The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the diagram to answer the following.

Which of these best describes the role of the blue crab in the estuary ecosystem?

The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the diagram to answer the following.

The croaker, menhaden, and striped bass are fished for food. Which of these graphs shows how a decrease in the fish populations would most likely affect the copepod population?

Which of these best describes the role of the krill in this food web?

Use the technical passage below to answer the following. Scientists Explore An Aspect of Fish Migration

In addition to eating fish eggs, the arctic grayling also eats insects and small fish. What is the ecological role of the arctic grayling?

A team of scientists conducted a study of a wetland. Using samples collected from the wetland, the scientists estimated the total biomass at each trophic level. Their data are shown below.

Explain the relationship between trophic levels and biomass. In your response, be sure to include

• the roles of the organisms found at the different trophic levels
   
• how each trophic level obtains energy
   
• why the available energy changes at each level
   
• why the amount of mass differs at each of the trophic levels
   

A marine environment provides a habitat for a variety of plants and animals. A small part of a marine food web is shown below.

Which of these describes the role of the sanderling in the marine food web?

The energy pyramid below shows the flow of energy through the organisms in a kelp forest ecosystem in the Pacific Ocean. Use the diagram to answer the following.

What is the lowest level of the energy pyramid that contains carnivores?

A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea ecosystem.

The scientists discovered a species of fish that eats other fish and decaying matter. Which of these does not describe the newly discovered fish?

A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea ecosystem.

Scientists have recently discovered hydrothermal vent communities on the ocean floor. A diagram of a hydrothermal vent community is shown in the figure below.

The organisms in this community live near heated vents. Inorganic compounds such as sulfides mix with extremely hot water when they are released from the vents. Bacteria use the sulfides to make food for themselves and other animals. Many of these bacteria live in the bodies of the giant tubeworms and the giant white clams that live in this community.

Hydrothermal vent communities are often destroyed by lava erupting from the ocean floor. After the lava has cooled, different organisms begin to inhabit the area. Over a period of a few years, organisms inhabit the area in the following order:

sulfur bacteria -> crabs -> giant tubeworms -> clams and mussels

Which of these best identifies this sequence of events?

Part of the food web in Yellowstone National Park is shown below.

Gray wolves were reintroduced into Yellowstone National Park in 1995. Two years later, the population of coyotes had decreased by 50%. Coyotes were found in all habitats of the park before the gray wolves were reintroduced. Now, coyotes are most often found in the hills and mountains.

Which of these describes the role of the vole in the Yellowstone ecosystem?

Use the diagram of the marine food web below to answer the following.

Which of these best describes the relationship between the phytoplankton and zooplankton?