Whales feed on fish and krill. Predict what would happen to the numbers of fish and krill in the ocean if the numbers of whales declined.

• The will stay the same

• The number of fish and krill will increase

• The number of fish and krill will decrease

Was your prediction correct?

• Yes

• No

Whales keep fish and krill alive by contributing to the health of the ecosystem in which these species live.

• True

• False

By eating at depth and releasing fecal waste near the surface, whale play a role in cycling which of the following nutrients?

• Potassium and sodium

• Sulfur and titanium

• Calcium and magnesium
• Nitrogen and iron

How do the nutrients, returned to the ocean's surface in whale feces, impact ocean food webs?

• Nutrients in whale feces fertilize plant phytoplankton, a primary producer

• Whale feces produce algal blooms, creating ocean dead zones

• Nutrients in whale feces are toxic to fish populations.
• Whale feces create barriers that block sunlight from reaching the ocean floor.

In addition to nutrient cycling, what other way do whales help plant plankton to survive, photosynthesize, and reproduce at higher rates?

• Whales consume plankton to reduce competition.
• They push up to the surface where it receives sunlight

• Whales create bubbles that block sunlight for plankton.
• Whales migrate to warmer waters to help plankton thrive.

What gas does plankton remove from the atmosphere through the process of photosynthesis?

• CH₄

• NO₂

• O₂

• CO₂

Whales DO NOT remove enough carbon from the atmosphere to impact the climate

• True

• False

Carbon dioxide is a greenhouse gas. In what way does the removal of carbon dioxide from the atmosphere impact global climate?

• It lowers average temperatures by returning more heat to space

• It has no net impact on global climate

• It raises average temperatures by trapping heat near the earth's surface

How would you describe whales impact on the health of their ecosystems?

• Positive; they play a large role in keeping oceans healthy

• Negative; their feces contaminates ocean water

• Neutral; they release as much carbon into the atmosphere as they remove