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Any field might be ecological, economical etc....... ty

2006-08-28 02:00:19 · 4 answers · asked by clearie 1 in Science & Mathematics Biology

4 answers

Protists, eukariotic unicellular beings can be very harmful to human health like Amoeba (amoebiasis) or Toxoplasma (toxoplasmosis).
Can endanger whole ecosystems like Dinoflagellata (red tide)
Economy of fisheries can be damaged by same dinoflagellates.

2006-08-31 10:45:26 · answer #1 · answered by pogonoforo 6 · 1 0

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h The term "red tide" is most often used in the United States of America to describe a particular type of algal bloom common to the eastern Gulf of Mexico, and is also called "Florida red tide". This type of bloom is caused by a species of dinoflagellate known as Karenia brevis, and these blooms occur almost annually along Florida waters. The density of these organisms during a bloom can exceed tens of millions of cells per liter of seawater, and often discolor the water a deep reddish-brown hue. The most conspicuous effects of red tides are the associated wildlife mortalities among marine and coastal species of fish, birds, marine mammals and other organisms. In the case of Florida red tides, these mortalities are caused by exposure to a potent neurotoxin produced naturally by Karenia brevis, called brevetoxin. It is unclear what causes red tides, but the frequency and severity of algal blooms in many parts of the world have been linked to increased nutrient loading from human activities. The growth of marine phytoplankton is generally limited by the availability of nitrates and phosphates, which can be abundant in agricultural run-off. Coastal water pollution produced by humans and systematic increase in sea water temperature have also been implicated as contributing factors in red tides. Other factors such as iron-rich dust influx from large desert areas such as the Saharan desert are thought to play a major role in causing red tides. Some algal blooms on the Pacific coast have also been linked to occurrences of large-scale climatic oscillations such as El Niño events. While red tides in the Gulf of Mexico have been occurring since the time of early explorers such as Cabeza de Vaca it is unclear what initiates these blooms, and how large a role anthropogenic and natural factors play in their development. Algal blooms in many parts of the world cannot be reasonably linked to human influence, and are generally accepted as a natural occurrence. It is also debated whether the apparent increase in frequency and severity of algal blooms in various parts of the world is in fact a real increase or is due to increased effectiveness of monitoring programs and species identification ability [1] [2]. Some red tide organisms produce large quantities of toxins, such as saxitoxin, ciguatoxin, and brevetoxin, which disrupt the proper function of ion channels in neurons. Domoic acid, a toxin produced by diatoms of the genus Pseudo-nitzschia, has been linked to neurological damage in certain marine mammals, and is frequently found in algal blooms on the U.S. West Coast. Some red tide toxins can become highly concentrated in various marine organisms that have the ability to filter and consume large quantities of toxic plankton directly from seawater. These include shellfish, finfish, baleen whales, and benthic crustaceans. Frequently, shellfish collected in areas affected by algal blooms can be potentially dangerous for human consumption, leading to closures of shellfish beds for harvesting. Initial signs of shellfish poisoning from red tide toxins such as domoic acid is tingling in the lips followed by a reduction of motor abilities and difficulty breathing and can be fatal if consumed in sufficient amounts. If these symptoms occur after eating shellfish, seek immediate medical treatment. Standard medical treatment is to give victims oxygen, or to hook them up to a breather. There exists no antidote, and treatment consists of keeping the patient alive until the toxin has passed from the system. Note that in some cases, the brevetoxin in Florida red tides can become aerosolized, causing respiratory irritation to beachgoers. Toxins commonly associated with red tide are brevetoxins, saxitoxins, domoic acid, okadaic acid, azaspiracid, and ciguatoxin

2016-04-09 05:05:33 · answer #2 · answered by Shirley 4 · 0 0

My awnser is

2015-10-22 09:40:04 · answer #3 · answered by chavi 1 · 1 0

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2014-09-29 01:58:55 · answer #4 · answered by Alexis Quijada 1 · 0 0

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