All Flashcards
Define Zone of Tolerance.
The range of conditions where an organism can survive and thrive.
What are indicator species?
Species sensitive to environmental changes, used to assess ecosystem health.
Define Dissolved Oxygen (DO).
The amount of oxygen present in water, crucial for aquatic life.
What is Biological Oxygen Demand (BOD)?
The amount of oxygen needed by organisms to break down organic waste.
Define hypoxic.
An environment with low oxygen levels.
Define anoxic.
An environment with no oxygen.
What is the Oxygen Sag Curve?
It shows how DO changes downstream from a pollution source.
What is the effect of high BOD on aquatic ecosystems?
Leads to low DO, causing hypoxic or anoxic conditions that harm aquatic life.
What are the environmental consequences of the Deepwater Horizon oil spill?
Killed wildlife, damaged fisheries, and released carbon through cleanup methods.
What are the environmental consequences of the Exxon Valdez oil spill?
Oiled coastlines, killed animals, and hurt the local economy.
How can increased nutrient levels affect aquatic ecosystems?
Leads to excessive algae growth. When these algae die, they are decomposed by microorganisms, which use up large amounts of dissolved oxygen in the process. This can lead to a decrease in DO levels, which can harm fish and other aquatic life.
What impacts water quality?
Recreation, drinking water, and fishing.
What is the relationship between BOD and DO?
High BOD leads to low DO, which is harmful to aquatic life.
How does temperature affect DO?
Cooler water holds more DO than warmer water.
What is the significance of indicator species?
Their presence or absence indicates ecosystem health and pollution levels.