Marine animals are impacted by ocean plastic because:

It is full of toxins
It traps them, and when they eat it they can starve
It takes up space in their natural habitat
It kills their food, meaning they're left with nothing to eat

All of the given reasons are correct. Marine animals are impacted by ocean plastic because it is full of toxins, it traps them, and when they eat it they can starve, it takes up space in their natural habitat, and it kills their food, meaning they're left with nothing to eat. When plastics are exposed to saltwater and sunlight they can break down into microplastics, which can be ingested by marine animals and cause health problems. Additionally, larger pieces of plastic in the ocean can entangle and trap marine animals, leading to injury or death. Plastics that accumulate in the ocean can also displace marine animals from their natural habitats, and harm or kill the animals that they rely on for food.