Genetics To Save Giant Kelp

The scientific search for thermal resilience

By CSIRO

In partnership with Institute for Marine and Antarctic Studies and The Nature Conservancy

Giant Kelp scientists (2023) by Matt MarrisonCSIRO

Careers with algae

Dr Anusuya Willis and Dr Cintia Iha are phycologists - algae biologists. They study all kinds of algae, from microscopic species that are the base of the food chain, to seaweed species like Giant Kelp.

Giant Kelp cuttings (2023) by Matt MarrisonCSIRO

Secrets in the genes

As climate change warms the ocean, the Giant Kelp forests that once surrounded Tasmania have declined by more than 95 per cent. But some Giant Kelp individuals are tolerant of warmer waters - and their genetic secrets could help save the species.

Testing Giant Kelp (2019) by Cayne LaytonOriginal Source: Institute for Marine and Antarctic Studies, University of Tasmania

Giants in the lab

In the seas around Tasmania, Giant Kelp grows to more than 30 meters tall. But its life cycle includes a microscopic stage, called gametophytes. Giant Kelp gametophytes can be grown and studied in a lab and used to breed new Giant Kelp babies.

A closer look (2023) by Matt MarrisonCSIRO

Breeding babies

We use selective breeding techniques, not genetic modification. Our goal is to maximise the trait of thermal tolerance while maintaining the full genetic diversity present in Tasmania’s remnant Giant Kelp populations.

Giant Kelp blades (2023) by Matt MarrisonCSIRO

Population genetics

Genetic diversity in remnant populations is also being studied and whether these sites are connected by gene flow. Giant Kelp sites off the northeast coast of Tasmania have more gene flow between them than those off the southeast coast.

Extracting DNA (2023) by Matt MarrisonCSIRO

It's getting warmer

To understand why some Giant Kelp individuals can survive warmer sea temperatures, we are using genome sequencing. This means reading the DNA sequence of giant kelp individuals and comparing them to discover which genes are associated with thermal tolerance.

Giant Kelp at Tinderbox Marine Reserve (2023) by Andrew WilsonOriginal Source: Google

Clues in DNA

We've found some promising signs associated with thermal tolerance, but there is more work to be done.

Baby Giant Kelp (2024) by Andrea WildCSIRO

Future forests

Based on these ongoing genetic studies, Giant Kelp babies will be bred from select gametophytes that are warm-tolerant. These will be grown in the lab to around two centimeters long, before being planted in the ocean to help restore Tasmania’s majestic underwater forests.

Giant Kelp cultures (2019) by Cayne LaytonOriginal Source: Institute for Marine and Antarctic Studies, University of Tasmania

Biobanking for the future

CSIRO is creating a biobank of Giant Kelp strains in the Australian National Algae Culture Collection for the purpose of long-term genetic conservation.

Microalgae in culture (2016) by Carlie DevineCSIRO

The Australian National Algae Culture Collection

This collection includes live cultures of more than 1,000 strains of microalgae and more than 100 different seaweeds. Many have been in continuous culture for decades. They are used for research and by industry.

Credits: Story

Story by Andrea Wild
The Tasmanian Giant Kelp Restoration Project is a partnership between The Nature Conservancy (TNC), the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS), Natural Resource Management South (NRM South) and CSIRO.
This TNC-managed project requires many levels of coordination and cooperation. Using a variety of sources TNC identifies sites most suitable for Giant Kelp restoration.
IMAS grows Giant Kelp strains from remnant populations with the best chance of success for the site. CSIRO uses population genetics to ensure diversity and increase thermal tolerance traits to future-proof restored forests.
This Giant Kelp is then grown in the lab at IMAS for about six weeks before TNC and IMAS plant the Giant Kelp at the restoration sites, using a proven technique developed by IMAS to attach the juvenile Giant Kelp to the seafloor. TNC, NRM South, and IMAS are using this experience to develop a nationwide roadmap to recovery for Giant Kelp forests. 

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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