Yes, we’re excited.
Yes, we’re excited.
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.
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.
In Jules Verne’s 20,000 Leagues Under the Sea*, the iconic Captain Nemo announced that “in the depths of the ocean, there are mines of zinc, iron, silver and gold that would be quite easy to exploit” while predicting that the abundance of marine resources could satisfy human need. If the pace of development for deep-sea mining projects and the estimated value of deep-sea ores is any indicator, it seems as though our misanthropic mariner was wrong on both counts.
In The abundance of seafloor massive sulfide deposits, an international team of geologists attempts to quantify the total available copper and zinc contained in deep-sea massive sulfide mounds. Seafloor massive sulfide mounds are a byproduct of the processes that create deep-sea hydrothermal vents. As super-heated sea water emerges from the vent, it deposits heavy metals and other elements and minerals along the walls of the vent. Over thousands of years, an active vent field can build up a huge mound of metal and mineral rich ore – a massive sulfide mound. In addition to copper and zinc, these mounds can contain gold and silver. Generally, the ore is of much higher quality than its terrestrial counterpart. Over the last few decades, many exploration companies were eyeing these deposits, but it’s only recently that technological developments and economic incentives have aligned to permit potentially profitable deep-sea mining.
Slimehead is not a word you would expect to find on the menu of a fancy restaurant. Like dolphin*, toothfish*, goosefish*, mudbug*, hog*, and gizzard fish*, slimeheads have undergone a bit re-branding over the last few decades to make their name as palatable as their fillets. Enter the Orange Roughy, a dull, uninspired name that captures nothing of the grandeur of Hoplostethus atlanticus and ignores the defining characteristic of these deep-sea fishes.
What does Orange Roughy mean to you? Well, it’s probably orange, and I guess roughy means it might be rough, or something. The name is pretty uninformative. But slimehead! Slimehead tells you quite a bit about this creature, and leads to some interesting ecological questions. Why is it’s head covered in slime? What does the slime do? How is the slime contained in its head?
The Okeanos Explorer is diving on the Cayman Rise – the location of the deepest known hydrothermal vent field, and they are broadcasting the ROV feed live, right now. You can be experiencing this:
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.
Megumi Shimizu is a second year PhD student at the Duke University Marine Lab. Since the news has so far only been reported in Japanese, we asked her to provide a short write-up of the discovery.
The first scaly-foot gastropod, Crysomallon squamiferum, was found in the Indian Ocean ten years ago (Van Dover et al 2001), and continues to attract deep-sea fan with its black appearance and iron-fortified shell and operculum. Last December a team from JAMSTEC (Japan Agency for Marine-Earth Science and Technology) reported the discovery of a white scaly-foot gastropod in the Indian Ocean. The exciting news was announced in Japan soon after the conclusion of the research cruise.
Except for its color, the shape and characteristics are the same as the black scaly-foot gastropod. Unlike the mysterious black one, the white one gives me different impression: pretty and innocent looking.
They found white scaly-foot gastropod during an investigation of habitats at newly found hydrothermal vents in November 2010. Several aggregations of white scaly-foot gastropods were found at the sites. Although scaly-foot gastropods are usually covered by iron sulfide shell and scales, the white scaly-foot gastropod does not assimilate iron sulfide.
The physiological details have not yet been revealed.
Many questions come to mind from this discovery: Are they same species? How did they evolved? Why do black scaly-foots need iron scales?
I am definitely looking forward to reading the final publication.
There are currently more than 7,500 offshore oil platforms actively probing the earth’s crust for black gold. Their relatively minimal appearance at the surface belies the shear magnitude of human construction beneath the waves. Oil platforms are among the world’s tallest man-made structures. Compliant tower platforms reach up to 900 meters in depth (in contrast, the tallest building is 828 meters). these rigs are not permanent structures. As the wells run dry and sea water corrodes steel jackets, the wells are capped and rigs decommissioned. At least 6500 offshore platforms are slated for decommission by 2025, which begs the question, what do we do with inactive oil platforms?
Now that Ocean of Pseudoscience Week has come to a close, we thought it would be a good time to talk about our favorite real sea monsters – amazing marine creatures that capture the imagination. For mine, we naturally have to take a trip to the deep sea to find Bathynomous, the giant deep-sea isopod.
Giant isopods are the monster cousins of the terrestrial isopod commonly know as the rolly-polly or pill bug. First discovered in 1879, these deep-sea scavengers can reach over a foot in length, dwarfing the much more minuscule common isopods, found on beaches and docks around the world.
Dr. M from Deep Sea News has done quite a bit of research on why these isopods get so big. Isopocalypse 2010 is a good place to start. IN short, giganticism is not uncommon in the deep sea, and may be a response to a food-limited environment. But you’ll have to check out the Deep Sea News post for more details.
The majestic Deep-sea Isopod
~Southern Fried Scientist