As our climate changes, the seas around Tasmania are experiencing a devastating loss. The towering forest of giant kelp that once thrived in shallow waters surrounding the island have declined by 95%. This is due to increasing sea surface temperatures and lower nutrients. 

Giant kelp forests are now enlisted as an endangered marine community.

Climate change continues to threaten the few remaining strongholds of giant kelp, but there is hope. We are working with partner organisations to restore giant kelp forests. Our first step is using genomics to learn more about why some strains of giant kelp are more tolerant of warmer water.

My name is Dr. Anusaya Willis. I'm the Director of the Australian National Algae Culture Collection at CSIRO in Hobart, Tasmania. 

Giant kelp is a large seaweed. It grows in shallow seas in a number of places around the world, including Tasmania. Seaweeds are not plants, but they have some similarities.

Giant kelp has a hold fast to attach to rocks on the sea floor. A long style, which is its stem and long leaf like blades supported by gas bladders that help them float. They can grow up to 50 centimetres per day and reach more than 30 meters tall. Giant kelp forms the structure of forests like trees on land.

These forests support an entire ecosystem of marine plants, seaweeds invertebrates, such as rock lobsters, young fish in nurseries and marine mammal. Large, dense forests of giant kelp used to cover significant areas of the near shore reef, particularly in eastern Tasmania. They're a key component of coastal ecosystems.

In our lab, we work with the microscopic stage of giant kelp, divers take cuttings from the blades of giant kelp individuals growing in the ocean. The blades produce spores on their underside. These spores grow into microscopic male and female gametophytes that we can keep in culture in the lab using different temperatures of wavelengths of light.

We keep the giant kelp in stasis, grow more cells for study or produce eggs and sperm to form baby giant kelp, which can be placed in the ocean. A baby giant kelp looks like a little leaf growing out of themselves. It starts a couple of millimetres long and it slowly gets longer and longer, and after about three months you can see them, they can be two centimetres long, and this is the stage when they start getting planted out into the field.

Some strains of Tasmanian giant kelp are naturally more tolerant of higher temperature. We are looking at the genetic basis of this. We're also looking at the genetic structure of the remnant populations of giant kelp in the coastal waters of Tasmania to understand the genetic diversity and connections between populations.

And we're establishing a biobank, which is like a seed bank of giant kelp to conserve genetic diversity for future restoration. We're part of a large group of organisations working to restore giant kelp and Tasmania. Our partners of the Nature Conservancy, the University of Tasmania, and Google.

We hope that our genetic work to understand giant kelp and select warm tolerance strains for replanting, will give giant kelp forests best chance to grow and recover.