Expedition 15 Videos

Not all vents are high-temperature “black smokers” like the ones shown in the video above. Some, like Crab Spa, shown here, are cooler and more slow-flowing. These types of vents form as cold seawater seeps below the ocean floor and mixes with the ultra-hot fluids that feed the vent. The seawater cools the fluids before they emerge from the rocks. Most large animals that live at vent sites seek out this sort of flow, because this is also where most of the chemosynthetic microbes live. The fluid coming out of a black smoker is too hot for life, but the water here is at a good temperature for living things, and full of the chemical nutrients that sustain the organisms in the ecosystem.

In this video, an oxygen sensor is placed into the mouth of Crab Spa amid a thicket of tubeworms and mussels. As a crab fights with the sensor, a Zoarcid fish floats by to survey the scene. Later in the clip, you’ll see another view of the vent after researchers removed the animals living there. These animals can change the chemistry of the vent site, so the scientists stripped them off for study and to gain access to the vent’s mouth with Jeff Seewald’s Isobaric Gas-Tight sampler. The white flecks coming out of the vent are actually a mix of sulfur and bacteria. The sulfur is created by some bacteria as they "eat” hydrogen sulfide, a chemical commonly found in vent fluid.