducted. Where a numerical value cannot be derived for a water quality indicator a target load may be set, for example the salinity guideline, or a descriptive statement for example for oil there should be no visible surface film, or an index of ecosystem health for example percentage cover of an algal bloom. The Australian and New Zealand Environment Conservation Council (ANZECC) Guidelines (2000 and 2006) provide threshold values for freshwater and estuarine systems for ph, dissolved oxyegen (DO), electrical conductivity (EC), salinity and nutrients such as nitrogen (N) and phosphorus (P). In addition, we used region-based trigger values for estuarine chlorophyll and turbidity developed by DECCW as part of the MER program. 7.3 Results Trends in Water Chemistry ph All of the estuarine sites in the Bellinger and Kalang Rivers (except Kalang Site 6) had ph values below the ph 7 ANZECC trigger value at least once during the study period, and all estuarine sites exceeded the upper ph trigger of 8.5 during the study (Table 5). Values for ph ranged from 5.88 in Spicketts Creek, to 9.03 at the Bellinger River estuary (BR8) (Figures 5, 8). Depth profiles in Bellinger River estuarine sites did not display consistent patterns of change in ph with depth, yet sites in the Kalang River Estuary had a consistent decrease in ph with increased depth. Similarly, there was no longitudinal trend evident for changes in ph in either river system. Salinity An expected increase in salinity/conductivity with distance downstream was evident in both river systems. None of the locations sampled exceeded the trigger value for salinity during the study, with freshwater riverine sites consistently below 0.1 ms/cm (Figures 5, 8). Estuarine sites that were replicated within salinity categories of 0-15 ppt, 15-30ppt and >30ppt were consistently within these ranges of salinity. A surface lens (<0.2m) of freshwater was often recorded at sites within the 15-30ppt category, and these sites also consistently displayed salinity stratification with increasing salinity with depth. 39

48 Dissolved Oxygen All of the estuarine sites in the Bellinger and Kalang Rivers had dissolved oxygen (DO) concentrations consistently lower than freshwater sites (except for Spicketts Creek), and consistently lower that the ANZECC trigger value of 80% saturation for estuarine reaches. This is seen as a clear trend of decreasing DO saturation with distance downstream in both river systems (Figure 5, 8). There was also a consistent pattern in both estuaries for a decrease in DO saturation with depth, most pronounced in the reaches categorized as 15-30ppt salinity. Temperature Temperature ranged from 16.3 degrees at Spicketts Creek to 30.1 degrees at BR5 in the Bellinger ppt salinity zone, a site with no riparian vegetation (Figure 6, 9). Temperatures were consistently lower in upper reaches and tributaries due to elevation and shading reducing temperatures, and higher in estuarine reaches. In estuarine reaches there was a consistent reduction in temperature with increasing depth, with differences between surface and epibenthic temperatures (maximum 5m) of approximately 2 degrees often recorded between October and April. There was no concomitant reduction in DO concentrations at depth to suggest persistent temperature stratification leading to hypolimnetic anoxia. Turbidity The trigger value for turbidity for freshwater sites was exceeded only in Spicketts creek, and only on one occasion (Figure 6, 9). In estuarine sites, the NSW MER turbidity value of 3.3NTU was not exceeded at any site. In both catchments, the tributaries sampled had relatively higher turbidity that the main stem of the river, suggesting these systems may be a source of suspended material. In the main stem of the Bellinger and Kalang Rivers, turbidity consistently increases in the 0-15ppt reaches suggesting the residence time for transported material is increased as the gradient, and therefore flow is reduced. However, the trend displayed by these data are not consistent with the direct measurement of total suspended solids, that shows a clear increase in concentration of suspended material with distance downstream, and is most pronounced in the Bellinger River (Figures 6, 9). This increase in suspended material may result from longitudinal transport, tidal exchange and resuspension, and planktonic organisms. Chlorophyll a Algal biomass as measured by Chlorophyll a did not exceeded the NSW MER trigger value of 2.3µg/L at any estuary site or 5µg/L at freshwater sites. There is a trend in both rivers of increasing water column concentrations of chlorophyll a with distance downstream, with estuarine sites consistently having higher concentrations. This result is expected in unregulated river systems as warmer temperatures and increased irradiance. 40

49 Nutrients Available nitrogen was high relative to the ANZECC thresholds in a number of sites. All freshwater sites in the Bellinger catchment and Spicketts Creek in the Kalang River were above trigger values for available nitrogen (Figure 7, 10). The trigger value for available phosphorus was exceeded in Spicketts Creek. The most upstream site on the Bellinger River had extremely high values for TN and TP, and again Spicketts Creek exceeded the ANZECC trigger value for TP. Available nitrogen was high relative to the ANZECC thresholds in all of the estuarine sites except for site 7 on the Kalang River. In the Bellinger catchment, available phosphorous exceeded the trigger value at 4 of the 5 sites, whereas in the Kalang River only the 3 most downstream estuarine sites exceeded this value during the study. Only site 5 on the Bellinger River marginally exceeded the trigger value for TP. However, 3 of the 5 estuarine sites exceeded the trigger value for TN in both Rivers. Spatial and temporal trends The a priori determination of salinity categories based on known regimes of tidal exchange was supported by salinity concentration measured within these categories throughout the study period. However, there were no minor or major flood events during the sample period to influence the downstream gradient of tidal influence. For all water chemistry variables measured, there were no significant differences between the two replicate sites within each salinity zone in each river system. This suggests that replicating sites within salinity zone in these systems during a period of prolonged low flows does not contribute additional information to the analysis or interpretation of data. Data for this project were collected monthly from the 22 study sites for a 12 month period. Figures 5 to 10 identify spatial patterns in data and present means and standard deviations for each site over the 12 month period. Analyses of differences between sampling periods revealed no significant difference in any water chemistry variable within defined seasons, suggesting reduced temporal sampling to a seasonal-based protocol would lose minimal resolution in detecting ecological change. However, as already stated, these data were collected during a period of reduced flow disturbance, and may more pronounced within season difference may emerge in periods of higher discharge. 41

50 BELLINGER RIVER Figure 5. Average ph, EC (ms/cm), Turbidity (NTU) and Dissolved Oxygen (mg/l) from monthly recordings from Oct 2009 to Sept