Nav: Home

Lake ecologists see winter as a key scientific frontier

November 28, 2016

PULLMAN, Wash. - As long as ecologists have studied temperate lakes, the winter has been their off-season. It's difficult, even dangerous, to look under the ice, and they figured plants, animals and algae weren't doing much in the dark and cold anyway.

But an international team of 62 scientists looking at more than 100 lakes has concluded that life under the ice is vibrant, complex and surprisingly active. Their findings stand to complicate the understanding of freshwater systems just as climate change is warming lakes around the planet.

"As ice seasons are getting shorter around the world, we are losing ice without a deep understanding of what we are losing," said Stephanie Hampton, a Washington State University professor and lead author of a study published in the journal Ecology Letters. "Food for fish, the chemical processes that affect their oxygen and greenhouse gas emissions will shift as ice recedes."

"A lake doesn't go to sleep when it's covered with a blanket of ice and snow," said Liz Blood, program director in the National Science Foundation's Division of Environmental Biology, which funded the research. "While winter's lower temperatures and light levels may force lake life into a slower mode, algae and zooplankton are still abundant.

"What will happen if lake ice cover decreases in warming temperatures?" she said. "These results are a significant step in understanding what may be far-reaching changes for lake ecosystems."

Ice clarity and algae growth

Fresh water is fundamental to society. We use it for drinking, manufacturing, energy production, irrigation and fish - a particularly important protein source in the developing world. Global warming is expected to change what we value in fresh water, as a study co-authored by Hampton last year found lakes warming around the world.

The new study finds that what happens in the winter can have a substantial effect on what happens during the rest of the year. This is especially true for lakes that let in a lot of sunlight, stimulating the growth of algae and zooplankton on the underside of the ice. These in turn serve as food sources for fish at the start of their growing season.

"In some lakes where the ice is really clear and there's not very much snow cover, there can be a lot of photosynthesis and a lot of productivity," said Hampton, who has extensive experience studying Lake Baikal in Russia, the world's deepest lake. "So there were some lakes in this study where the productivity in winter actually exceeded the productivity you would see in summer."

'Unique little microecosystem'

Hampton said her Russian colleagues have seen "a unique little microecosystem" under the ice, with filaments hanging down from the subsurface.

"It's interesting to think about these lakes that get a lot of light through the ice," she said. "Russian researchers who spend a lot of time on Baikal remind us that when you get ice, now you've got a new habitat. It can be a vast habitat extending across the entire lake."

Marine biologists have documented a key role of sea ice in supporting polar food webs.

"Under sea ice, you see the growth of foods higher in beneficial fatty acids and contributions as high as 30 percent to overall annual productivity," said Oregon Institute of Marine Biology's Aaron Galloway, a coauthor who was a postdoctoral fellow at WSU when the study began.

But until this study, freshwater scientists "were not able to make any sort of estimates like that at all," said Hampton. Investigations of frozen freshwater bodies were just too spotty. Indeed, the International Society of Limnology's Plankton Ecology Group, which has been highly influential in aquatic science, has developed a theoretical model of lakes incorporating the interplay of plankton, nutrients, temperatures and mixing. But in 2011 the group said, in effect, that winter was being overlooked.v

"It was a pretty strong statement about how little we know about winter," said Hampton.

140 sets of measurements assessed

So she and her fellow lake ecologists posted a request for data on a listserv of professional colleagues, expecting maybe 30 responses. They got 140 responses from researchers with measurements of various winter conditions, like plankton and nutrient levels, that could be compared to summer values.

Their findings varied a lot, often depending on whether a lake was covered with clear ice or covered with snow that blocked most light.

"In some cases, we know that zooplankton under ice are really important for seeding the populations that will take off in the summer and grow to be more abundant," said Hampton. In other cases, there may be algae consuming large amounts of nutrients under the ice so the summer algae have less for their own growth.

Effects of climate change

Climate change stands to introduce another set of considerations.

"A number of things are changing, with climate change, that actually affect the characteristics of the ice itself," Hampton said. The ice season can be shorter. There can be less snow, which will let in more light. Or there can be more rain during ice formation, making the ice cloudy.

Predicting these changes, she said, "will not be straightforward."

Regardless, lake scientists will need to break out their winter gear.

"Overall, this study tells us that limnologists no longer have any off-season," Hampton said. "No more down time, especially as we're losing ice so rapidly."
-end-


Washington State University

Related Climate Change Articles:

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.
Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.