4,450 timber pieces restored 110 km of the Murray River, tripling Murray cod numbers

Golden perch (Macquaria ambigua) Restoring woody habitat in a degraded section of Australia's Murray River has led to a major increase in the populations of two native fish species. In the research carried out over seven years, the number of Murray cod in the restored reach increased threefold, while the population of golden perch increased twofold. The aim of the study was to examine whether adding large pieces of coarse woody habitat could increase fish populations. The study was published in Ecological Applications in 2019.During the study, researchers put 4,450 pieces of coarse woody habitat back into about 110 km of the Murray River in south-eastern Australia. The timber was placed between 2007 and 2010 in four priority zones. Most of the pieces weighed more than one tonne and came from natural trees recovered from a large road project. Researchers then monitored fish populations over seven years, from 2007 to 2013.The work focused on Murray cod (Maccullochella peelii) and golden perch (Macquaria ambigua), two native freshwater fish that use woody structures for refuge, cover while hunting and spawning sites. Both species had declined in abundance and range since European sett...