Nutrient Cycles Page 1 Nutrient Cycles the earth

Nutrient Cycles Page 1

Nutrient Cycles • the earth is a closed system – matter and energy are continually recycled Page 2

Page 3

A closed System • Biosphere II today Page 4

A closed system • Biosphere I Page 5

• the availability of nutrients can be increased or decreased due to human activity – thus the balance is altered – this imbalance compromises sustainability Page 6

SUSTAINABILITY The Impacts of Human Activities Page 7

~ Eutrophication ~ Fertilizers in the Environment! Page 8

Eutrophication animation Eutrophication is a process in which nutrient levels in aquatic ecosystems increase. Eutrophication can lead to increased numbers of primary producers (algae) Page 9

Eutrophication Cultural Eutrophication – the process is accelerated due to human activities Page 10

Factors that influence Eutrophication Fertilizers and nutrients enter an ecosystem intentionally or accidentally: Example (intentionally) : Sewer system running into a river Example (accidentally) : Run off from agricultural land Page 11

Nitrogen and phosphorus are the two elements most responsible for eutrophication. nitrates nitrites ammonia phosphates Page 12

Human Factors that Influence Eutrophication: Nitrogen Concentrations Septic Systems Phosphorus concentrations Septic systems Detergents Fertilizer run off Animal excrements Industrial wastes Animal wastes Paving and development Industrial waste Water treatment plants Fossil fuels Forest fires Synthetic materials Page 13

What are the effects of Eutrophication? - Algal bloom - Low oxygen levels for aquatic organisms - Animal Mutations and death Page 14

To Do: Read Pages 302 -303 -Complete the back of your sheet of notes Page 15

• Answers to text questions • Science in the News! – Video – Battling the Bloom – Lake Erie Page 16

• Video – Sick Fish, Eutrophication and Dead Zones Page 17