Friday, November 26, 2010

Nose Hill Park Pond: How does human impact affect different interactions in the Nose Hill pond? by Jessica & Eric

Nose Hill Park is the second largest park in Calgary and one of the largest in Canada. It is a place in which you can escape from the city life and just enjoy the natural environment. Nose Hill Park is home to countless organisms and between all of the different organisms, there are varying symbiotic relationships and interactions. A symbiotic relationship is an interaction between organisms which can result in organisms benefitting and organisms being harmed. Four different types of interactions that occur in Nose Hill are as follows:
Commensalism: a symbiotic relationship between organisms which results in one organism benefitting and another organism being neither benefitted nor harmed.
For example, a tree being the home to a Richardson’s ground squirrel. The squirrel benefits, in this case, because it has shelter and a home provided by the tree. The tree is not affected because the squirrel does not harm or benefit it.

Mutualism: a symbiotic relationship between organisms in which both organisms benefit.
For example, a deer and a bird. Birds eat insects off a deer therefore this benefits both the deer and the bird. The deer gets cleaned while the bird gets food/energy.

Parasitism: a symbiotic relationship between organisms in which one organism benefits while the other is harmed.
For example, a mosquito biting a human. When a mosquito bites a human, the mosquito receives blood from a human, therefore is receives its necessary food for survival. The human is left with an irritant where the mosquito bit them. Therefore, the mosquito benefits while the human is harmed.

Predation: an interaction where an animal (predator) hunts/kills another animal (prey) for food/energy. Predator and prey are usually from different species’.
For example, a Swainson’s hawk hunting mice. A Swainson’s hawk needs mice for energy/food therefore needs to kill and consume mice to survive.

Figure 1. The pond that was studied in
Nose Hill Park.  A picture I took of
the pond upon arrival at Nose Hill Park.
            My Biology 20 class at Sir Winston Churchill High School had the opportunity to do research on three different biomes at Nose Hill Park. The three biomes were grassland, forest and pond. My partner and I were assigned to the pond biome and studied the many different symbiotic relationships and interactions that occurred both in the pond, and around it.

          When my partner and I arrived at Nose Hill Park, the first thing we noticed was the roads and houses that were so close to the pond. We wondered how the human impact affected the symbiotic relationships and interactions in and around the pond. The pond was near one of the entrances to the park; therefore it was also surrounded by a road, meaning that there were vehicles nearby polluting the pond and the air around it. Across the road and up a steep hill, there were houses. This meant that when it rained, all of the chemicals that had been leaked from the houses would end up in and near the pond. Also, the chemicals and garbage on the road would end up there through precipitation and wind.
Figure 2. Houses close to the pond. 
Figure 3. Cars on the road.
An example of human impact.  
            Contaminants that could leak into the pond are fertilizers. If fertilizer were to get into the pond from people fertilizing their yards, it would create a large increase in growth of algae. Algal bloom is an accumulation and increase in the population of algae in a body of water. If fertilizer were to run down the hill from the houses in figure #2, across the road, and into the pond, algal bloom could be a problem. Not only will the population of algae increase, but other plant species’ population will increase. This is caused by the phosphorus in fertilizers. The more plants you have in a pond, the fewer other organisms you can have. This is because of the dead organic matter that gets decomposed by bacteria. With more food for bacteria available, the population of bacteria will increase. This causes a decrease in the dissolved oxygen in the pond. If the dissolved oxygen decreases, so will the population of oxygen-dependent organisms. The entire pond food chain can be affected by one simple use of fertilizer by humans.  Organisms depend on other organisms for survival. If one organism dies, another organism which is dependent on that organism will be affected negatively. This causes changes in the interactions between organisms. An example of an affected interaction would be the diving beetle and its food. The diving beetle eats insects and tadpoles. If the large numbers of plants use up most of the dissolved oxygen, the insects and tadpoles will have a tougher time surviving and die. This affects the diving beetle because it now does not have its needed food; therefore it will also die. Also, the population of fish which feed on diving beetles will decrease and so on.
Figure 4. A diving beetle.
A diving beetle that was found
and caught while at the Nose Hill Park pond.

          Vehicles on the road would affect the interactions between the organisms in and near the pond because of pollution. Motor vehicles release carbon emissions which pollute the air and cause global warming. If harmful gases and chemicals are released through these emissions, the air will be contaminated and so will the pond. The oxygen that animals breathe in will not be as healthy as it could be without harmful pollutants. This would cause a hinge in the survival of the organisms and affect the food chain; therefore affecting the interactions between organisms.

Houses and roads were not the only signs of human impact, however. While at the park, evidence of human impact was found. Several times, we found garbage and an oil spill was even found on the edge of the pond.
Figure 5. A gum wrapper (beside pond)
Evidence of human impact in Nose Hill Park.

Figure 6. A Plastic Bag (in pond)Evidence of human impact in Nose Hill Park.
Figure #7: A chip bag (beside pond). 
Evidence of human impact in Nose Hill Park.
The garbage that was found surrounding the pond is a problem, not only for the environment, but for the well-being of the organisms living on and inside the pond. Plastic cannot decompose but gets broken down into tiny pieces when the sun hits it. It contains substances like polyethylene and when broken down, polyethylene releases harmful chemicals. If the plastic is ingested by animals, it can cause them to become sick or even die. If the plastic eventually gets turned into plastic dust, it can leak into the soil and into the pond. While at the Nose Hill pond, we noticed that there were ducks floating on the water. If a duck were to eat a piece of plastic, it could be severely harmed. If there is more garbage, there is a larger chance of the ducks consuming it. This would cause a decrease in the population of ducks and an increase of population in the fish that they consume. This would cause an issue with predation between the ducks and the fish (because the ducks are the predator to the fish, which are the prey) and would have a domino effect on the rest of the food chain; for example, what the fish ate and so on. If this affects ducks, think of all the other organisms that would be harmed due to the ingestion of plastic. That is how litter can affect the interactions between different species in the pond.

Figure 8. Ducks at Nose Hill.
A photo taken of ducks on the Nose Hill Pond.
            Part of the purpose of Nose Hill Park is recreation. Nose Hill is a great place to go for a walk and get exercise. But, when people walk over the grass and plants, it damages the vegetation. Not only will it damage the plants though, it will also kill insects and other organisms living where the individual stepped. This would also cause a domino effect with whatever eats the plant, animal, or insect that died and whatever the plant, animal or insect eats. This causes changes in the interactions between certain organisms.

            Roads and vehicles, houses, pathways, and litter are all evidence of human impact. All of these things have negative affects towards the pond and the other ecosystems of Nose Hill.  In conclusion, there are numerous ways that human impact can affect the interactions between organisms living in and around the pond. Nose Hill Park is a source of recreation and relaxation; it is a place that you can enjoy the natural environment away from the city.

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