The Australian Grayling is a slender fish varying in colour from silvery with an olive-grey back and whitish belly, to olive green or brownish in the back with a darker mid-lateral streak and greyish fins. The species has large eyes, which are usually bright yellow, a rounded snout and a small head. The Australian Grayling generally grows between 17–19 cm, but can reach 30–33 cm. The lower jaw is shorter than the upper jaw. It has a fleshy, fatty fin located between the dorsal and tail fins. The mouth reaches to below the eye. There are no scales on the head, nor is there a lateral line. This species has a strong cucumber smell when caught and first taken from the water.
Australian Grayling |
Status: Vulnerable on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Prototroctes maraena
Climate change Increased Known Lin et al. (2017) modelled the effects of climate disconnection current and change on the habitat of Australian Grayling and between habitats future demonstrated that the biggest challenge for the species is the disconnection between habitats (barriers to movement) required to complete their life cycle.
Shenton et al. (2011) modelled climate change scenarios on Australian Grayling spawning in the Latrobe River.
Increased Suspected While climate change does not directly cause intensity frequency of current and bushfire; it has caused an increase in the occurrence wildfire bushfire future of extreme fire weather and in the length of the fire season across large parts of Australia since the 1950s (CSIRO 2020).
Furthermore; bushfires can have direct and indirect effects on the species including changes in water chemistry and changes in the surrounding landscape which can lead to sediment run off into waterways post fire events (Lyon O Connor 2008).
The biggest indirect impact is post fire rainfall leading to runoff of sediment; ash; and nutrients or sediment slugs into waterways (Wilkinson et al. 2007 Lyon O Connor 2008 Alexandra Finlayson 2020).
Sediment slugs have been found to cause impacts to the aquatic ecosystem up to 80 km downstream of a fire impacted area (Lyon O Connor 2008).
The bushfires will not have impacted all areas equally; some areas burnt at very high intensity while other areas burnt at lower intensity; potentially even leaving patches unburnt within the fire footprint.
Additionally; it is estimated that a combined 63 percent of downstream catchments (up to 80 km) in NSW and Victoria are potentially fire impacted by sediment slugs (Legge et al. 2020).
The extent of bushfire impacts overlapping in NSW and Victoria suggests that number of locations for Australian Grayling has reduced.
Extreme weather Known Meteorological drought desiccates local water events current and sources for many freshwater fishes and for the future Australian Grayling; periods of no or low rainfall likely hinders the species migration and spawning cues (Lennox et al. 2019).