Seabed-to-surface exclusion barriers and enclosed swimming areas

Mechanism

Unlike a gillnet, an exclusion barrier is a continuous physical fence — modern versions use rigid or semi-rigid plastic mesh panels — anchored from the seabed to the surface and joined to the shore at both ends, fully enclosing a bathing area. Sharks are physically excluded; rigid-panel designs let smaller marine life pass, so bycatch is minimal to none. Tidal/ocean pools achieve the same separation by other means.

Where it fits

Suited to sheltered bays, harbours and gazetted swimming beaches rather than high-energy open surf. It is the most complete protection available for a defined swim area, and a strong fit where a community wants a guaranteed-safe zone without any lethal control.

Operating profile

• Protection inside an intact barrier is effectively total — programs report zero bites within the enclosure.
• Only the enclosed area is protected; surfers and swimmers outside it are not.
• Vulnerable to storm and swell damage and to biofouling; needs maintenance and is impractical to span large or exposed coastlines.
• Higher upfront capital and infrastructure cost than detection-only measures.

Evidence

Hong Kong has enclosed dozens of gazetted beaches with seabed-to-surface barriers since the mid-1990s, with no fatalities at protected beaches since 1995. In Western Australia, an eco-barrier has operated at Coogee Beach since 2014 following a 2013–14 trial. These are the clearest demonstrations that physical separation can eliminate in-zone risk while avoiding the bycatch of gillnets.