Question

build background
the activity on pages 324-325 of your textbook asks you to create a food web. a food web is a diagram that shows how energy and nutrients move through a community. the diagram below is an example. each organism in this food web is connected to another by an arrow. the arrows show the direction of energy flow in the ecosystem. finwhales eat zooplankton and get energy from zooplankton. this is represented in the diagram with an arrow that points from the zooplankton to the finwhale.
study this food web and answer the questions below to familiarize yourself with food webs before trying the from tiny to tremendous: marine food webs activity in your textbook.

1. what is the initial source of energy for this food web?
2. which organism in this food web is the producer?
3. which organism in this food web is a top consumer?
4. if the blenny population in this ecosystem suddenly decreased, what changes might occur in the ecosystem?

Explanation:

1. The food web diagram shows energy starting from the Sun, which is the ultimate energy source for most ecosystems as producers use it to make food.
2. Producers are organisms that make their own food using sunlight; phytoplankton in the diagram gets energy directly from the Sun, so it is the producer.
3. Top consumers have no predators shown in the web. Finwhale, tern, and scorpionfish have no arrows pointing away from them, meaning no other organism in this web eats them.
4. Blennys are food for hawfish, and blennys eat zooplankton. A decrease in blennys would reduce the food source for hawfish, lowering their population, and remove a predator of zooplankton, allowing zooplankton numbers to increase.

Answer:

1. The Sun
2. Phytoplankton
3. Finwhale, tern, scorpionfish
4. The hawfish population would likely decrease due to less food, and the zooplankton population would likely increase due to reduced predation from blennys.