Science Snippets: Cascading Ecological and Economic Consequences Start with Kelp in Arctic Ecosystems

Draft script:

Kelps are foundational species in many marine ecosystems. They are primary producers, and therefore carbon sinks, that also provide habitat for other species. Not only do they provide food for other species, they also offer shelter and nursery areas for countless fish, invertebrates, and marine mammal.

An article at Phys.Org introduces a peer-reviewed paper that elucidates the importance of kelp, with a focus on Arctic ecosystems. As I have mentioned many times in this space, Arctic ecosystems are fundamental to life on Earth. The Arctic is the planetary air conditioner, and this region serves many other important functions.

The article at Phys.Org is titled The unforeseen effects of melting glaciers on Arctic coastal ecosystems. It was published 7 March 2025. The first paragraph introduces the peer-reviewed paper: “In an interdisciplinary cooperation project … scientists investigated the consequences of climate change in the Arctic. They focused on a group of organisms that form the very basis of Arctic coastal ecosystems—brown macroalgae, known as kelps, which form dense and extensive underwater forests along rocky coastlines.”

The next paragraph demonstrates the importance of kelps: “The ecological role of kelps can be compared to trees on land: they provide food, habitat, and a nursery ground for a variety of organisms and thereby maintain complex ecosystems. The researchers focused on the effects of climate change on kelps in order to draw conclusions about the ecological and socio-economic consequences.”

Beneath a section titled Warming increases run-off intensities and influences element concentrations, we read something we already know, as well as new information: “The Arctic region is warming at a rate that is far above the global average. Consequently, snow, glaciers, and permafrost are melting—all of which are contributing to coastal run-off plumes.”

These “coastal run-off plumes” are important to kelps: “While many of the elements that are being washed into the fjords can act as micronutrients for kelps (e.g., sodium, magnesium, potassium), harmful elements, such as heavy metals (e.g., cadmium, lead, mercury) have also been found in higher concentrations.”

The Phys.Org articles hints at the importance of run-off intensity: “Across all investigated elements, the team found the same pattern: as run-off intensity increases, so do element concentrations.

In the case of mercury, kelps that were highly influenced by run-off were characterized by a 72% higher mercury content compared to kelps from the control area.”

An excellent overview is provided in the final subsection: “Further, the researchers analyzed how different run-off rates affect the kelp microbiome. The microbiome is highly important for the ecological function of kelps, such as their nutritional value or elemental cycling in the ecosystem. They found that the microbiome also changed with different run-off rates.

Both of these climate-related changes on kelps are likely to have cascading consequences for the entire ecosystem. The ingestion of metal-contaminated kelps was shown to have negative impacts, such as reduced development, growth, and reproduction, and might lead to a bioaccumulation of harmful elements across the Arctic food web.

Eventually, this might also have socio-economic consequences. The high biosorption potential of kelps has to be considered in the implementation of maricultures.

However, harvesting kelps in fjords with high levels of meltwater and metal contamination might be an environmentally friendly method to harvest rare earths ... Rare earths are increasingly being used in key technologies such as renewable energies and electronics.”

The peer-reviewed paper is found in the renowned Nature series of publications. Published on 16 December 2024, The peer-reviewed, open-access paper is titled Run-off impacts on Arctic kelp holobionts have strong implications on ecosystem functioning and bioeconomy. The paper was created by 11 scholars.

A holobiont is a concept that refers to a biological entity formed by the combination of a host organism and its associated microbial communities. These microbial communities include bacteria, fungi, viruses, and others. In short, the host and its microbes are viewed as a single, integrated unit rather than separate entities.

The Abstract of the peer-reviewed paper provides a compelling story: “Kelps … are foundation species along Arctic rocky shores, providing the basis for complex ecosystems and supporting a high secondary production. Due to ongoing climate change glacial and terrestrial run-off are currently accelerating, drastically changing physical and chemical water column parameters, e.g., water transparency for photosynthetically active radiation or dissolved concentrations of (harmful) elements. We investigated the performance and functioning of Arctic kelp holobionts in response to run-off gradients, with a focus on the effect of altered element concentrations in the water column. We found that the kelp Saccharina latissima accumulates harmful elements (e.g., cadmium, mercury) originating from coastal run-off. As kelps are at the basis of the food web, this might lead to biomagnification, with potential consequences for high-latitude kelp maricultures. In contrast, the high biosorption potential of kelps might be advantageous in monitoring environmental pollution or potentially extracting dissolved rare earth elements. Further, we found that the relative abundances of several kelp-associated microbial taxa significantly responded to increasing run-off influence, changing the kelps functioning in the ecosystem, e.g., the holobionts nutritional value and elemental cycling. The responses of kelp holobionts to environmental changes imply cascading ecological and economic consequences for Arctic kelp ecosystems in future climate change scenarios.”

According to the designed-to-fail Intergovernmental Panel on Climate Change, ongoing climate change is the most abrupt in planetary history. Ongoing climate change is also irreversible. The last thing I want to read about ongoing climate change is that there are “cascading ecological and economic consequences … in future climate change scenarios.” Apparently, I don’t always get what I want.