A) They eliminate oxygen from water. B) They act as predators to most fish. C) They can provide food for certain species. D) They filter pollutants from water.
A) Reduced salinity B) Cold water currents C) High pH levels D) Eutrophication
A) Coastal areas B) High mountain streams C) Open ocean D) Freshwater lakes
A) The Black Sea B) Lake Baikal C) The Amazon River D) The Arctic Ocean
A) They migrate during breeding season. B) They have a slow growth rate. C) They can reproduce both sexually and asexually. D) They require complex mating rituals.
A) Airborne surveys B) Satellite tracking C) Radioactive tagging D) Underwater sound monitoring
A) The polyp stage of jellyfish. B) The mature, free-swimming stage of jellyfish. C) The larvae stage of jellyfish. D) A type of jellyfish predator.
A) Their strong propulsion ability B) Their thick gelatinous bodies C) Their ability to swim against strong currents D) Their ability to drift with currents |