Coral Bleaching
What is coral bleaching and what causes it?
Coral bleaching occurs when corals expel zooxanthellae due to stress, like heat, causing them to lose color and health.
Define marine species and give two examples.
Organisms that live in saltwater ecosystems; e.g., dolphins and coral.
What is ocean temperature and why is it important?
It’s the measure of ocean warmth, crucial for weather, currents, and marine life.
What is El Niño?
A periodic climate event causing warm ocean temps in the Pacific.
What is sea-level rise?
The increase in average ocean levels due to melting ice and thermal expansion.
What role do zooxanthellae play in coral health?
They provide energy through photosynthesis and help corals build their skeletons.
What is an ectotherm, and how does it differ from an endotherm?
Ectotherms rely on external heat; endotherms generate internal heat.
Describe one way ocean temperature influences global climate.
Warmer oceans can intensify storms and change wind patterns.
How does El Niño affect ocean temperatures?
It raises surface temperatures in the equatorial Pacific Ocean.
Define sea ice levels and describe one reason they are decreasing.
Amount of floating ice on the ocean; declining due to global warming.
How does coral bleaching affect marine biodiversity?
It destroys habitat for many marine species, reducing biodiversity.
How do rising ocean temperatures affect the reproductive success of marine species?
It can reduce fertility, cause stress, and disrupt breeding cycles.
How does warmer ocean water contribute to sea-level rise?
Through thermal expansion—water expands as it warms.
Name one marine ecosystem that is impacted by El Niño and describe the effect.
The Peruvian coast—El Niño reduces upwelling, harming fish stocks.
How does the melting of polar sea ice influence marine species?
It destroys habitats like those for polar bears and seals.
Explain how increased ocean temperature leads to the expulsion of zooxanthellae.
Heat disrupts the photosynthetic process, causing corals to expel zooxanthellae to protect themselves from oxidative stress.
Explain the concept of metabolic stress and its effect on fish behavior.
Increased metabolism can lead to faster exhaustion and altered movement, affecting feeding and migration.
How can even a 1–2°C increase in ocean temperature disrupt marine ecosystems?
It can lead to coral bleaching, altered migration, and species death.
Compare normal Pacific Ocean conditions with El Niño conditions.
Normally, cold water upwells off South America; El Niño brings warm water and disrupts that flow.
Explain how greenhouse gases contribute to climate change.
They trap heat in the atmosphere, raising global temperatures.
Describe two long-term ecological consequences of repeated coral bleaching events.
Reef collapse and permanent loss of biodiversity and fish populations.
How might climate change shift the geographical distribution of marine organisms?
Warmer waters may force species to migrate poleward or to deeper waters.
Explain the feedback loop between ocean temperature and coral reef degradation.
Warmer temps bleach corals, reducing reef protection, which worsens erosion and local warming.
How could climate change intensify the effects of future El Niño events?
Warming oceans may make El Niño events more frequent and severe.
Predict one long-term consequence of sea-level rise on human coastal communities and marine life.
Coastal flooding displaces people and damages marine ecosystems like mangroves and estuaries.