The vast, shimmering expanse of the Great Lakes holds countless secrets, but sometimes, the most astonishing discoveries aren’t found beneath the waves, but clinging unexpectedly to the very vessels that explore them. Imagine a scene, not from a science fiction blockbuster, but from a genuine scientific expedition: a research ship, pulled from the depths for routine maintenance, begins to ooze a mysterious black substance. This isn’t the stuff of nightmares, but rather the beginning of an exhilarating journey into the microscopic unknown.
This incredible story unfolds with the research vessel Blue Heron, a floating laboratory dedicated to gathering vital data from the Great Lakes. The 87-foot-long, nearly 27-meter-long boat, the largest US academic research fleet vessel on these immense freshwater seas, had just concluded a significant cruise studying algae blooms in lakes Erie and Superior last September. Its mission was clear, its purpose defined, yet it was during an unanticipated repair that the truly bizarre emerged.
While docked in Cleveland for propeller repairs, the crew of the R/V Blue Heron noticed something profoundly out of place: a black, tar-like substance began seeping from the rudder shaft. This mechanism, crucial for the boat’s steering, typically operates with nothing more than lake water for lubrication. Captain Rual Lee vividly described the moment, noting how the “black ooze just didn’t stop coming,” and how there “really shouldn’t be anything in that space.
Naturally, Captain Lee’s initial concern was environmental pollution. He conducted immediate, informal tests, dropping a sample into water to see if it would leave a sheen – it didn’t. He even applied a blowtorch to it, hoping to ascertain its nature, but unlike grease, “it didn’t burn.” This enigmatic material defied common explanations, leaving the crew, and later, the scientists, utterly perplexed.
Doug Ricketts, the Marine Superintendent and senior research associate at the University of Minnesota Duluth’s Large Lakes Observatory, took the initiative that would lead to this groundbreaking discovery. He scooped a cup of the odd goo, labeled simply “ship goo” with haphazard marker strokes, and brought it to the observatory’s scientists for testing. His simple question, “Think you guys could do anything with this?” set in motion a chain of events that would stun the scientific community.
What followed in the laboratory was a cascade of revelations, beginning with a healthy dose of scientific skepticism. Cody Sheik, a microbial ecologist at the Large Lakes Observatory and lead researcher on this curious case, initially thought they’d find nothing. He candidly admits, “Usually, when you’re given a cup of tar,” you don’t expect much. He even handed it off to a graduate student with a simple “good luck.”
Yet, defying all expectations, the graduate student successfully extracted DNA from the seemingly inert substance. Even then, Sheik suspected routine sample contamination. It was only after preliminary, single-gene sequencing that the true magnitude of their find became apparent. The results were astounding: “A lot of the sequences came out really novel. I was like, ‘oh, oh no, okay– this is a whole different story’,” Sheik recounted.
The initial assessment proved startling: the mysterious tar-like material was teeming with life-forms, some of which were entirely unknown microorganisms. The substance, now informally named “ShipGoo001,” had been thriving in the most unlikely of places: the oxygen-free, semi-warm, and stable environment of the rudder shaft housing. As Doug Ricketts observed, “There’s no reason to expect any living organisms to be in this part of the ship,” especially as this specific part doesn’t move much and isn’t exposed to the outside world.
For a deeper dive into the goo’s microbial tapestry, Sheik and his colleagues sent the sample for a second round of sequencing, this time examining the whole genomes present. This comprehensive analysis confirmed that, despite a lack of immense diversity, the microbes were indeed unique. They painstakingly reconstructed the genomes of over 20 microbes, comparing them against vast global databases of previously identified organisms.
What they uncovered was nothing short of miraculous. Sheik confirmed the presence of “several novel archaea,” a distinct domain of single-celled, prokaryotic life differentiated from bacteria by their cell membrane composition. One particular microbe wasn’t just a new species, but represented an entirely new order of archaea, now officially referred to as ShipGoo01. Another promising, oddball microbe could even constitute a whole new bacterial phylum, which might eventually be christened ShipGoo002.
This discovery underscores just how much remains undiscovered in the world around us. Jeffrey Marlow, an assistant professor of biology at Boston University who was not involved in the find, noted that with potentially up to 1 trillion microbial species globally, finding a new one isn’t particularly surprising in itself. What truly excites scientists, he explained, is “where they’re found and what their genomic history or metabolic capacity is.”
The peculiar habitat of the Blue Heron’s rudder shaft presented an ideal, albeit unexpected, niche. ShipGoo01, for instance, appears to be anaerobic, flourishing in the absence of oxygen. Other microbes within the goo seem to consume oxygen, suggesting a delicate, mutually beneficial balance within this isolated ecosystem. This sealed environment clearly supported a complex food web, allowing these life forms to sustain themselves.
While some of the DNA from the black goo revealed previously unknown microorganisms, other genetic material in the sample had surprisingly familiar relatives. Researchers trawled global databases and found connections to microbes from a tarball-type substance in the Mediterranean, hydrocarbon-contaminated sediment in Calgary, Alberta, and other samples stretching from the coast of California all the way to Germany. “It’s kind of all over the board in terms of what sort of environments these things are being found in,” Sheik observed, highlighting the widespread nature of these hardy organisms.
This global connection only deepened the mystery of the goo’s origin on the Blue Heron, especially given that the ship sails the oxygenated waters of the Great Lakes. To piece together this baffling puzzle, Sheik and his team are delving into the ship’s history. The Blue Heron was purchased pre-owned by the University of Minnesota Duluth nearly three decades ago, in 1997, after serving as a fishing boat.
One intriguing hypothesis centers on the ship’s past. While the rudder shaft isn’t meant to be lubricated with anything other than water under current operation, it’s plausible that the previous owners applied some sort of petroleum-based lubricant to the area. These organisms, researchers theorize, could have laid dormant for years within that old grease, waiting for conditions to become just right for a bloom. Another crucial piece of the puzzle is the fact that no oozing or seeping was noted during the ship’s last inspection in November 2021, suggesting a recent change in the environment that triggered the microbial proliferation.
Jeffrey Marlow offers another compelling hypothesis: the ooze could have entered the rudder shaft by hitching a ride on marine snow. These clumps of dead organic matter, which slowly sink through the water column, often contain oxygen-free pockets that could have provided a temporary, protective haven for the microbes. Sheik acknowledges that there are many scenarios to explore, pondering whether the substance grew in the rudder shaft initially or simply hitched a ride.
Indeed, the researchers still grapple with many unanswered questions about this odd material, including its precise journey onto the ship and, more critically, whether it is capable of biocorrosion – essentially, eating or degrading the ship’s steel. Sheik underscored the seriousness of this potential threat, noting that biocorrosion is a major concern in vital infrastructure like oil pipelines. He mused, “for some of these ships, especially the ones that are really long-lived here on the Great Lakes, because they’re in fresh water, is this something where they could be corroding this area? It may be something to think about for future iterations of shipbuilding and things like that.”
Beyond these immediate concerns, the discovery of ShipGoo001 opens up a world of potential practical applications. Some of the organisms identified within the substance appear to be methane producers. This exciting metabolic capability could have significant implications for biofuel production, offering a novel source of clean energy. The university’s announcement specifically highlighted this promising avenue.
Researchers are now focused on obtaining more samples, ideally without disturbing the delicate oxygen-free environment. More careful study could lead to the further discovery of new species of microbes, expanding our understanding of life’s incredible adaptability. Sheik emphasized the importance of thinking “more broadly about the other environments that they’re found in” to better understand these organisms’ capabilities.
Cody Sheik and his team are diligently working towards a forthcoming research paper, which promises to shed more light on these mysteries. This paper will include the full genomes of the goo’s microorganisms, a crucial step that will allow other scientists across the globe to build upon their groundbreaking work. This spirit of open scientific collaboration is fundamental to advancing our collective knowledge.
The story of ShipGoo001 isn’t just a tale of scientific discovery; it’s a testament to the power of human curiosity and the importance of supporting basic research. Jeffrey Marlow eloquently captured this sentiment, stating, “One of the coolest parts of this story is the fact that the sample made it to the microbiologists in the first place – it speaks to a ‘microbiologically literate’ culture where several people had the awareness and curiosity to ask what might be living in an otherwise inconvenient ooze.”
Marlow’s observation underscores a profound truth: we are often surrounded by undiscovered life, hiding in plain sight, in the most unexpected places. Ricketts echoed this, asserting, “I don’t think this ship is unique. I really strongly suspect that if you took the rudder post of any ship anywhere, there’s a possibility of finding some organism–maybe a new organism–in that space.”
