Re-snagging the The north central CMA's lower Loddon River native fish Sections of the lower Loddon River, between Kerang Weir and Little Murray River confluence, recovery plan were de-snagged in the 1970s for attempted flood mitigation. Recent habitat mapping has aims to restore ecosystems, shown the density of timber for fish habitat in the river channel is low. historically The fisheries and tourism in the river supported good populations of Murray cod, golden and silver perch and freshwater Torrumbarry and Swan Hill catfish, all species that have a strong affinity with woody habitat. irrigation areas. In 2017, 10 fish havens constructed by Cohuna Men’s Shed and community volunteers, Instream woody habitat reinstatement complements other work THE ICONIC MURRAY COD RELIES ON were installed in the river to increase fish habitat downstream of Kerang Weir. The fish being undertaken as part of the plan. Building fishways to facilitate INSTREAM WOODY havens, which are small, woody structures, were funded through a Small Recreational fish movement, replanting river-side vegetation, fencing stock HABITAT FOR RESTING, FEEDING Fishing Grant. In 2018, a further 15 snag piles (a larger and more complex timber out of stream banks, and providing fish-friendly flows (to promote AND BREEDING structure that mimics natural habitat) were installed in deep pools near Benjeroop spawning and improve habitat during winter for recruitment in the with the aim of recovering populations of Threatened large-bodied fish species, irrigation off season) are all part of the plan. made possible through Victorian Government Biodiversity On-Ground funding. The lower Loddon re-snagging project complements woody habitat reinstatement Some of the fish being targeted through the plan: in Box-Pyramid Creek (32 structures installed between 2014 and 2017) and the Little Murray River (more than 40 structures installed in 2018) to provide native fish with habitat and resting points on the 180km fish highway from the Murray River through the Little Murray River, Loddon River and Pyramid Creek to the high-quality fish habitat in Kow Swamp. FISH HAVEN CONSTRUCTED BY THE COHUNA MEN’S SHED BEING INSTALLED IN THE LODDON RIVER BELOW KERANG WEIR. why do native fish need snags? Silver perch Golden perch Murray cod Snags, or instream woody habitat, provides: Bidyanus bidyanus Macquaria ambigua Maccullochella peelii peelii Distribution and habitat: Silver perch Distribution and habitat: Golden perch Distribution and habitat: Distribution and were once widespread and abundant are widely distributed in lowland, slow habitat: Formerly widespread throughout throughout lowland rivers, streams and flowing rivers and streams throughout the mid and lowland streams of the Murray sites to lay adhesive eggs for species such as Murray cod and river blackfish lakes throughout most of the Murray- Murray-Darling basin. They prefer deep, Darling Basin; now less abundant. Prefers Darling Basin. They have now declined slow flowing pools or weed beds and have large deep holes in rivers and cover such as to low numbers and disappeared from a strong association with woody habitat rocks, snags, stumps and undercut banks. diversity of habitat through formation of scour pools and bars much of their previous natural range. They and other cover. prefer flowing habitat and are often seen Size: Up to 1800mm and 113kg, more downstream of rapids and weirs. Status: Wild populations are listed as commonly 500 – 700mm. places for migrating fish to rest from high flows Vulnerable under the Victorian Flora and Status: Threatened under the Flora and Fauna Guarantee Act 1988. Diet: Apex predator with a diet of fish, Fauna Guarantee Act 1988; Critically crayfish, frogs, and occasional water birds. shelter from predators Endangered under the Environment Size: Up to 760mm and 23kg, more commonly 400 – 500mm. Biology: Spawning occurs in the spring Protection and Biodiversity Conservation and summer in temperatures between 16 Act 1999. Diet: Carnivorous, eating mainly yabbies, and 21°C. Females lay up to 40,000 eggs landmarks to define territories and aid navigation Size: Up to 610mm and 8kg, more shrimp, small fish, insect larvae and snails. which are deposited on hard surfaces, such commonly 300mm. as rocks, clay banks and in hollow logs. The Biology: Tolerant species surviving in eggs hatch 5-13 days later. Males guard ambush sites for predatory species such as Murray cod, trout cod and golden perch Diet: Omnivorous, feeds on algae, aquatic temperatures between 4 and 37°C and the nest before larvae disperse and drift plants, snails, shrimp and insect larvae. salinities almost that of sea-water. Adult downstream in the current, usually at night, fish move large distances (up to 1000 for 5-7 days. high productivity sites for feeding Biology: Individuals mature at 3-5 years, km) to spawn in spring and summer, and spawning occurs in schools in spring associated with rises in water level and Status: Threatened under the Victorian and summer following a long upstream increased day-length. Flora and Fauna Guarantee Act 1988 and migration. Eggs and larvae drift in the vulnerable under the Environment Protection current for up to 15 days. Immature fish Threats: River regulation, barriers to and Biodiversity Conservation Act 1999. then undertake an upstream migration migration such as dams and weirs, cold- between October and April. water pollution and removal of snags. Threats: Overfishing, habitat loss through sedimentation and removal of snags; altered Threats: River regulation, cold water flows and cold-water pollution. pollution and alien species (carp and IMAGE COURTESY redfin perch). OF MICHAEL BELL AND MDBA ILLUSTRATIONS COURTESY OF DEDJTR North central CMA acknowledges the traditional owners of this country. www.nccma.vic.gov.au Re-snagging the The north central CMA’s Little Murray River native fish The Little Murray River is a 46 kilometre anabranch of the Murray River. It leaves the Murray near Fish recovery plan Point, where it is joined by the Loddon River, and rejoins the Murray at Swan Hill. Historically, the river was used as a water carrier for the Swan Hill Irrigation Region. Habitat mapping has shown the river has aims to restore ecosystems, fisheries few snags available for fish habitat, especially downstream of the Little Murray Weir. and tourism in the Torrumbarry and Swan Hill irrigation areas. The Swan Hill Modernisation Project (SWMP), a Goulburn Murray Water Connections Project, aims to deliver water savings, environmental outcomes, and improved irrigation operations. Instream woody habitat reinstatement It is expected to greatly improve fish populations through: complements other work being undertaken as part of the plan. Building Increasing flowing water habitat in the Little Murray River. To complement the SWMP, North Central CMA has re-snagged the fishways to facilitate fish movement, Constructing fishways on Little Murray Weir and Fish replanting river-side vegetation, fencing stock Point Weir to allow fish passage to and from the Murray 20km reach between Little Murray Weir and Swan Hill. 10 snag piles River into the Little Murray and Loddon Rivers. and 10 fish havens were installed to provide native fish with habitat out of stream banks, and providing fish-friendly Installing over 20 instream woody habitat and resting points on the 180km fish highway from the Murray River flows (to promote spawning and improve structures between the two weirs. habitat during winter for recruitment in the THE ICONIC MURRAY through the Little Murray River, Loddon River and Pyramid Creek to COD RELIES ON Delivering fish-friendly flows for movement, spawning irrigation off season) are all part of the plan. INSTREAM WOODY and recruitment of Murray cod, freshwater catfish and the high-quality fish habitat in Kow Swamp. HABITAT FOR golden and silver perch. RESTING, FEEDING AND BREEDING come on the Irrigation channels are a one- Dams and weirs block fish Planting native species Increased fish journey of way trip for native fish. When from moving up and down populations leads fish move into channels, they on stream banks prevents stream to access new erosion, improves water to better fishing are effectively lost from the habitats, find food and opportunities, increased breeding population and quality, and creates fish People fishing and recovery breed. Weir pools reduce habitat through snags and tourismenjoying and the people waterway. exposed to a greater number flowing water habitat tree roots. Fencing protects river connecting with nature. of threats. preferred by species such banks from wandering as Murray cod. stock, improves water quality and allows native vegetation to flourish. Water for the environment increase flows, food, habitat availability and provides important cues for fish movement and spawning. Fallen logs create instream woody habitat which provides: Stock increase nutrients in waterways, trample Carp uproot water plants Self-cleaning irrigation and increase turbidity. river-side vegetation, screens mean more sites to lay adhesive eggs landmarks to define cause bank erosion, and Other pest species such fish stay in rivers, and territories and aid as redfin perch feed on diversity of habitat lead to infilling of deep Willows can take over irrigators can benefit through formation navigation small native fish. pools with sediment. river banks, blocking up from reduced debris Fishways and overshot of pools and bars ambush sites for waterways, increasing loads, allowing more weirs allow fish to safely predators such as places for migrating fish siltation, and causing efficient irrigation move upstream and to rest from high flows Murray cod, trout cod water-quality problems practices to be adopted. downstream. and golden perch shelter from predators when they drop masses high productivity sites of leaves during winter. for feeding. North central CMA acknowledges the traditional owners of this country. www.nccma.vic.gov.au.