As we said, these hydrothermal vents are releasing into the ocean depth this intensely hot water that contains a chemical called hydrogen sulfide, and also a gas, carbon dioxide.
With only a glass wall separating you and your guests from the mesmerising marine creatures that call these waters home, your wedding ceremony is beautifully surreal.
So we have been fairly thorough in our discussion about coral reefs, which of course are prominent, oceanic features made of hard limestone skeletons produced by tiny coral animals.
But daily vertical movements by zooplankton in the ocean—upward by night to seek food, downward by day to escape predators—can also be considered migration.
The fossils buried in Pleistocene and earlier ocean sediments were of foraminifera—small, single-celled marine organisms that secrete shells of calcium carbonate, or calcite.
For example, Peter Sheldon' s studies of trilobites, a now extinct marine animal with a segmented body, offer a detailed glimpse into three million years of evolution in one marine environment.