BIOL2108H - Marine Pollution and Acidification

increasing CO₂ is leading to…

ocean acidification

sources: where CO₂ is made

91% fossil fuels and cement, 9% land use change

sinks: where the CO₂ goes

50% atmosphere, 26% land, 24% oceans

oceans absorb…

CO₂ from the atmosphere, creating carbonic acid in the waters

ocean acidification

-occurs when CO₂ dissolves in the ocean, producing carbonic acid and lowering the pH

-decreases the availability of carbonate needed to make shells and skeletons

calicification of shells

-even small reductions in pH = Ca shells are harder to form

-warmer temperatures decrease the rate of acidification, but water still gets more acidic

energy and carbon (biomass) aren’t the only things passed through animals in a food chain

-persistent organic pollutants POPs) include some pesticides, pharmaceuticals, solvents, and other industrial chemicals

• slow to degrade in the environment

• can move long distances

• accumulate in fatty tissue

• passed on through blood, tissue, and breast milk

-heavy metals include mercury, lead, cadmium, and chromium

bioaccumulation

toxins build up in an individual as it ages through repeated exposure

biomagnification

toxins accumulate in higher trophic levels through consumption

main idea 2 recap

humans are altering marine ecosystems through ocean acidification and biomagnification, affecting both bottom and upper trophic levels