Degradation

As a result of poor land and water management practices over the last century, a number of the State’s waterways and river fisheries are now in a degraded state.

Examples of this  degradation includes:

• habitat loss both within the waterways and along the edges (riparian zones)
• alterations in natural flow regimes
• contaminants entering waterways
• erosion of riverbanks and scouring of river beds
• in-stream barriers have been erected and
• introduction of non-native plant species.

Many fish and invertebrates are very sensitive to the degradation that has taken place around them. Examples include:

• removing riparian and in-stream habitat, which removes fish shelter, spawning material and food sources
• changing water flows which can de-water preferred habitat also making fish more susceptible to predation
• contaminants directly killing fish and invertebrates
• erosion adds sediments that can smother eggs and kill some species
• erecting in-stream barriers can reduce fish movements and eliminate migrations and introduced plants can ‘choke’ waterways.