Are open ICOLLs better for fish?
ICOLLs are very complex environments and the impact of artificially opening entrances on fish species and fish habitats is not well understood. Many species of estuarine fish and prawns that are targeted by recreational and commercial fishers breed in oceanic or coastal waters and enter estuaries and ICOLLs from the ocean as larvae and juveniles. While some fish need to migrate to the sea to complete their breeding cycle, others reproduce in the estuary and do not require an open entrance for spawning. Long periods (i.e. 3 to 4 years or more) of entrance closure may restrict the recruitment of certain fish species to ICOLLs. However, some fish and fish larvae will enter an ICOLL from the ocean even if it is only open for a short period of time, or during ‘wash over’ events when seawater flows over the entrance berm during high tides and storm surges. Although enhancing the recruitment of fish and prawns is often cited as justification for artificially opening entrance barriers, fish an
