vast phytoplankton blooms may be lurking beneath antarctic ice
Credit: CC0 Public Domain

Until now, it’s been a common belief that the packed sea ice of the Southern Ocean blocked all light from reaching the sea beneath, preventing phytoplankton—tiny algae that are the base of aquatic food webs—from growing there. The less light available, the less the phytoplankton can photosynthesize and therefore the less phytoplankton there will be, heavily restricting life beneath the ice.

However, research inspired by increasing under-ice blooms of phytoplankton in the Arctic has shown that Antarctic waters also have unexpected denizens, indicating that there is underestimated ecological variability under the ice.

Blooms are often spotted as soon as the sea ice begins its seasonal retreat, supported by plenty of light and freshwater with high iron content. Yet a team led by Dr. Christopher Horvat of Brown University and the University of Auckland suspected that there would already be potential phytoplankton blooms in waiting. Writing in Frontiers in Marine Science, they described using sampling from independent BGC-Argo floats and climate model output to estimate light availability beneath the ice to test this hypothesis.

“We found that nearly all examples of floats profiling under Antarctic sea ice record increases in phytoplankton before sea ice retreats,” said Horvat. “In many cases, we observed significant blooms.” Horvat also pointed out that the floats only sampled a very small part of the millions of square kilometers of sea ice that might host these under-ice blooms, so there may be many more hidden phytoplankton blooms with the potential to support other life out there.

Floating laboratories

The floats are thrown overboard from research vessels and are left to take biogeochemical samples independently: They can even detect near-freezing conditions at the surface of the water and dive to avoid being damaged by ice. The key measurements in this case were levels of chlorophyll-a, a pigment shared by all phytoplankton, and particulate backscatter, which can be converted to an estimate of phytoplankton carbon because phytoplankton scatter light in proportion to their size and concentration. In the end, the team used data from 51 floats that made 2,197 under-ice dives from 2014–2021, which they collected into 79 sequences of measurements.

“We used a new data product derived from a new NASA satellite, the ICESat-2 laser altimeter, to understand the compactness of ice around Antarctica, and with a suite of global climate models considered how much light reached the upper ocean,” said Horvat.

“We found that 50% or more of the under-ice Antarctic might support under-ice blooms, because sea ice in the Southern Ocean is comprised of discrete floes, and small areas of open water permit light and therefore photosynthetic life.”

Hidden ecosystems?

Measuring under compact sea ice with complete or nearly complete coverage of the water below, the scientists found 88% of sequences of measurements recorded a rise in phytoplankton before the retreat of the sea ice, and 26% met the criteria for an under-ice bloom.

However, the authors cautioned that the floats could sample under the ice but couldn’t return data from these positions, meaning that the coordinates for sample locations are not completely precise. “It is possible some of the high productivity events might be recorded in regions with low sea ice cover,” Horvat said.

“Because the time we observe these blooms is close to when sea ice retreats, it is also possible some of the phytoplankton come from processes occurring outside of the sea ice zone, though we consider this unlikely given the sheer number of high-productivity measurements we found.”

The implications for Antarctic ecosystems could be significant. “Higher trophic levels migrate to where the productivity is, and if it is under the ice, one might expect the food web follows,” Horvat pointed out. Further research will be needed to understand how these hidden ecosystems function, and whether the phytoplankton blooms attract predators and prey beneath the ice.

More information: Evidence For Phytoplankton Blooms Under Antarctic Sea Ice, Frontiers in Marine Science (2022). DOI: 10.3389/fmars.2022.942799

Journal information: Frontiers in Marine Science

Provided by Frontiers

Citation: Vast phytoplankton blooms may be lurking beneath Antarctic ice (2022, November 17) retrieved 17 November 2022 from https://phys.org/news/2022-11-vast-phytoplankton-blooms-lurking-beneath.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

TECH NEWS RELATED

TikTok EU ban on the table if social network doesn’t comply with new laws

TikTok is one of the most popular social networks out there. But TikTok is also a cause of concern for western governments that worry about the company’s ties to the Chinese government. TikTok can’t run on most devices the US government issues, and there has been talk of a ...

View more: TikTok EU ban on the table if social network doesn’t comply with new laws

Don’t Buy a Foldable Until Samsung Brings This Prototype to Life

Samsung Display via The Verge The world of foldable phones is surprisingly stagnant. The Galaxy Z Fold gets a tiny little upgrade every year, and rival phone brands loosely copy Samsung’s homework. But a new Samsung Display prototype called the “Flex In & Out” could turn this narrative on ...

View more: Don’t Buy a Foldable Until Samsung Brings This Prototype to Life

Best free sports streaming apps in 2023

Cutting the cord on cable television is something tons of people have done over the past five years. But that hasn’t proven to be the smartest way to continue to watch sports. Whether it comes from premium sports website subscriptions to keep tabs on your favorite players, or even fantasy ...

View more: Best free sports streaming apps in 2023

Avengers 5 might have Ant-Man in it, Quantumania star teases

The first MCU Phase 5 movie will be Ant-Man and the Wasp: Quantumania, the third installment in the Ant-Man franchise and a film with much higher stakes than the previous episodes. The sequel will deliver the MCU’s first Kang (Jonathan Majors) villain after we met a somewhat good He Who ...

View more: Avengers 5 might have Ant-Man in it, Quantumania star teases

Sharing a Netflix Account? Get Ready to Pay For It

DANIEL CONSTANTE/Shutterstock.com Netflix is about to get serious in its efforts to eliminate freeloaders. If you share a Netflix account with family or friends outside your household, get ready to pay for it. A new “paid sharing” system could roll out starting next month, and you’ll have to pay a ...

View more: Sharing a Netflix Account? Get Ready to Pay For It

‘7 Wonders’ Board Game Gets a New ‘Edifice’ Expansion

Asmodee and Repos Production Board game lovers have a wonderful reason to celebrate today. Board game makers Asmodee and Repos Production announced their latest collaboration: 7 Wonders Edifice, an expansion to the popular board game 7 Wonders. The game launches on February 24th for $29.99. 7 Wonders: Edifice adds ...

View more: ‘7 Wonders’ Board Game Gets a New ‘Edifice’ Expansion

T-Mobile Kicks Off 2023 With Another Data Breach

r.classen / Shutterstock.com In a press release, T-Mobile confirms that it detected a data breach in its systems on January 5th. A “bad actor” managed to steal personal information (but not financial data) from around 37 million customers. This is the eighth T-Mobile data breach since 2018. The hacker ...

View more: T-Mobile Kicks Off 2023 With Another Data Breach

Apple appeals to UK competition watchdog investigation about mobile browser dominance

Apple has filed an appeal against the UK’s competition watchdog regarding its dominance of mobile browsers in the cloud gaming market, reports Reuters. The Competition and Markets Authority started investigating this dominance by the Cupertino firm and Google. Lawyers representing Apple believe the investigation should be reviewed as CMA ...

View more: Apple appeals to UK competition watchdog investigation about mobile browser dominance

Galaxy S23 Ultra release date and specs leak finally reveals everything about the new model

WhatsApp for iOS rolling out the ability to create a chat with yourself

Amazon Prime Music Unlimited changes streaming prices, now matches Apple Music

Deadpool 3 and Secret Wars to feature Fox’s X-Men, according to Marvel insider

Report: OLED iPad Pro still on track for 2024 release, 2026 for MacBook Pro

How to negotiate over practically anything

HomePod 2 praised in exclusive hands-on before launch

M2 Pro MacBook Pro Amazon preorder deal gives you $50 off

What “choice” means for millions of women post-Roe

Singapore FinTech firm Pilon secures $5.2M seed funding led by Wavemaker Partners

Capital Square Partners and Basil Technology team up for $700M tech fund in Asia

This feel-good movie about man’s best friend is dominating Netflix

OTHER TECH NEWS

Top Car News Car News