Abstract
This report documents the monitoring and evaluation of ecosystem responses to Commonwealth environmental watering in the Edward-Kolety-Wakool River System Selected Area in 2017-18. It is the fourth annual report of the Long Term Intervention Monitoring (LTIM) Project (2014-2019) funded by the Commonwealth Environmental Watering Office. This project was undertaken as a collaboration among Charles Sturt University, NSW DPI (Fisheries), Monash University, NSW Office of Environment and Heritage, La Trobe University and Murray Local Land Services. Field sampling for the project was undertaken by staff from Charles Sturt University, NSW DPI (Fisheries), and NSW Office of Environment and Heritage.
This report provides details of the Commonwealth environmental watering actions, indicators and an evaluation of the ecosystem responses to flows in the Edward-Kolety-Wakool Selected Area during the 2017-18 watering year. This report evaluates ecosystem responses to Commonwealth environmental watering actions in the Edward-Kolety-Wakool Selected Area from 1 May 2017 (start of watering action 1) until 30 June 2018. In 2017-18 six environmental watering actions were planned for the Edward-Kolety-Wakool system. Watering actions 1, 2, 4, 5 and 6 were delivered. Watering action 3 was not delivered due to unregulated flows occurring above channel capacity at the time of this planned action.
Base flow winter watering action from 1 May - 23 Aug 2017 in Yallakool Creek, mid and lower Wakool River, Colligen Creek-Niemur River
Small early spring fresh at beginning of e-flow with flow recession from 7 Sept - 22 Oct 2017 in Yallakool Creek, upper, mid and lower Wakool River, Colligen Creek-Niemur River
Maintain e-flow was not delivered
Summer fresh at end of e-flow with flow recession from 3 - 29 Jan 2018 in Yallakool Creek, mid and lower Wakool River
Autumn fresh with flow recession from 3 - 29 Jan 2018 in Yallakool Creek, mid and lower Wakool River
Summer fresh 11 Jan – 11 Feb 2018 Niemur River
Indicators monitored in 2017-18 for the Edward-Kolety-Wakool selected area evaluation were: river hydrology, water quality and carbon, stream metabolism, riverbank and aquatic vegetation, fish movement, fish reproduction, and fish recruitment (Murray cod, golden perch and silver perch). The Fish community (monitored in only zone three for the basin-scale evaluation. No selected area evaluation for the fish community was undertaken in 2017-18 as this is scheduled to be monitored in only years 1 and 5 of the project).
The following responses to the Commonwealth environmental watering actions from July 2017 to June 2018 were observed in the Edward-Kolety-Wakool system:
Overall water quality in the Edward-Wakool elected area during the 2017-18 water year was characterised by a return to normal conditions following two seasons of extreme events.
Commonwealth environmental water contributed significantly to primary production in reaches where water was delivered. The watering created more food at the base of the food web and more nutrients from ecosystem respiration.
There was some recovery seen of the riverbank and aquatic vegetation following the large unregulated flood in spring 2016. Submerged and amphibious vegetation species have recovered faster in river reaches where Commonwealth watering actions were implemented.
A number of positive outcomes observed in response to Commonwealth environmental watering in 2017-18 suggest the fish community is recovering.
The successful spawning and recruitment of Murray cod.
Silver perch moved greater distances in 2017 than in 2016. Silver perch were also detected spawning in Yallakool Creek in early December 2017 providing the first contemporary evidence of localised spawning.
In 2017-18, freshwater catfish larvae were detected in the Wakool River for the first time.
The abundance of Australian smelt was significantly higher in zones that received Commonwealth environmental water than those zones that received almost no Commonwealth environmental water.
This report provides details of the Commonwealth environmental watering actions, indicators and an evaluation of the ecosystem responses to flows in the Edward-Kolety-Wakool Selected Area during the 2017-18 watering year. This report evaluates ecosystem responses to Commonwealth environmental watering actions in the Edward-Kolety-Wakool Selected Area from 1 May 2017 (start of watering action 1) until 30 June 2018. In 2017-18 six environmental watering actions were planned for the Edward-Kolety-Wakool system. Watering actions 1, 2, 4, 5 and 6 were delivered. Watering action 3 was not delivered due to unregulated flows occurring above channel capacity at the time of this planned action.
Base flow winter watering action from 1 May - 23 Aug 2017 in Yallakool Creek, mid and lower Wakool River, Colligen Creek-Niemur River
Small early spring fresh at beginning of e-flow with flow recession from 7 Sept - 22 Oct 2017 in Yallakool Creek, upper, mid and lower Wakool River, Colligen Creek-Niemur River
Maintain e-flow was not delivered
Summer fresh at end of e-flow with flow recession from 3 - 29 Jan 2018 in Yallakool Creek, mid and lower Wakool River
Autumn fresh with flow recession from 3 - 29 Jan 2018 in Yallakool Creek, mid and lower Wakool River
Summer fresh 11 Jan – 11 Feb 2018 Niemur River
Indicators monitored in 2017-18 for the Edward-Kolety-Wakool selected area evaluation were: river hydrology, water quality and carbon, stream metabolism, riverbank and aquatic vegetation, fish movement, fish reproduction, and fish recruitment (Murray cod, golden perch and silver perch). The Fish community (monitored in only zone three for the basin-scale evaluation. No selected area evaluation for the fish community was undertaken in 2017-18 as this is scheduled to be monitored in only years 1 and 5 of the project).
The following responses to the Commonwealth environmental watering actions from July 2017 to June 2018 were observed in the Edward-Kolety-Wakool system:
Overall water quality in the Edward-Wakool elected area during the 2017-18 water year was characterised by a return to normal conditions following two seasons of extreme events.
Commonwealth environmental water contributed significantly to primary production in reaches where water was delivered. The watering created more food at the base of the food web and more nutrients from ecosystem respiration.
There was some recovery seen of the riverbank and aquatic vegetation following the large unregulated flood in spring 2016. Submerged and amphibious vegetation species have recovered faster in river reaches where Commonwealth watering actions were implemented.
A number of positive outcomes observed in response to Commonwealth environmental watering in 2017-18 suggest the fish community is recovering.
The successful spawning and recruitment of Murray cod.
Silver perch moved greater distances in 2017 than in 2016. Silver perch were also detected spawning in Yallakool Creek in early December 2017 providing the first contemporary evidence of localised spawning.
In 2017-18, freshwater catfish larvae were detected in the Wakool River for the first time.
The abundance of Australian smelt was significantly higher in zones that received Commonwealth environmental water than those zones that received almost no Commonwealth environmental water.
| Original language | English |
|---|---|
| Place of Publication | Australia |
| Publisher | Commonwealth Environmental Water Office |
| Commissioning body | Commonwealth Environmental Water Office |
| Number of pages | 159 |
| Publication status | Published - 2018 |