Marine Phytoplankton - Free Essay Example

Sample details Pages: 3 Words: 1022 Downloads: 1 Date added: 2017/09/11 Category Advertising Essay Did you like this example? Phytoplankton From Wikipedia, the free encyclopedia Jump to: navigation, search Diatoms are one of the most common types of phytoplankton. Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words (phyton), meaning plant, and (planktos), meaning wanderer or drifter. [1] Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, they may appear as a green discoloration of the water due to the presence of chlorophyll within their cells (although the actual color may vary with the species of phytoplankton present due to varying levels of chlorophyll or the presence of accessory pigments such as phycobiliproteins, xanthophylls, etc. ). Contents [hide] * 1 Ecology * 2 Aquaculture * 3 Blooms * 4 See also * 5 References * 6 External links [edit] Ecology Phytoplankton are the foundation of the oceanic food chain. Don’t waste time! Our writers will create an original "Marine Phytoplankton" essay for you Create order When two currents (in this case the Oyashio and Kuroshio currents) collide, they create eddies. Phytoplankton become concentrated along the boundaries of these eddies, tracing out the motions of the water. Phytoplankton obtain energy through the process of photosynthesis and must therefore live in the well-lit surface layer (termed the euphotic zone) of an ocean, sea, lake, or other body of water. Phytoplankton account for half of all photosynthetic activity on Earth. [2] Thus phytoplankton are responsible for much of the oxygen present in the Earths atmosphere – half of the total amount produced by all plant life. 3] Their cumulative energy fixation in carbon compounds (primary production) is the basis for the vast majority of oceanic and also many freshwater food webs (chemosynthesis is a notable exception). Since the 20th century, phytoplankton has declined by roughly 1% yearly, possibly linked to warming oceanic temperatures as of 2010 this means a decline of 40% relative to 1950. [4][5] As a side note, one of the more remarkable food chains in the ocean – remarkable because of the small number of links – is that of phytoplankton feeding krill (a type of shrimp) feeding baleen whales. Phytoplankton are also crucially dependent on minerals. These are primarily macronutrients such as nitrate, phosphate or silicic acid, whose availability is governed by the balance between the so-called biological pump and upwelling of deep, nutrient-rich waters. However, across large regions of the World Ocean such as the Southern Ocean, phytoplankton are also limited by the lack of the micronutrient iron. This has led to some scientists advocating iron fertilization as a means to counteract the accumulation of human-produced carbon dioxide (CO2) in the atmosphere. 6] Large-scale experiments have added iron (usually as salts such as iron sulphate) to the oceans to promote phytoplankton growth and draw atmospheric CO2 into the ocean. However, controversy about manipulating the ecosystem and the efficiency of iron fertilization has slowed such experiments. [7] While almost all phytoplankton species are obligate photoautotrophs, there are some that are mixotrophic and other, non-pigmen ted species that are actually heterotrophic (the latter are often viewed as zooplankton). Of these, the best known are dinoflagellate genera such as Noctiluca and Dinophysis, that obtain organic carbon by ingesting other organisms or detrital material. The term phytoplankton encompasses all photoautotrophic microorganisms in aquatic food webs. Phytoplankton serve as the base of the aquatic food web, providing an essential ecological function for all aquatic life. However, unlike terrestrial communities, where most autotrophs are plants, phytoplankton are a diverse group, incorporating protistan eukaryotes and both eubacterial and archaebacterial prokaryotes. There are about 5,000 species of marine phytoplankton. [8] There is uncertainty in how such diversity has evolved in an environment where competition for only a few resources would suggest limited potential for niche differentiation. [9] In terms of numbers, the most important groups of phytoplankton include the diatoms, cyanobacteria and dinoflagellates, although many other groups of algae are represented. One group, the coccolithophorids, is responsible (in part) for the release of significant amounts of dimethyl sulfide (DMS) into the atmosphere. DMS is converted to sulfate and these sulfate molecules act as cloud condensation nuclei, increasing general cloud cover. In oligotrophic oceanic regions such as the Sargasso Sea or the South Pacific Gyre, phytoplankton is dominated by the small sized cells, called picoplankton, mostly composed of cyanobacteria (Prochlorococcus, Synechococcus) and picoeucaryotes such as Micromonas. [edit] Aquaculture Diagrams of some typical phytoplankton. Main article: Algaculture Phytoplankton are a key food item in both aquaculture and mariculture. Both utilize phytoplankton for the feeding of the animals being farmed. In mariculture, the phytoplankton is naturally occurring and is introduced into enclosures with the normal circulation of seawater. In aquaculture, phytoplankton must be obtained and introduced directly. The plankton can either be collected from a body of water or cultured, though the former method is seldom used. Phytoplankton is used as a foodstock for the production of rotifers[10], which are in turn used to feed other organisms. Phytoplankton is also used to feed many varieties of aquacultured molluscs, including pearl oysters and giant clams. The production of phytoplankton under artificial conditions is itself a form of aquaculture. Phytoplankton is cultured for a variety of purposes, including foodstock for other aquacultured organisms[10], a nutritional supplement for captive invertebrates in aquaria. Culture sizes range from small-scale laboratory cultures of less than 1L to several tens of thousands of liters for commercial aquaculture[10]. Regardless of the size of the culture, certain conditions must be provided for efficient growth of plankton. The majority of cultured plankton is marine, and seawater of a specific gravity of 1. 010 to 1. 026 may be used as a culture medium. This water must be sterilized, usually by either high temperatures in an autoclave or by exposure to ultraviolet radiation, to prevent biological contamination of the culture. Various fertilizers are added to the culture medium to facilitate the growth of plankton. A culture must be aerated or agitated in some way to keep plankton suspended, as well as to provide dissolved carbon dioxide for photosynthesis. In addition to constant aeration, most cultures are manually mixed or stirred on a regular basis. Light must be provided for the growth of phytoplankton. The colour temperature of illumination should be approximately 6,500 K, but values from 4,000 K to upwards of 20,000 K have been used successfully. The duration of light exposure should be approximately 16 hours daily; this is the most efficient artificial day length[10]

The Progressive Era During The 1920 S - 973 Words

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Grading System free essay sample

Today’s world computer is more reliable when it comes to information. Computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem. Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU), and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit can change the order of operations in response to stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved. In World War II, mechanical analog computers were used for specialized military applications. During this time the first electronic digital computers were developed. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). |the inefficiency of the policies | | |ignorance |International declaration of laws for children. |promulgated by the government to | | |lack of education |â€Å"Sagip Batang Manggagawa† Program during Aquino’s |eradicate child labor. The government| | |exploitation of cheap and unorganized |governance |has tried to curb child labor, | | |labor |â€Å"Global March Against Child Labor† , an international|pushing for the enforcement of age | | | |campaign to champion the cause of some 250 million |limits in the work place, providing | | | |children worldwide who are forced to work for |protection for young workers. The | | | |survival. efforts have largely failed because | | | | |of the lack of muscles to back up | | | | |these laws. | Ways on how can I improve the status condition of the identified social problems and issues. My role as a teacher in society is both significant and valuable. It has far-reaching influence on the society and no other personality can have an influence more profound than that of a teacher. Students are deeply affected by the teachers love and affection, his character, his competence, and his moral commitment. My importance as a teacher is an architect of our future generations. Fails to find an opening in any other walk of life gets into this profession and recklessly plays with the destiny of the nation and contribute to a worst condition of the country’s social problems and issues Educating the young to meet these challenges has become a priority objective for every society. The young generation is entering a world which is changing in all spheres – scientific and technological, political, economic, social and cultural. The outlines of the ‘knowledge- based’ society of the future are forming. As a teacher I may say that I can lead my student anywhere. During their early education, the students tend to determine their aims in life and their future plans, in consultation with their teachers. Therefore, I can play a prominent role in making the future of my students. As a teacher I should consider my duty to educate and train my students and should feel responsible for it. My stand on the RH Bill As the issues about the RH Bill are getting hot and have become the center of a controversial national debate, still I am in support for it. The Reproductive Health bill, popularly known as the RH bill, aim to guarantee universal access to methods and information on birth control and maternal care. I stand within this government program not to go against the religious law but to be concerned on the good aspect within the RH Bill. One of the main concerns of the bill, is the rapid growth of population in the Philippines. It states that the Filipinos are responsive to having smaller-sized families through free choice of family planning methods. The rapid population growth worsens poverty while poverty spawns rapid population growth. And so this bill may be of help to improved quality of life through a consistent and coherent national population policy. The connection between rapid population growth and poverty affects the economic growth and population growth rates of Philippines. It indicates that the RH Bill program can be of great help for economic growth and poverty reduction. Prepared by: Precious Raizel J. Anonuevo

Ugly Essay free essay sample

The definition of beauty varies with one another. Not one human being in this world can perfectly define the word beauty. The word beauty carries so many explanations that Judge each person differently. Who are you to say what the true meaning of beauty is? I believe that everyone In this planet deserves to be called beautiful. Whether it comes from your own parent or a loved one, each and every human being deserves the right to be beautiful.When you define something as ugly hat goes through your head? Ugly doesnt mean not having the perfect face, body , or hair. The term ugly shouldnt define such person who doesnt deserve It. But what characteristics are needed to be seen to be defined as beautiful? When seeing a pretty person, do you automatically see them as beautiful? Do you even consider the fact that their personality may be considered ugly? People all over the world have become Judgmental and Judge a book by Its cover. We will write a custom essay sample on Ugly Essay or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Those people out there may not even be what you may see as beautiful. They may seem so self conscious that they look for what they dont have themselves. Having low self esteem may act as an effect in a persons judgment of another person. When you think of yourself as beautiful you may not see someone else as beautiful as you are. If you are consciously always thinking of yourself as ugly then you may see others as the true definition of beauty.Beauty can be a misused word because everyone has something that is beautiful. Appearance or your true self shouldnt be the only things that people judge as beautiful. It can also be the way you think and or any other talents you may have. I cannot define beauty myself because Im still on the route on finding what it truly means to me. Once I find out what I personally think about beauty then I may have a slight bit off definition of the term beauty.