In August last year we introduced you to our resurrected friend, the Southern purple-spotted gudgeon (Mogurnda adspersa) aka the Zombie Fish! When we last reported, 30 Southern purple spotted gudgeon (SPSG) broodstock were collected from the newly discovered Kerang lakes population for captive breeding at Middle Creek Farm and Aquasave-NGT hatcheries.
Since then, 13 potential “surrogate” sites consisting of farm dams and urban wetlands with a secure water supply, were assessed for suitability for SPSG by checking water quality, habitat cover, and the prevailing fish assemblage. Six wetlands were selected for SPSG releases, including three near Bendigo, and one each near Kerang, Mildura and Deniliquin. These “surrogate” sites were established with the intention of reducing extinction risk by providing secure, predator free backup populations in the landscape. Ideally these also act as ‘natural hatcheries’ that can later be used to source larger numbers of SPSG for translocation into suitable wild sites (permanent floodplain wetlands) throughout the Murray Corridor.
Selected surrogate sites were enhanced to make the best possible environment for the new arrivals. For example, in Mildura, this consisted of draining the wetland to remove pest fish, re-filling and adding rock and timber habitat for additional cover and spawning sites. Other sites were planted with aquatic macrophytes, and additional complex timber and brush piles were installed.
Release events took place in November and December of 2021 with the aid of project partners. This work would not have been achieved without the dedication and hard work of researchers, fish breeders, landholders, Working for Victoria crews, local councils, NSW Fisheries, fishing clubs, volunteer groups and the Tri-State Alliance.
Follow up surveys were undertaken at 5 of the sites in January and February 2022, to check that the SPSG juveniles had settled into their new homes. Not only had they survived at all 5 wetlands, but they had also thrived, having doubled in size in just over 2 months! Given the rapid growth and maturity of the SPSG, additional surveys were undertaken in March and April 2022 to check for recruitment. Baby zombie fish were found at 3 of the 4 sites surveyed with approx. 160 zombie babies captured in the sample at the Mildura wetland, and 2 zombie babies each in two of the Bendigo wetlands – A fantastic result!
The SPSG breeding and release program will continue throughout 2022 through the Tri-State Alliance as part of the Mid-Murray Floodplain Recovery Reach Program. Additional funding has been secured through a DELWP Icon Species grant to prepare an additional 2 surrogate sites and assess and select wild sites for conservation stocking.
The future of this undead zombie fish is looking bright!
Main photo: Adult Zombie Fish.
Source: Peter Rose.