Scientists hope small ocean zooplankton will help see if climate change targets are being met

Scientists have discovered that some of the tiniest animals in the ocean are having a huge impact in the fight against climate change.

It is estimated that microscopic phytoplankton capture up to 20 billion tons of carbon dioxide each year.

But what happens next is what is important to remove carbon dioxide from the atmosphere, according to zooplankton ecologist Svenja Halfter.

“Phytoplankton absorb carbon. Because they photosynthesize, zooplankton like to eat these microalgae and then store the carbon in their bodies, and that’s how they go up the food chain,” Dr. Halft explained.

“When these animals die, they transport carbon to the deep sea where it remains for a long time.”

In fact, scientists believe that carbon can remain on the ocean floor for hundreds, even thousands of years.

Small creatures that look like insects in a plastic bottle
Substances larger than one millimeter in size are filtered from sediment traps. (Supplied: CSIRO/Katherine Wayne Edwards)

Current research – conducted by the Institute for Marine and Antarctic Studies (IMAS) in conjunction with CSIRO – has found that zooplankton, which are not well represented in current CO2 capture models, play a much larger role than previously thought.

However, their research – which is part of the Long-Term Monitoring of the Oceans by the Integrated Marine Monitoring System (IMOS) – also found that the Southern Ocean is becoming warmer, fresher, less oxygenated and more acidic, and this may affect its ocean. The ability to absorb carbon dioxide into the atmosphere.

Young woman with long brown hair smiling at the camera
Dr Elizabeth Chadwick says the research will help determine how Australia will reach its emissions reduction targets.(ABC News: Marine Prius)

CSIRO Research Scientist Elizabeth Chadwick explained more about the team’s findings.

“We have released carbon dioxide into the atmosphere through burning fossil fuels, cement production, and deforestation, and the oceans are doing us a fantastic service by absorbing about a third of these emissions,” Dr. Chadwick said.

“Understanding and quantifying how much carbon is being absorbed by the oceans is really essential for us to make accurate predictions of climate change over real estate and century timescales.

“[It’s] It is critical for us to observe and appreciate the role the ocean plays in removing carbon dioxide from the atmosphere and storing it in the deep sea.

“Australia is committed to reducing emissions, we’ll see that in the atmosphere, but we have to be able to verify that what we’re doing really makes a difference.”

How do they watch the Southern Ocean?

A large yellow cone-shaped ship is taken on board a ship at sea
Sediment traps collect particles that sink to a depth of approximately 4,000 metres.(Supplied: CSIRO / Elizabeth Chadwick )

Every 12 months, scientists on the research vessel CSIRO RV Investigator travel 36 hours southwest of Tasmania to the sub-Antarctic region, releasing sediment traps, connecting each to a deep-water anchorage approximately 1,000, 2,000 and 4,000 meters deep.

On each sediment trap there are 21 cups, and these cups rotate under a large funnel to collect small particles that sink from the ocean surface, explains Catherine Wayne Edwards of IMAS.

    Plastic tubes with numbers written on the outside
Material from sediment traps is also archived so that future scientists can analyze it.(Supplied: CSIRO/Katherine Wayne Edwards)

“We picked up a mooring that was posted a year ago and put a new mooring in its place so it can continue to collect data,” said Dr. Wayne Edwards.

“Some assumptions go into that when it comes to climate models, but we measure them directly and that is the value of this work.

“There’s a lot of process going on in between, before this stuff I’m analyzing so deeply is over, so it’s a small part and a lot has happened to it before it becomes organic.”

Continuous monitoring of the oceans has been done for the past 20 years and scientists believe it will help verify the impact of global reductions in carbon dioxide emissions.

Young woman wearing a white lab coat and holding a small glass vial
Dr. Catherine Wayne Edwards says scientists will need sustained observations over many years to understand natural and human differences.(ABC News: Marine Prius)

“Having monitoring platforms in the ocean where 30 percent of the CO2 goes is really critical, not just for the doom and gloom of what’s going to happen to the climate, but to be able to say, ‘Look, we’ve reduced our emissions.’ Our goals.”

“There is no doubt that these observations are essential to increasing our understanding of how climate variability affects us now and how it will likely affect us in the future.

“We need sustained observations over many years to understand what the natural variations are and what our human footprints are on those processes.”

Young woman with long hair bending over to check equipment
Each sediment trap contains 21 cups to capture materials scientists need.(ABC News: Marine Prius)

Leave a Comment