Subscribe to our free daily newsletters
. Earth Science News .

Subscribe to our free daily newsletters

New 13-year study tracks effects of changing ocean temperature on phytoplankton
by Staff Writers
Cape Cod MA (SPX) Oct 21, 2016

Lead author Kristen Hunter-Cevera has isolated diverse strains of Synechococcus from water samples taken at the WHOI-operated Martha's Vineyard Coastal Observatory. The ability to grow and culture this phytoplankter in the lab allows for experiments to learn how this organism's underlying physiology and ecology contributes to the growth and loss patterns observed in the ocean. Image courtesy Dehann Fourie.

A new multiyear study from scientists at the Woods Hole Oceanographic Institution (WHOI) has shown for the first time how changes in ocean temperature affect a key species of phytoplankton. The study, published in the October 21 issue of the journal Science, tracked levels of Synechococcus--a tiny bacterium common in marine ecosystems--near the coast of Massachusetts over a 13-year period. As ocean temperatures increased during that time, annual blooms of Synechococcus occurred up to four weeks earlier than usual because cells divided faster in warmer conditions, the study found.

Shifts like these could have a major impact on marine ecosystems worldwide, says WHOI biologist Heidi Sosik, who initiated the study. "Synechococcus and other phytoplankton are sentinels. They can tell us how an ecosystem is responding to shifts in climate," she says. "If ocean temperatures continue warming over the next century, some ecosystems could become more and more dominated by small phytoplankton, eventually leading to shifts that could affect the livelihoods of larger species like fish, whales, and birds."

That shift to smaller phytoplankton isn't a sure thing, however. Although Sosik and her colleagues saw that Synechococcus cells reproduced more quickly than usual as conditions warmed, the overall size of the phytoplankton bloom didn't increase much during the course of the study.

As the bacteria grew more quickly, the team found, they also were consumed more quickly by tiny protozoa, viruses, and other single-celled organisms that prey on the Synechococcus. As a result, the overall levels of the bacteria stayed roughly the same from year to year, although the timing of the bloom shifted earlier or later as the water temperature changed.

"That was a surprise to us," says Sosik. "We didn't expect such a tight lockstep between Synechococcus and consumers as the spring bloom changed. It shows that the consumers are able to keep up." As a result, she says, this balance leads to a similar bloom cycle year after year, just with a shift in timing.

"The question is, 'how stable is that balance?,'" adds Kristen Hunter-Cevera, lead author on the paper and a graduate of the MIT-WHOI Joint Program in Oceanography. "In the future, will consumers be able to keep up? A mismatch is a huge concern. If the bloom expands, or moves earlier in the year, higher-level organisms that expect to feed on those consumers at a certain time of year might miss them entirely."

The WHOI team was able to determine division rates of Synechococcus by using a mathematical model and data from an automated sensor developed by Sosik and her WHOI colleague Rob Olson called "FlowCytobot," which continually sampled seawater for 13 years.

The device looks specifically for the physical characteristics of Synechococcus cells, which are roughly one micrometer in diameter, and contain compounds that glow orange and red under laser light. Tallying cells with this method has allowed the researchers to home in on just one species of phytoplankton among thousands in seawater--the first time a long-term experiment of this sort has been able to do so.

"Looking at physiology at the species level is sort of a holy grail in marine ecology," says Sosik. "Each species interacts with its environment in a different way, so to understand the impacts of something like temperature, it's critical to be able to look at a single one. Doing that every hour, every day, every year gave us a very high-resolution picture. There's nothing like this out there."

Earlier experiments have followed phytoplankton over long periods of time by using satellite imagery, Sosik notes, but that sort of remote sensing can only give researchers a big picture of all phytoplankton species, and can't reveal what's happening to a specific type of organism. Even the existing "gold standard" for analyzing a single species of phytoplankton--identifying it by hand in samples of seawater--has its own limitations.

Although the method offers a very accurate look at a given species, says Sosik, relying on field samples can provide only a "snapshot" of one particular moment in the ocean.

Flow Cytobot, however, offers the best of both worlds: it's sensitive enough to measure changes in a single species, and can do so around the clock, letting researchers see minute changes in the phytoplankton population over long periods of time.

"Now that we have the appropriate technology to study phytoplankton populations on time scales of hours to weeks, we're gaining a much better understanding of what controls productivity in coastal ocean ecosystems," says David Garrison, director of the National Science Foundation's biological oceanography program, which provided funding for the research.

The fact that Flow Cytobot could measure Synechococcus for so long--and at such regular intervals--was made possible by its installation at the Martha's Vineyard Coastal Observatory (MVCO), a platform of instruments stationed just off the Massachusetts island's coast. Cables carrying both power and data run between the MVCO and a small laboratory on shore, allowing sensors on the platform to stay submerged around the clock, and send real-time updates when any measurements are made.

Although the MVCO is a small observatory, Sosik notes, much larger ocean observatories are currently being built off the US Pacific and Atlantic coasts , and other locations worldwide. These new networks may enable similar studies in the future, offering a detailed look at ocean ecosystems around the globe.

"Looking at this sort of time scale, at this resolution, would be impossible without ocean observatories," says Sosik. "I'm hopeful we'll be able to invest in the sort of sampler and detection technology that can take full advantage of those newer platforms as well. It's really a much more sophisticated way of measuring ecosystems than our existing methods."

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
Woods Hole Oceanographic Institution
Water News - Science, Technology and Politics

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
Study: Bait worms a surprisingly valuable marine resource
Washington (UPI) Oct 17, 2016
A new study quantifies the economics of the bait worm industry, as well as its environmental impact. Globally, the bait worm industry accounts for $6 billion worth of business activity each year. Surprisingly, the price of bait worms is greater than many premium seafood products. A pound of bait worms goes for roughly $82 in the U.S. - more than lobster. Each year, roughly 120,0 ... read more

Impact of the Fukushima accident on marine life, five years later

Haiti hurricane victims lose hope of receiving aid

Power impact from Matthew nowhere near Hurricane Sandy

UN worried over attacks on aid convoys in hurricane-hit Haiti

Pushing the boundaries of magnet design

Polymer breakthrough to improve things we use everyday

Efficiency plus versatility

Achieving ultra-low friction without oil additives

Sharks are beautiful, diver says despite narrow escape

Ocean warning for Pacific's Melanesia

In drought, Los Angeles grapples with water-guzzling rich

Study: Bait worms a surprisingly valuable marine resource

Scientists launch unprecedented Antarctic research mission

Future of Antarctic marine protected at risk

Antarctica is practically defined by ice. What happens when it melts?

New permafrost map shows regions vulnerable to thaw, carbon release

Model predicts spread of harmful plant pathogen around the globe

Plants actively direct their seeds via wind or water towards suitable sites

Small-scale agriculture threatens the rainforest

Massive US health tab for hormone-disrupting chemicals

Millions in Philippines on alert for super typhoon

Honduras alert over heavy rains

Super typhoon smashes northern Philippines

Vietnam floods kill 25 as new typhoon approaches

Mozambique peace talks resume after negotiator's murder

20 dead in Pygmy-Bantu caterpillar clashes in DR Congo

Mali governor visits troubled region for first time in years

Three Burkinabe troops killed in attack near Mali border

Female chimpanzees don't fight for 'queen bee' status

New tools identify key evolutionary advantages from ancient hominid interbreeding

Capuchin monkey observed making stone flakes in Brazil

Wild chimpanzee mothers teach young to use tools, video study confirms

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement