After the Paper | Seaweed beyond carbon sinks

Our conclusions support the recognition of macroalgae (or seaweed) as essential contributors to oceanic carbon pools.
Published in Ecology & Evolution
After the Paper | Seaweed beyond carbon sinks

Share this post

Choose a social network to share with, or copy the shortened URL to share elsewhere

This is a representation of how your post may appear on social media. The actual post will vary between social networks

   During photosynthesis, marine primary producers convert atmospheric carbon dioxide into living biomass, further transferred to the food chain's upper levels. When a marine organism died, its organic carbon can be long-term sequestered in coastal or deep-sea sediments. The global carbon stock from marine living biomass and stored within sediments are referred to as blue carbon.

   Blue carbon is promoted as a nature-based solution to mitigate the climate crisis by capturing atmospheric carbon dioxide. However, not all blue carbon elements were equally recognized as important carbon sinks.

   Seagrass, mangroves and saltmarshes firmly anchor their roots into the substrate, forming sediments and holding measurable carbon stocks. On the contrary, macroalgae anchor weakly and are 'moving habitats' adrift from the wave's action. Still, macroalgae cannot be neglected from the blue carbon budget as they are impressive primary producers.

   It was hypothesized that adrift macroalgal biomass was sequestered somewhere else, but there was no practical method to track this organic carbon export. 

Satellite tags can track turtles and whales across the ocean. This method is impractical to follow a fragment of seaweed.

  We thought about using environmental DNA –the DNA shed by any organism in their surroundings, to track macroalgae export. Using this approach, one can recover an organism's DNA from an environmental sample even after the organism left. However, following the voyage of macroalgae from the coast to the open and deep ocean requires a large set of samples.

   Luckily for us, several expeditions surveyed microorganisms in the global ocean, sequenced hundreds of metagenomes and made the data publicly available. We 'recycled' those metagenomes and searched for macroalgal genes. To our surprise, we found that macroalgae are ubiquitously present from the coast to the open ocean, and that their abundance decreases from the surface to the deep sea. This evidence confirms coastal exports, making macroalgae important stocks in oceanic carbon pools. 

   If discovering the important contribution of macroalgae to oceanic carbon sequestration were not enough, macroalgae offer other natural solutions for anthropogenic issues. For instance, red macroalgae of the genus Asparagopsis contain anti-methanogenic metabolites that can reduce vast amounts of enteric methane when fed to ruminants.

Anti-methanogenic macroalgae can drastically reduce global ruminant methane emissions. 

Please sign in or register for FREE

If you are a registered user on Research Communities by Springer Nature, please sign in

Follow the Topic

Life Sciences > Biological Sciences > Ecology

Related Collections

With collections, you can get published faster and increase your visibility.

Indigenous peoples and the environment

In this Collection, we feature articles that explore the relationship between indigenous peoples and the environment and the value of indigenous knowledge in meeting Sustainable Development Goals.

Publishing Model: Hybrid

Deadline: Ongoing

Human health and the environment

In this Collection, we present articles that explore emerging threats to health and wellbeing posed by the environment, health benefits the environment can provide, and policies that can help improve air, water and soil quality, limit pollution and mitigate against extreme events.

Publishing Model: Hybrid

Deadline: Ongoing