Adding an organism to a food chain does not affect the other members of the food chain, but removing an organism does.

This is false. Say you have a food chain where a monkey is the top predator. Then you introduce something that eats what the monkey does. The monkey populations will plummet and that means that the things they eat will start to get more numbers. Adding and subtracting animals throws everything out of order.

Removing any level from an ecosystem disrupts a delicate balance that may have; and a diverse, with many levels and intricate relationships between organisms. More predators kill more prey, which, along with food scarcity, decreases the an attempt to control the population, but it had no effect on habitat degradation.