oceanography

Carbon Cycle

A biogeochemical cycle by which carbon is exchanged among Earth's atmosphere, hydrosphere, geosphere, biosphere, and cryosphere.

Coral Reef

A calcareous organic reef composed significantly of solid coral and coral sand. Algae may be responsible for more than half of the CaCO3 reef material. Found in waters where the minimum average monthly temperature is 18oC or higher. Coral are mixotrophs because they derive part of their nutrition from their algae partners.

Grazer

A grazer is any animal that relies on herbivory (feeds on plants) as its primary food source. Examples of ocean grazers include herbivorous reef fish and wana (sea urchins).

Clathrates/Gas hydrate

A lattice-like compound composed of water and natural gas (usually methane) formed in high-pressure and low-temperature environments such as those found in deep-ocean sediments. Also known as cathrates because of their cage-like chemical structure.

Deep scattering layer (DSL)

A layer of marine organisms in the open ocean that scatter signals from an echo sounder. It migrates daily from depths of slightly over 100 meters (330 feet) at night to more than 800 meters (2600 feet) during the day

Euphotic Zone

A layer that extends from the surface of the ocean to a depth where enough light exists to support photosynthesis, rarely deeper than 100 meters (330 feet).

Polar Bear

A marine mammal with white fur whose native range consists of Arctic ice and adjoining islands and landmasses mostly within the Arctic Circle. It feeds primarily on seals.

Prokaryote

A microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria.

Fossil Fuels

A natural fuel such as petroleum, gas, or coal that formed in the geological past from the remains of living organisms

Petroleum

A naturally occurring liquid hydrocarbon

Macrophytes

A plant, especially an aquatic plant, large enough to be seen by the naked eye.

Epipelagic

A subdivision of the oceanic province that extends from the surface to a depth of 200 meters (660 feet)

Scavenger

An animal that feeds on dead organisms.

Trophic Cascade

An ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling

Radiolarians

An order of planktonic and benthic protozoans that possess protective coverings usually made of silica. Also radiolaria (singular)

Foraminifera

An order of planktonic and benthic protozoans that possess protective coverings, usually composed of calcium carbonate. Also called forams.

Deep-water/cool-water reef

Diverse coral ecosystems have been found to be unexpectedly widespread in deep, cold waters. These corals are found below sunlit surface waters on continental shelves, continental slopes, seamounts, and mid-ocean ridge systems around the world. Most don't live in particularly deep water, so the term cool-water coral is more appropriate. They lack the symbiotic zooxanthellae algae relationship. They can still be brightly colored and use their stinging tentacles to capture tiny plankton or detritus concentrated by ocean currents. It is remarkable that they have remained unnoticed for so long.

Abiogenesis

In biology, abiogenesis, or informally the origin of life, is the natural process by which life has arisen from non-living matter, such as simple organic compounds.

Aerobic

In the presence of free oxygen. Aerobic respiration is a chemical process in which oxygen is used to make energy from carbohydrates

Endosymbiosis

Symbiosis in which one of the symbiotic organisms lives inside the other.

Seal

1) Any of several earless seals with a relatively short neck and small front flippers. Also known as true seals. 2) A general term that describes any of the various aquatic, carnivorous marine mammals of the families Phocidae and Otariidae (true seals and eared seals), found chiefly in the Northern Hemisphere and having a sleep, torpedo-shaped body and limbs that are modified into paddle-like flippers.

Polyp

A calcareous organic reef composed significantly of solid coral and coral sand. Algae may be responsible for more than half of the CaCO3 reef material. Found in waters where the minimum average monthly temperature is 18oC or higher. Coral are mixotrophs because they derive part of their nutrition from their algae partners.

Stromatolite

A calcium carbonate sedimentary structure in which algal assemblages trap sediment and bind it into forms that are often dome shaped. They are known to form only in shallow-water environments.

Macronutrients

A chemical element (e.g., potassium, magnesium, calcium) required in large amounts for plant growth and development.

Barrier Reef

A coral reef separated from the nearby landmass by open water. This is the second stage of development in a coral reef- it follows the fringing reef stage. They are linear or circular reefs. As the landmasse subsides, the reef maintains its position close to sea level by growing upward. If the landmass subsides at a rate faster than coral can grow upward, the coral reef with be submerged in water too deep for it to live.

Vent community

A deep bottom-dwelling community of organisms associated with a hydrothermal vent. The hot water vent is usually associated with the axis of a spreading center, and the community is dependent on sulfur-oxidizing bacteria that may live free in the water, on the bottom, or symbiotically in the tissue of some of the animals of the community. These bio communities have up to 1000 times more biomass than the rest of the deep-ocean floor.

Cyanobacteria

A division of microorganisms that are related to the bacteria but are capable of photosynthesis. They are prokaryotic and represent the earliest known form of life on the earth.

Zooxanthellae

A form of algae that lives as a symbiont in the tissue of corals and other coral reef animals and provides varying amounts of their required food supply. They give corals their distinctive bright coloration. The algae provide their coral hosts with a continual supply of food, and the corals provide the zooxanthellae with nutrients.

Trophic Level

A nourishment level in a food chain. Plant producers constitute the lowest level, followed by herbivores and a series of carnivores at the higher levels.

Positive Feedback

A positive feedback loop amplifies an initial change. Examples: clouds trap heat.

Toothed Whale

A predatory whale having teeth rather than baleen plates. Toothed whales include sperm whales, killer whales, beaked whales, narwhals, dolphins, and porpoises. They have one blowhole, while a baleen whale has two. The ability to emit and receive sounds is best developed in toothed whales compared to Baleen.

Chemosynthesis

A process by which bacteria or archaea synthesize organic molecules from inorganic nutrients using chemical energy released from the bonds of a chemical compound (such as hydrogen sulfide) by oxidation. Hydrogen sulfide (6H2S) + Water (6H2O) + Carbon dioxide (6CO2) + Oxygen (6O2) —-----> sugar (C6H12O6) + Sulfuric acid (6H2SO4).

Fringing Reef

A reef that is directly attached to the shore of an island or continent. It may extend more than 1 kilometer (0.6 miles) from shore. The outer margin is submerged and often consists of algal limestone, coral rock, and living coral. This is the first stage of development in coral reefs. They are often associated with active volcanoes whose lava flows run down the flanks of the volcano and kill the coral. Thus, the fringing reefs are not very thick or well developed. If sea level does not rise or the land does not subside, the process stops at the fringing reef stage.

Symbiosis

A relationship between two species in which one or both benefit or neither or one is harmed. Examples are commensalism, mutualism, and parasitism.

Atoll

A ring-shaped coral reef growing upward from a submerged volcanic peak that usually has low-lying islands composed of coral debris. This is the third stage of development in coral reefs and comes after the barrier reef stage. As a barrier reef around a volcano continues to subside, coral builds up toward the surface. After millions of years, the volcano becomes completely submerged, but the coral reef continues to grow. If the rate of subsidence is slow enough for the coral to keep up, a circular reef called an atoll is formed. Buildups of crushed coral debris often form narrow islands that encircle the central lagoon and are large enough to allow human habitation. However, a new theory suggests that atolls form from glacial cycles that cause sea level to fluctuate, leading to episodes of reef exposure and dissolution when global sea level is lower during ice ages.

Sea Otter

A seagoing otter that has recovered from near extinction along the North Pacific coasts. It feeds primarily on abalone, sea urchins, and crustaceans. They are one of the few types of animals known to use tools.

Banded Iron Formation

A sedimentary deposit that consists of alternating thin layers of iron oxides (such as magnetite or hematite) and iron-poor minerals (such as shale or chert). A rich source of information about the geochemical conditions that existed on Earth when the rocks were made.

Feedback Loops

A self-repeating process in which an initial change is modified. A positive-feedback loop amplifies an initial change, and a negative-feedback loop counteracts an initial change.

Echolocation

A sensory system in odontocete cetaceans in which usually high-pitched sounds are emitted and their echoes interpreted to determine the direction and distance of objects.

Parasitism

A symbiotic relationship between two organisms in which one benefits at the expense of the other.

Mutualism

A symbiotic relationship in which both participants benefit.

Commensalism

A symbiotic relationship in which one party benefits and the other is unaffected.

Baleen Whale

A whale that has plates of whalebone in the mouth for straining plankton from the water. Baleen whales include the rorquals, humpback, right whales, and gray whales. Baleen is a fibrous substance made of keratin found in parallel rows of long plates that hang down from the upper jaw of baleen whales. They have two blowholes.

Methane-hydrate

A white compact icy solid made of water and methane. The most common type of gas hydrate

Aerotolerant

Aerotolerant anaerobes use fermentation to produce ATP. They do not use oxygen, but they can protect themselves from reactive oxygen molecules. In contrast, obligate anaerobes can be harmed by reactive oxygen molecules.

Autotroph

Algae, plants, and bacteria that can synthesize organic compounds from inorganic nutrients.

Phytoplankton

Algal plankton. One of the most important communities of primary producers in

Predator

An animal that naturally preys on others.

Consumer

An animal within an ecosystem that consumes the organic mass produced by the producers.

Dugong

An aquatic mammal found on the coasts of the Indian Ocean from eastern Africa to northern Australia. It is distinguished from the manatees by its forked tail

Manatee

An aquatic mammal with a rounded tail flipper, living in shallow coastal waters and adjacent rivers of the tropical Atlantic

Seep

An area where water of various temperatures and/or salinities trickles out of the sea floor, such as in warm seeps, cold seeps, and hypersaline seeps. Also includes locations where hydrocarbons seep from the sea floor, which create hydrocarbon seeps.

Zooplankton

Animal plankton- plankton consisting of small animals and the immature stages of larger animals

Heterotroph

Animals and bacteria that depend on the organic compounds produced by other organisms as food.

Infaunal

Animals that live buried in the soft substrate (sand or mud).

Epifaunal

Animals that live on the ocean bottom, either attached or moving freely over it.

Sea Lion

Any of several eared seals with a relatively long neck and long front flippers, especially the California sea lion Zalophus californianus of the northern Pacific. Along with the fur seals, these marine mammals are known as eared seals.

Nonpoint source pollution

Any type of pollution entering the ocean from multiple sources rather than from a single discrete source, point or location. Examples include urban runoff, trash, pet waste, lawn fertilizer, and other types of pollution generated by a multitude of sources. Also called poison runoff

Marine Mammals

Aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include at least 117 species within the orders Carnivora, Sirenia, and Cetacea.Characteristics of mammals: 1) They are warm-blooded 2) They breathe air 3) They have hair (or fur) during at least some stage of their development 4) They bear live young (this is true except for a few egg-laying monotreme mammals of Australia from the subclass Prototheria, which includes the duck-billed platypus and the spiny anteater [echidna]) 5) The females of each species have mammary glands that produce milk for their young

Soft-bottom intertidal

Bottom composed of sediment where organisms can burrow easily. Also called sediment-covered interdital. Much less species diversity in sediment-covered shores. Nearly all large organisms that inhibit sediment-covered shores are called infauna because they can burrow into the sediment.

Biomagnification

Concentration of impurities as animals are eaten and the impurity is passed through food chains. Also bioaccumulation.

Icehouse Earth

Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously. Climatic proxies indicate that greenhouse gas concentrations tend to lower during an icehouse Earth. Similarly, global temperatures are also lower under Icehouse conditions. Earth then fluctuates between glacial and interglacial periods, and the size and the distribution of continental ice sheets fluctuate dramatically.

Ecosystem Services

Ecosystem services are the many and varied benefits to humans provided by the natural environment and from healthy ecosystems

Renewable Energy

Energy from a source that is not depleted when used, such as wind or solar power

Fisheries

Fisheries are fish caught from the ocean by commercial fishers

Natural Gas

Flammable gas, consisting largely of methane and other hydrocarbons, occurring naturally underground (often in association with petroleum) and used as fuel

Kelp

Large varieties of Phaeophyta (brown algae). Beds formed by kelp are called kelp forests and can often be found along the west coast of North America. Some kelp can grow up to two feet a day. Smaller species of kelp that are generally less than 0.6 meter (2 feet) tall are known as shrub kelp. They live in cool, relatively shallow waters close to the shore. Kelp forests have a greater variety and diversity of animals than almost any other ocean community

Micronutrients

Micronutrients are essential elements that are used by plants in small quantities. In spite of this low requirement, critical plant functions are limited if micronutrients are unavailable, resulting in plant abnormalities, reduced growth and lower yield

Negative Feedback

Negative feedback loop counteracts an initial change. Examples: clouds reflect sunlight.

Eukaryote

Organisms that belong to the domain Eukarya, one of the three major domains of life. The domain includes single-celled or multicellular organisms whose cells usually contain a distinct membrane-bound nucleus.

Mobile/Attached

Organisms that can move freely throughout the sea versus are attached to a certain point.

Hypoxia

Oxygen deficiency in a biotic environment.

Patch Reef

Patch reefs are small, isolated reefs that grow up from the open bottom of the island platform or continental shelf. They usually occur between fringing reefs and barrier reefs. They vary greatly in size, and they rarely reach the surface of the water

Nekton

Pelagic animals such as adult squids, fish, and mammals that are active swimmers to the extent that they can determine their position in the ocean by swimming.

Photoinhibition

Photoinhibition is defined as the decrease in photochemical efficiency experienced in response to intense illumination due to radiation damages.

Point source pollution

Pollution entering the ocean from a single discrete source

Decomposer

Primarily bacteria that break down nonliving organic material, extract some of the products of decomposition for their own needs, and make available the compounds needed for primary production

Anaerobic

Requiring or occurring in the absence of free oxygen. Anaerobic respiration is carried on in the absence of free oxygen. Some bacteria and protozoans carry on respiration this way.

World Sea Level Change

Sea levels are rising due to melting ice and thermal expansion related to global warming. This trend may have consequences for life on Earth. It could also cause extreme damages to certain human populations and make areas uninhabitable.

Seagrass

Seagrasses are the only flowering plants which grow in marine environments. Seagrasses can reproduce sexually or asexually. They are flowering plants that produce seeds

Invasive Species

Species that are introduced into waters in which they are alien and often cause severe problems by displacing native species. Also called exotic, alien, or non-native species

Cool seep community

Submarine seep environment that chemosynthetic supports bio communities and exists at much lower temperatures. One type of a hypersaline seep which released water with a higher salinity than the surrounding water, but its temperature was about the same as the surrounding water. There are hypersaline seep bio communities. There are also hydrocarbon seeps that are associated with oil and gas seeps and host biological communities. Additionally, subduction zone seep bio communities exist and produce water that is only slightly warmer than seawater at that depth.

Great Oxygenation Event/Crisis

The Great Oxidation Event, also called Great Oxygenation Event, was a time interval when the Earth's atmosphere and the shallow ocean first experienced a rise in the amount of oxygen. This occurred approximately 2.4-2.0 Ga, during the Paleoproterozoic era

Redfield Ratio

The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans.

Anoxia

The absence of oxygen; severe hypoxia

Producer

The autotrophic component of an ecosystem that produces the food that supports the biocommunity.

Abyssal

The benthic environment between 4000 and 6000 meters (13,000 and 20,000 feet).

Bathyal

The benthic environment between the depths of 200 and 4000 meters (660 and 13,000 feet). It includes mainly the continental slope and the oceanic ridges and rises.

Ecology

The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

Compensation Depth for Photosynthesis

The depth at which net photosynthesis becomes zero; below this depth, photosynthetic organisms can no longer survive. This depth is greater in the open ocean (up to 100 meters or 330 feet) than near the shore due to increased turbidity that limits light penetration in coastal regions.

Eutrophication

The enrichment of waters by a previously scarce nutrient; if caused by humans, called cultural eutrophication.

Benthos

The form of marine life that lives on the ocean bottom.

Speciation

The formation of new and distinct species in the course of evolution.

Contaminant/Pollution

The introduction of substance into the environment that result in harm to the living resources of the ocean or humans who use these resources

Intertidal Zonation

The natural organization of ecosystems relative to sea level that are caused by varying environmental conditions.

Abyssopelagic

The open-ocean (oceanic) environment below 4000 meters (13,000 feet) in depth.

Bathypelagic

The pelagic environment between the depths of 1000 and 4000 meters (3300 and 13,000 feet)

Mesopelagic

The portion of the oceanic province 200 to 1000 meters (660 to 3300 feet) deep. Corresponds approximately with the disphotic (twilight) zone

Deposit feeding

The process by which an organism feeds on food items that occur as deposits, including detritus and various detritus-coated sediments.

Filter feeding

The process by which an organism obtains its food by filtering seawater to collect floating organisms to ingest. Also known as suspension feeding.

Respiration

The process by which organisms use organic materials (food) as a source of energy. As the energy is released, oxygen is used and carbon dioxide and water are produced.

Photosynthesis

The process by which plants and algae produce carbohydrates from carbon dioxide and water in the presence of chlorophyll, using light energy and releasing oxygen.

Primary Productivity

The rate at which energy is stored by organisms through the formation of organic matter (carbon-based compounds) using energy derived from solar radiation (photosynthesis) or chemical reactions (chemosynthesis). Also known simply as productivity.

Rocky-bottom intertidal

The rocky shores that lie at the edge of the ocean, between the high and low tides, are called the rocky intertidal. A typical rocky shore can be divided into a spray zone, which is above the spring high tide line and is covered by water only during storms, and an intertidal zone, which lies between the high and low tidal extremes. Separated into the supratidal zone (spray zone), high tide zone, middle tide zone, and low tide zone.

Greenhouse Earth

Throughout Earth's climate history (Paleoclimate) its climate has fluctuated between two primary states: greenhouse and icehouse Earth. Both climate states last for millions of years and should not be confused with glacial and interglacial periods, which occur as alternate phases within an icehouse period and tend to last less than 1 million years. A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet. Additionally, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures (SSTs) range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions. Earth has been in a greenhouse state for about 85% of its history.