Far below the surface of the Pacific Ocean is a lab run by the Monterey Bay Aquarium Research Institute, MBARI. From here, scientists have been studying deep-sea communities, and they’ve been at it now for over 30 years.
This was cause for a special issue of the journal Deep-Sea Research Part II, in which marine scientists published 16 papers about their findings.
The papers cover a variety of topics, from quantifying how much carbon makes its way to the deep sea to ecological insights into the animals that live around the research site.
The site is called Station M. It’s located 180 miles off the coast of Santa Barbara and 2.5 miles below the surface. It’s one of the world’s only long-term monitoring sites at, what are called, abyssal depths.
Marine Ecologist Ken Smith started Station M in 1989 when he was working at UC San Diego’s Scripps Institution of Oceanography. For years, the National Science Foundation funded Station M, but when that funding ran out, Smith moved up to the Monterey Bay area. MBARI has operated the project since 2005.
The original goal was to study this part of the Northeast Pacific for decades. And that approach has proven valuable over time, especially with the increasing impacts of climate change.
Marine Biologist Crissy Huffard with MBARI said the 1980s were a popular time for launching these types of long-term research programs.
“But since then, many of them have either dropped off and new ones haven't necessarily been added at the same rate because funding for them requires a long term commitment,” Huffard said.
The deep seafloor covers more than 50% of Earth’s surface, but it’s one of the least known habitats on the planet.
“It's this huge part of our earth,” Huffard said, “and yet we've looked at just postage stamp sizes of it.”
Not only is this kind of research expensive, roughly $1 million a year to cover all the costs, it can be dangerous.
“You know, it's crazy to think that the average ocean depth is 4,000 meters. And that's about where we work,” Huffard said.
Well, technically, that’s where the robotic instruments work, full-time on or near the seafloor. They only come up for annual maintenance, when a crew heads out to sea to check on things.
MBARI Electrical Engineer Alana Sherman is in charge of directing that maintenance.
“So you go out there and basically you recover the rover and you have probably 48 hours to change all the batteries, fix anything that's broken, get all the data off of it, reprogram it and put it back in the ocean,” Sherman said. “And that's on a moving ship!”
Sherman said an SUV-sized Benthic Rover roams the seafloor taking photographs and measurements. There are time-lapse cameras and sediment traps. All of these instruments help scientists better understand the mysteries of the deep sea.
“It's a very inhospitable place to do your research,” Sherman added. “But, you know, people ask these big questions about how climate is affecting the ocean.”
Huffard, who co-authored several of the papers published in the March journal of Deep-Sea Research, said a main takeaway from their findings is that the deep sea changes in response to what happens on the surface and in the climate, sometimes rather quickly.
In other words, humans are impacting habitats far below the ocean’s surface.
As part of her research, Huffard and her colleagues studied how much carbon makes its way to the seafloor by analyzing sediment traps. These robotic funnels collect samples that can later be analyzed at the MBARI labs in Moss Landing.
Oceans play a key role in the Earth’s carbon cycles. They absorb a tremendous amount of the carbon dioxide that we have put into the atmosphere.
“So that is part of a process called carbon sequestration that people will talk about in the news,” Huffard said. “It's a way to draw down greenhouse gases without contributing further to global warming. And this is a natural process.”
She said that over the past ten years, the amount of carbon making its way down to the deep seafloor has increased dramatically.
It sinks in what’s called “marine snow” -- dead algae or animal parts like fish scales. It’s all food for animals on the deep seafloor.
“We might see big greenish globs on the seafloor. And that's like, you know, the big salad of the sea,” Huffard said.
She describes the deep seafloor as an expansive, muddy abyss with slow-moving, squishy creatures.
“It's hard to describe sea cucumbers as being charismatic, but they really are,” she said.
Click here for a timelapse video from 2019 of a sea cucumber eating a fresh glob of marine snow.
When there’s a marine snow event, Huffard said, the sea cucumbers “go gangbusters,” reproducing in large numbers.
Click here for a timelapse video of a spong on the deep seafloor.
That might sound like a good thing, but Huffard says the long-term impacts of this population growth are unknown. For example, when sea cucumbers eat more, they also respire more. That process releases carbon dioxide, which can acidify the water and lower oxygen levels.
“Over the past 30 years, we've seen a slight decline in the oxygen levels at Station M,” Huffard said. “And so we can't just pump more oxygen down there. That's not possible.”
Given how vast the deep-sea is, Huffard said undoing any negative impacts is something we can’t engineer our way out of, at least not right now.
“In general, I think many people know that protecting the ocean means more than just not littering,” she said. “It means being careful about your carbon footprint.”
Scientists plan to continue their research at Station M, exploring what they call “surprising changes” on the seafloor. Meanwhile, the next trip out to sea to check on the robotic instruments and collect data is set for this October.