As I watched the monitor as we descend a 75-foot-tall chimney. Charcoal black to grey fluid is violently erupting from the top and several cracks along the chimney’s surface. You could see the shimmering sheen in the water, indicating that the temperatures were far above those of the surrounding, freezing abyss. Hydrothermal vents are home to the highest recorded temperatures on Earth. At oceanic ridges, where rocks are often brittle and fractured, cold seawater percolates down through Earth’s crust, gets superheated by magma, and rises back to the surface. Currently, the “Two Boats” vent in the Turtle Pits field along the Mid-Atlantic Ridge holds the record for the hottest hydrothermal vent, with fluid temperatures reaching up to 867.2˚F (464°C), nearly four times greater than the boiling point of water at 212˚F (100˚C). The extreme pressure prevents this boiling from actually happening.

At some vents lives the curious little worm, Alvinella pompejana. Discovered in the early 1980s by French scientists, the Pompeii worm is about 4 inches long with tentacle-like, scarlet gills on its head. Its name hints at its high-temperature habitat, being derived from the ill-fated Roman city of Pompeii, destroyed abruptly during an eruption of Mount Vesuvius in 79 A.D. The scarlet worm is found on the sides of hydrothermal vents, with its tube often reaching across the chimney to access some of the hottest vent fluids. The worms can be briefly exposed to 212˚F (100˚C) waters, although temperatures adjacent to the worm’s tubes more often range between near freezing and 113˚F (45˚C). In fact, the rear end of the species likely experiences extreme heat while the front end experiences extreme cold, making it the most eurythermal (capable of surviving a wide range of temperatures) species on earth.

How Alvinella pompejana survives in this boiling hot environment is still somewhat of a mystery. One theory is that the worm can keep itself cooler, between 68-83°F, by pulling cold water into its tube when it moves in and out, and with the help of bacteria that circulate the water around its body. This gray layer of bacteria covering the worm’s back, besides moving water, may also provide it with a sort of thermal blanket. The worm’s skin and connective tissue also have the most heat-resistant proteins known, thanks to their special structure. Additionally, the worm’s DNA has more triple bonds from guanine-cytosine (GC) pairs compared to other similar species, which helps it stay stable at temperatures up to 190˚F (88°C).

The post A Journey to the Hottest Place on Earth: Hydrothermal Vents and the Resilient Pompeii Worm first appeared on Deep Sea News.

We fly along the shoreline and notice dozens of dead urchins.  The brine’s high density, which prevents it from mixing with the ocean above, also means that oxygen is not mixed in, creating an anoxic deathtrap for unsuspecting respiring organisms.  As we continue to explore, a small, semi-submerged mound in the middle of the brine pool begins to pulse and vent.  As we maneuver the Global Explorer closer, we see hundreds of cavities all venting fluid.  We take a sample of mud around one of these pits, in hopes of capturing its invertebrate builder.  Later on board the vessel, we examine the sample and discover a type of worm, a sipunculid, half the size of hot-dog with the bright green, gold, and purple colors. Students in my research group begin almost immediately referring to it as the Mardi Gras Worm.  How can this worm survive in such a toxic place?

Both cold seeps and their chemical and geological relatives, hydrothermal vents, are rich in reduced chemicals, particularly hydrogen sulfide.  These chemicals are toxic.  Sulfide and oxygen don’t naturally coexist for long because they react spontaneously and rather aggressively. However, this sulfide also provides a unique energy source, by willingly donating electrons, to chemosynthetic microbial live. These microbes use this to fix carbon and produce food. This makes vents and seeps different than the rest of the deep in being largely independent of sunlight and the photic zone above.  Many organisms in these environments either feed on free-living bacteria or form symbiotic relationships with chemosynthetic bacteria to obtain their food. This makes life challenging for both microbes and the animals that depend on them, as they need both sulfide and oxygen.

Despite these harsh conditions, these unique ecosystems flourish, showcasing the remarkable adaptability of life in extreme environments.  The hydrothermal vent worms, the Alvinellids, build tubes projecting from chimney walls, giving their gills access to oxygen-rich water.  The other end of the tube can then access the vent fluids rich in hydrogen suflide.  Mobile predators like the crab, Bythograea thermydron can move between areas with and without oxygen. Ice worms, so names because they are found on methane ice in the cold seeps of the Gulf of Mexico, circulate oxygenated water around itself using its bristle-bearing appendages. The adaptations extend well into the biochemical level.  The massive vent worm, Riftia pachyptila and the Alvnellids contain hemoglobins, giving them bright red colors, which bind insistently to oxygen.

But once dealing with oxygen issue, how do these species survive the toxic sulfide and heavy metal soup of vents and seeps. One way means of survival for these organisms is prevent sulfide from even reaching sensitive tissues.  Creating sulfide barriers may mean creating thick tubes or cuticles to prevent the skin from encountering suflide. For example, the Pompeii worm, Alvinella pompejana, at hydrothermal vents secretes proteinaceous tube that it shares with bacteria. Animals that inhabit chemosynthetic habitats also often possess a specialized blood protein that binds to sulfide—forever—preventing it from mucking up the business of respiring oxygen.  At hydrothermal vents, metals reach such high concentrations they precipitate out of water.   These heavy metal solids form the impressive chimney structures of vents and even coat the tubeworm tubes and the shells of snails and clams.  Chemosynthetic organism have ways of dealing with this too.  Special metal-binding proteins, called metallothioneins, grab toxic metals and even grouping together to form little bodies or particles distinct from the rest of the cell. These consolidated and enclosed heavy metals then stay out of the way and do not gum of the cellular works.

Overall, the exploration of these deep-sea ecosystems reveals the astonishing resilience and adaptability of life in extreme conditions, offering valuable insights into the limits of biological diversity and the potential for life beyond Earth.

The post Surviving Toxic Havens first appeared on Deep Sea News.

When whales die and sink to their watery graves, they bring to the seafloor bones rich in those fatty lipids. Thousands of bone-eating females, each just few millimeters high, will infest a whale carcass. So many will accumulate, the whale bones will appear to be covered in a circa 1970’s red shag rug-a rug that eats bones, has harems, and secretes acids, but otherwise a normal shag rug.  Originally, and with good reason, it was thought that Osedax was clearly a whale-fall specialist. The core of whale bones consists of a matrix rich in lipids – up to 60 percent.

But what about something wholly different?  Before the age of large marine mammals, large marine reptiles dominated the oceans. During the Mesozoic Era, rising to dominance in the Triassic and Jurassic periods, ichthyosaurs, plesiosaurs, and nothosaurs represented a diverse group of large marine predators terrorizing smaller creatures in the dark depths. The ichthyosaur Shonisaurus may have reached lengths of up to 21 meters in the Late Jurassic and Plesiosaurus may been 12–15 meters in length. The ancient sunken carcasses of these massive marine reptiles may have hosted ancient Osedax. We do know that prehistoric ichthyosaur falls are known to support communities similar to modern whale falls. 

Not to be outdone by other scientists in throwing random things on the seafloor to see what will eat it, in early 2019 I placed not one but three dead alligators on the seafloor in the deep Gulf of Mexico.  Alligators are nice modern analogues of the giant reptiles that once lurked in paleo-oceans and in my current state of Louisiana…well…readily available. And because we could, we place a packet of cow bones down there as well. 53 days later, my team and I visit the alligator carcass to find nothing but bones.  The reddish hue of fuzziness on them indicates Osedax are present.  On May 3, 2019, we overnight some of the collected bones out to California so Greg Rouse can inspect them in his lab and confirm their presence.  We wait patiently for an email from Greg.  On May 23, we get an email from him with the subject “Two new species :-)”. We are elated! Indeed, he finds females with well-developed ovaries and eggs.  Using genetics, he determines that the Osedax on the alligator and cow bones are both new species, previously unknown to science.

Fast forward to today when I get an email with the subject “Your species”. That Osedax from the alligator is named after me.

Osedax craigmcclaini n. sp. is named for Dr. Craig McClain, an esteemed deep-sea biologist and colleague who led the experimental alligator fall project (McClain et al., 2019) and provided the Osedax specimens for this study.

New Species of Osedax (Siboglinidae: Annelida) from New Zealand and the Gulf of Mexico

The post Introducing a New Species: My Namesake, a New Bone-Eating Worm first appeared on Deep Sea News.

To land-dwelling humans, deep sea hydrothermal vents would seem like a vision of hell, amidst the crushing darkness you have plumes of superheated water, mixed with noxious sulfides, erupting from fissures on the seafloor. But for many deep sea animals, this “hell” is in fact a vibrant oasis in the middle of the abyss. This lively habitat is made possible thanks to bacteria that are able to extract energy from the sulphurous waters billowing from those vents. In the absence of sunlight, these chemoautotrophs form the foundation of the food chain. Some tube worms have been able to co-opt the power of these bacteria by housing the microbes in their gills, enabling them to grow to enormous sizes. Their tubes form dense, forest-like habitats for many other animals including other polychaete worms, fishes, crustaceans, and molluscs. This sets the stage for all kinds of complex ecological interactions, and that includes parasitism.

https://dailyparasite.blogspot.com/2024/02/ascarophis-globuligera.html

The post Parasitism at Hydrothermal Vents first appeared on Deep Sea News.

Connecting the oceans to land are numerous carbon highways.  These conduits bring food from land to the ocean, supporting an abundance of life.  Our group explores these carbon chains and explores some potential methods of carbon delivery to the deep.  Thus, alligators on the abyss.

At first it may seem fanciful that an alligator carcass might find its way to the deep.  However, dozens of species of alligators and crocodiles are found across the globe, in high numbers, and often in coastal areas.  Through either their normal migrating or foraging activities, or during flooding events, individuals may be found offshore in the ocean.  If one of those individuals meets an unfortunate end, it may fall to the seafloor.

In prehistoric times, the impact to the deep oceans could have been even larger, as large reptiles such as ichthyosaurs and plesiosaurs dominated the sea. Deploying a reptile in the deep sea today may reveal the animals that specialized on the carcasses of long-extinct ancient emperors of the sea.

Earlier this year, our research group placed three alligator carcasses 1.5 miles deep on the seafloor of the Gulf of Mexico in the first-ever alligator fall experiment.  Each of the three alligators met a different fate.

The first alligator had been on the bottom of the ocean for less than 24 hours. Despite the tough hide of the alligator, scavengers quickly got through and began to gorge themselves on the flesh of the alligator. Football-sized animals called giant isopods, relatives of rolly pollys or pillbugs, penetrated the hide in this short time-frame.  This demonstrates the speed and precision with which deep-sea scavengers can utilize any carbon source, even food from land and freshwater systems.

A little over 60 miles to the east of the first alligator, the second alligator had been sitting on the seafloor for a little over a month and a half.  All the soft tissue of the alligator had been removed by scavengers.  A small animal called an amphipod was still darting around looking for scraps, but the only thing that remained was a skeleton.  All of the soft tissue had been consumed. The spine curved just as it had been left.  A depression in the sediments indicated where the full body once laid.  The skull was turned over, likely by scavengers while picking at the flesh on the skull.

A fuzzy carpet covering the bones of the second alligator represented a brand-new species, previously unknown to science.  These zombie worms, or Osedax, colonize the bones of many types of vertebrates and consume the lipids within.  This was the first time zombie worms had ever been observed in the Gulf of Mexico or from an alligator fall.  They also demonstrate yet another pathway in which carbon from land makes its way into deep-sea food webs.

Another 60 miles east lay the third alligator.  It had only been eight days since it was laid on the seafloor.  As the camera panned to the marking device, a floating bucket lid attached to a rope like an underwater flag, it became clear that the alligator was missing.  All that remained where it had been dropped was an alligator-shaped depression in the sediments.  Drag marks in the sediment paved a path to what remained of the alligator fall.  An animal dragged this alligator 30 feet and left only the 45-pound weight and rope.  The rope had been bitten completely through. To consume an alligator, and create this disturbance, the animal must have been of great size.  We hypothesize that most likely a large shark, like a Greenland shark or sixgill shark, consumed this alligator whole.

Three alligator falls in the abyss met three very different ends, from being consumed by football-sized cousins of rolly polys, to zombie worms eating their bones, to a large shark dragging it away and consuming it whole.  This research has given us a glimpse into what impact large reptiles had in past oceans, as well as the role they play today.  It is clear that deep-ocean scavengers have no qualms about successfully and quickly consuming food that originated on land or freshwater.

Read more about this research in our group’s recent publication in PLOS One: “Alligators in the abyss: The first experimental reptilian food fall in the deep ocean.”

The post Alligators in the Abyss: Part 2 first appeared on Deep Sea News.

The video is the actual video from my research group’s dive with a remotely operated vehicle in the deep Gulf of Mexico. The background on all this alligatorfall project and why a bunch of scientists would sink an alligator in the first place is in our previous post. You can also read Atlas Obscura’s great write up on our work.

The post The Video of Giant Isopods Eating an Alligator in the Deep Sea You Must Watch! first appeared on Deep Sea News.

Wait…what? What kind of mad science is this?

What you need to know is that the deep oceans, encompassing depths below 200 m, cover most of Earth and are especially food-deprived systems. Primary production of carbon is minimal only occurring through alternative pathways such as chemosynthesis. However, chemosynthesis is a tiny fraction of total ocean production (0.02–0.03%) and the energy that sustains most deep-sea organisms is sequestered in sinking particulate organic carbon derived from plankton hundreds of meters to kilometers above near the sea surface. At the abyssal seafloor, this sinking particulate organic carbon represents less than 1% of surface production.

This minimal amount of carbon available opens the door for more unique sources of carbon. Enter food falls and aligators.

The remains of large plants, algae, and animals arrive as bulk parcels that create areas of intense food enrichment. Deep-sea scientists have explored these food falls through both naturally occurring and experimentally deployed wood (#woodfall) and plant remains, cameras baited with animal carcasses, chance occurrences of and deployed intact whale carcasses several miles deep on the seafloor. These experimental and natural food falls have revealed the important role they play in deep-sea diversity. Many of these large food falls on the deep-sea floor, host highly diverse and endemic suites of organisms in kind of food island. In addition, food falls may represent significant transport highways of carbon into the deep oceans. For example, during Typhoon Morakot, wood was estimated to carry a total of 4*10¹² g of organic carbon into the oceans, nearly 25% of the total annual riverine discharge of organic carbon in the same region. On the deep-sea floor, a single wood fall can enrich sedimentary organic carbon by >25% even after several years.

But why alligators? With regard to animal falls, prior work as focused primarily on whales and other cetaceans, pinnipeds, large fish such as tuna, and elasmobranchs. However, it very likely that marine reptiles both currently, and even prehistorically, are an important source of carbon in the deep oceans. Before the existence of whales, perhaps large marine reptiles like ichthyosaurs, mosasaurs, and plesiosaurs hosted diverse and endemic invertebrate communities on sunken carcasses, similar to modern-day whale falls, and contributed significantly to the deep-sea carbon budget. From ichthyosaur and plesiosaur remains, there is evidence of molluscs that are also associated with Eocene seeps. A fossilized limpets are also found in close association with the bones of a fossil leatherback turtle from the Middle Eocene. In the modern oceans, carcasses of Alligator mississippiensis serve as the closest modern analog of ichthyosaur, mosasaur, plesiosaur food falls.

Alligator carcasses in the deep ocean are also not as nearly impossible as you might think.  Both live individuals and carcasses of alligators are frequent on beaches and in coastal surf.  A 3-meter individual came ashore at Folly Beach, South Carolina in 2014 and in 2016 a carcass of a 4-meter individual washed up on a beach in Galveston, Texas.  These individuals of A. mississippiensis may be easily carried offshore by major rivers or during large storm events, tropical storms, and hurricanes.  Live A. mississippiensis have been observed 30 kilometers offshore and after Hurricane Katrina in 2005, an alligator was found 25 kilometers offshore. During the 2011 Mississippi flood event, several dead alligators were observed in the mouth of Atchafalaya River.

Thus, I am on ship, 100’s of kilometers from shore, placing an alligator 2 kilometers deep on the seafloor.

*The three alligators were culled by the state of Louisiana to control population numbers and in aid of restoration efforts. The alligator carcasses were then permitted to us for scientific use. The conservation and any taking of alligators in Louisiana is a very serious and thorough process. You can read more about the conservation success story that is alligators in Louisiana here https://t.co/LQskiPyg6e.

The post Alligators in the Abyss first appeared on Deep Sea News.

The goal was to create a tree where the top represented the ocean’s surface and the base representing the abyssal floor. With a series of white, blue, and black ribbon and silver and blue miniature bulb ornaments, we created the effect of attenuated light as you move deeper. We wanted to make sure to include both a remotely operated vehicle on a lighted tether as well as lighted bathysphere. The tree also included a giant squid attacking a shark and whale fall complete with crabs and eels. We also made some tiny experimental wood falls to resemble the real ones we now have deployed all over the Gulf of Mexico.

You can print all of these decorations yourself. The complete collection can be found in my Thingiverse collection and include:

• The research vessel on top is the ICE – the icebreaker by vandragon_de (with the addition of little printed A-frame for the aft deck.
• The basic and blocky (or to sound like a sophisticated maker low-poly) remote operated vehicle was designed by us.
• Giant Squid by TheGreenFilament
• Shark! Sliced to Print by MacGyver
• Starfish model by Empiricus
• The Voyage of the Bathysphere by themindseye
• LOW POLY CRAB by RaffoSan (for whale fall)
• Eel by Benc (for whale fall)
• Whale by YahooJAPAN (whale for whale fall)
• Giant Deep-sea Isopod by the one and only Andrew_Thaler. (The model is actually based on a real specimen in our lab.)
• Puffer Fish (of awesomeness) by Dinoman (garland)
• A simple log by Montravont
• Vampire Squid by sinryan
• Hammerhead Shark by pmoews

The post 3-D Printing the Ulitmate Deep-Sea Christmas Tree first appeared on Deep Sea News.

User u/Karzdan posted the above image** of Nereis sandersi  to the Reddit forum. The polychaete worm is known from hydrothermal vents and described relatively recently by Blake in 1985.   Interestingly, N. sandersi is eyeless.

Furthermore, the presence of sunken depressions in places where eyes usually occur in N. sandersi is unique for the genus. The occurrence of such depressions is reminiscent of blind cave-dwelling vertebrates which have only vestigial, non-functional eye rudiments remaining from ancestral progenitors which had sight. The very large peristomial ring and enormous palps would appear to be appropriate sensory replacements for a sightless animal in the deep sea. -Blake (1985)

And so begins the Photoshops

**note I am trying to track down the original photographer of the image to credit them here. UPDATE: credit goes to Nicolas Gayet from Paulo Bonifacio lab.

The post Photoshop Battles with this Image of a Hydrothermal Vent Polychaete Worm first appeared on Deep Sea News.

Nearly two miles below the ocean’s surface, we are building new worlds. You might be surprised that these ecospheres are wooden—little log cabins hosting a cornucopia of sea life.  By controlling the size of these wooden homes, we can begin to answer fundamental questions about how the oceans will adapt to climate change. In our most recent, paper we are beginning to grasp the extent that food controls biodiversity, biological novelty, and the competition among species.

On the seafloor, chunks of wood—we call them wood falls—play host to a variety of invertebrate species often not found anywhere else in the ocean.  These species live their entire lives on waterlogged timber; settling out of the water column as larvae to consume wood, or to prey upon other species that do.  Once on a wood fall, these organisms can never leave, their dispersal limited to the beginning of their lives as plankton. And for all of these reasons, the island communities created by wood falls serve as the perfect experiment.

Because of humans, the oceans are radically changing.  They’re becoming warmer, more acidic, and less oxygenated.  But an even more disturbing trend has been uncovered; the oceans may be becoming less productive, providing less food and carbon for its denizens.  Scientists do not really have a handle on how life in the oceans will react to this finding. What will happen to individual species and whole communities of species?  This is an intractable question in many ways because it is hard to test. We cannot easily experimentally adjust how much food a swath of ocean gets. Or can we? In a wood-fall experiment we can change the amount of food the community receives by simply adjusting the size of the log. These species cannot leave to look for better meals once they arrive.  They are wholly dependent on the log we’ve provided in an otherwise barren patch of the deep ocean floor.

In 2006, Jim Barry (MBARI) and I placed 16 logs with a remote operated vehicle (ROV) over 2 miles down on the deep-sea floor off the California coast. We left them there for five years and then remotely and robotically harvested them.  After sorting, identifying, and analyzing, these wood falls are revealing yet another fundamental insight.

How does more food, or more specifically more carbon, allow for more species?  To explain the science, let’s visit a donut shop. At this donut shop, there are three types of donuts: chocolate, plain glazed, and raspberry filled. I ask the donut maker to make three new donuts and provide extra ingredients for them to do so.  

In Scenario A, the donut maker produces chocolate, plain glazed, and raspberry filled along with a dark chocolate, a plain glazed with sprinkles, and a blueberry filled.  The donut shop is still just serving three basic types of donuts: chocolate, plain glazed, and fruit filled. These new donuts are just slight deviations. We will call this Scenario A donut packing.  The donut maker is just packing the menu with variants of the original donuts.

Much like donuts in a shop, we can think of species in a community the same way.  As food increases and the number of species increase, are we getting slight deviations (donut packing) or something truly novel (donut expansion)?  In the ecological sense, are niches, i.e. the full set of characteristics that describe a species and their requirements, being packed into the community or are we expanding the overall niche diversity.

And so for our wood-fall species, we put numbers to each of their niches describing their feeding habits, how well and even if they move, as well as their preference for space on the wood fall. We found that as you increase the wood-fall size, and the amount of wood, you do not get truly novel species, rather you pack these species into the community.  They are just slight deviations. This suggest that increased food reduces competition among animals allowing them to coexist peacefully. Species do not have to be completely novel to join the community.

In the end this means that decreases of productivity in the oceans, will limit diversity by not allowing species to coexist.  Species will be vying for the same spots and in the end many may lose.

McClain, C.R., C.L. Nunnally, A. Chapman, and J. Barry. (2018) Energetic Increases Lead to Niche Packing in Deep-Sea Wood Falls. Biology Letters 

The post Wooden Homes on the Seafloor Yield Insights Into the Impacts of Climate Change first appeared on Deep Sea News.