In Alaska's Aleutian Islands, sea otters were heavily hunted and sea urchins became more abundant. What happened to kelp forests?

Wolves and mountain lions were eliminated from forests of the eastern United States. What feeding-relationship change contributed to widespread failure of tree seedlings to regenerate?

As Isle Royale's wolf population declined, moose faced less predation. What was the likely effect on balsam fir seedlings?

In Robert Paine's Washington rocky-shore experiment, Pisaster sea stars were removed. Which organism came to dominate much of the available space?

DDT biomagnification reduced peregrine falcon populations in North America. If falcons were lost from a local food web, what would likely happen to their small-bird prey?

After the northern cod fishery collapsed off Newfoundland, cod predation on prey such as capelin was greatly reduced. Reasoning from energy flow alone, what would you predict?

Where dingo populations are reduced by poison baiting in parts of Australia, kangaroos may increase. What is the likely effect on heavily grazed vegetation?

As cougars became scarce in Zion Canyon, mule deer browsing intensified. What happened to young cottonwoods?

After gray wolves were reintroduced to Yellowstone, elk spent less time browsing in some streamside areas. What effect on willow would less browsing predict?

Wolf reintroduction in Yellowstone altered interactions among predators. Which carnivore often declined where wolves became established?

In Yellowstone, fewer coyotes after wolf reintroduction changed predation on pronghorn young. What happened to pronghorn fawn survival in areas with fewer coyotes?

Sea otters were translocated back to parts of southeastern Alaska where urchins had grazed kelp. What response best predicts the restored food web?

Wolves were relocated to Isle Royale beginning in 2018 as moose browsing had increased. If the wolves establish a breeding population, what should happen to browsing pressure on fir?

On California's Channel Islands, bald eagle restoration helped discourage golden eagles that preyed on island foxes. What was the likely result for island foxes?

In Elkhorn Slough, recovering sea otters eat crabs that prey on sea slugs. What chain best predicts the effect on eelgrass?

Dams in the Pacific Northwest block salmon from reaching upriver spawning habitat. Bears then carry fewer salmon carcasses into nearby forests. What happens to forest soil nutrients?

After Nile perch were introduced into Lake Victoria, many native cichlid populations declined. Which food-web effect could follow if the lost cichlids had grazed algae?

Zebra mussels invaded the Great Lakes and filter large quantities of phytoplankton from the water. Which group receives less food energy in the open-water food web?

The brown tree snake introduced to Guam caused major declines in native forest birds. Which forest process can decline when fruit-eating birds disappear?

Deepwater Horizon oil damaged marsh vegetation along the Gulf Coast. How does a reduction in marsh plant biomass affect detritus-based food webs?

Nutrient runoff contributes to the Gulf of Mexico dead zone. After an algal bloom dies and decomposers use dissolved oxygen, what happens to energy transfer to fish?

Coral bleaching on the Great Barrier Reef expels symbiotic algae from corals. What happens to gross primary productivity by the coral-algae association?

Diversion of rivers for irrigation contributed to the Aral Sea's shrinkage and rising salinity. As fish populations collapsed, what happened to energy moving from aquatic producers to fish consumers?

In a kelp forest where sea otters are lost, urchins can remove much of the kelp. What happens to the energy that kelp would have fixed and passed into the food web?

The energy pyramid shows a recovering grassland. What percentage of producer energy reaches primary consumers?