How Bacteria can through a Wrench in an Ecosystem

The Salton Sea can be found in the Imperial Valley.  It has no rivers flowing into it to keep it replenished.  In fact, it was an accidental lake.   In 1905, the Salton Sea was formed when a levy on the Colorado River broke causing flooding of the Imperial Valley.  This led to an 18 month period where the water was freely flowing into the Basin.  From this free flowing water, the Salton Sea was created.  However, after the levy was fixed, there was no longer a flow of water into the lake.  At this point, the lake would be replenished by water coming from the agriculture fields.  The farmers in the Imperil Valley would flood their fields with water and then the run off would make its way into the Salton Sea.  The water would take with it the pesticides used in the fields as well.  However, the use of field flooding in agriculture has been decreasing over the years, which has led to a decrease in the Salton Sea’s size.

In all bodies of water you will find bacteria.  Most of the bacteria that exists in bodies of water is harmless in humans.  There are types that can cause harm to people.  However, people are not the only things that can be harmed by bacteria, fish can be too.  Bacteria can also decrease the level of oxygen that is present in a lake.  In order to survive, the bacteria needs to take up oxygen.  Therefore, in a lake it will eat away at the dissolved oxygen that is present in the water.

In this lab, we took water samples from the Salton Sea.  Once we were back in lab we created plates with the water to see what how much bacteria was present in the water.  We placed different amounts of the Salton Sea water onto agar plates in order to allow the bacteria to grow.  After five days, the plates were checked to see how much growth was present.  It was found that in the amount we plated there was around 120 bacterial colonies for every milliliter of water.  This means that for everyone milliliter of water in the Salton Sea there would be around 120 bacteria colonies present.

We also confirmed there was bacteria present in the water by taking a reading of the dissolved oxygen levels of the water.  A reading of the water was taken and then it was caped and placed in a dark cupboard for five days.  After five days the concentration of dissolved oxygen was checked again and it had decreased.  Due to the fact that there were no interaction s able to occur in the water, it was confirmed that there was bacteria present eating up the dissolved oxygen.

I think it is important to understand the presence of bacteria in the Salton Sea.  This is due to the fact that it is affecting the ecosystem.  Not only can some of the bacteria have the possibility to negatively harm the fish, it is also using up the limited supply of dissolved oxygen.  This is then in turn decreases the fish’s ability to survive.  This can in turn affect the migrating process of birds.  The Salton Sea is an important ecosystem for multiple facets so it is important to understand what is affecting it.  By understanding what is affecting the ecosystem we can begin to make changes to improve it.

3 thoughts on “How Bacteria can through a Wrench in an Ecosystem

  1. I agree that its important to know the bacteria living in our varying bodies of water as it has a ripple effect (pun intended)! Oxygen content of water is crucial to avoid dead zones and provide good living conditions for the water’s inhabitants! We should evaluate the bacterial levels of other bodies of water near us in San Diego because I’m sure some would be surprising.

  2. I think the Salton Sea is confusing to many people because of the odd way that it was created. It is difficult to decide on how to address its issues mentioned in this article since it seems harmless to leave it alone because of its man made origin. I know that the Salton Sea is viewed differently by locals vs outsiders. I hope that a good decision on what to do with it will be made relatively soon.

  3. It is interesting to look at the big picture how bacteria can effect a whole ecosystem. Without proper knowledge, we cannot make the changes that we need to in order to make the world a cleaner place. Before this class I did not realize that bacteria can contribute so much to changing migratory patterns of birds.

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