Dredging takes place in Queensland ports to keep channels sufficiently deep to accommodate our reliance on shipping and commercial trade. Dredging maintenance occurs on a regular, semi-regular or infrequent basis, depending on the characteristics of the channel.

Turtles often inhabit nearshore areas where dredges operate and can seek deepwater channels created by dredging where they may use the rough bottom to rest away from high velocity shallow-water areas. Each year there are a few reports (one to two) of marine turtles being injured or killed by dredges in Queensland. A Port of Brisbane Corporation report in 2000 resulted in State-wide actions to minimise the potential for dredging injuries to turtles.

Actions

• The Great Barrier Reef Marine Park Authority (GBRMPA) has a policy on dredging and the disposal of dredge spoil.
• Turtle deflectors have been fitted for use on drag-heads of the dredgers except where their use is prevented by practicality or safety concerns. A recent shift from rigid to flexible deflectors has assisted in addressing concerns about their use.
• On-board management is also used effectively to minimise risks to turtles (pumps are turned off when the drag head is lifted from the bottom, and jet pumps are used to provide a mobile water curtain). These measures appear to be as effective, if not more than turtle deflectors in reducing risks to turtles.
• In some places, dredging is scheduled to occur at times to avoid peaks in turtle abundance. For example, dredging in Bundaberg is mostly timed to minimise conflict with mating and nesting marine turtles at Mon Repos Beach. Similarly, other ports are dredged in the winter months, which are considered a lower risk to turtles.
• Reporting and specific management practices have been introduced to minimise the potential for turtle injury.