Shop Windows to the Universe

Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.

Life in the Deep Ocean

The deep ocean is very cold, under high pressure, and always dark because sunlight can not penetrate that far. The only light comes from bioluminescence – a chemical reaction inside the bodies of some deep sea creatures. Less life can survive in the deep ocean than in other parts of the ocean because of these harsh conditions.  For some animals, food comes from the bodies of dead fish, dead plankton, and even dead whales that rain down from the open ocean waters above.

But there are two extreme environments in the deep sea where life is more abundant: cold seeps and hydrothermal vents.  In these environments, communities of living things do not rely on sunlight and photosynthesis to begin their food chains.

Cold seeps, areas where methane and hydrogen sulfide are released into the ocean, are home to many extremophiles – unusual creatures that can live without light. These creatures include clams, mussels, shrimp, crabs, bacteria, and tubeworms. For food, these animals depend on certain types of single-cell Archaea and Eubacteria that live off the methane and hydrogen sulfide from the seep. There are cold seeps in many different areas of the world’s ocean including one off the coast of Monterey, California (US). They tend to occur at the edges of continents.

Hydrothermal vents, another extreme environment in the deep sea, are located at tectonic spreading ridges. While most of the water in the deep ocean is close to freezing, the water at hydrothermal vents is very hot. Water seeps under the surface of the rock and  is heated to 400 C (756 F) by volcanic activity at the spreading ridge. Then the hot water spews from holes in the crust called vents. The hot water looks like dark smoke as it gushes from the vents because it picks up dissolved chemicals underground. Most living things would die instantly in such a hot environment, but certain species of Archaea and Eubacteria thrive there. They are able to turn the chemicals from the hot water into the energy they need to survive.  And that starts the food chains at hydrothermal vents.  Many other types of living things including fish, shrimp, giant tubeworms, mussels, crabs, and clams thrive in this environment as well.  They, too, are adapted to the hot water and high pressure. Some of them, like mussels, clams, and the giant, 2-meter (6-foot) tubeworms, get the nutrition they need from microbes living within their bodies. Others, like shrimp and barnacles, eat the Archaea and Eubacteria microbes. 

Last modified October 30, 2008 by Lisa Gardiner.

Shop Windows to the Universe Science Store!

The Summer 2010 issue of The Earth Scientist, available in our online store, includes articles on rivers and snow, classroom planetariums, satellites and oceanography, hands-on astronomy, and global warming.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Science, Evolution, and Creationism

How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more

Pressure

When you inflate a balloon or a tire, you are increasing the pressure on the inside of the object in order to "blow it up". Pressure is a scientific concept that applies to gases and liquids. Pressure...more

Earth's Ocean

Earth's ocean covers more than 70% of our planet's surface. There are five major ocean basins. The Pacific Ocean is the largest. It’s so large that it covers a third of the Earth's surface. The Atlantic...more

Kingdom Animalia

With over 2 million species classified into 30 phyla, Kingdom Animalia surpasses the other 4 kingdoms in terms of its species diversity. But when you think of an "animal", what image comes to mind? While...more

Seafloor Spreading

This diagram provides evidence of seafloor spreading by showing the ages of ocean floor in the Atlantic and eastern Pacific Oceans. The red colors are the youngest parts of the seafloor, where fresh new...more

Volcanism

Volcanism is part of the process of bringing material up from the deep interior of a planet and spilling it forth on the surface. Eruptions also deliver fresh gases to the surface from the melted material...more

The Ocean Biome

The ocean holds the largest of all biomes on Earth. It covers 70% of the planet’s surface. Life in the ocean is diverse. The smallest creatures that call the ocean home are microscopic and made of a single...more

Ocean Literacy - Essential Principle 5

The ocean supports a great diversity of life and ecosystems. Fundamental Concept 5a. Ocean life ranges in size from the smallest virus to the largest animal that has lived on Earth, the blue whale. Fundamental...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA