A new hydrothermal vent site in the Southern Mariana Trough has been discovered using acoustic and magnetic surveys conducted by the Japan Agency for Marine–Earth Science and Technology’s (JAMSTEC) autonomous underwater vehicle (AUV) Urashima. The high-resolution magnetic survey, part of near-bottom geophysical mapping around a previously known hydrothermal vent site, the Pika site, during YK09-08 cruise in June-July 2009, found that a clear magnetization low extends ~500 m north from the Pika site. Acoustic signals, suggesting hydrothermal plumes, and 10 m-scale chimney-like topographic highs were detected within this low magnetization zone by a 120 kHz side-scan sonar and a 400 kHz multibeam echo sounder. In order to confirm the seafloor sources of the geophysical signals, seafloor observations were carried out using the deep-sea manned submersible Shinkai 6500 during the YK 10-10 cruise in August 2010. These discovered a new hydrothermal vent site (12°55.30′N, 143°38.89′E; at a depth of 2922 m), which we have named the Urashima site. This hydrothermal vent site covers an area of approximately 300 m x 300 m and consists of black and clear smoker chimneys, brownish-colored shimmering chimneys, and inactive chimneys. All of the fluids sampled from the Urashima and Pika sites have chlorinity greater than local ambient seawater, suggesting subseafloor phase separation or leaching from rocks in the hydrothermal reaction zone. End-member compositions of the Urashima and Pika fluids suggest that fluids from two different sources feed the two sites, even though are located on the same knoll and separated by only ~500 m. We demonstrate that investigations on hydrothermal vent sites located in close proximity to one another can provide important insights into subseafloor hydrothermal fluid flow, and also that, while such hydrothermal sites are difficult to detect by conventional plume survey methods, high-resolution underwater geophysical surveys provide an effective means.
Welcome to the world. I know it must feel like a very small world right now–just big enough to keep you safe and sheltered and loved–but trust me, as you keep growing, so will the world. Even after you stop growing, it will keep getting bigger. This big, old world that you have suddenly appeared in is huge and strange and beautiful and mysterious. There is more to discover in this world than all of us who have ever lived, working together, can ever know. Even before you can speak, you will think things and know things that no one has ever thought or known before. That is wonderful.
We are explorers. Not just your aunt and uncle, or your family, but all of us: this whole, gigantic group of people that call ourselves “humanity”. Today, there are over 7 billion of us and every last one, every person you will ever meet, can trace their heritage back, through thousands of millennia, to a small tribe of primates somewhere on the African savannah We were explorers then, too. This tribe made its way across Europe and Asia. They sailed across the Pacific to Australia and a thousand tiny islands. They marched across the Bering Sea–land once connected Alaska to Russia–and traveled all the way down to the tip of South America. And, no matter how far they traveled, no matter how much they explored, the world just kept getting bigger.
We’re still exploring, today. We’ve built an enormous machine called the Large Hadron Collider–some say it’s the most complicated machine humanity has ever built—that allows us to explore the tiniest things in the universe: the sub-atomic particles that hold our world (and every world) together. We’ve even begun to explore beyond our own world. We have massive telescopes that allow us to explore distant galaxies. We’ve built probes that have left our own solar system. We have satellites orbiting Jupiter and Saturn. This summer, we landed a robot on Mars. It has already discovered that Mars was once more like our own world than we previously believed. We named that robot “Curiosity”.
Last time I paid the hapless mariner a visit, many readers interpreted my incisive criticism of the science behind Aquaman as evidence that I had it out for our scale-clad hero. Since you all know that I’m going to take the misguided marine science in this volume to task, let’s start with all of the good stuff in this reimagination of DC’s oft-mocked champion.
The central conceit of New 52 Aquaman is that the comic book world has the same perception of Arthur Curry that we do–a hero with oddly specific and mostly useless powers that talks to fish. In addition, the citizens of the DC Universe believe that Atlantis is a fairy tale, so Aquaman’s kingly status is meaningless to the surface dwellers. The hybrid of a human father and Atlantean mother, Aquaman feels out of place in Atlantis and chooses to return to the surface with his wife, Mera. Comparing himself to his lighthouse-keeper father, he explains that even though he loves the sea, someone must protect the shore.
Deep-sea mining is once again in the news. As Kevin Zelnio frustratingly points out on twitter, news articles often fail to mention the primary research that has been conducted at these sites or make more than a cursory statement concerning their ecology. This has the effect of marginalizing an entire ecosystem and makes it difficult for the public to grasp the richness and diversity of deep-sea hydrothermal vent communities, some of which may face commercial exploitation. Here is a selection of recent primary literature, with abstracts, on the ecology of deep-sea hydrothermal vents at the center of the mining debate, Manus Basin (you may recognize some of the authors).
As a marine biologists just beginning my deep-sea education, conservation as a priority was an alien concept. The deep sea was the last true wilderness, distant and alien, impossibly difficult to access. We knew that exploitation was coming, companies had been exploring the potential of deep-sea mining for decades, but they always seemed to be generation away. Conservation was a question for my scientific descendants. For my peers and me, we still had a few good decades left in the golden age of exploration that began in the 1970’s with the first discovery of deep-sea hydrothermal vents. That age is about to end.
The reality of deep-sea exploitation is imminent. The first hydrothermal vent mining lease has been issued in the territorial waters of Papua New Guinea. The International Seabed Authority, which regulates seafloor extraction in international waters, has approved the first two mining exploration permits for seafloor massive sulfides in international waters. Manganese nodule extraction, once quashed by a global decline in metal prices, has recently reappeared. Crustal metal deposits are fast becoming a viable resource. The isolation of rare earth elements from the seafloor, a newcomer in deep-sea exploitation, could open up new, massive deposit for critical electronic components. All of these are likely to occur within the next few decades.
From hairy-chested yeti crabs to the deepest known fields, hydrothermal vents have been enjoying a bit of science celebrity in the last few weeks. Beneath the headlines, there has been an eruption of vent-related research published in the scientific literature and some exciting new expeditions just left port.
'Hoff' crabs in paradise. Image from ChEss Southern Ocean Consortium
The exhaustive author list on this paper reads like a who’s who in hydrothermal vent biogeography. This is the paper that introduced “the Hoff” crab to the world, but the findings are far more significant. Hydrothermal vent systems are sorted into biogeographic provinces, with different regions supporting different communities. The iconic giant tube worms dominate the eastern Pacific, while the western Pacific (prominently featured in Deep Fried Sea) plays host to fist sized snails, and the Atlantic features shrimp as its dominant species. There are several missing gaps in our understanding of how these qualitatively different communities are connected – the Southern Ocean, the south Atlantic, the Indian Ocean, and the Cayman Trough, among others. Filling in these gaps in our knowledge can help us understand the history and evolution of hydrothermal vent ecosystems.
Bathymetric map, click for GEBCO high resolution image
The deep benthos is simultaneously the largest and least explored ecosystem on the planet. Covering nearly 60% of the Earth’s surface, it supports an almost unimaginable reservoir of biodiversity, rivaling all terrestrial habitats combined. Its microbial and metabolic diversity have revolutionized our view of how life is sustained, not once, but twice (first with the discovery of chemoautotrophic organisms at hydrothermal vents, and again with the discovery of cognate communities at methane cold-seeps). In spite of these major discoveries, the deep benthos is essentially invisible. Only a select few will ever witness it first hand, while for the rest, it will remain a dark and unfathomable abyss.
This places the deep benthos in a precarious position. Human activities that influence the deep sea go unnoticed. Without a thorough understanding of its ecology, it is impossible to assess the damage caused by anthropogenic impacts. Although recent and ongoing studies have shed light on many species and communities, the deep benthos remains largely unexplored. Two studies, both released this week, reveal simultaneously how little we know about the deep benthos and how human impacts, even unintentional ones, could shape this ecosystem.
Of all the questions I am asked as a deep-sea biologist, the hardest to answer is “why conserve deep-sea hydrothermal vents?” Sure there are the classic canards of economics (vents produce valuable minerals) and biotechnology (vents house unique organisms that may produce useful pharmaceutical or technological products) but these are hollow, belie a conservation ethic driven by human selfishness, and pander to an exploitative system. Beyond those lie a series of high minded, though vague, ethics about preserving biodiversity, protecting unique habitats, and understanding an ecosystem more alien than any science fiction story before destroying it.
Our global society is coming around to the idea that biodiversity is valuable in its own right, that species are precious, and that we have a duty to minimize the damage we inflict upon the world. We still have a long way to go, but the wind is in the sails and the ship is coming about. Despite this growing environmental ethic, the tragic reality is that before 1977 we didn’t even know hydrothermal vents existed and if every vent community was wiped from the face of the seafloor, few outside of a handful of fortunate scientists and deep-sea enthusiasts would notice.