Predator and Prey
The balance of nature is how animals depend on each other for food. When nature is in balance the populations of the animals are controlled. However, if one type of animal eats most of its natural prey, the prey's population goes down too far and recovering its population through natural reproduction may become a big problem. Without enough food, the predator's population may also die and both animals could become extinct.
Our class talked about how the balance of nature controls both predator and prey populations. One animal depends on another. For example, the deer, which can be prey to other animals and even humans, may face extinction because too many people hunt for deer for sport, food, and their skins for clothing. As another example, if too many fish are caught or otherwise killed, there won't be enough left to lay eggs and have babies and they, too, may become extinct.
Other factors affect the balance of nature as well. For example, the amount of certain types of animals decrease by forest fires destroying their homes. Without food and shelter, the animals may die.
Dams on the rivers can cause problems for fish returning to spawn. If the fish can't get over the dams, they can't return to their spawning grounds where they were born, and they die before they lay their eggs. Humans catch fish on their trips to the spawning grounds. Between sport fishing and the need for electricity from our dams, many fish are killed and their populations become very low. Fishing also affects whales and dolphins who accidentally get caught in fishing nets.
There isn't much of a way to stop how low a certain animal's population gets in nature. We need to be careful about how humans affect other animals. We talked about whether or not it is important for certain animals to live and we discussed if there are ways to stop unnecessarily taking lives.