Here are the solutions to the questions: a) Name the type of ecosystem represented by the above food web Aquatic ecosystem b) Name the organism in the food web that i) Is a producer Phytoplanktons ii) Occupies the highest trophic level. Hawks c) i) Write a food chain that ends with the hawk as a quaternary consumer. Phytoplanktons → Zooplanktons → Frogs → Snakes → Hawks ii) State two short terms effects on the above ecosystem if all the small fish were killed • The population of snakes and hawks would decrease due to a lack of their food source. • The population of zooplanktons and snails would increase due to reduced predation. d) i) How does oil spills lead to death of fish? Oil coats the gills of fish, preventing them from absorbing oxygen from the water, leading to suffocation. Additionally, toxic components in the oil can poison the fish. d) ii) Name one other cause of water pollution apart from oil spills. Industrial waste (or sewage, agricultural runoff, plastic waste)