Pollution

2. A type of pollutant concentrated in the tissues of shellfish
4. Heavy metals found in marine organisms as pollutants (7 letters)
5. This metal, along with mercury, is toxic to aquatic life (4 letters)
6. Substance used in agriculture that can leach into water, causing pollution
12. The general term for substances that harm the environment
14. sewage The term for untreated human or animal waste in water (9 letters)
15. A water pollutant often found near nuclear power plants
16. Organisms like sludge worms that thrive in polluted water
18. The effect of algal blooms on underwater plants
19. A gas produced by anaerobic respiration in cattle and flooded fields

1. A pollutant that encourages the growth of algae and bacteria in water
3. Tiny organisms that respire anaerobically and contribute to pollution
7. The process of algae using up oxygen at night
8. Process by which fertilizers are washed into rivers and lakes
9. The type of oxygen depletion caused by high levels of organic waste (7 letters)
10. The element in fertilizers that leads to eutrophication
11. A condition caused by excessive nutrients in water, leading to algae blooms
13. waste The type of waste that includes paper and plastics
15. A visual pollutant that also contains harmful leaching chemicals (7 letters)
17. bloom The aquatic effect of fertilizers leading to plant and fish death