In the face of climate change could seaweed become a favourite food?

Seaweeds can often be found along the borders between land and sea; better known as the coast. Seaweed can be found in these coastal locations as either either have permanent inhabitants, such as the intertidal seaweeds, or beach debris where pieces of seaweeds are washed ashore by waves and tides.

green seaweed

Green (Ulva spp) and brown (Fucus spp) seaweed at low tide. Saltdean. East Sussex. UK.

As borders between land and sea, coastal locations can often be important transitional zones for animals to supplement their diet. Polar bears, wolves and brown bears are well known to appreciate the bounty of a stranded whale carcass washed upon the shore (Lewis & Lafferty, 2014; Laidre et al., 2018).

It is not just carnivores that benefit from the sea’s bounty though. In the isolated Svalbard archipelago, located 800km north of mainland Norway in the middle of the Arctic Ocean, well north of the Arctic Circle, coastal seaweed is becoming an important resource in the face of climate change.


Longyearbyen. Svalbard.

Warming temperatures in the archipelago are creating more frequent rain on snow conditions, whereby thick layers of ice cover the land vegetation, including mosses and lichens. These impenetrable ice-locked pastures make foraging for food difficult for Svalbard’s herbivorous animals.  Including the Arctic’s most famous grazer, the reindeer.


Reindeer. Svalbard.

Svalbard’s reindeer (Rangifer tarandus platyrhynchu) is a peculiar type, thanks to its unique habitat. They are shorter and stockier than mainland European and north American reindeer, being well suited to the cold of the far north. Unlike their mainland relatives Svalbard reindeer do not show migratory behaviour, instead they could be considered rather lazy, being characterized by a stationary, energy‐saving lifestyle. This lifestyle is only possible in Svalbard by virtue of the unusual lack of predation. The Svalbard reindeer population is instead controlled by climate and density dependent processes, with starvation being the most common cause of death.


Reindeer. Svalbard.

With the availability of food being a very important factor effecting survival, the increasing occurrence of ice-locked pastures could pose quite fatal for Svalbard reindeer.  

But some have come up with a clever coping mechanism. On the northwestern coast of Spitsbergen, the largest island in the Svalbard archipelago, 13% of the total reindeer population turned to the coast for food (Hansen and Aanes, 2012). They were found to developed a taste for eating kelp and other seaweeds that had been washed ashore.

Svalbard reindeer eating seaweed. Photo: Brage B. Hansen/NTNU.

However the reindeer cannot sustain themselves entirely on seaweed, being observed to frequently move between beaches and more accessible pastures. The seaweed scraps were being used as an exotic supplement to the reindeer’s normal plant‐based diet.

By adjusting their behavioural the reindeer utilise resources of sea origin to help survival during harsh winters. With the prediction of far more frequent harsh winters due to climate change, seaweed could act as a vital buffer in the face of environmental variation.

And Svalbard reindeer are not unique, many other herbivores eat kelp or seaweed too. From the sheep (Ovis aries) on Orkney [Scotland] (Hall, 1975), red deer (Cervus elaphus) on the Isle of Rum [Scotland] (Conradt, 2000), to black‐tailed deer (Odocoileus hemionus) of channel island [Alaska] (Parker et al., 1999).

North Ronaldsay sheep  2006

Sheep feeding on seaweed along the shoreline. North Ronaldsay. Orkney. Scotland.

So seaweed is not just important in the sea world, it could be helping many land species too, especially in the face of climate change.

This post was based on the research of Hansen et al., (2019). If you enjoyed this post you can find the open access article here:

Hansen, B.B., Lorentzen, J.R., Welker, J.M., Varpe, Ø., Aanes, R., Beumer, L.T. and Pedersen, Å.Ø., 2019. Reindeer turning maritime: Ice‐locked tundra triggers changes in dietary niche utilization. Ecosphere10(4), p.e02672.


Conradt, L. 2000. Use of a seaweed habitat by red deer (Cervus elaphus L.). Journal of Zoology 250:541–549.

Hall, S. J. 1975. Some recent observations on Orkney sheep. Mammal Review 5:59–64.

Hansen, B. B., and R. Aanes. 2012. Kelp and seaweed feeding by High‐Arctic wild reindeer under extreme winter conditions. Polar Research 31:17258.

Laidre, K.L., Stirling, I., Estes, J.A., Kochnev, A. and Roberts, J., 2018. Historical and potential future importance of large whales as food for polar bears. Frontiers in Ecology and the Environment 16(9), pp.515-524.

Lewis, T.M. and Lafferty, D.J., 2014. Brown bears and wolves scavenge humpback whale carcass in Alaska. Ursus, International Association for Bear Research and Management 25(1), pp.8-13.

Parker, K. L., M. P. Gillingham, T. A. Hanley, and C. T. Robbins. 1999. Energy and protein balance of free‐ranging black‐tailed deer in a natural forest environment. Wildlife Monographs 143:3–48.

What’s all the fuss about foundations?

What do kelp forests, mussel beds, seagrass meadows and coral reefs have in common? They are all given their name by the foundation species that creates them.

But what does being a foundation species entail?

Great Barrier Reef, Australia

Just as the foundations of your house provide structural stability keeping you house strong and stable, so too does a foundation species within an ecosystem. Because of this they are vitally important in structuring the community and maintaining a healthy ecosystem.

With the growing influence and uncertainty of human activity and environmental change the stability of the world’s ecosystems is questionable. It is therefore imperative that we understand what keeps ecosystems stable.

We know that foundation species are pivotal in ensuring ecosystem stability; but few have quantified it. Fortuitously nearly two decades worth of data and observations exists courtesy of the Santa Barbara Coastal Long-Term Ecological Research Project. Using this data researchers at the UC Santa Barbara’s Marine Science Institute posed the question:

‘Does a stable giant kelp forest result in a more stable understory community?´

MBNMS - Anemone in Kelp

Anemone in Kelp, Monterey Bay National Marine Sanctuary, USA

Well it turns out it does. Just as stable foundations ensure your house stays up, so too does a stable forest of kelp help in maintaining the stability of the under-story community of plants and animal.

Unfortunately in the face of climate change the stability of kelp is likely to change in the future. This could have devastating effects of all the plants and animals that rely on the kelp forest. Not only this, but this new research suggests that all habitats reliant on foundations species may also face such similar problems. Without the important species providing a foundation for all the other plants and animals, we could see devastating changes to these iconic habitats.

So the take home note:

Just as you have to take care of the foundations of your house to prevent it collapsing, so too do we have to take care of the foundations of our ecosystems or face calamitous consequences.

Scorpionfish In Seagrass

Scorpionfish in Seagrass, NOAA Florida Keys National Marine Sanctuary, USA

If you want to read more about this research check out this link or article below:

Lamy, T., Koenigs, C., Holbrook, S.J., Miller, R.J., Stier, A.C. and Reed, D.C., 2020. Foundation species promote community stability by increasing diversity in a giant kelp forest. Ecology, p.e02987.

Sea Urchin Ranching – the new restorative fishing practice?

Vast plains of barren emptiness, devoid of life, bar one animal: the purple sea urchin. These barrens used to be some of the most productive habitats on the planet, now they are empty wastelands. 

Urchin Valley

Purple sea urchin barren – San Miguel Island, California, United States

So what happened? 

Like a story from the bible, plagues rained down on this once pleasant land. First came pestilence. The sea stars started wasting away. Next came years of extreme heat, with coastal Californian waters reaching record breaking temperatures. And finally an explosion. An explosion of purple sea urchins. Everywhere you look would be purple sea urchins. These ravenous monsters devoured the plentiful forests, one unfortunate kelp individual at a time, until nothing was left but the barren wasteland we see today. 

Sea Star Wasting Syndrome

Ochre sea star suffering sea star wasting disease – North Beach, Washington, United States

Soon there were terrible consequences for the locals as well. With the loss of kelp forests, commercial shellfisheries collapsed. Red abalones declined by 80% and many livelihoods were shattered.

All is not well on these urchin barrens either, for too much competition leads to empty stomachs. Each urchin, competing against its brothers and sisters, now finds food scarcity a real pressing problem. So many mouths to feed, nowhere near enough kelp to eat.

Purple Sea Urchin - Strongylocentrotus purpuratus

Purple sea urchins – Santa Cruz Island, California, United States

So it seems that no individual is particularly happy after this catastrophic chain of events, not the starving sea urchins, the decimated kelp, or the troubled fishermen. 

But there may be a solution, and one in which may please all involved parties, at least in part. 

The urchins are hungry, so firstly why do we not just feed them? This sounds like such an obvious idea. So let’s take the urchins from their barrens and rehome them in special ranches, where they are provided with plentiful food and allowed to grow plump. This is where the urchin’s story gets a little less happy for them. Unfortunately for them, they are considered quite the delicacy, which conversely is quite pleasing for the fishermen, who can make a good living from fattening up urchins for slaughter. Though the urchin’s eventual fate is not necessarily such a pleasant one, they have at least had a good life eating as much as they please up until the end. And the fishermen make a tasty profit. 

But best of all, the biggest beneficiary from all of this is the kelp itself. Once the ravenous urchins are removed the kelp can grow at an enormous rate, one of the fastest on the planet, and restore the wasteland to its former glory. 

So by choosing Californian sea urchins, you as a consumer can help support perhaps the only restorative fishing practice known today, one bite at a time. 

Ollie, the residential sea otter

Sea otter taking a nap in bull kelp – Race Rocks, British Columbia, Canada

Interested in finding out more? Check out the link below where you can find more info from the authors and the freely available article: