How many food chains are there in the food web picture

Based on the information below, list the following species in order of lowest to highest on the food chain: Mackerel, Dolphins, Birds, Krill. (Hint: If two species occupy the same level, they would be located at an equal position in the food chain).

3) Below is a simple food chain that represents the food chain in Yellowstone National Park in the Western Region of the United States. Use this image to help you answer the questions below a) Why are so few apex predators supported in this food chain compared to the number of producers or primary consumers?  b) If someone accidently introduced a poison like DDT into this food chain what type of effects would you expect to see to happen to animals higher in the food chain over animals that are on the lower end of the food chain?  c) Wolves although at the top of the food chain, are important in controlling this entire system. What type of species is that called and why are they so important?

Based on the food web shown the lion, the vulture, and a snake are all consumers . Identify the type of consumer they represent .Explain what this means