Ecosystem energy flow, nutrient cycling, and responses to disturbance.
Test your knowledge with these top questions!
During a toxic red tide, which seafood can collect toxins by filtering seawater?
Algal toxins can remain in shellfish after the water clears, outlasting the visible discoloration of a bloom.
Which pesticide built up in food chains and helped cause bald eagles to lay thin-shelled eggs?
DDT breaks down into DDE, which interferes with the calcium needed to form strong eggshells.
When a large algal bloom dies and decays, which dissolved gas can drop to dangerously low levels?
Bacteria use oxygen as they break down dead algae, leaving fish with less oxygen to breathe.
Antarctic blue whales feed mainly on which tiny crustaceans?
Krill eat microscopic algae, turning food too small for a blue whale to catch directly into a large meal.
Roughly what share of energy typically passes from one feeding level to the next?
Organisms use much of the energy they take in for movement and metabolism, leaving less for the animals that eat them.
What is pollutant buildup within a single organism over time called?
An animal can absorb a contaminant faster than its body removes it, so levels can rise even when its diet stays the same.
Which two nutrients are major drivers of algal blooms caused by fertilizer runoff?
Rain can carry fertilizer off fields and lawns into lakes, giving algae the same nutrients that help crops grow.
In a food web, a bear eating both berries and salmon is classified as what?
An omnivore can feed at different levels in a food web, depending on whether a meal comes from plants or animals.
Which property helps a pollutant biomagnify in food chains?
Some persistent pollutants collect in fatty tissues, so predators receive stored contamination when they eat prey.
If mercury biomagnifies through algae, zooplankton, small fish, and tuna, which has the highest concentration?
A tuna eats many contaminated fish over its lifetime, so mercury from separate prey collects in one predator.