What is the impact of mercury on an aquatic community?

Question

How does mercury affect aquatic life? What is the effect of it? and Is the effect linked to bio-magnification? If so, how?

Answer 1

Mercury is a pollutant that is classified as a persistent bioaccumulative toxin, or PBTs. It does not degrade and cannot be destroyed and thus builds up in the food chain over time. An aquatic ecosystem typically consists of aquatic plants, small fishes and larger predatory fishes—which are at various trophic levels (their respective positions in a food chain) and are dependent on each other for subsistence. Hence, once mercury enters a trophic level it will affect the entire ecosystem. As we move higher and higher in the food chain, the concentration of mercury is increasingly elevated.

Contamination of the Water



Mercury is released in the atmosphere as a result of human activities, such as industrial emissions, or from natural sources such as volcanic and geothermal activity. When rain or snow absorbs mercury present in the atmosphere or when a dry deposition of mercury occurs, it may eventually be washed into water bodies by rain. Bacteria present in soils and sediments then transform mercury into methylmercury, which is a more toxic substance. Methylmercury subsequently enters the food chain in the aquatic ecosystem.

Answer 2

Some info I copied from a project I had done before:

Once released to the air, mercury will eventually fall back to the land and water streams. It is then

consumed by bacteria and is converted to “methylmercury”, a type of mercury that can be easily

absorbed by fish, animals, and plants. Methylmercury is concentrated in food chain through

bioaccumulation, building up in older and larger fish and animals. Since it is not mobilized well, it

cannot be removed from body.



Adverse health effects of mercury on human include mental retardation and damage to nervous

system. The extent of damage from mercury to human body is highly dependent on dosage and

timing of exposure. It is generally recommended that child bearing women, pregnant

women, and children under twelve years of age carefully watch their mercury consumption.



According to CSP report, maximum allowable concentration of mercury in freshwater is 1.4 µg/lit.

Toxicity threshold for fish content of mercury is 1.0 mg/kg (wet weight) (CSP, 2006).



Treatment technologies for low concentrations of mercury in water i.e. up to 10 µg/lit include:

• Filtration

• Lime softening

• Reverse osmosis

Lime softening is a water treatment method that removes ions in the water through chemical

reaction by utilization of calcium hydroxide. Filtration of water includes various methods; reverse

osmosis can be considered as a filtering technique as well.



For more info, search in google "mercury factsheet". should come up with documents like:

http://www.akaction.org/Publications/Fact_Sheets/MD_Mercury_fact.pdf



hope it helps

Answer 3

properly one thank you to attitude it is to think of a few waterborne pollutant that has effects on the backside point of your nutrients chain. to illustrate a pollutant that has effects on the quantity of light or oxygen that is transmitted/ dissolved during the outdoors of the water. this would effect the photosynthetic algae and flora on the backside of your nutrients chain. in the event that they don't look to be waiting to photosynthesize, they don't stay and secondarily do not feed the organisms that consume them. think of of the cascade effect -> small fish consume flora/ algae medium fish consume small fish super fish consume medium fish birds consume super (medium and small) fish greater predators consume the birds in case you do not have the flora and algae on the commencing up of the nutrients chain -- particularly you do not have something. the biomagnification is supplied in once you think of of all the nutrients chains that are blended to create the nutrients internet of that aquatic community. each and all the chains in that internet are based on the manufacturers on the commencing up of the hyperlink. all chains in the internet would be afflicted by a decline in manufacturers in the aquatic community. wish this facilitates :)

Answer 4

Well its Bad... and it does gets magnified in food chain as it is a Heavy metal.



http://en.wikipedia.org/wiki/Minamata_disease



go to this link for better research...