The coastline of Chilean Patagonia is crinkly edged. The Andes Mountains begin their slow eruption for the sea here, leaving behind them a steep-sided landscape punctuated by some of the world’s most spectacular fjords. It’s a perfect landscape when seen from the water on an expedition cruise or by kayak, but until relatively recently little was known of the extraordinary biodiversity that lay beneath the surface.
That hidden picture has slowly been revealed thanks to the work of Dr Vreni Häussermann, a marine biologist who started scuba diving in these waters 30 years ago and discovered the huge cold water coral banks that make the fjords so special. We spoke to her to learn more about her life’s work.
Beneath the surface
Häuserman first came to Chile in 1994 as a PhD student with her husband, planning to scuba dive the length of the country’s coastline, from Arica by the Peruvian border all the way down to Punta Arenas, studying sea anemones.
‘We got robbed actually the first day before we went diving,’ says Häussermann. ‘We were standing there for half an hour in our diving gear and the waves were so big that we didn’t dare to go in. When we went back to the car, all our camera equipment was gone!’ After an appeal in the local media, the local fisherman who had taken their kit handed it back to them for the reward money. ‘They didn’t know how to sell it, because everybody talked about it!’
With their cameras safely restored, the divers were able to start exploring, and what they found was completely unexpected.
‘At 25 metres down, there was a wall of tentacles. But they weren’t anemones, they had calcified skeletons, so they must have been corals.’ At this time, cold water corals in Chile were completely unknown.
This discovery shaped the rest of Häussermann’s career. After completing her PhD, she and her husband returned to Chile, where they eventually helped establish the Huinay Scientific Field Station on the Comau Fjord, not far from Hornopirén National Park.
‘We call these corals marine animal forests,’ she explains. ‘Cold water corals are all over the world, but they’re generally in very deep waters. Here in Chile, we found the shallowest ones just eight metres below the surface. They’re a fascinating marine community, because they harbour so many other species.’ The coral is an important nursery for fish, as well as sheltering many crustaceans.
Coral catalogue
Chile’s cold water corals were so unknown that much of Häusermann’s work had just been cataloguing what’s there. After more than a thousand dives, she recorded over 1900 species just in Comau Fjord, mapping out its ecosystem. Around 70 of these were completely new to science, as as lead researcher she was even able to name three completely new species of anemone after her husband and children. But the scope of the work could last many lifetimes.
‘I had a PhD student with me and he took a picture of a gorgonian [coral], which he thought was the common one species, and when I saw his photo it was one I’d never seen before.’
Häusserman gestures to the files stacked up on her shelves behind her during our video call. ‘A lot of the work is about establishing what’s there, and then there’s the question of protecting it. We have hundreds of new species that we haven’t described yet. Two thirds of the common sponges aren’t described yet. I have about 20 to 30 undescribed anemones over there in jars. These species could disappear one day and have never been described. It’s a very sobering thought.’
This diversity is particularly concentrated in the Los Lagos area. Closer to Punta Arenas, she says, you might find a single coral on every fifth dive. ‘But here you’ll dive once and see 10,000.’ Exactly why this area is just so rich in marine life isn’t well understood yet – and unlocking the reasons why is a key part of Häussermann’s research.
‘The three fjords here open to the Gulf of Corcovado [by Chiloé Island], while the fjords further south open up to a network of channels and islands. But what this means for the corals, we don’t know.’
Häussermann admits this makes her work thrilling and challenging in equal measure. ‘There are different species in the fjord compared to channels and exposed coasts, but sometimes we go back to a spot after a couple of years and it looks completely different. It makes it very difficult for conservation because you do not really know what is where.’
Threats from salmon farming
While the biodiversity is clearly dynamic, one thing that Häusserman is very clear on is that these ecosystems are very fragile. One of the biggest threats to the biodiversity of the Chilean fjords, she tells me, is the intensive salmon farming industry.
‘There are concessions all along the coast,’ she says, which are far more densely concentrated and produce more pollution than in other salmon-producing countries. There is such overuse of antibiotics in feed and such an abundance of organic matter accumulating beneath the cages from dead fish, that it can produce a dead zone. ‘When you have many cages in the same fjord,’ explains Haussermann, ‘You also have eutrophication.’ In plain speak, that means that algal blooms and a complete
‘When the algae blooms die off, they are consumed by bacteria, which take up all the oxygen in the water. It became so extreme that in Comau Fjord (which fringes the edge of Pumalín National Park) where they had 23 huge farms in 2012, now they don’t have a single cage. That’s not because they wouldn’t want to, it’s because there’s no oxygen left.
In some places, salmon farmers have actually resorted to pumping oxygen into the cages to keep the fish alive. ‘But the rest of the fjord didn’t have oxygen, of course, so we lost a lot of biodiversity,’ says Hausserman. ‘We’ve observed that between 2003 and 2013, the abundances of the most common species have been reduced by 75%, and several species have disappeared completely.’
Astonishingly, there are more than 400 salmon farms currently in the marine sections of national parks and reserves in southern Chile. In a hopeful conservation move, the week before we spoke, a coalition of 37 Chilean non-governmental organisations launched the Salvemos a la Patagonia (Save Patagonia) campaign, whose goal is to eliminate salmon farming completely from this part of the country. It’s a big step, but the campaign has taken inspiration from neighbouring Argentina, which banned open net salmon farming completely in 2021, in part due to the ecological damage being seen in Chile.
Soft corals
In the meantime Häusserman is continuing her lifelong study of the fjord’s rich ecosystems. After a long spell of lecturing at local universities Patagonia, she now works with the conservation-focussed Blue Marine Foundation. And her love of Chile’s anemones and corals remains undiminished.
‘I fell in love with them at once, because of this ocean of tentacles. All yellows, oranges and whites. They are so very beautiful.’
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