How harmful is marine debris? Objective Students will be able to: 1. Define the vocabulary term marine debris. 2. Explore the effects of marine debris on animals, people, vessels, and habitats. 3. Identify which marine debris is most harmful. Background Marine debris can have serious impacts on both marine wildlife and humans. Debris can entangle, maim, and even drown many wildlife species. Animals can also mistake some debris for food; once ingested, these materials can cause starvation and/ or choking. Although almost any species can be harmed by marine debris, certain species – including se Duration: 60 Minutes.