Human Impact Drag the terms to fill in the blanks about the effects humans have on resources, play an important part in the health of Earth. Human activity such as can originate from small or large sources, such asoil spills, and recreation. Any pollution runoff can affect beaches and ocean habitats. food from the ocean can create an imbalance in existing ocean food webs. Human activity can also cause and spread disease. Humans often also introduce to natural areas, which can be dangerous and damaging to an ecosystem. ​