Rottnest Island Seagrass Pilot Study
2016 Pilot Study by Louise Benson
The weekend of March 19-20th saw 100s of swimmers set-off on the fundraising Port to Pub 20 km swim from Perth to Rottnest Island, while the WADDI team headed back to the island to continue its seagrass mapping project. What was set to be a weekend of rain and wind turned out to be great conditions for divers and swimmers alike. I was lucky enough to be part of a team of 6 volunteers who mapped 2 more bays over the course of the weekend.
After a slightly delayed start due to car trouble (life would be too simple if there wasn’t something that goes wrong!!), we set off to our first site, Mabel Cove. The cove is relatively small, compared to bays previously mapped, but we were pleased to see large areas of seagrass, providing enough area for the divers to carry out their survey. After a few camera hiccups and masks going MIA, we completed the survey in good time, ending with 7 points and 21 quadrats.
Once we finished here, we headed off to our next site at Rocky Bay. We were greeted with a huge white sandy beach and a blanket of seagrass as far as the eye could see, which is great news for the ecosystem and coastline! We were accompanied by lots of marine life, including a rather old looking eagle ray that kept us company for most of the afternoon and again the next day. This site took the rest of the weekend and we covered a lot of ground going out to around 100 m from the beach. In total, we finished 46 points and 138 quadrats in the bay. For both Mabel Cove and Rocky Bay, we measured percent cover, species composition and photographed each quadrat. In total, we found five species of seagrass, Posidonia australis, Posidonia sinuosa, Amphibolis griffithi, Amphibolis antarctica, and Syringodium isoetifolium.
It was great seeing so many people out there raising money for our oceans and meeting some truly inspiring people working to protect such an important part of the ecosystem. As a new volunteer with WADDI, I have a new found respect and interest in seagrass. I look forward to helping continue the important work WADDI and the Rottnest Island Authority are doing as the project moves into more detailed analyses of the seagrass at Rottnest Island. And to top it off, I got my first quokka selfie. A great weekend all round!
2015 Pilot Studies
On the 14th and 15th March 2015, WADDI kicked off its first seagrass monitoring pilot program at Rottnest Island in Western Australia.
Volunteer divers Alicia Sutton, Ben Jones, Cecile Decazes, Eloise Ashworth, Grace Keast, Harriet Davies, Kevin Smith, Niko Striega, Paul Day and Sam Jones lodged at the research station and dived in teams of three along predefined transects from the shores of Geordie and Thompson Bays.
Our goal is to map seagrass cover and species composition using Seagrass-Watch methodology to provide the necessary information to design an appropriate long term monitoring strategy.
We thank Helen Shortland-Jones of Rottnest Island Authority for generous support with logistics, transport and accommodation and Dr Mike Van Keulen for his in-kind support.
WADDI completed the second part of its seagrass mapping program at Rottnest Island on the 9th and 10th May 2015.
Diving from the shore in Thompson Bay and near Green Island, divers resumed the collection of seagrass species composition and abundance data under the curious eye of the native fish fauna. A third weekend is planned in June to complete the mapping program.
A big thank you goes to volunteers Cecile Decazes, Eloise Ashworth, Kevin Smith, Lauren Taafe, Max Wellington, Niko Striega, Paul Day and our dedicated driver, Raif Douthwaite. We also thank the Rottnest Island Authority, particularly Helen Shortland-Jones, for generous support with logistics, transport and accommodation and Dr Mike Van Keulen for his in-kind support.