Click to edit Master title style Click to edit Master subtitle style Habitat makes fish happen! Luke Pearce Fisheries Manager Greater Murray
Outline • Status of Native Fish in the Murray Darling Basin • Status of Native Fish in the Murrumbidgee • History and Status of Fish in the Yanco Creek • Reasons for decline • SDL Risks • Approvals Process • What can we do
Native Fish Status Murray Darling Basin Current levels are estimated at 10% of pre European settlement levels. That’s a 90% reduction. 26 of the 46 native species in the Basin are now recognised as either rare or threatened on state, territory or national listings. So over half of our native species are in trouble. Without intervention, it is predicted to fall to near 5% in the coming 40-50 years. 11 Alien species which comprise 80-90% of fish biomass at many sites. Localised extinction of some native species
Murrumbidgee Catchment Fish community in the Murrumbidgee catchment is severely degraded. 8 of the 21 native species which previously existed in the catchment are either locally extinct or survive in very low abundances. 89.84% of the total biomass is made up of alien species. Without substantial intervention, the status of fish species and communities in the Bidgee will not improve.
Yanco Creek system — What was here • 18 Species
What’s Replaced them? • 5 Species
What’s Missing
May Still be Present
How do we know this • Historical Records • Early explorers journals • News paper articles • Photos • Museum and scientific records
Reasons for Decline Habitat modification – Erosion and Sedimentation – De-snaging – Degradation of the riparian vegetation – Loss of aquatic plants Modification of natural river flows – Dams, weirs, road crossings – Altered flow patters – Reduced floodplain and wetland inundation – Thermal Pollution – Water extraction – Water quality decline Non Habitat related – Predation, competition and disease from introduced species – Fishing pressure commercial and recreational
Carrying capacity 140 120 100 fish per hectare 80 60 40 20 0 1 2 3 4 5 age
Migration – barriers
De-snaging
Erosion and Sedimentation
Degradation of Riparian Vegetation
Loss of Aquatic Plants
Cold Water Pollution
Survival and Growth
Spawning
Carrying capacity 140 120 100 fish per hectare 80 60 40 20 0 1 2 3 4 5 age
Highlights of the Yanco Yanco system has some fantastic habitat High conservation value Current flow regime has developed a specific ecological character At least 4 threatened species Part of an Endangered Ecological Community Huge potential for recovery Fish populations won’t recover without our help
Risks from Proposed SDL Project Loss of connectivity/fish passage Reduced natural flow variability Reduced natural ques Loss of flow hydrodynamics/flowing water habitat Increased weir pool inundations Changes to current ecological character
Risks from Proposed SDL Project Can the ecological and water saving objectives of the project be met without creating the risk??
Approval Process Section 199 – Under s199 of the FM Act, the Minister for Primary Industries is required to be consulted over any dredging or reclamation works carried out, or proposed to be authorised, by a public authority (other than a local government authority) (i.e. any excavation within, or filling or draining of, water land or the removal of woody debris, snags, rocks or freshwater native aquatic vegetation or the removal of any other material from water land that disturbs, moves or harms these in-stream habitats). Section 219 – permit to obstruct the free passage of fish Section 218 - provide fish passage on the modification, or installation of dams and weirs
Environmental Assessment Determine the impacts and mitigation measures Threatened Species Test of Significance A finding of Significance then requires a Species Impact Statement
These days, as I drift back through the years and think about my fishing in the Murrumbidgee, I can only say it may not have been heaven, but it was next door. Thank you for your time
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