Day to Day 3 Flashcards
Can oysters have high mercury levels?
Like other metals, mercury accumulates in tissue as it moves up the food chain, which means larger, carnivorous fish contain more mercury than smaller ones. Thus the FDA advises children and pregnant women not to eat swordfish, king mackerel or tilefish. “
Oysters are first order consumers. They eat phytoplankton.
biomagnification
when toxins become more and more concentrated in the the tissues of organisms as you go up the food change.
high level consumers
consumers at a higher trophic level either secondary or tertiary.
MD. Bald eagles suffered from the ddt. It affected reproductive abilities including severe thinning of egg cells. Strange because eagles did not eat the small insects that ddt affected
how does biomagnification occur?
organisms only keep 10% of energy from the trophic level below. The remaining energy is lost as heat. As you move up trophic levels, the animals will have to consume far more biomass from the level below to be able to compensate for this and survive. And everything it consumes below could have the toxins in its tissues.
Cricket example: a cricket has 1 calorie of energy and for it to get that 1 calorie of energy it had to eat 10 calories of lettuce. Where did the other 9 calories go? It is not turned into cricket flesh, most of it is used just to live like to power its muscles or run the sodium potassium pumps in its neurons. So only 1 calorie of the 10 calories of food is leftover as actual cricket stuff.
Elements like mercury which are puffed out of smoke stacks of coal fired power plants end up getting absorbed in the ocean by green algae and marine plants. While the tiny animal that eats the algae only stores 10% of the energy it got, it keeps 100% of the mercury, so as we move up the chain, each trophic level consumes ten times more mercury than the last and that’s what we call bioaccumulation. Concentrations get much higher at each trophic level until a human gets a hold of that giant tuna that’s at the top of the marine food chain and none of that mercury has been lost, it’s all right there in that delicious tuna flesh. Because organisms only hold 10% of the energy they ingest, each trophic level has to eat about 10 times its biomass to sustain itself. And beacuase 100% of that mercury moves up the food chain, that means that that it becomes 10 times more concentrated with each trophic level it enters. That’s why it’s probably safest to eat lower on the food chain. Primary producers or primary consumers, the older, bigger higher in the food chain, the more toxic it’s going to be.
MD picture showing 10 times more mercury with each trophic level.
How does mercury get into oceans
Nearby anthropogenic sources, such as coal burning and mining of iron, can contaminate water sources with mercury. After mercury enters lakes and ponds, bacteria transform mercury into a more easily absorbed toxic substance called methylmercury, which is efficiently absorbed in the bodies of fish. Through the process of biomagnification, mercury levels in each successive predatory stage increase.
“Mercury pollution is produced when rock is heated during processing to form taconite pellets. Gogebic says that in addition to a large open pit mine, the site will include a taconite plant. The pellets are used to make steel. Mercury is an air pollutant that converts to its toxic form in water and is consumed by fish.”
Already, the DNR said that iron ore mines and processing plants in Minnesota and Michigan are the largest source of airborne mercury pollution in the Lake Superior basin.
MD - Coal burnging
anthropogenic
(chiefly of environmental pollution and pollutants) originating in human anthropogenic emissions of sulfur dioxide.
MD anthropo- + -geny, attested 1839. As it were from a Greek ἀνθρωπογένεια (anthrōpogéneia), hypothetical abstract noun of ἀνθρωπογενής (anthrōpogenḗs, “born of man”).
Born of man. anthro man - genesis - the origin or formation of something.
Why does oxygen level in the atmosphere remain constant
The reason why the oxygen percentage is constant for many years is because that the green plants who are capable of photosynthesis are taking up CO2 and producing 02 in exchange. Amazon forests are said to be responsible for 20% of the world’s oxygen.
The content of Oxygen mainly depends on the content of CO2. Every time a CO2 molecule is produced from burning fossil fuels we lose 3 molecules of Oxygen. Oxygen levels have dropped down a lot since the industrialization.
MD. show amazon forest producing 20% of world’s oxygen and CO2 emissions from burning fossil fuels squeezing out O2 in the atmosphere.
+ ocean phytoplankton responsible for 70%
What is the composition of gasses in the atmosphere
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
why is radiation bad?
Radiation damages the cells that make up the human body. Low levels of radiation are not dangerous, but medium levels can lead to sickness, headaches, vomiting and a fever. High levels can kill you by causing damage to your internal organs. … Exposure to radiation over a long time can cause cancer.
How does coal generate electricity?
Simply put, coal-fired electricity generation is a five-step process: Thermal coal (either black or brown) that has been pulverised to a fine powder is burned. The resulting heat is used to turn water into steam. The steam at very high pressure is then used to spin a turbine, connected to an electrical generator.
MD - Picture of Coal
how does a generator create electricity
An electric generator is a device that converts mechanical energy obtained from an external source into electrical energy as the output. … Faraday discovered that the above flow of electric charges could be induced by moving an electrical conductor, such as a wire that contains electric charges, in a magnetic field.
how does coal make energy
Thermal coal (either black or brown) that has been pulverised to a fine powder is burned
The resulting heat is used to turn water into steam
The steam at very high pressure is then used to spin a turbine, connected to an electrical generator
The spinning turbine causes large magnets to turn within copper wire coils; this is called the generator
The moving magnets cause electrons in the wires to move from one place to another, creating an electrical current and producing electricity.
(https://www.originenergy.com.au/blog/about-energy/what-is-coal.html)
