IN PATAGONIA’S GIANT KELP FORESTS, A KEY ECOSYSTEM REMAINS, BUT BIODIVERSITY FOUND AT RISK
A new scientific publication details surprising results from marine surveys of Patagonia’s kelp forests, comparing current conditions to data collected 50 years ago. While these vast underwater ecosystems remain largely intact, several species are in sharp decline due to human activities. Giant kelp forests are crucial breeding grounds for marine biodiversity, providing food and shelter, and serve as major carbon sinks. (Header photograph by Eduardo Sorensen)
A researcher underwater measures giant kelp during Rewilding Chile’s latest marine expedition. (Photograph by Eduardo Sorensen)
Coyhaique, CHILE—Working with international researchers, Rewilding Chile is gaining important insights into the current state of Northern Patagonia’s vast giant kelp forests (Macrocystis pyrifera). The research is taking them on a series of ambitious expeditions in the footsteps of American scientist Paul Dayton, a key figure of modern marine ecology whose pioneer observations of Chile’s underwater forests took place fifty years ago. The expedition’s initial findings are now published in the journal Regional Environmental Change.
The researchers were relieved to see that Patagonia’s giant kelp forests, amongst the most extensive on the planet, have largely remained intact. Expedition member Albert Pessarrodona, a marine ecologist at the University of Western Australia, noted, “it’s quite encouraging, considering that kelp forests around the world have declined or disappeared due to climate change.”
Other discoveries indicate looming threats. The invasive anemone Metridium senile, new since Dayton’s study, now covers up to 88.4% of the seafloor of sheltered fjordlands. Researchers also saw a proliferation of sea lettuce (Ulva spp.). In excess, both species create ecological dead zones that wipe out marine life as they take over habitats. The uptick of Ulva spp. has been related to excess nutrients produced in salmon farming.
Invasive sea anemones Metridium senile. (Photograph by Eduardo Sorensen)
Species in decline include the red sea urchin (Loxechinus albus), a bottom-dweller propelling the world’s largest sea urchin fisheries, whose population has plummeted by 59% to 90%, depending on water depth, since Dayton’s study, conducted prior to its intensive harvesting in southern Chile. Dwarf sea urchin (Pseudechinus magellanicus)—historically very abundant—has altogether disappeared from shallow waters, where it plays an important role keeping algae in check.
According to Mathias Hüne, director of Rewilding Chile’s Marine Program, the loss of these species has greater consequences: the disappearance of ecological processes, connectivity, and the environmental conditions that afford long-term resilience. Hüne concludes, “It’s crucial to move forward with a bill or a declaration designating giant kelp forests as a natural monument.”
“Footprints of global change in Patagonian kelp forests after half a century,” is authored by Albert Pessarrodona (University of Western Australia), Mauricio Palacios (Rewilding Chile), Julieta Kaminsky (CADIC-Conicet, Argentina), Alejandra Mora-Soto (University of Victoria), Mathias Hüne (Rewilding Chile), with collaboration from Paul Dayton (University of California).
An Expedition Rooted in Scientific History
Almost 200 years after Charles Darwin made his first observations of giant kelp forests aboard the Beagle, and more than 50 years after the study by renowned marine ecologist Paul Dayton of the Scripps Institution of Oceanography (University of California), a new team of scientists has returned to survey the same waters using state of the art technology, inspired by Michael Fay’s legendary African Megatransect, which contributed to the creation of a network of national parks in Africa.
Rewilding Chile’s boat above Patagonia’s giant kelp forests. (Photograph by Nicolas Munoz)
The Patagonian Megatransect is an ambitious marine research initiative covering more than 1,200 kilometers from the Gulf of Corcovado to Cape Horn. It seeks to provide essential scientific evidence to establish a new blue geography to promote the creation of marine protected areas in southern Chile. These expeditions are contributing to the creation of an unprecedented database and visual archive of one of the last pristine underwater forests on the planet.
International partners supporting the initiative include the Prince Albert II of Monaco Foundation, the Ecological Restoration Fund and the Plum Foundation. The scientific team is led by the director of the Marine Program of the Rewilding Chile, Mathias Hüne, with Mauricio Palacios and Jonathan Poblete, and collaboration from Iván Gómez (Austral University, Chile), Alejandra Mora (University of Victoria, Canada), Julieta Kaminsky (CADIC-Conicet, Argentina) and Albert Pessarrodona (University of Western Australia).