These Remote Kelp Forests Noted by Darwin Haven't Changed for Almost 50 Years

Recent surveys of the remote and biodiverse kelp forests of Tierra del Fuego in South America suggests they have remained relatively untouched for almost fifty years.

"Due to their remoteness, extremely rough sea conditions, and limited human activities, these are some of the least impacted kelp ecosystems on earth," Alan Friedlander of the National Geographic Society's Pristine Seas project told Newsweek.

Friedlander and colleagues used field notes and data from marine ecologist Paul Dayton to survey the underwater forests for the first time since 1973. The results suggest it remains remarkably unchanged by human activity in comparison to other parts of the world.

"We were surprised at how similar the communities were 45 years later," said Friedlander. "The same can't be said for most marine ecosystems around the world."

The study's authors drew this conclusions from extensive observational data collected from 11 locations originally studied in 1973 in the easternmost part of Tierra del Fuego. Populations of native species, from urchins to sea stars to kelp, have remained relatively stable over the last half-century or so.

The researchers say even the structure of species remained similar. Loxechinus albus, for example, accounted for 66.3 percent of sea urchin abundance in 2018 compared to 61.1 percent in 1973.

Satellite images show the kelp canopy has remained relatively stable too, despite changes every four years correlated with sea surface temperature and the El Niño.

But this could change, the scientists warn. Kelp forests are vulnerable environments and are under attack in many parts of the world thanks to a combination of local threats, like overfishing and pollution, as well as worldwide phenomena, like climate change and marine heatwaves.

Friedlander describes kelp communities as "one of the most endangered" marine ecosystems on the planet and explains they are in decline globally.

"Climate change, particularly marine heat waves, are expected to increase in the future, which will affect kelp ecosystems around the world," he added. "If you control local threats, then you can buy time while trying to deal with climate change."

Frieldlander calls for greater protections to maintain the health of Tierra del Fuego's unique ecosystem. "Large marine protected areas that limit activities are the most effective method to conserve marine ecosystems," Frieldlander said.

The researchers note research tracking changes in kelp forests over extended periods is lacking, which makes a full global assessment difficult. Why should we care?

"Kelp community are important habitats for endangered species, important habitat for fisheries species, and a hotbed of unique biodiversity," said Friedlander. "They sequester carbon and protect shorelines from coastal erosion."

Next up, Friendlander plans to return to the Southern Line Island of Kiribati to investigate the regions coral reef communities — and specifically, how resilient they are to climate change.

Starfish in the kelp forest
Starfish in the kelp forest of Tierra del Fuego. A new survey shows these environments are almost untouched by human activity, but that could change. Enric Sala/National Geographic