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As the search for organic life on other planets and celestial bodies intensifies, especially on NASA’s end since the charge of the Obama Administration, it has become increasingly clear that marine biology will play a vital role in the astrobiological research that is now so integral to the search. New research shows that a certain microbe found in the deepest reaches of Earth’s oceans may actually be capable of surviving on one of Saturn’s moons, which lends credence to searching said moon for preexisting, organic life in the near future. To do this efficiently, though, we have to get more adept at not just space exploration but also deep-sea exploration, and a new study published by the Monterey Bay Aquarium Research Institute shows that the latter is already happening.
A first-in-kind study published by experts from the University of Hawaii are now prepared to deploy long-range autonomous underwater vehicles that are uniquely equipped to gather and catalog seawater samples without any manned assistance. This is expected to revolutionize researchers’ abilities to study and track microbial life in Earth’s oceans with unprecedented specificity — likely a historic milestone. Part of the gravity of this accomplishment comes from the fact that a minimum of 50 percent of Earth’s atmospheric oxygen is produced by ocean microbes who also remove mass quantities of carbon dioxide.
Ocean microbes are collectively the cornerstone of marine food webs on which global ocean fisheries and other industries and organisms depend greatly. Two oceanographers from the University of Hawaii, Mānoa — David Karl and Edward DeLong — conduct research at the university’s School of Ocean and Earth Science and Technology, and their research has focused on ocean microbes for several decades. In this particular study, they and multiple teams of experts worked with engineers from the Monterey Bay Aquarium Research Institute to test new adaptive sampling methods for oceanographic features including open-ocean eddies, which are like mobile whirlpools that move around in the Pacific Ocean. These are known to have significant impacts on ocean microbes.
The researchers and engineers finished development and testing of three new LRAUVs and sent them for deployment readiness last week. These vehicles are prepped to navigate Hawaiian waters and collect data on water chemistry, water temperature, and chlorophyll content, the latter being a microscopic algae indicator. The data collected is relayed to in real-time to either onshore scientists or scientists on a nearby vessel. The lead engineer from Monterey Bay, Jim Birch, said, “When we first talked about putting an [Environmental Sample Processor] in an [autonomous underwater vehicle], I thought to myself, ‘this is never going to happen.’ But now I really think this is going to transform oceanography by giving us a persistent presence in the ocean — a presence that doesn’t require a boat, can operate in any weather condition, and can stay within the same water mass as it drifts around the open ocean.”
That’s the kind of innovation that drives discoveries likely to impact astrobiology in significant ways in the future. It was 2005 when NASA’s Cassini spacecraft found geysers erupting on Enceladus, one of Saturn’s icy moons. Researchers have been trying ever since to figure out if the moon can host alien life, and they were led by the innovations of NASA’s flagship-class robotic spacecraft, the Cassini probe, an innovation of the ‘90s. University of Vienna scientists far more recently engineered a series of simulations aimed at modeling the conditions on Enceladus. The simulations varied pressure as a way to simulate the changes in depths, temperatures and ph levels there.
They tested three different species; one of which was Methanothermococcus okinawensis, which is found in the hydrothermal vents of the East China Sea. It proved capable of thriving in all conditions with or without the administration of vitamins or the exposure to toxic chemicals. Results from the experiments indicate that similar life could survive in Enceladus’s oceans, too. They published these findings in Nature Communications, and lead researcher, Simon Rittmann of the University of Vienna, said, “We’ve extended the boundaries within which we know methanogens can live.”
Despite the good that has come from all this exploration, though, marine biology is also turning up concerns that scientists didn’t realize until recently. As Rittmann added, “Life is present under so many different conditions on Earth and researchers who work on the origins of life in different environments keep on extending the boundaries under which it can thrive.” On the other hand, the conditions to which we subject some of that life can have adverse effects even when that marine life seems to still be thriving. That’s what another Nature Communications publication from researchers at the University of Technology in Sydney found out about krill who can apparently break down plastic through digestion.
It’s bad enough that we pollute the oceans with as many foreign substances as we do, especially plastics, but we’re inclined to think it’s great to find out that krill are naturally breaking it down for us with their own digestive systems. It’s actually creating a separate problem, though. Co-author Willa Houston recently explained in an interview: “What we found is that Antarctic krill actually eat microplastics. The krill takes that in and digests it through their normal digestive processes, converting the microplastics into nanoplastics. This is the first time that we’ve understood that krill actually degrade plastic down to smaller sizes — that was a real surprise to us.”
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Other studies have found the same thing, but what Houston’s team discovered breaks new ground in that they upended the preconceived notion that these plastics are just excreted or that they’re merely translocated through organs. “The new side is that the krill physically breaks down the plastic into smaller particles. They do excrete some of those fragmented microplastics, but they also do end up [staying] inside the krills’ bodies and their organs. Which means that any creature that then feeds on krill is taking up microplastics that are broken into nanoplastics.”
This means that other marine animals that humans eat who also eat krill, like squid, for instance, are accumulating incredibly small bits of plastic within their own tissues. This represents a potential, albeit unsubstantiated, health risk for human beings. It’s a means by which our own pollutants might be coming right back to us in the form of food.