The sea forests at the end of the world

The southernmost tip of the Chilean and Argentinian Patagonia coastline accounts for 47% of global M. Pyrifera kelp distribution, rendering the region one of the world's last pristine ecosystems. Yet, extending over almost 6,000km, the Argentinian coastline is one of the least explored in the world. The recent approval of a law to permanently protect the area gives hope for the future.

Words by Maia Gutierrez
Photographs by Joel Reyero, Por el Mar

Over the last decades, most conservation efforts have been focused on land-based ecosystems. The protection of terrestrial ecosystems has far exceeded marine protection and restoration initiatives. Although we truly live on a blue planet, and the ocean represents 90% of the living space on Earth, we are just beginning to understand the urgency with which we need to attend to the health of the ocean.

As part of my work with Por el Mar, a non-profit marine conservation organisation driven by a team of scientists, activists, communicators, and policy experts, we have been working hard to protect the Mitre Peninsula, the easternmost part of Isla Grande de Tierra del Fuego in Patagonia. The region is Argentina’s biggest carbon sink and is one of the few places that truly remains wild. Home to a large portion of Argentina’s kelp forests, it is also the last refuge for the Southern river otter, a species on the brink of extinction.

While kelp forests worldwide have struggled or disappeared altogether in recent decades, the macroalgal ecosystems along Patagonia’s rugged southwestern coast have “shown remarkable stability for almost 200 years”, according to the American Geophysical Union. Researchers argue that this could be due to frequent marine cold spells in the region which seem to keep the kelp happy. Southwestern giant kelp forests in Patagonia haven’t experienced any extreme marine heat waves since 1984, according to a study published in 2022 in the Journal of Geophysical Research: Oceans, called A Song of Wind and Ice: Increased Frequency of Marine Cold Spells in Southwestern Patagonia and Their Possible Effects on Giant Kelp Forests. It established that the region around the Mitre Peninsula saw extreme marine cold spells between 2014 and 2019, which also grew more intense. Experts believe these localised cooling events could have been caused by glacial melt and increased wind activity. It is well-known that kelp thrives in cold, nutrient-rich waters.

As an example, if the water temperatures go up too much, sea otters might disappear in Patagonia which, in turn, would make sea urchin populations explode. They could then overgraze the kelp forests, as has happened in some parts of California. Combining this with a general loss of kelp forests could be a disaster. In central and northern Chile, for example, unregulated kelp harvesting for the alginate industry has led to annual losses of 2% of kelp forests. In Patagonia, however, the situation is different. Kelp forests look like they did in the early 20th century, according to marine geographer Alejandra Mora-Soto, lead author of the aforementioned study. According to her, when comparing historical nautical charts with modern satellite images of kelp, little has changed.

And something else is on the kelp’s side here: current climate and ocean models predict that the waters around Patagonia’s kelp forests will not warm dramatically in the near future. But researchers warn that further glacial melts might bring lower water temperatures, different nutrients or sunlight-blocking sediments to the region which might end up harming the kelp.

To help protect these vital kelp forests in Patagonia and beyond, Por el Mar which means ‘for the ocean’, has been working hard in recent years. ‘The Sea Forests at The End of the World’ is one of our four current projects; a conservation initiative that seeks to explore and protect Patagonia’s pristine sea forests. Further protection of these vital and resilient kelp forests is urgently needed to find out more about them before it is too late. Getting to know the macroalgal forests in the region, we were amazed by the incredible ecosystem that surrounds the rocky coastlines of Patagonia. We wondered how we could best preserve it and asked ourselves a simple question: Why is the coast so important to us humans?

Coasts represent the transition between the two largest domains for life on this planet – land and ocean – and are amongst the most diverse ecosystems. It is no wonder our species’ history is so profoundly connected to coastlines around the world. Inspired by this simple question and driven by the need to protect these underwater forests we understood that it is at this meeting point where we have the possibility to redefine how we want to relate to the ocean, and restore our connectedness to it.

Kelp forests stand as silent guardians, surrounding coasts all around the world. They purify the surrounding water, regulate pH levels, sequester carbon, release oxygen, and slow coastal erosion. As one of the most biodiverse ecosystems in the ocean, they are also home to thousands of species. But these ocean forests have long been overlooked.

Photographs by Joel Reyero, Por el Mar

Continue reading...

To continue reading this article – and enjoy full digital access across Oceanographic – sign up to Ocean Hub today! More info below…

Keep reading by signing up for an Ocean Hub subscription

Ocean Hub. More than a magazine subscription.
As well the delivery of all new editions, members unlock access to exclusive products, services and discounts, as well as EVERY digital back issue we have published.

Hub package PRINT_ banner_37
Find out more about Ocean Hub subscription
Issue 28
Supported by WEBSITE_sponsorlogos_arksen

This feature appears in ISSUE 28: SEA FORESTS of Oceanographic Magazine

Issue 28
Supported by WEBSITE_sponsorlogos_arksen
Supported by WEBSITE_sponsorlogos_arksen

Printed editions

Current issue

Back issues

Enjoy so much more from Oceanographic Magazine by becoming a subscriber.
A range of subscription options are available.