Marine ecosystem
What is a marine ecosystem?
An aquatic environment that supports marine life, including both biotic and abiotic factors.
What causes tides on Earth?
The gravitational pull of the moon and the sun.
What is the base of most marine food webs?
Phytoplankton
What organisms build coral reefs?
Coral polyps
What is overfishing?
Harvesting fish faster than they can reproduce.
What type of symbiotic relationship benefits both species involved?
Mutualism
What is a spring tide?
A tide with the greatest difference between high and low water, occurring during new and full moons.
What is a primary consumer in the marine food chain?
An organism that eats producers, like zooplankton.
What is the symbiotic algae that lives in coral tissue called?
Zooxanthellae
What type of pollution causes toxic algae blooms?
Nutrient pollution (eutrophication) from fertilizers.
Give an example of a keystone species in a marine ecosystem.
Sea otters (help control sea urchin populations in kelp forests)
Name one major surface ocean current.
The Gulf Stream
What happens when top predators are removed from a food web?
It can cause a trophic cascade, disrupting the balance of the ecosystem.
What type of water do coral reefs need to thrive?
Warm, shallow, clear, and low-nutrient water.
How does plastic pollution affect marine animals?
They can ingest or become entangled in plastic.
What is the difference between the pelagic and benthic zones?
Pelagic is open water; benthic is the ocean floor
How does the Coriolis effect influence ocean currents?
It causes them to curve right in the Northern Hemisphere and left in the Southern Hemisphere.
What’s the difference between a food chain and a food web?
A food chain shows one path of energy flow, while a food web shows many interconnected paths.
What causes coral bleaching?
Stress (like warm water) causes corals to expel their zooxanthellae.
What is ocean acidification?
A decrease in ocean pH due to CO₂ absorption from the atmosphere.
Why are estuaries considered highly productive ecosystems?
Because they receive nutrients from rivers and the ocean, supporting diverse life.
What drives thermohaline circulation?
Differences in water density caused by temperature (thermo) and salinity (haline).
Why is energy lost between trophic levels?
Most energy is used for metabolism or lost as heat, so only about 10% moves to the next level.
Name two threats to coral reefs caused by humans.
Overfishing and pollution (or climate change and coastal development).
How can Marine Protected Areas (MPAs) help ocean health?
They limit human activity to protect biodiversity and allow ecosystems to recover.