A team of researchers from the University of Miami has shed new light on stromatolites, the rare, microbial reefs that represent one of the world's most diverse ecosystems of living microbes. The growth and structure of these reefs could give scientists a better look into the emergence and evolution of life on Earth.
Much like coral reefs, stromatolites are created by the buildup of limestone but instead formed by microbial mats, and the activities of microorganisms such as cyanobacteria results in grain accretion and the precipitation of cements. Not only do these microbial buildups hold the secrets to the ancient life of approximately 75 percent of the Earth's history, the microbes that they harbor created oxygen for the atmosphere that stimulated the evolution of higher organisms such as humans.
Using three years of data collected from Shark Bay, Western Australia, where one of the few living stromatolite communities left in the world resides, the map revealed eight unique provinces of the rare microbial reefs, each with its own morphological structures. Many of these structures were previously unknown to scientists, and the results of the study alter previous growth models for Shark Bay stromatolites and reveal the importance of mineral precipitation for the formation of stromatolite framework.
"The stromatolites in Shark Bay are a spectacular living laboratory that should be the best studied microbial system in the world," Pamela Reid, co-author of the study, said in a press release.
"The time to study Shark Bay stromatolites is now as they are vulnerable to rising sea levels in the coming decades," added Erica Suosaari, lead author of the study. "Continued monitoring and detailed studies of the Shark Bay World Heritage site will be critical for management and conservation of this unique landscape, and will advance our understanding of early Earth."
The findings reveal new insights into the morphological diversity of stromatolites as well as characteristics of the microbial communities and mineral precipitation in the stromatolites in Shark Bay, highlighting the importance of examining these unique microbial reefs to reconstruct ancient environments and understand how they interacted with early microbial communities.
The findings were published in the Feb. 3 issue of Nature.
