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The Pacific White Line is a periodic but random natural feature in the Pacific Ocean. It is a huge collection of fish, foam and algae that usually occurs between January and August. When conditions are right it can be seen from space. [1]
The line can clearly be seen from space when at its greatest, being around 2 kilometres (1.2 mi) wide and up to several hundred kilometres long. [2] Although only covering 0.1% of the surface, it provides 50% of all the fish caught in the Pacific Ocean. [1]
The white line is formed because the currents bring fresh, cool and nutritious water loaded with minerals from the depths of the ocean to the surface. When this occurs, it moves west along the surface, with a 70-metre zone of cool water and a 40-metre zone of warm water, that has been subducted under the cold water leading to a lot of turbulence quite often. When these conditions are present tiny algae called Rhizosolenia, part of the diatom family, begin to flourish. No thicker than two or three times the width of a human hair, they pile up ahead of the line as it moves west. They breed once a day to form baby diatomettes and this creates a very localized food source, that all the fish are attracted to. The white color of the line is caused by the huge collection of diatoms, the cooler water and the whitecaps, formed by the turbulence in the water. [1]
Even since 1926, records of the white line and associated features have been taking place. In that year an unnamed ocean explorer described the white line and its collection of diatoms as having the consistency of soup due to the abundance of ocean fauna. In these early days scientists were able to discover the time at which the line formed (between January and August, as mentioned earlier).
During a 10-year international study called the Joint Global Ocean Flux Study the white line was photographed for the first time, as the scientists were studying how currents, chemicals, ocean color, and temperature affected the overall ocean and it was during this study that the line was photographed and the scale of the event was discovered, by the Space Shuttle.
Also, scientists have measured the concentrations of these diatoms by lasers in low flying aircraft, during normal conditions and during the time in which the white line is present, and it has been found that the concentrations of these algae is up to 100 times greater in the white line period. [1]
These conditions are only rarely present and once one of the needed conditions fails, the Pacific returns to its normal state. Often, the line collapses because of the currents returning to normal and the cool waters return to the depths, causing the diatoms to die out (they need the difference in ocean temperature to flourish), the turbulence to cease and the fish to move elsewhere.
The Antarctic Circumpolar Current (ACC) is an ocean current that flows clockwise from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and has a mean transport estimated at 100–150 Sverdrups, or possibly even higher, making it the largest ocean current. The current is circumpolar due to the lack of any landmass connecting with Antarctica and this keeps warm ocean waters away from Antarctica, enabling that continent to maintain its huge ice sheet.
Marine biology is the scientific study of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy.
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems, and is often recognized by the discoloration in the water from their pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic, multicellular organisms like seaweed and microscopic, unicellular organisms like cyanobacteria. Algal bloom commonly refers to rapid growth of microscopic, unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest.
Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface. Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean. Polar packs undergo a significant yearly cycling in surface extent, a natural process upon which depends the Arctic ecology, including the ocean's ecosystems. Due to the action of winds, currents and temperature fluctuations, sea ice is very dynamic, leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs, which are chunks of ice shelves or glaciers that calve into the ocean. Depending on location, sea ice expanses may also incorporate icebergs.
The surface layer is the layer of a turbulent fluid most affected by interaction with a solid surface or the surface separating a gas and a liquid where the characteristics of the turbulence depend on distance from the interface. Surface layers are characterized by large normal gradients of tangential velocity and large concentration gradients of any substances transported to or from the interface.
The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America. It is an eastern boundary current flowing in the direction of the equator, and extends 500–1,000 km (310–620 mi) offshore. The Humboldt Current is named after the Prussian naturalist Alexander von Humboldt. In 1846, von Humboldt reported measurements of the cold-water current in his book Cosmos.
The seabed is the bottom of the ocean, no matter how deep. All floors of the ocean are known as 'seabeds'.
High-nutrient, low-chlorophyll (HNLC) regions are regions of the ocean where the abundance of phytoplankton is low and fairly constant despite the availability of macronutrients. Phytoplankton rely on a suite of nutrients for cellular function. Macronutrients are generally available in higher quantities in surface ocean waters, and are the typical components of common garden fertilizers. Micronutrients are generally available in lower quantities and include trace metals. Macronutrients are typically available in millimolar concentrations, while micronutrients are generally available in micro- to nanomolar concentrations. In general, nitrogen tends to be a limiting ocean nutrient, but in HNLC regions it is never significantly depleted. Instead, these regions tend to be limited by low concentrations of metabolizable iron. Iron is a critical phytoplankton micronutrient necessary for enzyme catalysis and electron transport.
Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment models and different proxies enable the scientific community to assess the role of the oceanic processes in the global climate by the re-construction of past climate at various intervals. Paleoceanographic research is also intimately tied to paleoclimatology.
Iron fertilization is the intentional introduction of iron to iron-poor areas of the ocean surface to stimulate phytoplankton production. This is intended to enhance biological productivity and/or accelerate carbon dioxide sequestration from the atmosphere.
A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems, which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two fields form the more general study area of freshwater or aquatic ecology.
The oceanic or limnological mixed layer is a layer in which active turbulence has homogenized some range of depths. The surface mixed layer is a layer where this turbulence is generated by winds, surface heat fluxes, or processes such as evaporation or sea ice formation which result in an increase in salinity. The atmospheric mixed layer is a zone having nearly constant potential temperature and specific humidity with height. The depth of the atmospheric mixed layer is known as the mixing height. Turbulence typically plays a role in the formation of fluid mixed layers.
The coastal zone color scanner (CZCS) was a multi-channel scanning radiometer aboard the Nimbus 7 satellite, predominately designed for water remote sensing. Nimbus 7 was launched 24 October 1978, and CZCS became operational on 2 November 1978. It was only designed to operate for one year, but in fact remained in service until 22 June 1986. Its operation on board the Nimbus 7 was limited to alternate days as it shared its power with the passive microwave scanning multichannel microwave radiometer.
The deep chlorophyll maximum (DCM), also called the subsurface chlorophyll maximum, is the region below the surface of water with the maximum concentration of chlorophyll. A DCM is not always present - sometimes there is more chlorophyll at the surface than at any greater depth - but it is a common feature of most aquatic ecosystems, especially in regions of strong thermal stratification. The depth, thickness, intensity, composition, and persistence of DCMs vary widely. The DCM generally exists at the same depth as the nutricline, the region of the ocean where the greatest change in the nutrient concentration occurs with depth.
![Harmful algal bloom Population explosion of organisms (usually [[algae]]) that can severely lower oxygen levels in natural waters, killing marine life](https://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/2008-08-22_White_German_Shepherd_swimming_in_algae.jpg/213px-2008-08-22_White_German_Shepherd_swimming_in_algae.jpg)
A harmful algal bloom (HAB) contains organisms that can severely lower oxygen levels in natural waters, killing organisms in marine or fresh waters. Some HABs are associated with algae-produced toxins. Blooms can last from a few days to many months. After the bloom dies, the microbes which decompose the dead algae use up even more of the oxygen, which can create fish die-offs. When these zones of depleted oxygen cover a large area for an extended period of time neither fish nor plants are able to survive.
An ocean is a body of water that composes much of a planet's hydrosphere. On Earth, there are five oceans. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans.
This is a glossary of terms used in fisheries, fisheries management and fisheries science.
The North Pacific Subtropical Gyre (NPSG) is the largest contiguous ecosystem on earth. In oceanography, a subtropical gyre is a ring-like system of ocean currents rotating clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere caused by the Coriolis Effect. They generally form in large open ocean areas that lie between land masses.
Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea. A habitat is an ecological or environmental area inhabited by one or more living species. The marine environment supports many kinds of these habitats.
Haida Eddies are episodic, clockwise rotating ocean eddies that form during the winter off the west coast of British Columbia’s Haida Gwaii and Alaska’s Alexander Archipelago. These eddies are notable for their large size, persistence, and frequent recurrence. Rivers flowing off the North American continent supply the continental shelf in the Hecate Strait with warmer, fresher, and nutrient-enriched water. Haida eddies are formed every winter when this rapid outflow of water through the strait wraps around Cape St. James at the southern tip of Haida Gwaii, and meets with the cooler waters of the Alaska Current. This forms a series of plumes which can merge into large eddies that are shed into the northeast Pacific Ocean by late winter, and may persist for up to two years.