South Australia's harmful algal bloom has entered its second year, local divers are witnessing dramatic shifts in marine life. A national community of dive operators, divers and marine scientists take these stories into classrooms, forums, and screenings across South Australia this week.
RAPID BAY, SA, March 4, 2026 — Marlene has been diving Rapid Bay and Second Valley two to three times a month since 2022. She knows this reef intimately, the temperature of the water, the fish that shelter in a particular crevice, the slow seasonal rhythms of the kelp. And in recent months, she has watched something extraordinary happen.
Weedy seadragons, once so rare at Rapid Bay that spotting one was an event worth talking about for weeks, have exploded. Marlene has counted up to 30 in a single dive. Six months ago, seeing one at all was considered lucky.
At the same time, South Australia's state marine emblem, the leafy seadragon, has moved in the opposite direction. A population of 45 known residents at the site has collapsed to just one or two.
"We're the ones in the water. We see the temperature shifts, we see the species moving, we know our dive sites like no one else. What's happening out there isn't abstract, it's right in front of us every time we go under." —Marlene, local diver, Rapid Bay
Sea Dragon Diving Lodge, which has operated at Rapid Bay for years, has been closely tracking these changes. Their observations and Marlene's are exactly the kind of frontline data that Divers for Climate was built to amplify. A national survey of nearly 1,000 Australian divers found that 91% have directly experienced climate impacts underwater. Marlene is one of them.
This week, Divers for Climate is taking these stories on the road. The organisation is hosting a series of community events across South Australia, bringing together divers, scientists, candidates, and ocean lovers to talk openly about what is happening beneath the state's coastline.
South Australia's harmful algal bloom, which first appeared on March 15 last year, remains active along the coastline a full year later. Its impacts on dive tourism, marine ecosystems, and coastal livelihoods have largely faded from the news cycle. 'This week is about taking the frontline experiences of South Australia's dive community to the media, decision makers and the general public. Amplifying what their divers are experiencing underwater," — Dr. Yolanda Waters, CEO and Founder, Divers for Climate
EVENTS THIS WEEK
Thursday March 5 Dive at Rapid Bay Sea Dragon Diving Lodge, Rapid Bay
Local divers enter the water at one of South Australia's most storied dive sites, home to the seadragon population shifts documented above. Media welcome to attend and photograph. Underwater footage and photography from Rapid Bay are available on request.
Friday, March 6 Night at the Museum 5pm onwards — Rodney Fox & Mark Tozer's Shark Museum and Research Centre, Adelaide
