Care must be taken to ensure that such effects are avoided, or at least minimized. Giant ships ply the oceans and large lakes of the world, carrying raw materials and manufactured products. In northwestern Ontario, the waterways were the only practical means of travel for native peoples and for the first Europeans who traded with them. These uses of water should be sustainable, provided ships are careful to avoid dumping waste materials, and provided accidents do not result in the spillage of toxic pollutants such as oil. Unfortunately, both of these problems continue to occur all too frequently.
Water is valuable to humans as a recreational resource.
We use it for swimming, boating, and fishing. We ski on it, skate on it and play with it. Again, if done properly, these uses should have minimum impact on its future use and on other users. However, overuse, or careless use, can affect other people and other living things which also rely on this water, both now and in the future. Aquatic Ecosystems Water is so fundamental to our very existence that we must seek to learn how it affects our lives, and how our lives affect it and the other living things that rely on water for their existence.