A series of exploratory expeditions into new regions and submarine systems – many of which were “never before seen by humans” – has unearthed a treasure trove of new discoveries, including an eel so famous it has its own poem and an encounter with a possible 60 new species of marine life.

Plunging into previously unexplored regions to survey some 20 methane seeps and four new-to-science submarine canyon systems, an international team of scientists aboard Schmidt Ocean Institute expedition of exploration, have brought back with them a feast of discoveries – all made right on the front doorstep of the Chilean marine ecosystem.

An abundance of sea life – including a possible 60 (“or more”) new species and the famous red cusk-eel – has been perhaps the biggest discovery made by scientists piloting the R/V Falkor (too)  to bring home brand new evidence of a series of ‘surprisingly diverse ecosystems’ in and around these under-studied methane seep habitats.

The 55-day cruise is the first in the region to have used a remotely operated vehicle (or ROV) to transmit imagery in real-time. The expedition was co-led by Dr Jeffrey Marlow of Boston University in the USA, Patricia Esquete of the University of Aveiro in Portugal, and Eulogio Soto from the University of Valparaiso in Chile.

Among the surprises was the sighting of one of Chile’s most famed and commercially valuable species of fishing, previously unknown to inhabit such areas.

Red cusk-eels – one of the most highly-valued and commercially important fish in the Chilean economic market – and an 892-square metre tube worm mound were among some of the most impressive observations made during the expedition, found – to the surprise of researchers – located near a methane seep.

So revered is the red cusk-eel, a species called congrio colorado (Genypterus chilensus) is the subject of an ode written by the poet and Nobel Laureate, Pablo Neruda in celebration of his home country and life.

While these fish have been observed around reefs and soft-bottom mangrove ecosystems before, there has been little documentation of their behaviour swimming near methane seeps. The discovery has now kickstarted a pursuit of further research to better understand the species’ relationship with methane seeps to determine how essential these marine environments are to sustaining their populations.

Methane seeps are chemosynthetic environments where methane bubbles up from the seafloor, feeding microbes that – in turn – support an array of life. While clues from water chemistry measurements and images captured from previous expeditions to the region suggested the presence of some seeps off Chile, many sites had not been fully surveyed and sampled before.

In addition, several seep sites were entirely new to science with some located in shallow waters while others were in deeper regions.

“These exploratory expeditions are incredible – and essential – opportunities for the science community to improve our understanding of the planet,” said Esquete. “After extensive sampling, we suspect our team has found at least 60 species new to science and will be working over the next few years to confirm this.”

The expedition saw the team explore four unnamed submarine canyons in southern Chile for the first time, mapping them to a high resolution. The largest of the canyons is approximately 2,000-square-kilometres while the deepest is over 3,000 metres deep. Such submarine canyons are critical ecosystems connecting land to the open ocean, providing structures for habitat-building animals like glass sponges and deep-sea corals, which support species from tiny bristle stars to octopus.

An additional methane seep was discovered in one of the canyons near Chile’s triple junction, a place on the seafloor where three tectonic plates meet.

Other notable observations made include large congregations of humboldt squid feeding near the seeps, a sighting of a glowing anglerfish scientists are still working to identify, “massive” chemosynthetic clam beds, and a shimmering polychaete worm that drew the attention of millions on social media during the expedition.

“This expedition is yet another example of the tremendous value of bringing together cross-disciplinary science teams and cutting-edge technology to little known regions of our global ocean,” said Dr Jyotika Virmani, executive director of Schmidt Ocean Institute.

“The diverse marine life swimming contentedly in this geologically interesting ecosystem was beautiful to watch – a strong reminder that what is out of sight should perhaps not be out of mind.”

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