Hitchhiking across the Pacific with imported shellfish, on boats, or in bilge and ballast water, alien sea squirts known as tunicates have been busy colonizing marinas and dive spots throughout Puget Sound.
Over a single year, two individual squirts managed to smother and slime Sund Rock in Hood Canal, a popular dive spot. They have been known to cluster-smother mussel and aquaculture beds.
“By the time we’d recognized what was going on at Sund Rock, it was bonkers, they were all over the place,” says Janna Nichols, the acting field general for taming the tunicate infestors. Nichols has trained and certified over 175 slime-fighting divers. Last October at Sund, with divers from Portland and Olympia, they removed over 1,500 tunicates — which, once above the water, resembled a 90-pound heap of snot.
The creatures have no predators here, and they multiply in Hood Canal’s “fish-kill-die-offs” that occur when oxygen levels plummet in late summer.
Nichols wonders if the ill-health of the South Sound explains the slimers’ success, but is confident that vigilant divers won’t let the situation get out of hand again.