Published in [environmental DNA] on May 17( https://onlinelibrary.wiley.com/doi/10.1002/edn3.299 ) 》A new study in the journal is an important step in monitoring the biodiversity of marine systems, detailing how researchers at the Monterey Bay Aquarium Institute (MBARI) used autonomous underwater robots to sample environmental DNA (Edna)** Edna allows scientists to detect the presence of aquatic species from the tiny genetic material they leave behind. This "DNA soup" provides clues about changes in biodiversity in sensitive areas, the existence of rare or endangered species, and the spread of invasive species - all of which are essential for understanding, promoting and protecting healthy oceans.
The researchers combined two new autonomous platforms developed by MBARI for this study: long-distance autonomous underwater vehicle (lrauv) and environmental sample processor (ESP). Lrauv is a flexible underwater robot that can travel to remote areas of the ocean for a long time. ESP is a robot's "laboratory in a tank", which can filter seawater and save electronic DNA for future research. The space and time allocation of AUV can be expanded through the space and time allocation of LRV researchers. In contrast, traditional marine Edna sampling takes weeks on an expensive research ship and can only be carried out in local areas. Technological innovations like this are revolutionizing marine protection.
"We know Edna is a very powerful tool for studying marine communities, but we have been limited by what we can do with manned research ships. Now, autonomous technology is helping us make better use of our time and resources to study new parts of the ocean," said kobun truelove, a biological oceanographer at MBARI and the lead author of the paper.
Marine biodiversity is a measure of the abundance of individuals and species in the ocean. This interconnected biological mosaic - from the smallest plankton to the largest whale - supports the food web, generates the air we breathe, and regulates our climate. Autonomous tools such as lrauv and ESP enable MBARI researchers to maintain a lasting presence in the ocean and monitor changes in sensitive ecosystems in ways previously impossible.
"Organisms move with changing conditions in our oceans and the Great Lakes region, affecting people and economies that depend on these species. We need cheaper and more flexible methods to monitor biodiversity on a large scale. This study provides the collaborative development of Edna and non crew technology we need, and directly responds to the priorities set out in NOAA's omics strategic plan," said the study's co-author Kelly Goodwin, a partner with the National Oceanic and Atmospheric Administration (NOAA), said.
Research background
In this study, MBARI completed three visits to the Monterey Bay National Marine Reserve in cooperation with researchers from NOAA Atlantic Oceanography and meteorology laboratory and the University of Washington. The team coordinated sample collection among the three research vessels of MBARI, the NOAA fishing vessel Reuben Lasker and the lrauvs fleet of MBARI.
The team on board lowered the bottle to a specific depth to collect and preserve water samples. At the same time, lrauv equipped with ESP automatically samples and saves Edna at similar positions and depths. These Edna samples were sent back to the laboratory for in-depth sequencing.
Related organisms have a common DNA part, which is called gene marker. In this study, the researchers analyzed Edna samples using a technique called metaarcoding. This method looks for short DNA extracts and provides a classification of the populations present in the sample. This technology is particularly helpful in translating Edna data into measures of biodiversity. The researchers analyzed four different types of genetic markers, each representing a slightly different level of the food web. Together, these results produce a more comprehensive community composition map. Samples collected from research vessels and autonomous underwater vehicles show similar patterns of biodiversity.
Truelove noted that the results of the study marked an exciting step in monitoring marine ecosystems. "This work is about increasing the scale of Edna research." "We can begin to describe the structure of biological communities in the ocean more broadly than focusing on individual species," he said
"Good data is the cornerstone of sustainable ocean management," said Francisco Chavez, a senior scientist at MBARI and co-author of the study. "Regular environmental DNA monitoring tells us who is there and what is changing over time. This information is crucial when it comes to understanding the impact of climate change, one of the biggest threats to marine health."
Lrauvs can travel for several weeks and hundreds of kilometers at a time. They can sample more frequently in areas of interest than traditional research ships, which usually visit remote areas only irregularly. Autonomous robots will enable researchers to study marine areas that have not been investigated before. Filling these data gaps is crucial to strengthening global marine health. Ship based research will continue to play an important role in oceanographic research, but the addition of new autonomous technologies to the toolkit will expand research, monitoring and resource management capabilities. Eventually, MBARI researchers envisioned deploying a fleet of lrauvs equipped with ESP technology.