For many years, people believed that only two types of large creatures lived in the Great Salt Lake in the United States: brine shrimp and brine flies. Besides these, the lake was known to host only bacteria and algae due to its extremely salty water. However, recent discoveries have unveiled a third multicellular organism thriving in this harsh environment, a discovery that remained unnoticed until now.
Researchers from the University of Utah have made an exciting find by examining clumps of calcium carbonate mud, known as microbialites, on the lake’s bed. These formations are created by microorganisms. The team has unveiled that various species of worms are living beneath the lake’s surface, hidden from view. This marks the most saline habitat where nematodes, a type of worm, have been found, showcasing their incredible adaptability as they inhabit nearly all of Earth’s extreme environments.
The discovery was led by biologists Julie Jung and Michael Werner. In the spring of 2021, they embarked on an intensive search in parts of the lake that are three to six times saltier than the ocean. Initially, they collected samples by scooping up segments of the lake bed. When they stumbled upon microbialites, they carefully extracted small pieces to preserve their structure and analyzed them back in the laboratory.
Their success came where others had not, thanks to a sophisticated technique that isolates macromolecules such as DNA, RNA, and proteins. This method allowed them to identify living nematodes in every sample they collected. Byron Adams, a biologist from Brigham Young University who contributed to the research, noted his own previous attempts had not targeted the same locations, highlighting the novelty of their approach.
The lake continues to reveal its secrets, even after 170 years of study. The researchers believe these hidden worms feed on the bacteria within the microbial mats, which also offer protection from the sun and prevent dehydration when water levels drop. Although the team couldn’t grow the nematodes in the lab, they turned to the well-studied roundworm, Caenorhabditis elegans, for insights. In experiments, these worms survived over 24 hours in water 50 times saltier than their normal environment when fed bacteria from the lake’s microbial mats, unlike those fed E. coli, which perished within five minutes.
This unexpected success suggests a unique dietary adaptation allows these nematodes to endure the lake’s extreme salinity. Genetic analysis revealed up to 80 different nematode species, with three belonging to a genus found in marine and coastal sediments and the majority being previously unidentified.
These findings suggest the Great Salt Lake’s nematodes are unique, likely resulting from extended reproductive isolation. However, as the lake diminishes due to water diversion for human use and climate change, these newly discovered species face the threat of extinction. The lake’s shrinking size forces researchers to adapt, swapping kayaks for mountain bikes to access certain areas.
With the ecosystem possibly collapsing within five years, understanding these organisms and their limits of survival becomes crucial. The study, published in the Proceedings of the Royal Society B: Biological Sciences, emphasizes the urgency of this research.