The Pond, by Mariam and Stanley

September 15^th, 2010:

            Dr. Pike and Ms. Wilson’s biology 20 class went to Nosehill Park from Sir Winston Churchill high school to learn about ecology and make connections about different ideas, questions and concerns about the ecosystems there. The ecosystem that we looked at was the pond.

Figure 1.  the pond at Nose Hill.

First Impressions

Human interference didn’t seem too bad. From the exterior, the pond seemed perfectly healthy, filled with organisms thriving and interacting with one another. A hawk circled the sky, perhaps looking for its prey, something like a mouse. This would be an example of predation, an interaction in which one species kills and consumes another species to gain energy. Walking forwards, we found a variety of organisms around the pond, such as a black salamander (figure 2). We hypothesized that, because of the approaching cold weather of September, it was looking for a place to stay to keep warm, perhaps a hole dug by another organism; if the other organism was unaffected, this would be a commensalistic relationship, whereas if the other organism was negatively affected, it would be parasitism. We were surrounded by interactions.

Figure 2.  A tiger Salamander found under
some wood at the pond.

A Closer Look

The pond, in all its interactions, looked healthy, but we decided to take a closer look. Strapping on his chest wader, Stanley braved it out and walked into the pond to collect a water sample as well as organisms with a net (figure 4). There were a great number of organisms with a wide variation, but we also noticed that we did not see any fish. We decided to look further into the chemicals in the pond. Researching, we found that the pond was acidic. It had a pH of 6.

Some Explaining To Do

           Why was the pH acidic? A variety of reasons. Firstly, pH, the measurement of free hydrogen ions in a substance, determines the acidity of a substance. Natural functions can contribute to this process. These may include:

·         Biological filtration

o       When releasing ammonia (NH₃), nitrogen and hydrogen ions are released. Bacteria break this ammonia down into nitrite (NO₂), causing the three hydrogen ions to release. H+ ions cause a drop in pH. _{(Roocroft, 2010)}

Figure 3.  An interaction between a spider
and a thistle plant; commensalism.

·         Photosynthesis

o       Plants, fish and bacteria constantly undergo photosynthesis, a process where carbon dioxide (CO₂), energy and water (H₂O) are used to create oxygen (O₂) and glucose (C₆H₁₂O₆). _{(Roocroft, 2010)}

Figure 4.  Stanley collecting a pond sample.

Unfortunately, living in such an urbanized area, with roads right at the top of the hill beside the pond, humans must have interfered with the acidity of the pond in some way or another. Another reason for the acidity being unnaturally high is chemicals from humans washing into the pond. Since there are homes at the top of the hill parallel to the road, chemicals may have washed in from things like soaps, fertilizers, and other interfering factors. Litter does not prove to be an enormous problem at the pond; however it was present in small amounts. The chemicals may have also seeped through to the pond water because of rain, as water levels rise significantly and much washes into the pond. For more information on this pond, including what YOU can do to help keep it healthy, check out Mariam R. and Stanley C’s podcast or vodcast!

Bibliography

Roocroft, Tony. (2010.) pH levels. Retrieved from the internet:

http://www.pond-doctor.co.uk/longpHlevels.html

Is the Nose Hill Park Pond Healthy? by Keerthanaa and Emily

          The pond we examined at Nose Hill Park, which is located in Calgary, Canada. Our goal was to test whether the pond is healthy or not. We tested for characteristics of the pond: water quality, soil quality, insects in the pond and plants that surround the pond. A healthy pond will have the right amount the required elements and also organisms that normally live in and around a healthy pond.

Figure 1.  A soil sample.

Pond Water

The first thing we tested was the water quality. We tested the concentration of free iron, chelated iron, ammonia, phosphate, nitrate and calcium in the pond water. We also tested the pH and the temperature.

           When we conducted the free iron test, the water sample remained colourless, which meant that there is 0mg/L of free iron present in the pond water. This is an ideal level of iron for the pond water. When we conducted the chelated iron test, the water sample turned into a yellow colour. The water sample was supposed to remain colourless or turn into different shades of purple. This means that water may be contaminated with other substances or there might be no chelated iron in the pond water. When we conducted the ammonia test, the water sample turned into a yellow colour. This means that there is 0ppm (or mg/L) of ammonia present in the pond water. In an established aquarium, the ammonia level should always remain at 0ppm. The presence of ammonia indicates possible over-feeding, too many fish, or inadequate biological filtration. When we conducted the phosphate test, the water sample remained colourless. This means there is 0mg/L of phosphate present in the pond water. For fresh and saltwater, the ideal concentration of phosphate should never be greater than 1mg/L of phosphate. When we conducted the nitrate test, the water sample remained colourless. This means that there is 0mg/L of nitrate present. This is an ideal level of nitrate for the pond water. When we conducted the calcium test, the water sample turned from a light pink to a purple colour in 30 minutes. This means that there are 5mg/L of calcium in the pond water. When we checked the pH level of the water sample, the pH paper turned into a light green colour. This means that the pond water has a pH of 7. The pH level for a healthy pond should be around 6-7. The temperature of the water was 10^oC which is normal for ponds in Calgary.

Pond Soil

          Soil quality is also another factor which can tell us if the pond is healthy or not. We tested the amount of free iron, chelated iron, ammonia, phosphate, nitrate and calcium in the pond water. We also tested the pH and the temperature. When we conducted the free iron test, the sample remained colourless. This means there is 0mg/L of free iron in the soil. This is an ideal level of free iron for the soil. When we conducted the chelated iron test, the sample turned into a light bluish-purple colour. This means that there is 0.25mg/L of chelated iron in the soil which is ideal. When we conducted the ammonia test, the sample turned into a light green colour. This means that there is 0.50ppm of ammonia in the soil, which is almost healthy. When we conducted the phosphate test, the sample turned into a light yellow colour. It was supposed to remain colourless or turn into different shades of blue. This means that the soil is contaminated with other substances and/or may not have any phosphate at all. When we conducted the nitrate test, the sample turned into an orange colour. This means that there is about 4.0mg/L of nitrate in the soil which is ideal. When we conducted the calcium test, the sample turned from light to pink to violet in 30 minutes. This means that the calcium measure is below 20mg/L as Ca²⁺ which is ideal. When we checked the pH level, the pH paper turned a dirty yellow colour. This tells us that the pH level of the soil is 5, which means the soil is acidic. This is not good as the pH level for pond soil should be around 6-7.

Figure 2.  Snowberry.

Plants

          A few of the plants that surrounded the pond are Snowberry plant and Canada Thistle.

         Snowberry is a multi-branched, evergreen, vine-like shrub that climbs in neighbouring vegetation to heights of up to 10'. The fruits are clusters of conspicuous, round, small, white drupes with crystal clear, fleshy pulp. The seeds resemble coffee beans. Snowberry grows best in rich, fertile soils and is often found in hardwood hammocks and coastal shell mounds. It prefers sunny locations and is often found in association with cabbage palm.

Figure 3.  Canada thistle.

          Canada thistle is an age,gressiv creeping perennial weed that infests crops, pastures, rangeland, roadsides and non-crop areas. Generally, infestations start on disturbed ground, including ditch banks, overgrazed pastures, tilled fields or abandoned sites. Canada thistle reduces forage consumption in pastures and rangeland because cattle typically will not graze near infestations. In 2002, the Colorado Department of Agriculture surveyed counties and while incomplete, the results showed more than 100,000 acres infested with Canada thistle. Canada thistle grows in a variety of soils and can tolerate up to 2 percent salt content. It is most competitive in deep, well-aerated, productive, cool soils. It usually occurs in 17- to 35-inch annual precipitation zones or where soil moisture is adequate. It is less common in light, dry soils.

Animals

Figure 4.  Our animal samples.

          Lastly, some of the insects we found in the pond water are Damselfly order, Giant Water Bug Backswimmer, leeches and Caddisfly.

Figure 5.  Damselfly larva.

          Damselflies can be found in the ponds, marshes, and in slow moving steams. It is one of the common insects found in the pond. It shares similar functions with the dragonfly but is more small and delicate.

          Diving Beetle is found in freshwater areas. These beetles may be found in nearly any body of water. They fly into small ponds and puddles and can even be found in saline ponds.

Figure 6.  A Diving Beetle.

Figure 7.  A Backswimmer.

          Backswimmer is a common insect that found in the ponds, running water in streams and intertidal marshes. Backswimmers have middle and hind legs covered with long swimming hairs like water boatman but swim on their back.

           Leeches are usually in freshwater, terrestrial and marine leeches. They are hermaphrodites and some are hematoplagous.

Figure 8.  A Leech.

           Caddisfly order can be found in streams and ponds. When they grow into adults, they become land dwelling flies. Many Caddis fly larvae can be recognized by soft which are covered by tube like cases that the larvae build from twigs, grasses, pebbles, and sand grains. Some larvae do not build cases where the current is not strong such as pond larvae.



Figure 9.  A Caddis Fly larva.

 Conclusion

          According to most of our test results, our pond seems to be pretty healthy. Although there were some impurities, most of the water and soil tests showed the results of a healthy pond. The insects and plants found usually exist in a healthy pond, which

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.

Grasslands, by Eric and Livia

Figure 1.  This is the entrance to Nose Hill the pond is to the left and in the center of the hill, there is a forest and next to that is the grasslands we did our transect in.

            Nose Hill Park is one of Canada’s largest municipal parks spanning over 11.27 km² of Calgary. Many Calgarians use it as a refuge site to get away from the city life and a place to enjoy nature, but being surrounded by the city and its people, how have we as humans affected Nose Hill?

At the beginning of the trip Dr. Pike told us a story about the sign that was put up near the pond. He said that a few years back, when the sign was not there, bodies of ducklings were scattered around the pond. Now that the sign is up, the ducks have time to learn to fly and can go south for the winter. This is because the sign tells dog owners to keep their dogs away from the pond so that the animals don’t get disturbed. This is beneficial to the hill and its animals but many things we’ve done have caused many organisms to suffer.

One of the major things that I thought that affected Nose Hill was going up there and finding things for our project. We tore up a lot of grass for biomass. The dimensions we were to tear up were 50cm by 50cm, if we had 7 groups in grasslands, and 7 groups in forest that would mean we tore up 14x2500cm² (35000). If there were 8 classes doing this project, and they had the same number of groups, that would mean that we tore up 280,000cm² of grass. Not only did we rip up a lot of grass from the biomes, but we trampled over a lot of it while we were going back and forth from our transects to our supplies. Many of us did a good job to stay on the path when walking up the hill to get to the grasslands from the pond, but we didn’t have a direct path to our exact transects, which meant that we couldn’t see under the grass as we walked up and we might’ve stepped over a lot of insects or even trampled over their homes. We also found candy wrappers that were littered across the grasslands of Nose Hill and took it along with us as evidence and to clean up the hill. As we were conducting our tests, such as gathering soil, we had to stick a soil probe to gather our soil sample, when we stuck it in there, we ripped up a lot of roots from the plants around the transect. Even though a few roots weren’t much for a bush, we still affected it’s growing.

Not only does going up the hill affect it, but the city and pollution is also changing the health of the hill. Luckily, we don’t have a lot of industrial work that would pollute the city greatly, but we do have a lot of motor vehicles that can play a large part. If the sky was always foggy, and the air didn’t feel clean, there would be a big problem with pollution. Factories release nitrogen oxide and sulphur dioxide into the air, which causes acid rain. If the acid rain fell onto Nose Hill, the soil would be acidic. We did soil pH tests and discovered that the soil’s pH level is 4, which is slightly acidic and the same level as acid rain, which means that the city around Nose Hill has affected the soil.

Figure 3.  This is an image of me
sticking the soil probe into the
ground and retrieving soil. We had to go 25cm deep.

At the end of the day, Nose hill was still just the same as ever since it’s only been a small number of people deteriorating the park and as for the classes, the grass and plant life will grow back. Unless the park starts becoming a landfill for its visitors and more classes use its plants and wildlife to collect data, it will keep its natural beauty and wilderness.

Figure 2.  This is when we removed

a 50 by 50 cm plot of grass from our

transect to weigh as biomass.





Figure 4.  This is a piece of litter
we found near our transect.
Many other groups found litter as well.



Grasslands, by Eric and Livia

            Nose Hill Park is one of Canada’s largest municipal parks spanning over 11.27 km² of Calgary. Many Calgarians use it as a refuge site to get away from the city life and a place to enjoy nature, but being surrounded by the city and its people, how have we as humans affected Nose Hill?

At the beginning of the trip Dr. Pike told us a story about the sign that was put up near the pond. He said that a few years back, when the sign was not there, bodies of ducklings were scattered around the pond. Now that the sign is up, the ducks have time to learn to fly and can go south for the winter. This is because the sign tells dog owners to keep their dogs away from the pond so that the animals don’t get disturbed. This is beneficial to the hill and its animals but many things we’ve done have caused many organisms to suffer.

One of the major things that I thought that affected Nose Hill was going up there and finding things for our project. We tore up a lot of grass for biomass. The dimensions we were to tear up were 50cm by 50cm, if we had 7 groups in grasslands, and 7 groups in forest that would mean we tore up 14x2500cm² (35000). If there were 8 classes doing this project, and they had the same number of groups, that would mean that we tore up 280,000cm² of grass. Not only did we rip up a lot of grass from the biomes, but we trampled over a lot of it while we were going back and forth from our transects to our supplies. Many of us did a good job to stay on the path when walking up the hill to get to the grasslands from the pond, but we didn’t have a direct path to our exact transects, which meant that we couldn’t see under the grass as we walked up and we might’ve stepped over a lot of insects or even trampled over their homes. We also found candy wrappers that were littered across the grasslands of Nose Hill and took it along with us as evidence and to clean up the hill. As we were conducting our tests, such as gathering soil, we had to stick a soil probe to gather our soil sample, when we stuck it in there, we ripped up a lot of roots from the plants around the transect. Even though a few roots weren’t much for a bush, we still affected it’s growing.

Not only does going up the hill affect it, but the city and pollution is also changing the health of the hill. Luckily, we don’t have a lot of industrial work that would pollute the city greatly, but we do have a lot of motor vehicles that can play a large part. If the sky was always foggy, and the air didn’t feel clean, there would be a big problem with pollution. Factories release nitrogen oxide and sulphur dioxide into the air, which causes acid rain. If the acid rain fell onto Nose Hill, the soil would be acidic. We did soil pH tests and discovered that the soil’s pH level is 4, which is slightly acidic and the same level as acid rain, which means that the city around Nose Hill has affected the soil.

At the end of the day, Nose hill was still just the same as ever since it’s only been a small number of people deteriorating the park and as for the classes, the grass and plant life will grow back. Unless the park starts becoming a landfill for its visitors and more classes use its plants and wildlife to collect data, it will keep its natural beauty and wilderness.

Why is the Forest? by Group 2

What differences between the forest and grassland areas in Nosehill allow the forest to exist?

Due to the large area covered by Nosehill, the terrain from one section can differ greatly from that of another.  This allows many different ecosystems to exist.  Our focus would be on the forest area within Nosehill.  Though the forest area appears to be very similar to the rest of Nosehill at first glance, many differences exist to allow the forest to strive.  The differences that will be compared will be mainly focused on soil contents and pH levels.  Soil samples were collected at the edge of the forest, 10 metres into the forest, and in the grasslands.  1.00 gram of soil was then taken and mixed with 100mL of diluted water.

The soil content is very useful in the identification of possible reasons to why the forest only exists in one area.  Ammonia in soil can cause the soil to acidify.  A test showed that the Ammonia contents were the lowest at the edge of the forest with a 0.3mg/L.  However, results show that it was the most acidic with a pH of 5.5.  The Ammonia contents was much higher in the grassland and 10 metres into the forest with 0.9mg/L and 0.6mg/L respectively, but the pH at both of these two locations were only 6.

Phosphate is essential in the growth of plants.  The Phosphate contents both inside the forest and at the edge were 1.00mg/L.  The Phosphate content in the grassland area was close to doubling that amount with 1.75mg/L.  This is to be expected because trees require much more phosphate than the low shrubs and grasses that grows in the grassland.  If the consumption of the Phosphate was taken into consideration, the Phosphate reserve in the forest should much higher than that of the grassland. 

Calcium exists in adequate amounts in most soils.  It is also essential to plants as it is the substance which is responsible for Nitrate uptake and metabolism, enzyme activity, as well as various other functions within the plant.  Inside and at the edge of the forest, Calcium contents exist at the level of 300mg/L and 400mg/L respectively.  The Calcium contents in the grassland showed similar relative ratio as Phosphate, with a level of 1080mg/L.  Once again, this did not come as a surprise because of the same reason as Phosphate.

Nitrate is another substance which is essential for plant growth because it is a basic component in proteins.  Nitrate, nitrite, amides, free amino acids and small peptides make up the most of the part of the Nitrate in the plants which does not form into proteins.  The Nitrate contents at both inside and edge of the forest were surprisingly low with 0.0mg/L in both areas.  The content level was slightly higher in the grassland with 10mg/L.

Iron is a micro nutrient for plant, this means that although it is required by the plants, it is only in small amounts.  The iron contents were quite low in all three areas.  It is only 0.1mg/L inside the forest and at the grassland.  It is 0.0mg/L at the edge of the forest.

Some other observations made inside the forest area include, species of snowberry shrubs can be found at about a 28/m² density.  Grasses can be found at about a 320/m² density.  Aspen trees can be found at about a 1/m² density. Saplings of Aspen trees can found at about a 0.8/m² density.  From that information, it can be concluded that the forest area is currently at the stage between Shrubland and Young forest in the Succession progress.  The area was also in a sheltered dip between two hills.  Little to no wind is found within and around the area.  Because of these factors, it can be concluded that almost no erosion occurred to the soil in that area.  High levels of moisture are also found within the forest area.  However, this may be caused by weather conditions.

POND ECOSYSTEM AT NOSEHILL PARK by Pawan

INTRODUCTION

            Situated close to the Shaganappi-John Laurie intersection in the Northwest of Calgary in the province of Alberta, Canada, Nosehill Park is a grassland dominated area situated amidst an urban environment surrounded on all sides by residential communities. The park is approximately 11.3 km² in area and comprises of various ecosystems such as the grassland ecosystem, the forest ecosystem and the pond ecosystem.



Figure 1. Storm water reteinton pond at Nose Hill.
Taken by Pawan on October 10, 2010



BRIEF HISTORY

  
          The pond ecosystem at Nosehill Park is presently a storm-water retention pond.  8 years ago, the City of Calgary unveiled a project that would move the hill on the Northern side of the pond to the Southern side of the pond. This would in turn allow storm runoff to flow into the pond from high-level areas in Edgemont. Over the years, the ecosystem in the pond has changed drastically. Chemicals in the pond that were present in mild concentrations began to accumulate to form large quantities, native species populations in the pond ecosystem began to decrease only to be replaced by populations of non-native species and direct human activity on the pond was on the incline as well.

IN THIS BLOG I AM TALKING ABOUT:

 - background information that relates to how human activity has affected biological life in and around the pond ecosystem at Nosehill Park. More specifically, the impact of fertilizers, invasive plant species, and garbage on the pond ecosystem of Nosehill will be conveyed in this blog.

            This is how the storm-water retention pond in Nosehill Park looks like:

FACTORS AFFECTING A POND’S ECOSYSTEM

1. Light and the temperature of the water.
2. The presence of nutrients such as nitrates (in mg/L), phosphates (in mg/L), sediments and dissolved solids such as sand and soil particles in the water.
3. The dissolved oxygen content in the water (in ppm).

            The area of human activity that impacts all of the three factors is the use of fertilizers and other nutrients on surrounding rural areas in the pond ecosystem.

IMPACT OF FERTILIZERS ON POND ECOSYSTEMS

What are fertilizers?

            Fertilizers are materials that are used by humans to restore low-level nutrients in the soil to that of a higher concentration and to increase plant production from land. Estimates suggest that fertilizers containing nitrogen and phosphates double crop yields such as wheat and barley. However, at times the use of fertilizers can have devastating impacts to terrestrial and aquatic ecosystems and must therefore be used in a responsible manner. Negative impact of fertilizers on the terrestrial ecosystem is the build up of nitric acids in the soil it is used in. As soil bacteria convert the nitrogen content of fertilizers into nitrates, the presence of high levels of nitrates can result in the increase in concentration of nitric acids in the soil which can affect all organisms in the soil including the soil bacteria.

            The impact of fertilizers on aquatic ecosystems such as ponds can similarly be detrimental to the organisms that live in them.

How do nutrients enter aquatic ecosystems?

The three most common sources of nutrients in the pond ecosystem are:

1. Runoff of water from surrounding areas.
2. Sources of incoming water.



Figure 2.  Nutrient cycling in the pond. 
Texas Parks and Wildlife
Development. (2007). Life in a Pond.
Retrieved October 2, 2010 from
http://www.tpwd.state.tx.us/learning/webcasts/txwild/pond.phtml

3. Bottom Silt and dead vegetation in the pond.

How do fertilizers enter pond ecosystems?

The most common source of nutrients is runoff from farms and other outlying areas.

The USGA reports that up to 4% of fertilizer material applied to areas close to ponds may eventually runoff into the lakes and ponds through the drainage and sewage pipelines at times of heavy rainfall. When precipitation occurs, gases in the atmosphere mix with the water polluting it. When liquid water falls on land areas as precipitation, it forms runoff which may collect above the ground in areas called ‘surface water’ which includes lakes, rivers, ponds, oceans etc. It may also fall directly onto land surfaces and may filter into the ground through a process known as percolation over time. This involves the movement of water down the layers of the ground assisted by Earth’s gravitational force. Through water transport systems such as drainage and sewage pipelines, the precipitation that falls directly onto land surfaces is transported to nearby water bodies such as rivers, lakes, oceans and pond ecosystems. In the process, the precipitation also carries the nutrients, minerals and other sediments in the soil into the water bodies which may also include the nitrogen and phosphorus fertilizers that you have applied to your lawns. Also, leaves, grass clippings and other such materials too are carried into these water bodies through precipitation and heavy rainfall raising the nutrient levels in the pond. The transport of nutrients and other soil particles into the aquatic ecosystems resulting in a rapid increase in nutrient levels in the aquatic ecosystems is called nutrient loading. Nutrient loading causes the rate of plant growth in an aquatic ecosystem to increase which have devastating effects to life in the aquatic ecosystem.

What happens when fertilizers enter an aquatic environment?

Fig # 3: Algae Species 1 at Nosehill Pond

Taken by Pawan on October 10, 2010

Fig # 4: Spiked Water-Milfoil Myriophyllum

 spicatum at Nosehill Pond.

Taken by Pawan on October 10, 2010

            Fertilizers usually contain phosphorus and nitrogen compounds which are important for plant growth. When an aquatic environment gets loaded with too much of these nutrients, algae and other aquatic plants in the water grow at a rapid pace. The rapid increase in algae (called an algal bloom) and aquatic plant growth can affect factors such as light, temperature and dissolved oxygen content in the aquatic environment. Abundant aquatic plant growth on the water surface in a nitrogen and phosphorous-rich aquatic environment can decrease the amount of sunlight that penetrates the surface of the water. Since aquatic plants (such as algae) on the water surface utilize sunlight to carry out the process of photosynthesis (which is the reaction of carbon dioxide, water vapour and sunlight to produce oxygen and glucose), they reduce the amount of sunlight that enters the water thereby decreasing the temperature of the water. The decrease in sunlight that enters in the water and the temperature of the water can harm other aquatic organisms that live in the water since most aquatic organisms cannot survive below water temperatures of 5.0 °C. As algae and aquatic plants die, bacteria in the water use dissolved oxygen in the water to decompose them. Because decomposers flourish in an environment where a food source is abundant, the dissolved oxygen levels in the water drop quickly killing fish and other aquatic organisms that live in the environment. As more organisms die, the aquatic ecosystem slowly becomes unbalanced with the drastic decline in dissolved oxygen levels in the water used by the rapidly growing population of decomposers in the water.

IMPACT OF INVASIVE PLANT SPECIES ON AQUATIC ECOSYSTEMS

            What are invasive plants?

Fig 5. Spiked Water-Milfoil Myriophyllum 

spicatum at Nosehill Pond

Taken by Pawan on October 10, 2010.

The invasive plant species shown in Figure 5 and 6 were found in the Nosehill pond ecosystem.

Fig 6. Common peppergrass Lepidium densiflorum
Taken by Pawan on October 10, 2010



            Invasive plants are plants which grow aggressively and quickly in ecosystems that are not naturally their own, displacing and often destroying other plants that grow in the area. When introduced, invasive plant species pose a great threat to terrestrial, coastal and freshwater ecosystems. They cause extinction of various species and loss of biodiversity in aquatic environments worldwide. They destroy and displace the native species which in turn decrease the biodiversity of the entire ecosystem. Since invasive plants often do not have predators in the ecosystem they have been introduced to, the population of the invasive plants grows in a very short period of time competing with native plants for food and resources. When two different species compete with one another over similar resources, this relationship is called interspecies competition. Compared to the invasive plants however, native plants have natural predators in the ecosystem that are dependent on the native plants for food and survival. Therefore, native plants are often unable to compete with the invasive plants and over time the population and biodiversity of the native plants dwindle.

How do invasive plants enter ecosystems?

Terrestrial invasive plant species can be introduced to new areas as ornamental plants in lawns and gardens. Once established, non-native terrestrial plants can spread by seed since the seeds are light enough to be carried by wind, fire, water, or animals. They can hitchhike on the shoes of hikers, tire treads of vehicles, boats and boat trailers, and in the furs and intestines of animals such as livestock, horses, and wildlife. Some invasive plants also have the ability to reproduce by sending out underground shoots which form new plants. Plants that reproduce by this method include the Camelthorn and the Bermuda grass species.

Aquatic invasive plant species can also be spread to native ecosystems through the transport of their seeds by wind, water and animals. An interesting example of the transportation of invasive aquatic plants by water could be through the dumping of fish tanks and aquariums that contain non-native aquatic vegetation into storm drains, lakes and ponds which is common when their owners can no longer care for them. An invasive aquatic plant species that is thought to have spread this way is the Giant Salvinia.

IMPACT OF GARBAGE ON AQUATIC ECOSYSTEMS

            Garbage or waste is unwanted or unusable materials that are disposed off on a regular basis. Waste types may be of different types such as municipal waste, construction waste, industrial waste, commercial waste, medical waste, hazardous waste, and biodegradable waste. Garbage or waste such as tissue, plastic, rope, paper, foil, cans, bottles etc, are at times improperly disposed off (thrown away) by humans inside natural environments and in turn affect terrestrial and aquatic ecosystems all around the world.

How does garbage enter ecosystems?
 

     Figure 7. Garbage littered around a beach.

Retrieved October 6, 2010

from http://www.pebpond.com/about-the-issue.html



Human garbage can enter aquatic ecosystems through improper waste disposal which may then be carried by water (runoff at times of heavy rainfall) and by wind to form large deposits in aquatic ecosystems.

An example is the Great Pacific Garbage Patch, a nebulous floating junkyard stretching for miles in the Pacific Ocean. Sometimes called ‘a trash island’ the Garbage Patch is made up of plastic, the most commonly disposed type of garbage in the world. According to research some of the plastic is washed away from interior continental areas to the sea through sewers and other drainage systems and accumulates into the Great Pacific Garbage Patch with the help of  

Fig # 8 the Great Pacific Garbage
Patch (underwater)
 

Retrieved October 4, 2010

from http://www.mnn.com/earth-matters/

translating-uncle-sam/stories/

what-is-the-great-pacific-ocean-garbage-patch

converging ocean currents at two main zones in the Pacific Ocean; the North Pacific Subtropical Gyre and the North Pacific Subtropical Convergence Zone. This area is known to be a ‘trash superhighway’ where plastic garbage is ferried between both zones from different continents at both sides of the Garbage Patch. At times, garbage (such as fishing nets and steel containers) may also be disposed directly onto the Pacific Garbage Patch from fishing boats and large cargo ships (which dispose hockey pads, computer monitors, resin pellets and LEGO octopuses yearly into the sea).

How does garbage affect ecosystems?

Garbage especially plastic are known to cause grave threat to the environment, harming ocean and marine life. Fish, birds, sea mammals and other water creatures are becoming poisoned and deformed because of plastic consumption. Plastic alone has resulted in deaths of a number of sea creatures.

Unlike other trash, plastic is not biodegradable, meaning that microbes that break down other substances do not recognize plastic as food. Even though sunlight and radiation does eventually ‘photodegrade’ or break down the bonds in plastic substances, the plastic never goes away from the ecosystem. Instead the plastic polymers are reduced to smaller and smaller substances which it makes it easier for marine life to eat and transfer to other organisms through the food chain, a process known as bioamplification.

Figure 9. Turtle entangled in a net.
Retrieved October 4, 2010
from http://www.mnn.com/
earth-matters/translating-uncle-sam/
stories/what-is-the-great-pacific-
ocean-garbage-patch

Figure 10. A chick albatross
whose stomach is filled
with debris.
Retrieved October 4, 2010
from http://www.mnn.com/
earth-matters/translating-uncle-sam/
stories/what-is-the-great-pacific-
ocean-garbage-patch

            A growing number of abandoned fishing nets in the sea are one of the largest dangers from marine debris. Nets entangle seals, turtles and other aquatic organisms, a phenomenon called ‘ghost fishing’ which drowns these organisms. Even more, plastic items can also be mistaken by marine animals as a source of food. Most often sea turtles are the most susceptible to being endangered by plastic. Often mistaking floating plastic bags as jellyfish, their common prey, sea turtles swallow plastic bags. They can also be caught into a variety of other objects such as plastic rings which constricts around their body often killing them in the process.

            Plastic resin pellets are another example of how plastic items affect marine animals. Since plastic resin pellets are a common industrial item, used at manufacturing sites and remoulded into commercial products, they often escape out of their confined facilities and accumulate in seas and other aquatic areas. They tend to float on the surface of water bodies and eventually photodegrade, but that takes a long time. In the meantime, the pellets pose a threat to coastal ecosystems and harm organisms such as the short-tailed albatross. Albatross parents rely on coastal ocean areas in the Pacific for food, mainly protein eggs of which they can use to feed their chicks. These protein eggs are similar in appearance to the plastic resin pellets. Unfortunately, albatrosses scoop up these pellets and other shiny items such as cigarette lighters from the ocean and feed them to their chicks. This causes rupture of organs and eventually death of these creatures.

CONCLUSION:



Fertilizers, invasive species and garbage have adverse impact on aquatic ecosystems. They destroy the native species and cause imbalances in the ecosystem finally destroying the ecosystem itself. Human activities have resulted in high levels of pollutants entering these ecosystems causing extinction of various species besides causing environmental hazards. Our aquatic ecosystems need to be protected and pollution controlled through strict legislations curtailing such human activity.