Editing Murray cod (section)

====Habitat degradation / siltation====
Hundreds of thousands, perhaps more than a million, submerged timber "[[snags]]", mainly [[River Red Gum]], have been removed from lowland reaches of the Murray-Darling basin over the past 150 years.<ref name=MacNally-et-all2002>
{{Cite journal
  | last = MacNally  | first = R. |author2=Parkinson, A. |author3=Horrocks, G. |author4=Young, M.
  | title = Current Loads of Coarse Woody Debris on Southeastern Australian Floodplains: Evaluation of Change and Implications for Restoration
  | journal = Restoration Ecology
  | volume = 10
  | issue = 4
  | pages = 627–635
  | year = 2002
  | doi = 10.1046/j.1526-100X.2002.01043.x | bibcode = 2002ResEc..10..627M | s2cid = 84135006 }}
</ref> The removal of such a vast number of snags has had devastating impacts on Murray cod and river ecosystems. Snags are critical habitats and spawning sites for Murray cod. Snags are also critical for the functioning of lowland river ecosystems — as one of the few hard [[Substrate (marine biology)|substrates]] in lowland river channels composed of fine silts snags are crucial sites for [[biofilm]] growth, [[macroinvertebrate]] grazing and general in-stream productivity.<ref name=Koehn2004/><ref name=MacNally-et-all2002/>

Vegetation clearing and cattle trampling river banks create severe [[siltation]], which fill in pools, degrade river ecosystems and make rivers and streams uninhabitable for Murray cod.<ref name=McDowall1996/> This is exacerbated by removal of [[riparian]] (riverbank) vegetation which causes siltation and degrades river ecosystems in many ways.<ref name=nfacod/>