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Earth Science Finals

Terms in this set (13)

There are multiple threats and ways in which we can help restore our endangered rivers. The first threat to endangered rivers is climate change. Climate change can affect various factors within these habitats. One example of this is when the water temperature changes, it makes it harder for the fish to survive because they are cold-blooded reptiles and can't adapt to temperature change as easily as humans can, therefore they prefer cooler water. One way in which we can help restore our rivers is by reducing the amount fossil fuels we burn or atmospheric pollution in general. Another threat to endangered rivers is daming. Daming can hurt many natural ecosystems. One example of this is when fish try to swim through the dams and get caught in the turbine blades. Often times, when fish are migrating, they will inevitably come across a dam. There is really no way for the fish to go on with their lives after passing a dam. They can either be shredded to death by turbine blades or take the exhausting journey up and down a fish ladder, where they will later be too tired to reproduce. The only actual way to help restore river ecosystems is by eliminating dams once and for all. The final threat to endangered rivers is the pollution of water quality. The pollution of water quality is a major threat because it can affect the amount of drinking water we will have in the future. Since we have cut down so many of our forests, it has damaged our natural filtration system. The natural filtration system is what will remove pollutants from the originally clean water. One way in which we can prevent this from happening is by protecting and defending important forest lands along our rivers.
There are 5 ways in which a scientist proves that a substance is a mineral. The first way is that the substance must be a solid. This means that the object must be rigid and not fluid. The second way is that the substance must be inorganic. This means that the substance can not have been a living thing at any point in time. The third way is that the substance must be made by processes that occur in the natural world. One example of a mineral that was made by processes that occur in the natural world is quartz. Quartz is made from magma that cools and hardens deep inside of earth's surface. The fourth way is that the substance must have a definite chemical composition. This means that a mineral always contains certain elements in precise proportions. The final way is that the substance must have a definite crystalline structure. This means that the fragments of the structure must match up creating a repeating pattern. If a friend were to tell me that a pencil were a mineral, I would have a few reasons to convince them why it wasn't. My first argument would be that the pencil wasn't made by processes that occur in the natural world. It's eraser, paint, and metal ring were most likely made in artificial factories with machines making thousands at a time. My second argument would be that the pencil is not 100% inorganic. The wood that the graphite is covered with would probably be made from a tree, which was most certainly alive at one point in time. Although a pencil is still a solid, it was not made by processes that occur in the natural world and does not have a definite chemical composition. It also doesn't have a definite crystalline structure. These are all reasons why a pencil is not a mineral.
he four possible solutions relating to sustainable fishing are fish farming, fish quota, decrease in the amount of time allowed to fish, and closing marine reserves. Fish farming can be considered a possible solution because the farmers are only taking few fish from the ocean and creating hundreds more. One reason why this will not work is because the farmed fish are being fed with fish that were hunted and coming from the ocean, therefore they are still killing a significant amount of fish. Fish quota can also be considered a possible solution because it forces fisherman to limit the number of fish they take from the ocean, take fish population into consideration, and to choose their catches wisely. One reason why this will not work is because if a fisherman happens to catch more fish than they are allowed, the fisherman must throw the fish overboard. This leads to millions of pounds of fish meat being wasted each year because of this law. This system is extremely wasteful.
Another possible solution relating to sustainable fishing is to decrease the amount of time that fisherman can fish for. This might work because if fisherman aren't fishing for as much time, they won't be able to catch as many fish, therefore leaving more and more fish unharmed and still alive inside of the big, blue sea. One reason why this system will not work is since fisherman are only given a limited amount of time to fish, they will try to make their time at sea as efficient as possible, therefore they will use much more destructive equipment to catch as many fish as they possibly can. The final solution relating to sustainable fishing is to close off marine reserves. This might work because it helps the it allows the fish in that area's population to recover and then the area can be re-opened while another area is closed off because that population seems low. If this pattern continues to repeat itself, then each marine reserve should have a healthy fish population. One reason why this possibility will not work is because in theory, it is difficult to know which area to close off and for how long because you never know when a school of fish from a neighboring area is swimming by and might give officials the wrong idea.