Baja California  

Some interesting critters including the pelagic red crab, a krill, and some deep-sea fish larvae

Bottle-nosed dolphins

el Canal de San Lorenzo between the mainland (and La Paz) and la Isla Espiritu Santo (Holy Ghost)

Leg 2, the picture show a nice chimney on top of the12-meter-tall Rebeccaбпs Roost that was collected

Leg 2,One of the biggest surprises was a channel in the mud spouting hydrothermal fluid and surrounded by multicolor microbial mats. Low temperature structures in the south looked like great rose bushes covered with tubeworms

Tubewarms

the б░Busted Mushroomб▒ site, so named because we knocked over a large mushroom-shaped deposit (see left) so that we could get to the vent opening. Many of the hydro-thermal structures are built of awnings, flanges, or pagoda structures. Trapped underneath these structures is extremely hot fluid, which pours upward around the edges. The Busted Mushroom had 300б╞ C fluid pooled beneath it

Leg 3-the Cerralvo Trough, the blackbelly dragonfish Stomias atriventer, Stomias is replaced by the viperfish, Chauliodus macouni. Both species feed on shrimp and other fishes and both make a living in roughly the same way. The only place that they co-occur is where the cool waters of the California Current meet subtropical waters in the southern California borderland

Leg3 -3,100 meters down into the deepest part of the Gulf of California.

leg3 -the Farallon Basin. We''re at 25 27.0071N and 109 50.0021 W diving in the midst of a huge red tide

Farallon Basin. A digital shot of the acoustic profiler''s data screen. Tiburon''s path is the red and green line. Horizontal depth references are 50 meters apart. There is a blue band of surface scatter at the top of the chart. The principal scattering layer starts at about 250 meters and extends down to about 375 meters with a narrow layer deeper at about 425 meters.

Farallon basin, suspended sediment

Farallon Basin.Cyclosalpa

Farallon Basin. Stygeomedusa gigantea lives in cold, deep water and is only very rarely seen

Leg3 -Guaymas Basin, Munnopsis (a.k.a. "spiders" like the one seen here hanging in the water column) feeding like daddy-long-legs on the sea floor two days ago and yesterday, finding the feather-foot "spider"

Leg3-swomming sea cucumber

the hot vents and the huge clumps of tubeworms living around them

Siphonophore

Pescadero Basin, The ctenophore was Thalassocalyce, a transparent lobate with a delicate, diaphanous body.

Pescadero Basin.Cephalopod. Oxygen levels are astonishingly low at mid-depths in the Gulf of California. In fact, between 300 and 800 meters, oxygen is nearly undetectable by the oxygen sensor on the submersible. Animals require oxygen to harvest the chemical energy in the food that they eat. Large, active animals require more oxygen than small, slow animals.

Pescadero Basin.Parasitic crustaceans called amphipods, which are usually examined after being preserved from plankton tows

48 miles to the south of Pescadero basin towards Alarcмхn seamount. Aan echosounder registered the topography of the scattering layer. There no organisms that produced the layer on 250–400 meters deep. Some organisms include medusae, siphonophores, appendicularians, small fishes, and pteropods. At about 550 meters, we observed another scattering layer with the echosounder, but not the animals that caused it

a siphonophore of the family Rhodaliidae, probably Stephalia corona.

blue Sapphirina, stinging Athorybia

Carmen Basin. The depth of the sea floor between the two basins (Farallon basin is other) is about 1,500 meters, far too deep to have an influence on the upper 500 of the oxygen profile, right at the depth where the contrasting animal distributions occur. It may be that mixing extends deeper in Carmen Basin, carrying more oxygen with it, and thus increasing the vertical range that these animals can occupy. While this looks like an exploded experiment in omelette class, it''s a medusa named Phacellophora, found very much deeper today than we have ever seen it before.

Carmen Basin. Triphoturus mexicanus, the most abundant midwater fish species in the Gulf. Many of them are oriented like this, either head up or head down as we come upon them during a dive. That''s another puzzle because it means they aren''t using their ventral photophores for counter-illumination, which is what we were all taught they were for.

Led3, It is a cranchiid squid, probably Helicocranchia. But out here it is being called the rastafarian, pig-nosed, helicopter-tailed, hippo-squid,

Leg3. Cerralvo Trough. Serrivomer, a slender midwater predator, sculls with the tip of its tail to hold itself vertically in the water column. We assume that it scans the water above for prey, but its eyes seem too small to be very effective at these depths. Maybe it''s tuned in with another sensory system.

Led4, Guaymas Transform Fault. Collected three types of vestimentiferan tubeworms, five species of clam, including six individuals of an unusual genus of bivalve called Solemya, and numerous gastropods, polychaetes, and brachiopods, push cores over bacterial mats within the cold seeps. These push cores smelled strongly of sulfide (rotten eggs) and crude oil, which is actually a good sign that interesting microbes will be living within these cores

Bacterial mat of the Guaymas Basin, located in theCentral Gulf of California,

a short sulfide mound covered with Riftia tubeworms.

a very extensive visual survey (about 6 kilometers over the bottom) at the site of the hydrothermal plume, but found no sign of a hydrothermal vent or its associated community. The axial valley of this mid-ocean ridge is an asymmetrical ridge with steep faulted terrain to the northwest within 50 meters of the axis, whereas the southeast side extends with only small fault scarps to at least 700 meters from the axis. Along the axis, the youngest flow in the survey area extends for at least 1.8 km. However, it is not a flow erupted within the last 50-100 years since it has substantial sediment cover. On the other hand, it is a very interesting flow since it consists of sheet flows that have been extensively folded and broken during emplacement to form a jumbled sheet flow.

a sea cucumber that had attached numerous brachiopod shells (similar to small clam shells) to the outside of his body, perhaps to avoid detection (although it actually made them rather conspicuous to us) or perhaps to make them less palatable. In any case, none of us had ever seen a cucumber that agglutinated particles to itself.

a holothuroid, or sea cucumber, that looks a bit like a small pig..

Anemones on the trash

Wood. Sometimes nature dumps her own trash at the bottom of the sea. We found several piece of wood wrack that were heavily colonized by all sorts of critters. Crabs, similar to those found at vents and seep sites, were found all over one piece of wood, as were some little shrimp-like creatures that we found only under the wood. We even collected a pink, frilly sea cucumber, one that we had never seen before, to have it identified

Pink cucumber

Pink cucumber

hydrothermal vent, cylinder pillars in mid-ocean ridge

Lava dribble, pillow basalts and elaborate lava sculptures 2400 meters below

Guaymas. giant clams (Calyptogena magnifica) up to one foot long

a unique type of sponge that grows from a stalk and is shaped like a mushroom

tubeworm (Riftia) bushes

б░golf-ballб▒ sponge (Chondrocladia sp.)

clamshells

Black smoker

Lobster. Hanging Gardens at 21вк N on the East Pacific Rise is a good example. The terrain was very rough with collapsed lava pits, lava pillars, and sheer walls lining the walls of the axial caldera. The pilots had to negotiate their way through this dark maze and simultaneously manage the cable so that it would not be entangled or mangled by the sharp lavas or tall, hot hydrothermal chimneys

From MBARI -http://www.mbari.org/expeditions/GOC/sites.htm


March 8, 2003: Leg 2, Day #7


б░One merges into another, groups melt into ecological groups until the time when what we know as life meets and enters what we think as non-life: barnacle and rock, rock and earthбжб▒ -The Log from the Sea of Cortez, John Steinbeck

This is my third visit to the seafloor of the Sea of Cortez. Every time I return, I leave in awe—in awe of one of the most beautiful deep-sea vent sites in the world, in awe of the spectacular diversity of colors of animals, rocks, and microbes that reside in this murky sedimented seafloor. Two thousand meters below the surface, we drop down onto brown sediments, pock-marked with activity of benthic organisms, anemones, large spider crabs, and brilliant white starfish.

Suddenly, in this dark world, large patches of white appear, like a localized snowfield. Closer inspection with illumination from the ROV, reveals gentle orange, yellow, and white hues. As we get closer, the patches are clearly a biological mat made up of filamentous microbes, fluffy masses, providing a habitat for millions of other microbes and small invertebrates. Occasional red, feather-like creatures poke out from under this mat of microbes, and then suddenly you see more color, more animals. Huge clumps of tubeworms, white, so white, with fleshy plumes lazily moving in the current. Zoarcid fish and crabs cruise by the view, opportunistically looking for scraps of potential food.

Look up and the mat extends up a rocky mound, with tubeworms between crevasses, large shelf-like structures covered in animals and microbes— delicately balanced like caps of toadstools— strange rocks that look like spiresбж Zoom in and the water emanating from areas in the mat appears viscous and shimmering. Fluid under the rocky shelves is mirror-like, and tips of the spires seem to be smoking like chimneys. And here, associated with all these structures, is the answer to this unusual ecosystem.

The water is hot, hydrothermal fluid, rich in metals and gases. It''s fueling the ecosystem with energy for microbes—microbes that live at high temperatures in the chimneys, in the porous rock of the shelves (б░flangesб▒), microbes that make up the mats, and microbes that live inside the tubeworms. The diversity of microbes in these ecosystems far exceeds that of the animals, and we have only started exploring the vastness of this microbial world.

These microbes can precipitate minerals, contributing to minerals and colors in the mats we see. Some live off a little hydrogen and carbon dioxide and make much of the methane we measure in the fluids, and some probably can utilize the hydrocarbons—that oily mess we collected a few days ago. The microbes that live in the tubeworms are called endosymbionts, and enable these animals to thrive on hydrogen sulfide, carbon dioxide and oxygen. Most animals cannot live in the hydrogen sulfide concentrations that the tubeworms can! So here, the microbes play a critical role in the life of these animals. б░Microbe, tubeworm, hot water and rock, rock and earthбжб▒

Again, I am left in wonderment about the diversity of life on earth, how geology, geochemistry, biology, are all so interlinked, and how little we understand our oceans and our planet. I am then reminded of the trip the Western Flyer took into the Sea of Cortez with Steinbeck and Doc Ricketts, and how much of the excitement of discovery that we are experiencing on today''s Western Flyer, is much of the same they experienced on their little Western Flyer more than half a century ago. I look out to the setting sun on the mountains in Baja and on the golden reflections on the Sea of Cortez, and I am reminded again of a passage from their research expedition:

б░Then one can come back to the microscope and the tide pool and the aquariumбж And it is a strange thing that most of the feeling we call religious, most of the mystical out crying which is the most prized and used and desired reactions of our species, is really the understanding and the attempt to say man is related to the whole thing, related inextricably to all reality, known and unknowableбж The knowledge that all things are one and that one thing is all things—plankton, a shimmering phosphorescence on the sea and the spinning planets and an expanding universe, all bound together by the elastic string of time. It is advisable to look from the tide pool to the stars and then back to the tide pool again.б▒

-Anna-Louise Reysenbach

Gulf of California
Ecosystem

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