Eutrophic Dead Zones

Question 1

Steps of creation of EDZs

Answer 1

1) Nutrients washed into sea increasing productivity of marine ecosystems
2) algae build up on surface crating algal bloom
3) algal blooms prevent light penetrating surface to organisms below and prevent oxygen Being absorbed
4) filter feeds such as shellfish absorb microbes associated with algal blooms and cause sickness when the shellfish are eaten by humans

Or 1,2,3…
4) the number of diversity of organisms reduce

5) lack of fish below algal blooms impacts wading birds that rely on fish for food
6) algal. Looks die out quickly because not enough oxygen to support them
7) dead organisms sink to seabed to be decomposed by bacteria
8) decomposition uses up almost all the oxygen creating a dead zone where most aquatic species cannot survive

Question 2

Example of eutrophic dead zone

Answer 2

Baltic Sea is one one of the largest in the world

This is due to increased runoff from fertilisers

Question 3

What are dead zones

Answer 3

Areas of oceans where low concentrations of oxygen are aren’t able to support marine life mostly cause by humans pollution on the sea