Balanced environments, Algae and Phosphates (5/1-5/5)

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Summary:

Mountain Lions and Deer

People think of mountain lions as predators that simply eat and kill deer. There is much more to mountain lions than that. Mountain lions eat and kill deer that are usually sick, old, weak, or young and can't get away from mountain lions that are hunting for food. This makes the population of deer healthier. On the other hand, hunters kill a lot of deer that are healthy, which is not as good.

People think of deer as harmless, innocent animals, but they are very dangerous. They are responsible for death, injuries, and damage to property because of many car crashes. Deer can also cause overgrazing, which can cause erosion because different plants that are meant to prevent erosion cannot grow back.

Algae and Phosphates

Algal blooms are when there is an increase of algae in a body of water. Algae are water plants that live in fresh and saltwater. They make food from the sunlight, also known as photosynthesis. Some algae in the water is important for fish because they are producers food web, but too much algae in the water can harm fish in many different ways. 

Many fish and water insects cannot breathe oxygen from the air. Fish live in water but they breathe dissolved oxygen from air bubbles. Fish tanks often have pumps which bubble oxygen so that the fish can breathe. Some animals need less oxygen, but other animals need more. Without the oxygen that they need, some animals die. This can ruin a food chain because the animals that were depending on the other animals will also die. Water plants make oxygen in the water, but too many water plants can cause oxygen to be taken away because when they die and rot, bacteria use up all of the dissolved oxygen. Warmer temperatures can also cause low oxygen because warm water cannot hold as much oxygen. Water life like trout, which need a lot of oxygen will die. Some other water life like carp don't need as much oxygen, can live, but they might not survive in very low oxygen.

Phosphates are chemicals that are needed for plants and animals to grow. There is always a small amount of phosphates in the water, but too much can harm the fish. Phosphate pollution comes from human waste, animal waste, and factory waste. Too many phosphates build up in the water and can also come from laundry detergent, manure, and fertilizer. Phosphates are important because they help algae grow. Too many phosphates cause too much algae in the water. You can tell when there is more algae because the water becomes green. 

Water Pollution

Farms are big polluters of rivers and streams. They pollute with chemicals from different fertilizers, sediment from erosion and overgrazing, and animal waste. Animal waste has phosphates, which can cause algal blooms, fish kills, and non-drinkable water. Waste gets washed into streams from livestock areas, and from fields where it is used as fertilizer for crops.

Losing clear water can happen because of algal blooms and sediment. Cars and lawns may be to blame. The clarity of a lake is a key measure of the lake's health and is determined by how deep a Secchi disk can be seen. Algal blooms are caused by too many phosphates and nitrates in the water. Phosphates may come from golf courses and homes. Nitrates can come from air pollution, from cars and cities.

SP8: Obtain, Evaluate and Communicate Information

This week, we obtained, evaluated, and communicated information. We used scientific text to obtain important information, evidence, and ideas. We evaluated this information by doing small experiments and thinking about and answering questions on a google form. Lastly, we communicated this information by having a class discussion, where we talked about the information and what we read in the articles. This process helped us understand more about the topic and information.