Read Before Swimming: What Research Shows About Local Lakes

June 17, 2021

Read Before Swimming

What Research Shows About Local Lakes

Dr. K. David Hambright

Every summer, Oklahomans visit local lakes to swim, fish, boat and enjoy nature with friends and family. Researchers from the University of Oklahoma are tracking data that show Oklahoma lakes, as well as many others around the globe, may be less hospitable than we assume for some of those popular pastimes.

Dave Hambright, a Regents’ Professor of Biology in the College of Arts and Sciences and a member of the Geographical Ecology Group, represents OU in a worldwide consortium of nearly 900 researchers from 62 countries in the Global Lake Ecological Observatory Network. Hambright said the consortium enables its members to share information and data more easily to help scientists understand, predict and communicate the effects of global climate change on freshwater lakes.

In a series of recent papers published in Nature, Nature Climate Change and Scientific Reports, several GLEON working groups in which Hambright collaborates, each consisting of approximately 40 to 60 researchers, have demonstrated that lakes around the world are getting warmer and losing oxygen at alarming rates.

“We’re seeing lake temperates rise at ~0.37°C per decade, and losing oxygen at ~0.12 mg/L per decade, rates that are alarmingly three to nine times faster than rates observed in the world’s oceans,” Hambright said.

Hambright, working with Oklahoma state and municipal agencies, supplied long-term data, spanning up to four decades, on temperature, dissolved oxygen and nutrients in five Oklahoma lakes: Texoma, Thunderbird, Grand, Eucha and Spavinaw, that reveal similar patterns.

Blue-green algal boom in Lake Hefner, 2017

“The thermal and oxygen changes have resulted in spatial and temporal shifts in habitat availability for fish and other organisms, and if allowed to continue, could dramatically affect global freshwater biodiversity,” he said. “Interestingly, a subset of highly productive lakes, exemplified by Lake Thunderbird, revealed similar long-term increases in temperatures, but also showed increases, rather than thermally based decreases, in dissolved oxygen concentrations in summertime surface waters due to increased productivity, particularly of harmful (toxigenic) cyanobacteria, also known as blue-green algae.”

Multiple ongoing projects sponsored by the National Science Foundation and the United States Geological Survey in Hambright’s Plankton Ecology and Limnology Lab, and in conjunction with professor Lee Krumholz’s lab group in the Department of Microbiology and Plant Biology at OU, include analyses of potential biological consequences of water-quality changes induced by climate change and other environmental change.

“These harmful algae species appear to have unique microbiomes that provide useful metabolic functions, such as nutrient recycling and vitamin supply, to cyanobacteria, giving them an advantage in warm, nutrient-rich waters, over otherwise less problematic algal species,” Hambright said.

By better understanding how these algae interact with their microbiomes, Hambright’s research aims to uncover important interactions between blue green algae and their microbiome communities that might be conducive to the development of new lake management strategies based on ecology and evolutionary biology for controlling harmful algal blooms.

PELL Lab post-doc and graduate students, 2019

Early career researchers are playing major roles in this research effort. Jessica Beyer, research assistant professor of biology and manager of Hambright’s lab, along with Haiyuan Cai, a postdoctoral researcher, are leading current genomic- and transcriptomic-based efforts to unravel the complex interactions between harmful algae and the many microbial species with which they live. Additionally, Katherine Cook, a graduate student in biology, and Chuang Li, a graduate student in microbiology and plant biology, are leading research on harmful algal blooms and their global geographic ecology, as well as their roles in cycling of the greenhouse gas, methane.

Cook recently was awarded the Department of Biology’s Graduate Research Award for her paper, coauthored by Li, Krumholz, Hambright and others. In this paper, “The global Microcystis microbiome,” published last year in the journal Limnology and Oceanography, she analyzed patterns in diversity and biogeography in the bacteria associated with the common harmful algal blooms taxon, Microcystis, from lakes around the world.

Through continued partnerships in GLEON and elsewhere, Hambright hopes to understand the unique roles of specific bacterial species on metabolic processes within harmful algal blooms and to identify potential new mitigation strategies for controlling harmful algal blooms under continuing climate and environmental change scenarios – mitigation strategies that could help ensure that lakes locally and globally are once again hospitable for popular lakeside pastimes.