Gunbower Forest Report Card 2020–21

2020-21 Water Summary

B
Dry conditions over several years has resulted in deteriorating health of trees and plants and an overall slight decline in the condition of Gunbower Forest. In an otherwise dry landscape, delivery of water for the environment to Gunbower Creek and wetlands has provided important habitat for fish and waterbirds to feed and breed.
Overall
B Vegetation
B Waterbirds
B Fish

Vegetation

B

Aims

Promote functioning and resilient floodplain and wetland ecosystems
Facilitate suitable habitat for wetland-dependant fauna including frogs, fish, birds and macro-invertebrates
Increase abundance of threatened plants

Outcomes

Across Gunbower Forest the health of river red gums and understorey plants declined. While there was higher rainfall in 2020-21 compared to previous years, it was not enough for the vegetation to recover after 3 years of record dry conditions.
47% of understorey plant species recorded were terrestrial species and not the water-dependent species more typical of red gum communities. This is a higher percentage than previous years, and likely reflects the extended hot, dry conditions and lack of overbank flows through the forest, allowing terrestrial species to invade lower parts of the floodplain.
Water for the environment was delivered to 114 hectares of wetlands (around 8% of the forest wetlands) including Reedy Lagoon. This provided important habitat and refuges for waterbugs, frogs, fish and waterbirds in an otherwise dry landscape.
69 wetland plants were recorded across 11 wetlands, with around 80% of these being native. 8 of the 11 wetlands surveyed were in a planned drying phase, and as expected the number of plants recorded was lower than in the previous year. Cycling between wet and dry phases is important for sustaining healthy wetlands.
Wetlands where water for the environment was delivered in the previous year had a higher number of aquatic plant species compared to wetlands that had not been watered.
Water for the environment delivered to wetlands supported the nationally vulnerable river swamp wallaby grass, and the endangered Victorian cotton sneezeweed and wavy marshwort. The number of threatened wetland plant species was lower than in the previous year due to fewer wetlands holding water.

Waterbirds

B

Aims

A suite of waterbirds present including waterfowl, colonial waterbirds and other wetland dependent species
Successful waterbird breeding events proportionate to scale of flooding across the forest
Provide refuge and feeding grounds for waterbirds in drier years
Contribute to population recovery of threatened waterbird species

Outcomes

1,650 birds were recorded over the year with the highest species diversity occurring in November 2020 at Reedy Lagoon.
At the wetlands that held water, 21 waterbird and 29 woodland bird species were recorded.
Given dry conditions no colonial waterbird breeding was observed. However, at Reedy Lagoon several duck species and black swans bred.
Herons, cormorants, Australian darters, ibis and several species of ducks were all recorded. This suggests that there was suitable refuge and feeding grounds for a range of waterbirds at wetlands that held water such as Reedy Lagoon and Black Swamp.
Musk ducks and hardhead ducks, that are listed as a vulnerable species in Victoria, were observed at Reedy Lagoon.

Fish

B

Aims

Increase abundance of native fish species
Restore presence of locally extinct fish species to Gunbower Island
Allow movement of native fish across habitat types (creek, river, floodplain etc) for feeding and breeding

Outcomes

30,369 fish from 16 species, 11 native and 5 non-native were recorded. Native fish made up 66% of the count with carp gudgeons found in large numbers. Murray cod, golden perch, silver perch and non-native carp were the most common fish recorded in Gunbower Creek and the adjacent River Murray.
For the eighth year in a row Murray cod bred in Gunbower Creek. 31 young of year (less than one year old) Murray cod were counted, which is slightly less than the numbers recorded in the previous year.
Adult and young of year freshwater catfish were recorded in the Gunbower lagoons for the fourth year in a row. This is a positive sign for local freshwater catfish populations as prior to 2018 young of year were only recorded 3 times in 10 years. However, overall numbers are still relatively low.
200 southern pygmy perch were released into Black Charlie Lagoon to assist with the recovery of local populations of threatened and locally extinct native fish.
Delivery of water for the environment connected areas of Reedy Lagoon and Black Swamp with Gunbower Creek and the forest, allowing fish to move between creek and wetland habitats.

12.9 GL

water for the environment delivered at this site

12.9 GL

water used at this site

0 GL

flowing back to the river system

Actions

Water for the environment delivered.

Climate conditions

Moderate - Conditions were milder compared to the previous 3 hot, dry years. River flows were around three-quarters of the long-term average.

Works

Are there works at this site?

Works in use this year?

Highlights

First Nations

Yorta Yorta Traditional Owners helped release 200 southern pygmy perch into Black Charlie Lagoon to assist with the recovery of local populations of native fish.
(Photo: North Central CMA)

Community

Gunbower Creek and Forest provide great spots for locals to enjoy recreational activities such as fishing.
(Photo: North Central CMA)

Vegetation

Following delivery of water for the environment to Reedy Lagoon aquatic plants such as the wavy marshwort flourished.
(Photo: D Cook)

Waterbirds

Black swans successfully bred at Reedy Lagoon with 13 cygnets spotted during waterbird surveys.
(Photo: D Cook)

Fish

Ahead of the construction of Koondrook weir fishway in Gunbower Creek, 28 trout cod, a species listed as endangered in Australia, were captured and relocated in winter 2021. Previously only one trout cod has been detected in the 2008, 2016 and 2019 Gunbower Creek fish surveys.
(Photo: P Brown)

Past reports for Gunbower Forest

Overall

Vegetation

Waterbirds

Fish

Other

2020-21

B

-

2019-20

B

A

B

2018-19

A

B

-

2017-18

B

A

B

C

-

2016-17

B

A

B

-

2015-16

B

A

B

-

2014-15

B

A

B

-

2013-14

B

A

B

D

-

2012-13

B

A

C

-

2011-12

C

B

C

-

2010-11

B

A

C

-

2009-10

C

B

C

D

B

2008-09

C

B

D

2007-08

D

C

-

2006-07

-

Show/hide 5 oldest years

Climate conditions

Grades

Dry	Very Wet
Wet	Moderate

A

B

C

D

-

Excellent

Most (75-100%) of ecological objectives have been met

Good

More than half (50-74%) of ecological objectives have been met

Fair

Fewer than half (25-49%) of ecological objectives have been met

Needs attention

Few (0-24%) of ecological objectives have been met

Data not available

Each year, water is released into the environment depending on the climatic conditions. See the outcomes of water over time for a long-term view of how natural and released water affects the health of rivers.

Follow the science and more information

Report cards are a result of the work we and our partners do with scientists across the Basin, including site monitoring as part of The Living Murray program.

The Living Murray is a joint program funded by New South Wales, South Australia, Victoria and the Commonwealth governments.

If you want to know more about our monitoring and the results — read the monitoring reports

Read The Living Murray – Icon site condition report – 10 years of ecological monitoring

Southern Connected Basin Environmental Watering Committee Reports