Can our collections combat climate change?

Changing the tide on coral reefs

Coral reefs are important habitats for many animals, supporting an estimated 25% of marine species, but they are at risk. The International Union for the Conservation of Nature (IUCN) lists 44% of reef-building coral as at risk of extinction.

We have around 200,000 corals in our collections. These specimens can offer insight into how coral has behaved in response to past pressures and indicate how we could mitigate the impact of human activities on them in the future.

Increasing ocean temperatures can cause corals to expel the nutrient-providing algae that they have a symbiotic relationship with. This means coral lose their colour, in what is known as a bleaching event. Repetitive bleaching events can kill the coral, but this bleaching doesn’t happen equally across the ocean.

Museum scientists Ken Johnson and Nadia Santodomingo have been researching species of coral that are thriving in cloudy, turbid waters. These species appear to undertake fewer bleaching events when compared to clearwater coral and could hold the key to helping other species become more resilient.

“These turbid reefs have never been studied, so we don’t have the knowledge around how many unique species could disappear if we lose these reefs, and they don’t have the same protection as more well-known sites such as the Great Barrier Reef,” explains Ken.

The local environment is extremely important when looking at these reefs. For example, an area covered by this research is Darvel Bay in Malaysia.

“Researchers found that coral reefs living in Darvel Bay seemed to be more resistant to bleaching than nearby reefs living in clearer water, but the reefs were also impacted by local stressors such as plastic and other pollution from the land and fishing.” Ken says, “It is important to reduce those local impacts to help the reefs remain resilient to the global impacts.”

The results of the research helped colleagues at the University of Malaysia campaign for Darvel Bay to become a Marine Protected Area. It is hoped that what we learn about the resilience seen in the turbid reefs could be applied to other reefs in the future. Whether this is through introducing more diverse genes that could help coral adapt to new ocean temperatures or through sharing best practice of human action to protect local ecosystems worldwide.

Delving into changing diversity in our Oceans

Another natural phenomenon impacted by temperature increase is known as Tropicalisation. This is a term used to describe the collective movement of marine species in response to climate change.

Tropical and subtropical species are experiencing range expansions towards the poles, whereas the temperate species that previously flourished in these areas are experiencing range retractions. Museum collections and records are crucial for documenting tropicalisation because we have collections data dating back over 200 years.

PhD student Karolina Zarzyczny used collections to set a reference point for species ranges when researching the ecological and evolutionary consequences of this phenomenon.

“I use museum collections to help determine past species distributions, which I can compare with current distributions,” says Karolina. “Based on that data, I can determine whether species have undergone a range expansion or retraction.”

Tropicalisation might reduce genetic diversity of resident species, eliminating unique adaptations and altering food chain dynamics. For example, in Western Australia, dugongs are expected to experience range expansions and green sea turtle abundance may increase, which may lead to increased pressure on Australia’s seagrasses.

As the species ranges shift at different rates, this can have consequences for ecosystem stability and the evolution of interdependent species.

The role of genetics in species adaptation to climate change is important. If tropicalisation leads to a loss of genetically unique populations, this may influence their ability to adapt. Karolina is currently researching this and focusing on rocky shore gastropods that play essential ecological roles but are perhaps not as well studied as larger, more charismatic species.

To get a comprehensive picture, extremely large data sets are needed. Karolina is looking at harnessing environmental DNA (eDNA) to document tropicalisation.

eDNA sampling methods change the way we monitor biodiversity. They can be faster, cheaper and easier to scale up than traditional approaches, but Karolina is looking at how we can use them more reliably.

“eDNA allows us to detect species from water, soil or air samples, without having to find the species,” says Karolina. “However, this technology comes with its limitations, so I am developing ways to incorporate a range of data sources that can increase the reliability of using eDNA surveys in documenting tropicalisation.”

Using eDNA to learn more about understudied groups of animals means that conservation measures recommended to help fight climate change can be actioned quicker.

Impacting decision makers

This blog has explored just two of the many projects that our scientists are undertaking to understand and provide nature-positive solutions to climate change. But our Policy Unit is harnessing this science to influence change on an international scale.

Charlie Gold, who joined the Policy Unit last year, says, “We want the Museum to become a ‘go to’ source of policy-relevant evidence and advice on the natural world. The Museum has an incredible reputation as a world-leading scientific institution that is key to understanding how nature is impacted by threats like climate change.”

To increase the awareness and maximise the impact of our science, the Museum has sent delegations to the United Nations Conventions of the Parties (COP) for several years.

At last year’s climate COP29 in Azerbaijan and biodiversity COP16 in Colombia, the Museum teamed up with partners at Kew Gardens and ZSL to form the UK Biodiversity Alliance. The aim was to raise the profile of biodiversity loss amongst key decision-makers and to highlight the links between the climate and biodiversity emergencies.

We also advocated for rigorous approaches to measuring biodiversity change through metrics such as our very own Biodiversity Intactness Index – which is now recognised as a component indicator in the draft monitoring framework for the Global Biodiversity Framework.

The natural world is intrinsically linked to climate change, so as an institution that aims to inspire people about nature, so are we. The Natural History Museum has collections that date back hundreds of years. These are vital to understanding how nature has been impacted by human actions, and our scientists are working with global experts to understand how we can live in harmony with our planet.