Download Invasive Fish in the Murray- Darling Basin

Invasive Fish in the MurrayDarling Basin
Symposium on Genetic Biocontrol of
Invasive Fish, 21-24 June 2010
Contents
• Background
• The Murray-Darling Basin Native Fish
Strategy
• Invasive Fish Species in the MDB
• Control of Invasives in the MDB
• A Basin Invasive Fish Plan
• Conclusions
The Murray-Darling Basin
•>1 million km2
• 1/7 of Australia
• Covers 5 States and
Territories
• > 2M people
• > 40% Australia’s
agriculture
• Currently worst
drought in recorded
history
Dire Straits
• Native fish suffered – both in terms of
distribution and abundance – due to
human impacts and declining river health
• Expert panel concludes - native fish
abundance and diversity now at a level of
10% of their status 200+ years ago
• Approximately half of the native fish are
recognised under conservation concern
Native Fish in the MDB
• 35 species
• 16 are threatened
Critically Endangered – Trout Cod
Endangered – Barred galaxias
Vulnerable – Murray Cod
Native Fish Strategy
• 50 year plan approved in 2003
• Aim is to restore populations to 60% of preEuropean settlement levels
• Addresses 10 key threats to native spp
• These include habitat loss, lack of fish
passage, extraction, poor water quality,
overfishing, and invasive fish.
Invasive Fish in the MDB
• Atlantic salmon
• Brook char
• Brown trout*
• Carp*
• Eastern gambusia*
• Goldfish
• Oriental weatherloach
• Rainbow trout*
• Redfin perch
• Roach
• Tench
* = IUCN list of world’s worst invasive species
Invasive Fish in the MDB
Invasive Fish in the MDB Impacts
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Predation (eg Brown trout, Redfin)
Competition (eg Carp)
Disease (eg Redfin)
Injury and stress (eg Gambusia)
Damage to infrastructure (eg Carp)
Turbidity, undermining banks
Unknown, benign, or sleepers (eg tench,
roach)
Next Invader?
The next invasive -Tilapia
• Also on IUCN list of world’s worst invasive
species
• Established and abundant in catchments
adjacent to northern MDB
• Sought after recreational fish
• Projects underway – investigate likely
impact; mitigate risk
Control - Biological
“Daughterless” technology
A genetic construct using species-native genes
that is inheritable and that biases off-spring
sex ratios towards males
HindIII
mArom
EcoRI
pBITaB
8400 bp
tTA
SV40pA
BamHI
Bglo-pA
eGFP
HindIII
EcoRI
TRE
PstI
CMVmin2
Hinge
m/zAr-cDNA
m/zAr-cDNA
CMVmin
1
Control - Biological
Koi herpesvirus
Skin necrosis
Control - Pheromones
Control - Physical
• Carp separation cages
• Exclusion screens at wetlands
• Impact of removal of invasive fish
• Fishing
Carp separation cage
Carp separation cage
Carp disposal - Sea to Hume
P
P
P
F
P
F
P
F
F
F
Key
F = fishway
P = PIT-tag reader
F
• Carp at Lock 1 video goes here
Carp jumping
Carp screen
Commercial removal of carp at
fishways
• Commercial Carp separation facility at
new fishway at Lock 1
• 100 tonnes of Carp removed in 2007,
2008, 2009 seasons (October –
December)
• Part of a “whole of river” solution to
disposal of Carp at fishways
Carp
Exclusion
Screens
Carp exclusion screens
Impact of alien
spp removal
Impact of alien invasive
removal
Gambusia
Gambusia aggression
• Gambusia and golden perch
(used in experiments).
Hypothetical e.g. of integrated
pest management
IPM
Achieve y % target through
cumulative effects
Adaptive management:
refine targets
Population decline
To ↓ damage by x %
need to ↓ population by y %
y%
TARGET
SMEC QLD
SMEC
Brenda Park
Wetlands
Plot types:
fully-fenced (top),
semi-fenced
(middle), unfenced
(bottom).
An Open water location showing vegetation
cover in the fully fenced plot (bottom) versus
a semi-fenced plot (top).
Regional carp plans
Condamine
Katarapko
Tahbilk
Katarapko
Condamine
Tahbilk
Some other projects
• A rapid response manual
• Review of biocides
• Identification of carp hotspots
Basin Alien Fish Plan
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Focus on prevention
Rapid response capacity
Manage existing problems
Target communications & engagement &
capacity building
• Due for completion in 2011
Conclusions
• NFS supports an integrated approach to
invasive spp management
• In turn, invasive spp mgt forms part of a
holistic approach to river rehabilitation
• A large investment, and particular interest
in, daughterless carp, pheromones, and
other potential biological controls
Questions?
Integrated pest management
1. Apply a range of carp control
techniques, as an integrated package,
to intensively reduce carp at a
particular location (e.g. a “hotspot”),
and measure the response.
2. Demonstrate to the community the
commitment to address the carp
problem at an on-ground, pragmatic
level.
‘Open Water’ Plot
‘Edge’ Plot
Carp cage and Lifting Gantry fitted to Inlet Culvert