Doug Johnson: Lakes are Heating Up

Ars Technica

New research identifies the interrelated challenges that the world’s lakes face. According to Sapna Sharma, co-author of the research and an associate professor of York University’s biology department, many of the climate change-related impacts that affect these watering holes remain relatively hidden despite these waters potentially facing an extensive collection of problems. “I hope that people get a sense of how widespread the effects of climate change on lakes are,” she told Ars. “If you just go look out at a lake, you might not know all the changes it’s experiencing.”

To study this, Sharma and colleagues at different universities around the world pored over hundreds of research papers about lakes. These papers came from across the globe, and some date back to the 1930s, she said. Sharma and her fellow researchers all have differing areas of expertise, allowing them to review and synthesize the existing literature...

The hundreds of papers painted a complex picture of lakes’ past, present, and future under a rapidly changing climate. On a purely mechanical level, a warmer planet means less ice cover. More and more, ice is taking longer to grow on lakes in the fall and winter, and it leaves sooner in the spring and summer. The heat also causes the waters to stratify sooner—meaning that the colder, heavier water will sink below the warmer, lighter water.

Northern Lakes Warming 6x faster

York University:

Lakes in the Northern Hemisphere are warming six times faster since 1992 than any other time period in the last 100 years, research led by York University has found.

Lake Superior, the most northern of the Great Lakes which straddles the Canada/United States border, is one of the fastest warming lakes, losing more than two months of ice cover since ice conditions started being recorded in 1857. In Lake Suwa, in Japan, ice formed close to 26 days later per century since 1897 and is now only freezing twice every decade, while Grand Traverse Bay in Lake Michigan had one of the fastest ice-off trends, melting about 16 days earlier per century.

”We found that lakes are losing on average 17 days of ice cover per century. Alarmingly, what we found is that warming in the past 25 years, from 1992 to 2016, was six times faster than any other period in the last 100 years,” says Associate Professor Sapna Sharma of the Faculty of Science at York University, who led the study with Professor David Richardson at the State University of New York at New Paltz and climate scientist Iestyn Woolway, Ph.D., of the European Space Agency Climate Office, United Kingdom.

More information: Sapna Sharma et al, Loss of Ice Cover, Shifting Phenology, and More Extreme Events in Northern Hemisphere Lakes, Journal of Geophysical Research: Biogeosciences (2021). DOI: 10.1029/2021JG006348

Prioritizing Lakes for Conservation

Lake and Reservoir Management:

Abstract:
Identifying lakes in which to invest water quality conservation efforts can help more effectively target efforts and more efficiently utilize limited resources. The objective of this study was to compare different approaches to prioritize Minnesota lakes primarily for water quality protection or restoration. Lakes were objectively ranked using a multi-criteria values-based model that included phosphorus-loading resilience, level of watershed degradation, and feasibility of water quality protection or restoration. We explored how the list of priority lakes might change when incorporating benefit:cost ratios that used a hedonic model to predict land value increases with total phosphorus loading reductions. In addition, we examined the influence of including data on lakes with unique or high-quality biological communities. The multi-criteria values-based model was moderately correlated with the benefit:cost ratio approach; however, the exclusion of benefits and cost in the prioritization would likely result in the loss of a modest amount of potential benefit ($20%). A focus on impaired waters would likely result in considerable forgone benefit ($80%) and substantially higher costs. We provide recommendations on how to combine prioritization approaches along with a peer review process to produce lake priority lists that are both defensible and practical.

This article is available as a pdf for a limited time at this link.

Maddie Stone: Drilling to Reach an Antarctic Lake

Gizmodo:

the Subglacial Antarctic Lakes Scientific Access (SALSA) team announced they’d reached Lake Mercer after melting their way through an enormous frozen river with a high-pressure, hot-water drill. The multi-year effort to tap into the subglacial lake—one of approximately 400 scientists have detected across Antarctica—offers a rare opportunity to study the biology and chemistry of the most isolated ecosystems on Earth.

The only other subglacial lake humans have drilled into—nearby Lake Whillans, sampled in 2013—demonstrated that these extreme environments can play host to diverse microbial life. Naturally, scientists are stoked to see what they’ll find lurking in Lake Mercer’s icy waters.

“We don’t know what we’ll find,” John Priscu, a biogeochemist at Montana State University and chief scientist for SALSA, told Earther via satellite phone from the SALSA drill camp on the Whillans Ice Plain. “We’re just learning, it’s only the second time that this has been done.”

Karla Lant: The National Lakes Assessment

Environmental Monitor:

The EPA (and others, such as this separate analysis from Dr. Dina Leech) are now reporting on observations of conditions and changes from 2007 to 2012. For most indicators, no change occurred, but changes in total phosphorus, two algal toxin indicators, and a physical habitat indicator are exceptions.

“While EPA did not observe changes in the condition categories for the nutrient phosphorus, Leech et al. 2018 found an 18.2 percent decline in the percentage of oligotrophic lakes (very clear lakes with less than 10 μg/L of total phosphorus) and an overall increase in the median concentration of phosphorus across all lakes,” comments Lynn. “The NLA 2012 Assessment Report observed a change within algal toxin measures. An analysis of cyanobacteria cell density, a measure of the density of cells that could produce cyanotoxins, showed a statistically significant increase (+8.3%) in the percentage of lakes in the most disturbed category between 2007 and 2012. The NLA identified a significant increase in the detection of microcystin among lakes in 2012 (+9.5%). However, concentrations of this algal toxin remained low and rarely exceeded WHO recreational levels of concern (<1% of the population) in both assessments.”

The NLA 2012 Assessment Report also found fewer lakes in the least disturbed category and more lakes in the moderately disturbed category for the habitat complexity indicator—which has to do with lakeshore habitat and buffering qualities.

Samantha Oliver: Altered Nutrient Flows into Lakes

UW-Madison Center of Limnology:

Humans have drastically changed the distribution of nutrients (nitrogen and phosphorus) across the landscape through urbanization, food production and burning fossil fuels. This has come at a cost to water quality; excess nutrients are transported to surface waters where they can fuel toxic algal blooms, foul drinking water and disrupt the ecosystem. We’ve made progress on point source pollution like sewage discharge since the Clean Water Act was established in 1972. But diffuse nutrient sources like runoff from agricultural areas are difficult to manage and still plague surface waters.

Natalie Wolchover: Longer Time to Recover is a Warning Sign

Atlantic:

Systems that exhibit such “critical transitions” tend to be so complicated and riddled with feedback loops that experts cannot hope to calculate in advance where their tipping points lie—or how much additional tampering they can withstand before snapping irrevocably into a new state.

At Peter Lake, though, Carpenter and his team saw the critical transition coming. Rowing from trap to trap counting wriggling minnows and harvesting other data every day for three summers, the researchers captured the first field evidence of an early-warning signal that is theorized to arise in many complex systems as they drift toward their unknown points of no return.

The signal, a phenomenon called “critical slowing down,” is a lengthening of the time that a system takes to recover from small disturbances, such as a disease that reduces the minnow population, in the vicinity of a critical transition. It occurs because a system’s internal stabilizing forces—whatever they might be—become weaker near the point at which they suddenly propel the system toward a different state.

Canada's Research Lakes

NewsBlog at Nature:

Fans of environmental science can now have a direct role in helping Canada’s unique Experimental Lakes Area (ELA) continue to do the research it has done for decades.

The International Institute for Sustainable Development (IISD), based in Winnipeg, took over running the ELA on 1 April, after the federal government eliminated funding for the decades-old environmental research facility (see ‘Test lakes face closure’ and ‘Last minute reprieve for Canada’s research lakes’). The Canadian provinces of Ontario and Manitoba have stepped in to provide money to run the facility and conduct research for the next several years, but more cash is needed to restore research at the ELA to its former levels.

So the IISD has turned to the public. It launched an appeal on the crowdfunding site Indiegogo seeking contributions to expand research and make the ELA less dependent on government largesse.
Click on image to learn more

Click on image to learn more

Glimmer of hope for freshwater research site

Hannah Hoag reports:

 

The Ontario provincial government has stepped in to keep open the Experimental Lakes Area. The freshwater research facility located in northern Ontario was closed in March by the government of Canada, despite protests from scientists.

Good news, as an incredible amount of lake research was produced from the ELA, including eutrophication and acid rain studies. xplore the work from this facility at: http://www.experimentallakesarea.ca