There would be no life in the oceans without organisms called ______ and ______.

This article is also available The ocean covers 70 percent of Earth's surface. It contains about 1.35 billion cubic kilometers (324 million cubic miles) of water, which is about 97 percent of all the water on Earth. The ocean makes all life on Earth possible, and makes the planet appear blue when viewed from space. Earth is the only planet in our solar system that is definitely known to contain liquid water. Although the ocean is one continuous body of water, oceanographers have divided it into five principal areas: the Pacific, Atlantic, Indian, Arctic, and Southern Oceans. The Atlantic, Indian, and Pacific Oceans merge into icy waters around Antarctica. Climate The ocean plays a vital role in climate and weather. The sun’s heat causes water to evaporate, adding moisture to the air. The oceans provide most of this evaporated water. The water vapor condenses to form clouds, which release their moisture as rain or other kinds of precipitation. All life on Earth depends on this process, called the water cycle. The atmosphere receives much of its heat from the ocean. As the sun warms the water, the ocean transfers heat to the atmosphere. In turn, the atmosphere distributes the heat around the globe. Because water absorbs and loses heat more slowly than land masses, the ocean helps balance global temperatures by absorbing heat in the summer and releasing it in the winter. Without the ocean to help regulate global temperatures, Earth’s climate would be bitterly cold. Ocean Form...

Dead zones are low- oxygen, or hypoxic, areas in the world’s oceans and lakes. Because most organisms need oxygen to live, few organisms can survive in hypoxic conditions. That is why these areas are called dead zones. Dead zones occur because of a process called eutrophication, which happens when a body of water gets too many nutrients, such as phosphorus and nitrogen. At normal levels, these nutrients feed the growth of an organism called cyanobacteria, or blue-green algae. With too many nutrients, however, cyano bacteria grows out of control, which can be harmful. Human activities are the main cause of these excess nutrients being washed into the ocean. For this reason, dead zones are often located near inhabited coastlines. Understanding the eutrophication process provides the clearest picture of how and why dead zones develop. Causes of Eutrophication Eutrophic events have increased because of the rapid rise in intensive agricultural practices, industrial activities, and population growth. These three processes emit large amounts of nitrogen and phosphorous. These nutrients enter our air, soil, and water. Human activities have emitted nearly twice as much nitrogen and three times as much phosphorus as natural emissions. Different regions of the world emit different levels of these nutrients. In developed countries, such as the United States and nations in the European Union, heavy use of animal manure and commercial fertilizers in agriculture are the main contributors...

Water may not seemspecial. It's clear. It has no taste. It doesn't smell like anything. But if it couldn't do the things it does, life on Water is a tiny molecule. It consists of three Water is a shape-shifter. It exists in three states on Earth: liquid, gas, and solid: • Liquid water is a jumbled bunch of water molecules. It comes out of our faucets, flows underground and in rivers and oceans, and forms clouds and fog in the air. • When water molecules escape from liquid water and float into the air, they turn into an invisible gas called water vapor. The spaces between the molecules are much bigger than the molecules themselves. • When water freezes into a solid, it does a strange thing: it floats! (Most other solids become denser and sink.) As ice forms, water molecules arrange themselves neatly in a crystal structure. The empty spaces between the molecules act as flotation devices — the way a life preserver holds you up. Earth's water is always in motion. It moves inside the planet, across its surface, and in the atmosphere above. Water in lakes, rivers, and oceans turns into vapor and moves into the air through evaporation. Plants draw water from the soil and return it to the air. Can you imagine how far the water in your shower has traveled? (Remember, it's been on Earth for over 4 billion years!) Where do you think it will go next? Water runs easily through your fingers. It may not feel powerful. But lots of water, acting over time, shapes the world around us. Falli...

A chimney structure from the Sea Cliff hydrothermal vent field located more than 8,800 feet (2,700 meters) below the sea’s surface at the submarine boundary of the Pacific and Gorda tectonic plates. Credit: Ocean Exploration Trust In the strange, dark world of the ocean floor, underwater fissures, called hydrothermal vents, host complex communities of life. These vents belch scorching hot fluids into extremely cold seawater, creating the chemical forces necessary for the small organisms that inhabit this extreme environment to live. In a newly published study, biogeoscientists Jeffrey Dick and Everett Shock have determined that specific hydrothermal seafloor environments provide a unique habitat where certain organisms can thrive. In so doing, they have opened up new possibilities for life in the dark at the bottom of oceans on Earth, as well as throughout the Journal of Geophysical Research: Biogeosciences. On land, when organisms get energy out of the food they eat, they do so through a process called cellular respiration, where there is an intake of oxygen and the release of carbon dioxide. Biologically speaking, the molecules in our food are unstable in the presence of oxygen, and it is that instability that is harnessed by our cells to grow and reproduce, a process called biosynthesis. But for organisms living on the seafloor, the conditions for life are dramatically different. "On land, in the oxygen-rich atmosphere of Earth, it is familiar to many people that making...

\( \newcommand\) • • • • Global Distribution Phytoplanktons are the major primary producers in Ocean, and the rest of marine animals rely on the primary productions for energy sources. Therefore, we can map the global distributions of marine life based on the distribution of chlorophyll and primary productions, see figures below 1: High primary productivity regions clustered in coastal regions where nutrients come from the lands, east side of ocean basins as well as polar regions where upwelling occur, and equatorial regions where surface water diverge and nutrient-rich deep water move upwards 1. These are also likely to be the regions with most marine organisms. To "assess and explain the diversity, distribution and abundance of life in the oceans" 2, the Census of Marine Life was formed as a global network with researchers in more than 80 nations 2, and the newly published map highlighting discoveries of ocean life in a decade's investigation could be found at www.comlmaps.org/oceanlifemap...tion-abundance 3. Distribution In the Ocean As with the global distribution of marine organisms, lives in the ocean are not evenly distributed throughout the ocean either, and are mostly controlled by the abiotic factors of marine environment such as temperature, salinity and light availability 4. Therefore, oceans could be divided into three general zones which are euphotoic, twilight and deep sea zones 4. • Euphotic Zone • Twilight Zone • Deep Sea Zone The Deep Sea The majority of ...

Bioluminescence is light produced by a chemical reaction within a living organism. Bio luminescence is a type of chemiluminescence, which is simply the term for a chemical react ion where light is produced. (Bioluminescence is chemiluminescence that takes place inside a living organism.) Bioluminescence is a " cold light." Cold light means less than 20% of the light generates thermal radiation, or heat. Most bioluminescent organisms are found in the ocean. These bioluminescent marine species include fish, bacteria, and jellies. Some bioluminescent organisms, including fireflies and fungi, are found on land. There are almost no bioluminescent organisms native to freshwater habitats. Chemistry The chemical reaction that results in bioluminescence requires two unique chemicals: luciferin and either luciferase or photoprotein. Luciferin is the compound that actually produces light. In a chemical reaction, luciferin is called the substrate. The bioluminescent color (yellow in fireflies, greenish in lanternfish) is a result of the arrangement of luciferin molecules. Some bioluminescent organisms produce ( synthesize) luciferin on their own. Dinoflagellates, for instance, bioluminesce in a bluish-green color. Bioluminescent dinoflagellates are a type of plankton—tiny marine organisms that can sometimes cause the surface of the ocean to sparkle at night. Some bioluminescent organisms do not synthesize luciferin. Instead, they absorb it through other organisms, either as food or in...