Fish passage technologies

Fish Passage Solutions: Restoring Connectivity for Aquatic Species

• Fish passage refers to the ability of fish to move freely between habitats without obstruction.
• When habitat access is compromised by physical structures such as culverts, fish passage can be restored by managing flow conditions to support movement through the structure.
• Fish pass facilities, such as fish ladders, can help fish swim around barriers that impede natural migration that suit a range of contexts (e.g. barriers of different heights, sites subjected to differing changes in water level etc.) and various species with differing swimming abilities.
• There are various types of fish ladders designed for different contexts, including:  
  • Vertical slot fishways – allowing fish to navigate barriers with controlled water flow.
  • Submerged orifice fishways – designed for species requiring deeper passage routes.
  • Cone fishways – suitable for sites with fluctuating water levels.
• Nature-like fish passes replicate natural river conditions by integrating engineered riverbed features like rock ramps and gradual slopes, providing an ecological solution for fish movement.
• Fish-friendly culverts improve passage in smaller waterways, using gentle slopes, roughened surfaces, and adequate water depth to prevent obstruction and facilitate free movement.