Drift into trouble? | Borneo Bulletin Online
PLYMOUTH, UNITED KINGDOM (AFP) – The bizarre metal box pulled out from the waves and on the ship’s deck looks like a fished spaceship in a child’s imagination.
But when scientist Clare Ostle opened it and took out the rolls of silk inside, she was looking for the telltale green glow of some of Earth’s most important creatures: plankton.
It is a continuous recorder of plankton, torpedo-like devices that for 90 years have been towed by merchant ships and fishing boats over a vast network of roads.
They help researchers better understand the ocean by collecting some of its smaller inhabitants.
What they saw was that as climate change warms the seas, plankton are on the move – with potentially profound consequences for ocean life and humans.
Plankton – organisms carried by the tides – are at the base of the marine food web.
But they’re also part of a finely balanced system that helps us all stay alive.
In addition to helping produce much of the oxygen we breathe, they are a crucial part of the global carbon cycle.
“The big thing we are seeing is warming,” said Ostle, coordinator of the Pacific CPR survey. AFP while demonstrating the plankton recorder off the coast of Plymouth in Britain.
The CPR Survey has documented a decisive shift in plankton toward the two poles in recent decades, as ocean currents change and many marine animals move to cooler areas.
The smaller warm-water plankton also replaces the more nutritious cold-water plankton, often also with different seasonal cycles, which means that the species that feed on them also have to adapt or move.
“The big worry is when the change occurs so quickly that the ecosystem cannot recover,” Ostle said, adding that dramatic temperature spikes can lead “to the collapse of entire fisheries”.
With nearly half of humanity dependent on fish for around 20 percent of their animal protein, this could be devastating.
Plankton is a generic term in the Greek for “drifting” and encompasses everything from photosynthetic bacteria several times smaller than the width of a human hair, to jellyfish with long, trailing tendrils.
There are two main types: phytoplankton, various plant cells commonly called algae; and zooplankton, animals like krill and the larvae of fish, crabs and other sea creatures.
Photosynthesis in phytoplankton uses the sun’s rays to convert CO2 into energy and oxygen.
In fact, scientists estimate that the seas produce about half of the oxygen on Earth, and that’s mostly thanks to phytoplankton.
They are also essential to the ocean’s “biological carbon pump”, which helps the sea retain at least a quarter of the CO2 emitted by the combustion of fossil fuels.
While trees store carbon in wood and leaves, phytoplankton stores it in their bodies.
It crosses the food web, with phytoplankton being consumed by zooplankton which, in turn, is eaten by creatures, from birds to whales.
“Almost anything you can think of in the sea at some stage in its life cycle will eat plankton,” said David Johns, director of the CPR Survey.
When organic matter from dead plankton or its predators sinks to the ocean floor, it carries carbon with it.
But scientists have warned that climate change has put stress on the system, with ocean temperatures rising, less nutrients reaching the upper ocean from deep levels, and increased levels of acidifying seawater into CO2.
Climate change has “exposed ocean and coastal ecosystems to conditions unprecedented for centuries if not millennia, with consequences for ocean plants and animals around the world,” said the Intergovernmental Panel on Evolution (IPCC) of the United Nations (UN) in a press release. a draft report on climate impacts, due for release next year, predicts “an escalation in impacts on marine life”.
While phytoplankton are relatively resilient and are likely to continue to move as seas warm, the IPCC expects that deteriorating conditions in the oceans will ultimately lead to a general decline during this century.
The global average phytoplankton biomass – a measure of weight or total quantity – is expected to drop by about 1.8-6%, depending on the level of emissions.
But because of its disproportionate importance, even modest reductions can “amplify the marine food web”, eventually leading to reductions in marine life of around 5-17%.
There could also be “changes in the carbon cycle and carbon sequestration, as our plankton community changes” with smaller plankton that could reduce CO2, said Abigail McQuatters-Gollop, plankton ecologist from the University of Plymouth.
As world leaders prepare to meet at a crucial United Nations climate change summit, the question is a vivid example of how accelerating human impacts are destabilizing complex life support systems.
Tackling this problem isn’t as easy as planting trees, McQuatters-Gollop noted.
But fishing sustainably, reducing pollutants and reducing CO2 emissions can help improve
In the past, she has said conservation focused on “the big things, the cute things, or the things that are directly worth the money” – like whales, turtles and cod.
But all of them depend on plankton.
While this “blindness” may be due to the fact that they are microscopic, people can see traces of plankton on the beach – in the foam on the waves, or the nocturnal flicker of the bioluminescence.
Or on the children’s TV show Sponge Bob SquarePants, whose Plankton character is “the most famous plankton in existence,” said McQuatters-Gollop.
And when they “bloom” in large numbers, the plankton are visible from space, transforming the water into a surprising emerald or creating Van Gogh swirls of milky blue, in seasonal exposures essential to ocean life.
Like land plants, phytoplankton need nutrients like nitrates, phosphates, and iron to thrive.
But they can have too many good things: Runoff from nitrogen-rich fertilizers is blamed for creating harmful algal blooms, like the gooey “sea snot” off Turkey’s coast this year. These can poison marine life or suffocate oxygen from the water and can be exacerbated by warming, the IPCC has warned.
Meanwhile, research published in Nature Last month it was discovered that iron carried in smoke from the massive 2019 and 2020 wildfires in Australia had triggered a huge swell of phytoplankton thousands of miles away, which could have sucked up substantial amounts of CO2. .
Flowers can be sown by nutrients from sandstorms or volcanic eruptions and it is these “natural processes” that inspired Cambridge Center for Climate Repair founder David King.
King supports a much-debated idea of ”fertilizing” plankton blossoms by sprinkling iron on the surface.
The theory is that this would not only help suck in more CO2, but lead to an increase in ocean life, including possibly helping to increase whale populations devastated by hunting.
More whales equals more whale waste, which is packed with nutrients plankton needs to flourish, and King hopes he can restore a “wonderful circular economy” to the seas.
A pilot project will test the technique in an area of the Arabian Sea carefully sealed in a “large plastic bag,” but King acknowledges the idea raises fears of unintended consequences: “We certainly don’t want to deoxygenate the oceans. and I’m pretty confident we won’t.
Ocean organisms have photosynthesized for billions of years, long before terrestrial plants. But we still have a lot to learn about them.
It wasn’t until the 1980s that scientists named the planktonic bacterium prochlorococcus, now considered the most abundant photosynthesizer on the planet.
It turns out that some “vagabonds” can swim, while others are masters of living together. Take the partnership between corals and plankton – it’s so important that when it breaks due to warming, corals turn white. Or Acantharea, a single snowflake-shaped cell that can collect photosynthetic algae and manipulate them into an energy-generating “battery pack”, said Johan Decelle of the French research institute CNRS and the University of
They have been “overlooked” because they dissolve in chemicals used by scientists to
To study plankton under a high-resolution electron microscope, Decelle used to collect samples on the French coast and bring them back to Grenoble for hours in a special cooler.
But this year, he worked with the European Molecular Biology Laboratory on a pioneering project bringing high-tech freezing virtually to the beach.
This makes it possible to study these delicate organisms as close as possible to their natural environment.
In contrast, continuous plankton loggers end up crashing their samples into “roadkill,” Ostle said.
But the value of the investigation, which began in 1931 to understand how plankton affected herring stocks, comes from decades of data.
Scientists have used it to track climate change and it has played an important role in the recognition of microplastics.
Ostle used CP ship logs to show that “macroplastics” like shopping bags were already in the seas by the 1960s.
By the time he received a Guinness World Record for the longest distance sampled by a marine survey last year, he had studied the equivalent of 326 laps of the planet.
From the boat in Plymouth, the water appears calm as sunlight glides over its surface. But every drop is bursting with life.
“There’s just a whole galaxy of things going on underneath,” Ostle said.