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Patagonian Fjords Expedition: Cold Water Corals

Follow along as NG Grantee Rhian Waller explores the surprisingly diverse corals that dwell deep in the fjords of the southern tip of South America, and discover what they can tell us about the rest of the ocean as well.   Where the high Andes Mountains touch the South Pacific Ocean, the Patagonian fjords sit,...

Follow along as NG Grantee Rhian Waller explores the surprisingly diverse corals that dwell deep in the fjords of the southern tip of South America, and discover what they can tell us about the rest of the ocean as well.


Where the high Andes Mountains touch the South Pacific Ocean, the Patagonian fjords sit, formed thousands of years ago by extensive glaciers carving out the landscape. As the icefields in the Chiloé Interior Sea began to open, they left behind over 15,000km2 of deep fjords, channels and gulfs. Deep-ocean waters upwell into this region, bathing the shelf in cold nutrient rich water and influencing the marine fauna and flora. In addition this area sits on a steep climatic gradient, where temperatures, precipitation and wind intensity changes dramatically as you move from North to South, creating a wealth of different habitats, both above and below the ocean surface. As a result, the Patagonian fjords of Chile boast extremely high biodiversity and endemism, yet at present we know very little about their marine habitats.

Only recently it was discovered that these fjords, just south of Puerto Montt, are one of a few unique areas in the world where deep-water fauna can be found, can survive, and often thrive, in shallow water habitats. It is these deepwater emergent animals, one coral in particular, we are currently headed south to study.

Scientists rarely pack lite! We did manage to cram all our dive and science gear into our little red truck. Photo by Rhian Waller.

Desmophyllum dianthus is a true deep-sea coral. Lacking photosynthetic alage and found usually in waters over 2000m depth, this is a species I’ve been following around the globe trying to study for the better part of the last ten years. I’ve seen swaths of old, fossilized Desmophyllum on the ocean floor in the middle of the Drake Passage; I’ve looked out of a 6 inch thick submersible window amazed at one solitary live coral on the side of a seamount at 2500m depth in the North Atlantic; I’ve been endlessly frustrated after multiple six week research cruises that my collections totaled less than the fingers on one hand – not enough to even begin to understand this elusive species. Though in times past (many tens of thousands of years) this species was dominant in much of the deep ocean, today it is a rare occurrence in most areas.

The thought of walls of thousands of these corals living at just 10m depth has captured my imagination since I first heard about them in 2003. Let me repeat that – thousands, living and 10m depth. That’s shallow enough to SCUBA. If you’re interested in jumping into the icy fjord waters that is.  This region presents a unique window into the deep-ocean, being able to study organisms without having to resort to submersibles and ROVs, and being able to observe and sample year-round – a task almost impossible in most deep-sea environments.

Osorno Volcano looms as we head into Puerto Montt. Photo by Rhian Waller.

Today Christopher Rigaud (the University of Maine Diving Safety Officer) and I arrived in Puerto Montt, and tomorrow we head South, almost as far as the roads go to Hornopiren. We will then catch a boat to the Huinay Scientific Field Station, our home for the next two weeks, and our base from which we, and scientists from the station, will be SCUBA diving each day. We’ll be setting up monitoring sites in the fjords to look at how these corals reproduce and disperse for the next year – a key component of how and why these corals found their way into the fjords from the depths of the South Pacific, and why they are doing so well here.

The small town of Puerto Montt, the northern terminus of the Patagonian fjords, and the jumping off point for our expedition. Photo by Rhian Waller.

I’ve been planning this expedition for what seems like forever. Yet the last few days have been a whirlwind of questions. Many of the same questions that have gone through my head before each and every expedition I’ve organized to remote locations around the world. Do we have everything? Have I missed some key component? Will the weather let us dive everyday? Just how cold is that water going to be? Have I done everything I can to ensure my team will be happy and productive over the next two weeks? Do I have enough spares in case something breaks? Will the airlines balk at the amount of baggage we have? Where did I pack my toothpaste?

As I sit looking out over the ocean lapping the shoreline in Puerto Montt tonight a feeling of excitement has washed over me. Tomorrow I’ll finally be going there, and seeing with my own two eyes a coral I’ve only dreamed about swimming amongst in the deep ocean. Tomorrow I will be that kid in a candy store. Let the science begin!

Sunset over Puerto Montt, and looking over the road to Hornopiren, where we'll be headed tomorrow. Photo by Rhian Waller.


Follow Us Daily on Our Expedition

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Twitter – @OnlineExped


Learn More

Deep Sea Corals

Huinay Scientific Field Station

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Meet the Author

Rhian Waller
Dr. Rhian Waller is a professor of Marine Sciences at the Darling Marine Center (University of Maine, USA) and specializes in the ecology of deep-sea and cold-water organisms, particularly corals. Rhian has led or participated in over 40 international research and exploration cruises and expeditions to some of the most remote parts of the planet, and has published over 30 scientific papers and book chapters in her 9 year career. She is passionate about educating the next generation of scientists, and conserving our little known deep-sea and polar ecosystems to be studied and enjoyed in the future.