Can selective breeding of super kelp’ save our cold water corals from the heat?

Australia’s vital kelp forests are disappearing in many areas as our waters warm and our climate changes.

While we wait for rapid action to slash carbon emissions – including the United Nations climate talks now underway in Glasgow – we urgently need to buy time for these vital ecosystems.

How? By ‘future-proofing’ our kelp forests to be more resilient and adaptable to changing ocean conditions. Recent trials have shown that selectively bred kelp can be replanted with greater heat tolerance and used in restoration.

This matters because these large seaweed species are the foundation of Australia’s Great Southern ReefA vast and little-known area of the world. temperate reef systemThis is a world-famous hotspot for biodiversity.

The reef’s kelp forests run along 8000 km of Australia’s southern coastline, from Geraldton in Western Australia to the Queensland border with New South Wales. These forests are important for coastal fisheries and food webs. You can think of the mass-spawning of Australian Giant Cuttlefish off Whyalla. Also, abalone and rock lobster fisheries.

Unfortunately, these seas are hotspots in the literal sense, with the nation’s southeast and southwest waters warming several times faster than the global average suffering from some of the worst marine heatwaves recorded.

These rising temperatures and other climate-change impacts are destroying our kelp. This includes shrinking forests, permanent losses of golden and other kelp.Ecklonia radiata) on the eastAnd west coasts, staggering declinesThe now-endangered giant Kelp (Macrocystis pyrifera) forests in Tasmania.

Read more:
Australia’s ‘other’ reef is worth more than $10 billion a year – but have you heard of it?

We need new measures to buy the time needed for climate action

Australian researchers are leading the charge in trying to future-proof our crucial ocean ecosystems, like kelp forests, by demonstrating how they can do so. coral reefs. In part, that’s because climate change is hitting our ecosystems early and hard.

Climate change is happening faster than kelp species can adapt. All the species that depend on these forests are at risk. including us.

If climate change wasn’t happening, we could try to halt or reverse the losses of kelp forests by using traditional restoration methods.
However, in a world that is becoming increasingly hotter, this is in many cases futile. Even if we reduce carbon emissions quickly, decades of warming are still possible already locked in.

We must now look at cutting-edge ways to help kelp survive the current and future ocean conditions. While governments work to reduce emissions, this is a way to preserve these forests of the sea.

How to futureproof an underwater forest

Together and separately, we’ve been exploring techniques to speed up the natural rate of evolution to boost kelp resilience. Along with other researchers, we’ve put several techniques to the test in the real world, with promising results. Others are still hypothetical.

Currently, there are several broad approachesTo ensure future-proofing restoration work. These include:

• Genetic rescueIt focuses on increasing the genetic diversity and adaptability of genetically challenged populations. This involves planting and restoring a mixture of kelp from disconnected populationsof the same species. Increasing genetic diversity can increase the forest’s ability to adapt to climate change. This approach could prove especially useful in areas where climate changes pose a limited threat.

• Assisted gene flowStrategies include introducing tolerant or naturally adaptable kelp individuals to threatened populations to increase their resilience to specific threats such as hotter seas. This could help kelp forests in climate-sensitive areas. In these situations, the genetic rescue technique could be counterproductive if the new genetic diversity introduced isn’t able to cope with the heat.

• Selective breedingThis is a well-known farming technique and can be used for identifying the best kelp to use. In short, we look for kelp with higher tolerance. These are then used as the basis of restoration efforts. These can be transplanted into ailing forests of kelp. Trials are presently underwayGiant kelp is used in Tasmania. Early results are exciting, with the largest ‘super kelp’ growing over 12 metres high a year after being planted.

We may need to develop new strategies in the future to adapt to changing conditions. These include:

• Genetic manipulation. This technique extends what is possible with selective breeding by directly manipulating genes to enhance the traits or characteristics that might further boost kelp’s ability to thrive in hotter waters.

• Assisted expansionThis is where species that are unlikely to survive are moved to better and more interesting locations, assuming they exist. This technique could also lead to new species of kelp being planted in order to replace the existing species. It is guided by the need for forest ecosystems to be protected, not specific species.

Read more:
Underwater health check shows kelp forests are declining around the world

Are these methods ethical?

Each of these techniques – tested or untested – pose challenging ethical questions. That’s because we are not undertaking traditional conservation, where we work to restore a historic kelp ecosystem. We are changing these ecosystems to make them more resilient to extremes of their survival limits.

This means that we need to be careful and weigh potential downsides such as genetic pollution and maladaptation (accidental poor adaption to other stressors) against the possibility of further destruction of kelp forests if we do nothing.

These future-proofing interventions might be well-suited for areas already hard hit by severe kelp forest loss, those that are likely to be in danger in the near future, and those where kelp loss would be especially damaging economically, socially or environmentally.

One thing is certain: communities that depend on our southern coasts need to talk about what they value in kelp forests and how they would like them to look and function in the future.

Given the current rate and magnitude of disruption in our oceans, we believe that traditional approaches to recreating old ecosystems will prove more difficult.

It is important that we don’t just look back nostalgically at ocean conditions that are rapidly changing. Instead, we work to ensure the long term survival of these incredible underwater forests while waiting for urgent action to reduce carbon emission.