Geography KS3 / GCSE: Kelp reforestation in Tasmania
Ade Adepitan travels to Tasmania to find out about the work being done to protect the carbon-capturing underwater kelp forests.
Giant kelp is one of the fastest-growing plants on the planet, it can capture carbon more quickly than a rainforest.
However, the giant kelp in Tasmania is struggling. Almost all of it has died because of warmer sea temperatures and a new invasive species of sea urchins. They eat kelp and can create underwater deserts, pretty much empty of life.
This clip is from the BBC Two series, Climate Change: Ade on the Frontline.
Before watching the film
This film can build on students’ understanding of climate change impacts and the interdependence of natural systems. It is helpful if students have some understanding of global circulation patterns and realise that some parts of the world are affected more than others as a result of climate change caused by human activity.
You may wish to recap what students know and think about climate change, carbon dioxide, and other greenhouse gases arising from human activity. It could also be useful to know what students know about the ability of natural systems such as forests, to capture carbon.
Equally, the film can provide an enquiry point for developing early understanding about climate change and its related impacts on people and environments.
During the film
You may wish to stop at relevant points during this short film to pose questions and check understanding or wait until the end. You might want to ask students, for example, how they felt when they were told that giant kelp can grow up to 40-50 centimetres in a day and can capture carbon more quickly than a rainforest.
You might also want to ask:
- What other benefits might giant kelp forests like this one offer apart from helping to combat climate change? E.g. providing sanctuary and shelter for other creatures, supporting eco-tourism and biodiversity.
- Why is just a small percentage of the giant kelp managing to survive the increased temperatures?
- You could use this as an opportunity to discuss how one of the major problems with the rate of climate change that we are currently facing is that many species cannot adapt sufficiently quickly. Processes such as natural selection take time which is why intervention strategies such as actively replanting kelp can be effective.
- Why is this area now plagued with sea urchins?
- Can you give an example of local mitigation (e.g. afforestation, planting kelp) and adaptation (e.g. eating sea urchins)?
- You might discuss how mitigation and adaptation are interlinked and how these problems require local and global solutions working together.
- You could also ask students if they would be willing to try eating sea urchins and if they think incorporating them into the human diet is a useful and sustainable approach to avoid these migrated creatures stripping kelp forests bare and creating so called ‘urchin barrens’.
Following on from the film
Establish locational context.
Use maps and globes to establish where the island of Tasmania is and note the latitude and ocean context; locate and name the Tasman Sea.
It could be useful to create a glossary of important definitions and terminologies such as ‘urchin barrens’ and use this to support a map and / or diagram indicating some of the connected problems caused by temperature rise in the seas around Tasmania.
You could ask students to research where else in the world naturally occurring forests of giant kelp might be found and map these, noting climate zones and biomes. For example, in some kelp forests off the coast of California, populations of sea otters thrive and eat sea urchins. Students might do a comparison of the stresses facing these kelp forests at different locations.
Although there is some disagreement about the exact rate of temperature increase here, it appears that temperature rise is happening more quickly in Tasmania than other parts of the world: it is an ‘ocean hotspot’. Older students could research and present climate data alongside a timeline of kelp decline, explaining the causes and impacts of sudden temperature rise on these marine eco-systems.
You may also wish at this point to reinforce the terms ‘mitigation’ and ‘adaptation’ and ask students to identify mitigation strategies we can use here to combat climate change impacts elsewhere (e.g. ways we can reduce our own carbon footprint and increase carbon capture by planting more trees).
This short film is suitable for teaching KS3 and KS4 students. It can be used alongside the other Ade Adepitan films about climate change or watched on its own. All the films build on students’ understanding of climate change issues and enable them to make global connections.
This film supports the KS3 geography curriculum by investigating our changing climate and how human and physical processes interact to influence and change landscapes and environments.
At KS4, the film supports understanding about the impacts of rapid climate change on environments and people’s lives. The film might also be used for example to investigate how strategies, such as afforestation, are used to respond to natural hazards and help manage the impacts of climate change (AQA).
This clip could be used to support the delivery of geography to KS3 and KS4 students. Specifically, this topic appears in OCR, Edexcel, AQA, WJEC KS4/GCSE in England and Wales, CCEA GCSE in Northern Ireland and SQA National 4/5 in Scotland.