2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINAL · 2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINAL | Issue Number 2 Core monitoring The core monitoring

2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINAL | Issue Number 2

Core monitoring The core monitoring of the MER Program is successfully under way in all

disciplines:

• Hydrology - a baseflow and a pulse was delivered in December.

• Fish - weekly drift net surveys were undertaken to capture fish spawning.

• Riverbank vegetation – low-flying drone images allow the tracking of

vegetation establishment and survivorship.

• Macroinvertebrate condition - three rounds of sampling show an

increase in freshwater prawns and a decrease in freshwater shrimp.

• Stream metabolism - data will be available for next quarterly newsletter.

• Bank condition - processing of drone imagery shows changes of the

physical form.

Hydrology

Image 1: Hydrograph for the lower Goulburn River from July-December 2019

at McCoys Bridge

Following the spring fresh, which was delivered with a peak magnitude of

approximately 8,000 ML/day in September and running into October 2019

(Image 1), a baseflow averaging approximately 900 ML/day was delivered

from the beginning of December. In December, river operators requested

the delivery of 50 GL of water from the Goulburn inter-valley trade to the

Murray River. To meet this request, a pulse with a peak magnitude of

approximately 2,700 ML/day was delivered down the Lower Goulburn River.

The water was delivered in a pulse rather than a high steady flow to reduce

bank erosion and minimise bank vegetation loss.

2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINALIssue Number 2 | 31 December 2019

In this issue

Core monitoring successfully under way

Contingency monitoring of sediment and seed deposition using turf mats has progressed

— Monitoring, Evaluation

and Research Program

Contact:

Associate Professor Angus

Webb

Address:

Water, Environment and

Agriculture Program,

The University of Melbourne,

Level 3, 333 Exhibition St,

Melbourne


LTIM monitoring identified the spring fresh as essential to the health of the lower Goulburn. It has been convincingly

linked to:

• Increased carbon production to underpin the food chain

• Renewal of biofilms that underpin the food web

• Increased biomass of large-bodied crustaceans that are an important food resource for native fish

• Improved bankside vegetation condition through the summer months, with wetting of the bank in early

spring helping plants to survive hotter and drier conditions later in the year

• Movement and spawning of the iconic native fish species golden and silver perch.

The baseflow environmental flow action provides habitat for native fish and macroinvertebrates.

Fish

Surveys of drifting fish eggs and larvae were undertaken at four sites (Yambuna, McCoys Bridge, Loch Garry, and Pyke

Road) on the Goulburn River, using three drift nets at each site once per week from October to December 2019

(Image 2). The primary aim of these surveys is to assess the spawning responses of golden perch and silver perch to

flows including targeted environmental watering actions. However, no such actions were delivered in 2019, and no

response from golden and silver perch was expected. Samples are currently being sorted and identified in the

laboratory. Preliminary results indicate the following species were collected: Murray cod (Image 3), trout cod,

Australian smelt and flat-headed gudgeon. The collection of trout cod larvae is significant, demonstrating the

existence of breeding populations of this nationally threatened species. Spawning of trout cod has been detected in

the last three years (2017-2019). As expected, no eggs or larvae of golden perch or silver perch were detected in 2019.

A large flow event (peak magnitude of 7,900 ML/day) occurred in early-mid October 2019, but water temperatures

around this time were too low (i.e.


Image 4: Vegetation mostly absent along the water’s edge, but with various grasses and Juncus spp. persisting higher

up the bank at McCoys Bridge.

Image 5: New seedlings at water’s edge Image 6: Vegetation on the in-channel bench at McCoys Bridge

Macroinvertebrate condition

Three rounds of macroinvertebrate sampling have now been completed. The first round occurred in September 2019

prior to the spring fresh on 17th September. The second and third rounds respectively occurred in December 2019 and

January 2020. Laboratory processing of the crustaceans has begun for the first and second rounds. River levels were

low during the September sampling, which meant there were almost no macrophytes submerged along the river’s

edge. In December, river levels were approximately 20 cm higher than that in September. However, this was still not

enough for most sites to have submerged macrophytes. Crustacean sampling for these two rounds targeted other

complex habitats such as submerged snags.

Early results show an increase in the number of freshwater prawns and a decrease in the number of freshwater

shrimp (Image 8) at sites as the river progresses downstream. This finding is consistent with the winter crustacean

monitoring conducted in August 2018.


A comparison of prawn and shrimp abundances between September and December shows that these animals respond

differently to flows. Freshwater prawn abundances increased from 35 to 95 (pooled across sites) whereas freshwater

shrimp abundances remained similar (dropping from 18 in September to 15 in December). Biomass closely matches

abundance for both species.

Macroinvertebrates collected using sweep nets are currently being processed in the laboratory. They will be identified

to family level and will have their abundances recorded.

Image 7: A freshwater prawn (Macrobrachium australiense - left) and a freshwater shrimp (Paratya australiensis - right) alongside a five-cent coin for size comparison

Stream metabolism

By the end of December, no metabolism data had been supplied from ALS. Daniel Lovell from the Goulburn Broken

CMA has since negotiated for an automated data download to be supplied monthly and we will be able to report the

first months of data in the next quarterly newsletter.

Bank condition

Two surveys have now been undertaken for the MER Program on the Goulburn River. Using drone-based

photogrammetry, these surveys have focused on bank condition and changes to the physical form due to flows. The

drone surveys were done immediately following flow events when there was minimal vegetation on the riverbank.

This ensured a detailed image of the bank condition. The first survey undertaken for the MER Program was in mid-

September 2019 just prior to the spring fresh (Image 8). Following the spring fresh event, a subsequent field survey

was undertaken at the end of October 2019 (Image 9b). The IVT drone assessment undertaken in 2018–2019 is also

shown in Image 9a, along with the difference between these two images (9c).

Image 8: Hydrograph at McCoy’s bridge with timing of the Goulburn river drone survey events


a) b) c)

Image 9: Point cloud model of focus area of a bank on the Goulburn River at Loch Garry a) Bank captured in April 2019 b) Bank

captured in October 2019 c) Differences in surface elevation illustrating changes in the bank and with an indication of related flows

(blue lines)

The processing of imagery is underway to produce some highly detailed point clouds that can be used for detecting

and measuring changes in the physical form in relation to flows and events along the river. Changes have already

been seen and the physical form is captured for ongoing monitoring (Image 9). Following capture and comparisons,

the next stage is then relating this information to hydrologic conditions and flow operations to gain a better

understanding of the drivers of change.

Contingency activities

Monitoring sediment and seed deposition using turf mats

By the end of 2019, three visits have been undertaken to the Goulburn River for MER Program turf mat monitoring

(Table 1). This included the initial deployment prior to the winter fresh and two subsequent retrievals.

Table 1 Goulburn River MER Program turf mat field visits with events captured

Date Field Trip Event Captured

27th June 2019 Deployment Establishing Turf Mat Locations

12th September 2019 Retrieval 1 Winter Fresh

30th October 2019 Retrieval 2 Spring Fresh

The first retrieval was just after the winter fresh and prior to the spring fresh, and the second after the drawdown of

the spring fresh (Image 10). The current deployment will collect seed and sediment data for the duration of the IVT

flows which commenced at the end of November 2019. Image 11 shows the McCoys 'Bar' and 'bank' site before (a)

and after (b) the spring fresh event.

Image 10: McCoys Bridge hydrograph from May 2019 to December 2019 with timing of turf mat visits


a) b)

Image 11: a) Turf mats at ‘McCoys Bar’ in September B) Mats at ‘McCoys Bank’ feature after the spring fresh

Communications and engagement

Between October and December 2019 press releases, newspaper ads and social media posts provided information

supporting the Victorian Water Minister’s announcement that inter-valley trade transfers from the Goulburn to the

Murray would be limited to 50GL/month between December and April. This decision was in response to community

and Goulburn‐Broken Catchment Management Authority concerns about the damage to the Goulburn River caused by

the record high IVT deliveries during the previous two years. Bank condition assessments undertaken as part of the

MER and LTIM monitoring programs were critical in persuading the Minister that steps were urgently needed to

reduce damage to the river’s banks. Other communication and engagement activities highlighted monitoring (fish

larvae, vegetation and bank condition) activities.

To acknowledge the intrinsic link the Traditional Owners have with the land and water (Woka Walla in Yorta Yorta

language), Yorta Yorta Nation Aboriginal Corporation (YYNAC) has been engaged to help with native fish larvae

monitoring. Yorta Yorta man Shannon Atkinson, who also carries out cultural surveys for YYNAC, joined ARI’s Dave

Dawson for 10 weeks of drift net fish larvae monitoring at four sampling sites (Yambuna, McCoys Bridge, Loch Garry

and Toolamba) along the Lower Goulburn (Kialla) River. Collecting larvae (Images 12 and 13) and emptying nets, as

well as learning about how and why sampling is carried out, Shannon said he enjoyed spending time on the Goulburn.

“There’s so much wildlife – wallabies, kingfishers – it’s great.” Preliminary results show that there are plenty of larvae

of Murray cod and trout cod but not golden perch and silver perch.

Image 12: Shannon collecting larvae at Pykes Rd near Toolamba

https://www.premier.vic.gov.au/delivering-for-irrigators-and-protecting-the-goulburn/https://www.premier.vic.gov.au/delivering-for-irrigators-and-protecting-the-goulburn/


Image 13: Heading out to check the nets, and labelled samples for the lab

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2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINAL · 2019 12 30 Lower Goulburn Quarterly Outcomes Newsletter FINAL | Issue Number 2 Core monitoring The core monitoring