Scientists race to discover and protect what lives in the ocean

Scientists say not knowing what lives in our oceans is holding back efforts to protect them. Because of that, many are racing to discover and document the wild and diverse species in marine environments that are often hard for humans to access.

Ocean Census, a global collaboration of scientists and non-profit organizations, estimates that scientists have documented less than 10 per cent of some 2.2 million fish, marine mammals, shellfish, plankton, squid, jellyfish and other species that live in our oceans.

"It's very difficult to protect what you don't know," said Michelle Taylor, head of science at Ocean Census. 

A sea cucumber with horned appendages, nicknamed Loki, and a bright red-orange coral with fans of slender branches are among 57 new species announced and identified in October from an Ocean Census expedition off Argentina last year.

This new sea cucumber species was nicknamed Loki because of its prominent horned appendages, reminiscent of the god in Norse mythology. It was found in the Mar del Plata submarine canyon off Argentina. (ROV SuBastian/Schmidt Ocean Institute)

A striking, bright red-orange octocoral was photographed nearly 2,000 metres below the surface of the ocean in Argentina's Mar del Plata canyon. (ROV SuBastian/Schmidt Ocean Institute)

A landmark UN biodiversity agreement in 2022 committed to protecting 30 per cent of the world's land, water and marine areas by 2030, but has been falling short on ocean protection, with just 12 per cent of oceans (compared to 27 per cent of lands) set to be protected by 2030.

Canada has so far protected 15.5 per cent of its oceans, according to the Canadian Parks and Wilderness Society (CPAWS).

Claire Goodwin, a research scientist at Huntsman Marine Science Centre in St. Andrew's, N.B., said the goal is to protect areas with high biodiversity.

"But if you're not surveying some of your marine life and you don't know what's living there, you can't say which those biodiverse areas are."

A cone jelly captured by the remotely operated vehicle SuBastian off the coast of Argentina. (ROV SuBastian/Schmidt Ocean Institute)

Sponges that eat meat, provide housing

The problem is that even within Canada, many areas are difficult to explore. Goodwin was part of an expedition in the Saguenay Fjord in Quebec in 2023. 

On its steep walls, where only one species of sponge had previously been recorded, her team discovered 20 or 30 sponge species, including some new to science. 

Carnivorous sponges were found in Quebec's Saguenay Fjord in 2023. (Claire Goodwin/HMSC)

Among them were carnivorous sponges that trap shrimp with glass, velcro-like appendages to engulf and digest slowly, "which was really exciting," said Goodwin, since most sponges are passive filter feeders.

Goodwin says sponges have important roles in the ecosystems — as food for sea stars, homes for some worms and a place to lay eggs for some fish. Sponges in Canadian waters can also grow to half the size of an adult human.

Claire Goodwin collects sponges in the Bay of Fundy off the coast of New Brunswick. (Torben Brydges/Fisheries and Oceans Canada)

The sea slug Dendronotus yrjargul was recorded on a recent expedition led by the Innu Nation. It was the first time the species has been found off the coast of Canada. (Claire Goodwin/HMSC/Innu Nation)

Now Goodwin is working with the Innu Nation in Labrador to survey uncharted waters in their territory. "We literally don't know what the seabed's going to be like, let alone what's going to be living on it."

Climate change impacts and solutions

The race is on to find out as the ocean warms rapidly, and climate change shifts where species are found. 

Already, Goodwin says, some species have completely disappeared from regions where they were once common. She points to basket stars, "really cool sea stars that have branching arms," which were once common around St. Andrew's, but haven't been seen there since a rapid warming around 2016.

A basket star, Gorgonocephalus arcticus, is seen in the Saguenay Fjord. The species used to be common in the Bay of Fundy but seems to have disappeared due to climate change. (Claire Goodwin/HMSC)

Loïc Jacquemot, a postdoctoral researcher at Université du Québec à Rimouski, said in many areas, we don't even have much of a baseline from which to compare changes.

He's currently surveying Baffin Bay off the coast of Nunavut using a technique called eDNA, which identifies species from DNA shed into the water by organisms' skin, poop and tissues. That way, they can be surveyed without actually seeing or catching them — all you need is a water sample.

Loïc Jacquemot samples water for eDNA in B.C.'s coastal fjords. (Submitted by Loïc Jacquemot)

He said species adapted to colder waters are expected to move into a smaller and smaller area "because, of course, they cannot go much more north," while warmer water species may expand their range.

That can have big impacts on things like the food chain — including fish and shellfish humans eat — and on the way carbon is moved around the ocean by zooplankton species that migrate each day between the depths and the surface. 

"It's important for the climate because all these changes impact the way carbon is stored in the ocean," Jacquemot said.

This tiny copepod is one of 20 new species identified by the Ocean Census in October. These organisms are among the zooplankton that move carbon between the surface and depths of the ocean. (The Nippon Foundation-Nekton Ocean Census/Schmidt Ocean Institute)

Photosynthetic algae called diatoms from fjords in Greenland. Diatoms are important for capturing carbon dioxide in the oceans. (Submitted by Loïc Jacquemot)

The carbon stored by the ocean and its species is known as blue carbon. So far it includes 30 per cent of carbon dioxide generated by humans, along with 90 per cent of the excess heat trapped by climate change, said a recent UN report, which warned that the ocean's ability to absorb more CO2 and heat is weakening.

Meanwhile, coral reefs, known as biodiversity hotspots with the ability to store huge amounts of carbon, are one of the ecosystems most threatened by climate change.

The impact of the ocean and its species on climate change are at the forefront of this year's UN climate summit, COP31, underway in Antalya, Turkey. Protecting marine ecosystems and "unlocking blue carbon for climate resilience" is one of 10 items on the meeting's "action agenda."

This week at COP31, former U.S. Secretary of State John Kerry and groups representing island states pushed for a strong reference to oceans in next year's global "stocktake" of climate policies, supported by the European Union and African countries.

This grenadier fish was observed with parasitic copepods attached to its head during a 2025 Ocean Census expedition off Montagu Island near Antarctica. (ROV SuBastian/Schmidt Ocean Institute)

This marine worm, Harmothoe imbricata, was found off Canada's Atlantic coast. (Christy Carr/HMSC)

For the 'biogeochemical functioning of our planet'

Taylor with Ocean Census said marine ecosystems are important for humans — even people who live far from the sea, not just for producing food and medicines, but also on a bigger scale. "You know, it's part of the biogeochemical functioning of our planet. We're very reliant on it, whether we realize it or not."

Taylor, Goodwin and Jacquemot all hope that by sharing with people the amazing diversity of life in the ocean, they can help people appreciate the importance of saving it. 

"When we show people pictures and videos of what's underwater, they're always amazed by what we actually have down there," Goodwin said.

Michelle Taylor, head of science for Ocean Census, checks out views from the cameras on the ROV SuBastian during a mission to catalogue deep sea species. (Paul Satchell)

Taylor describes them as an incredible diversity of "wild looking creatures" and says for some of them "you wouldn't believe they were of this planet."

She said she's very worried about coral reefs especially, but "you have to have the attitude that there are solutions to this." In the meantime, she added, "we need to find as many species as we can, so we can understand diversity on this planet before it is lost."

This is part of a series of articles highlighting the work of scientists looking at disappearing groups of species you may not have thought much about. It's a chance to get to know them and how they impact our lives, and find out what can be done to keep them around.