March 23: Ocean Acidification Flashcards
Can you explain how increased CO2 concentrations in the atmosphere cause decrease in ocean pH?
Carbon dioxide dissolves in water and it forms carbonic acid. The carbonic acid splits part to form a bicarbonate ion and a hydrogen ion. The release of the hydrogen ion reduces the pH, because pH is the negative log of the hydrogen ion concentration.
Can you list factors that increase the acidity of coastal waters relative to the open ocean and explain why?
Higher fallout of atmospheric compounds and acid rain that contributes to ocean acidification.
Rivers carry carbonic acid that drains from soils in the watershed, the carbonic acid is formed during decomposition.
Can you explain how acidification of ocean waters is linked to eutrophication?
When you add more nitrogen in the water, it gets morea cidic, and since nitrogen is normally limited in water sources, the addition of nitrogen causes more algae to grow.
Can you explain how increased CO2 and acidity directly impact marine organisms?
Marine organisms can form calcium carbonate from carbonate ions and calciums ions to build their shells or other structures.
Finfish: Elevated carbon dioxide levels interfere with a major neurotransmitter, creating confused fish that will actually swim towards predators
Can you explain how increased CO2 and acidity indirectly impact marine organisms?
The loss of one species due to CO2 and acidity can result in the loss of another species that was eating the first one. The loss of coral due to CO2 and acidity means the loss of habitat for many species.
Why does seawater has a lower decrease of pH compared to freshwater?
Because seawater has a natural capacity to buffer against pH canges due to the natural presence of CO3 2- in seawater. But as more CO2 is added in the ocean, its capacity to buffer against pH change is reduced.
What does upwelling mean?
It occurs as winds move surface waters away from the coast.
Deeper water hold nutrients, so as the wind push the water on top of the ocean, water (and nutrients) from the bottom come up and then go away from the coast, following the way the wind goes.
