Introduction

advertisement
Macquarie Perch Habitat Restoration Project
– Stage 1
Introduction
The Lachlan Catchment Management Authority (LCMA) has initiated a large project on the Lachlan
River above Wyangala Dam to save the endangered Macquarie perch Macquaria australasica also known
as Mountain perch or Black bream.
Figure 1: Macquarie perch Macquaria australasica (source: Gilligan & Heath, 2008)
Known as the Macquarie Perch Habitat Rehabilitation Project, it involves local landholders, Upper
Lachlan Council, Tablelands LHPA and the Onerwal Lands Council agreeing to improve the habitat for
native fish along the Lachlan River. This has included restoring native vegetation on the banks (riparian
area), construct erosion control works, instal alternate stock water supply and in one area recreating
desirable habitat using recently felled trees (snags) from nearby road works to place in strategic locations.
The project is the result of detailed survey work undertaken by Department of Primary Industries (DPI)
Fisheries. In 2006 DPI Fisheries identified four separate populations of the endangered native fish species
in the Upper Lachlan and Abercrombie Rivers (Gilligan & Heath, 2008) (Figure 4). They also found
Lachlan catchment contains the most significant remaining inland (Murray Darling Basin) population of
the endangered Macquarie perch population in NSW (NSW DPI, unpublished data, 2008). A partnership
was entered into with the LCMA to undertake a survey of habitat characteristics that the Macquarie Perch
preferred to live and breed in.
Gilligan & Heath (2008) found that the presence of Macquarie Perch was linked to a few key
characteristics. These included the presence of snags (submerged or partly submerged trees) providing
protection and food source (macroinvertebrates), run and riffle sequences with cobble substrate, shallow
reaches (<2m deep), shade minimising fluctuations in water temperature and low sediment loads
(erosion). They avoided sandy substrate, deep pools and reaches with active erosion.
LCMA & DPI Fisheries determined that the best focus for investment was to link isolated populations in
the Lachlan River by habitat rehabilitation. A judgement was made to first stabilise and perhaps increase
these populations before attempting to link them to the Abercrombie population. The LCMA approved a
budget for $737,000 of which $578,000 was allocated to fund onground works in cost-share arrangements
with landholders over the target area (Figure 2).
It was recognised that an additional eight native aquatic threatened species and a further four native fish
species could benefit from the rehabilitation measures implemented as part of the project (LCMA, 2008).
Project Area
The project is located in NSW in the Upper Lachlan catchment above Wyangala Dam (Figure 4). As a
result of the population survey and habitat assessment, the Macquarie Perch Habitat Rehabilitation
Project saw an area targeted between Gunning and Wyangala Dam The target area comprised a 91km
section of Lachlan River that included the three isolated populations of Macquarie perch.
Figure 2 shows a typical reach that provided good habitat features (snags, shade, shallow <2m deep and
stable banks). There were also less desirable features such as excessive sediment load (sediment slugs)
contained in the target area (Figure 3)
Figure 2: Good habitat for native fish on the
Lachlan – “Numby” Photo Fin Martin
Figure 3. Sand (sediment slug) covering cobble
substrate “Battery Crossing” Photo Geoff
Minchin
Late 2007 the LCMA approached landholders along the Lachlan and developed projects aimed at fencing
and revegetating sections, providing off-stream water points and soil conservation works for significant
erosion sites.
A strategic snagging project was also carried out in early 2008 on a 2km section of the Lachlan to recreate
suitable habitat using ‘snags’ and rock. Snags offer refuge to native fish and are seen as an essential
characteristic of good habitat in the Lachlan River. Upper Lachlan Council provided suitable felled trees
and rock for erosion protection from recent roadworks close to the project.
Abercrombie River
Lachlan River
Figure 4: Study area detailing Macquarie perch populations and target area for onground
works (source: adapted from Gilligan, D. and Heath, P. 2008)
A total budget of $737,000 was expended in a twelve-month period following the study results.
This was specifically aimed at improving habitat characteristics along the targeted 91km section of
the Lachlan River. Eleven landholders entered into agreements with the Lachlan CMA to
implement on-ground works that is outlined in Table 1.
Table 1: Summary of onground works (source: LCMA, 2008)
Onground works
Result
Habitat assessment
323km of river - $99,000
Fencing for stock management
54 km of stream (38km of Lachlan River)
Conservation of existing habitat
572 ha ($336,000)
Revegetation for habitat enhancement
110 ha ($170,000)
Improved grazing management
2134 ha
Erosion control reducing point source sediment
24 km ($15,000)
Snagging for fish habitat
83 snags + rock ($57,000)
Habitat assessment (2008/09)
120 km of river ($60,000)
With the exception of some tree planting (planned for Spring 2008) all works have been complete
and management conditions in the LCMA landholder agreements are being met. Results showed
42% of target area had works to rehabilitate habitat with an additional 16km of tributaries
rehabilitated.
Extensive baseline data collection at the beginning of the project will ensure outcomes can be
monitored by both LCMA (onground works) and DPI Fisheries (fish population changes) into the
future. An ongoing monitoring program has been agreed to by DPI Fisheries who will survey fish
populations every three years to determine if onground works are effective in enhancing
populations of the Macquarie perch (and other native species). LCMA will monitor site condition
for 10 years to ensure management is enhancing habitat values.
Ongoing funding is being actively sought by the LCMA to continue linking the populations of
Macquarie perch with suitable habitat. It is estimated that it will take $1.8-2.2 million to fence,
revegetate and supply alternate stock water to the remaining reaches to complete rehabilitation and
link the four populations of Macquarie perch. In 2008/09 further habitat and species assessment will
take place in the Crookwell River and Blakney Creek (known site of the endangered Pygmy Perch)
to determine if other populations exist in tributaries to the Lachlan River.
5 key points
1. The Abercrombie and Lachlan Rivers above Wyangala Dam contain the most significant inland
(Murray Darling Basin) population of the endangered Macquarie perch population in NSW.
2. Department of Primary Industries - Fisheries and Lachlan Catchment Management Authority
were able to determine the preferred habitat features of the Macquarie perch and develop a
rehabilitation strategy for the lachlan and Abercrombie rivers above Wyangala Dam.
3. The Lachlan Catchment Management Authority was able to provide incentives of $578,000 to
landholders for onground works in less than twelve months entering into 11 agreements. This
resulted in 42km of stream rehabilitated, 682ha of native vegetation conserved or revegetated,
2134ha of improved grazing management adjacent to the river, 24km of erosion prevention to
flowlines and 83 snags placed for improved habitat.
4. An additional eight native aquatic threatened species and a further four native fish species could
benefit from the rehabilitation measures implemented as part of the project.
5. An ongoing monitoring program will ensure that outcomes (changes to fish populations) of the
project will be recorded and that works will be maintained over the life of the landholder
agreements.
Fish species identified in the Upper Lachlan catchment
Native species
Present
Potential
Threatened 1
Macquarie perch Macquaria australasica


Silver perch Bidyanus bidyanus


Purple-spotted gudgeon Mogurnda adspersa


Southern pygmy perch Nannoperca australis


River blackfish Gadopsis marmoratus


A water snail Notopala sublineata


Murray cod Maccullochella peelii


Freshwater catfish Tandanus tandanus


Trout cod Maccullochella macquariensis


Olive perchlet Ambassis agassizii


Golden perch Macquaria ambigua

Flat headed gudgeon Philypnodon grandiceps

Australian smelt Retropinna semoni

Murray jollytail Galaxias rostratus

Dwarf flat-headed gudgeon Philypnodon
macrostomus

Carp gudgeon Hypseleotris spp.

Exotic species
1
Brown trout Salmo trutta

Carp Cyprinus Carpio

Mosquito fish Gambusia holbrooki

Goldfish Carassius auratus

Rainbow trout Oncorhynchus mykiss

Redfin Perca flluviatilis

Lintermanns, M. (2007). Fishes of the Murray-Darling Basin – An introductory guide, MDBC, Canberra, ACT.
Enhancement works targeted 6 threatened native fish species present

Macquarie Perch Macquaria australasica, Silver Perch Bidyanus bidyanus, Purple-Spotted Gudgeon
Mogurnda adspersa, Southern Pygmy Perch Nannoperca australis, River Blackfish Gadopsis
marmoratus and a water snail Notopala sublineata.(Present)
4 threatened native fish species that have similar habitat potential and were belived to be present

Freshwater catfish Tandanus tandanus, Trout cod Maccullochella macquariensis, Murray Cod
Maccullochella peelii, Olive Perchlet Ambassis agassizii (Potential)
and 6 non-threatened species:

Golden Perch Macquaria ambigua, , Australian Smelt Retropinna semoni, Flat Headed Gudgeon
Philypnodon grandiceps, Murray jollytail Galaxias rostratus, Dwarf Flat-Headed Gudgeon Philypnodon
macrostomus, Carp Gudgeon Hypseleotris spp.
Habitat charateristics mapped on the Lachlan, Abercrombie,
Crookwell, Retreat Rivers & Blakney’s Ck
Category

Mesohabitat

Substrate

Rocks

Snags






Erosion
Willows
Undercuts
Macrophytes
Photo point
Thalweg Depth at each 1km intersection
Snag placement locations at “Numby”
Sub-category



















Run
Rapid
Riffle
Pool
Dry
Sand
Gravel
Cobble
Boulder
Bedrock
Mud
Small Simple
Small Complex
Large Simple
Large Complex
Large simple
Large complex
Small simple
Small complex
Download