Answer:
Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants.
Just go with 78 as the answer
Right there are 440 known species of sharks around the world right now discovered by humans so far there are more sharks around the world that we hadn't discovered yet. Here are some sharks: Hammerhead Sharks, Sand Sharks,Saw Sharks, Carpet Sharks and much more.
