The line was among a huge haul of more than 12,500 items collected by 80 volunteers on land and in the water during the Ammo Jetty Clean Up dive.
Co-organiser Connor Smith said the event had been a huge success.
“I was blown away,” he said. “Just the support we had from volunteers and members of the public coming up to us and asking what we were doing was great.”
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READ NOWAmong the 356kg of rubbish collected from the Coogee site was discarded plastic food wrappers, lures, hooks, floats, rods, chairs, cigarette butts, bottles and balloons.
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Sea Shepherd’s Perth Marine Debris Team volunteer Marina Hansen said the amount of waste collected showed people needed to take more care.
“I think it goes to show people who use the area need to act responsibly,” she said. “The amount was shocking.”
Mr Smith said more clean-ups could be held along the metropolitan coastline this year.