‘Habitat complexity’ refers to the variety of shelter available for fish and other aquatic species in a river or waterbody. More diverse and complex habitat will support a greater diversity and abundance of native fish. Native fish use different habitat types and areas at different life history stages. They have evolved with the natural Australian riverine landscape - complete with fringing aquatic vegetation, deep refuge pools, shallow riffle zones, overhanging trees, large woody habitat and waterbodies that periodically dry up. Many native fish are classed as habitat specialists due to their use of a range of specific habitat types.

More complex and diverse habitat provides more areas for native fish and other wildlife such as turtles, yabbies, platypus and frogs to shelter and breed. For example, it may look ‘messy’ but fallen timber in a river, creek or wetland provides essential habitat for native fish.

Alien species such as carp and goldfish tend to ‘make do’ with whatever habitat is around, often thriving in disturbed habitat. As such, these habitat generalists, if given a chance, will out-compete native fish for food and shelter. By increasing habitat complexity, you increase the opportunities for native fish to establish and use an area.

MANAGEMENT OPTIONS

• Maintain complex diverse habitat on your property
• Consider what your property can provide to native animals in your area

MANAGEMENT ACTIONS

• Retain 'messy' riparian and aquatic habitat areas with complex vegetation and woody debris
• Let sleeping logs lie or, if needed, seek advice to realign problem snags
• Seek advice on reintroducing woody habitat into waterways
• Control stock and vehicle access to riparian areas and protect these areas from disturbance
• Re-establish riparian areas with plantings of grasses, understorey shrubs and overstorey trees