Jesse's+Journal

Free Journal: Manoa Stream is a stream that starts deep in Manoa Valley (I believe that it is fed by Manoa Falls) but the portion that my group members and I are researching is an area where it flows directly through Manoa Park. The stream has many different plants living along its edges. Some of debris like fruit and branches from these plants can be found propped up against rocks in the stream. The animals living in and around the stream would be ducks who generally seem to live off of the bread they are always receiving from people, fish and tadpoles who eat the algae growing on the rocks, and insects. The soil directly adjacent to the stream is wet and muddy while the soil farther up is dry. The wet soil at the stream tends to be a dark brown color while the higher and dryer dirt is a red-brown. Other features that are most likely having an effect on the stream are things like sunlight, rain, humidity and water current. The stream is flowing from the North-East to the South-West and has either houses or large vegetation on either side, this would cause the Western bank of the stream to get sun in the morning, the whole thing to get sun at noon, and the eastern bank to get sun in the afternoon. I can also easily tell the location of the stream all the way back into the valley from satellite view because there is a line of trees on either side of the stream going from our spot all the way back into the valley. This tells me that the stream is the key provider of water for the plants around it. This spot is ideal for my group and I because we all live in Manoa and it is easily accessible by foot. It also has rocks sticking out of the water that we can use as stepping stones to get from side to side and to get a closer look at what is in the stream. It is a real stream, not just a trickle and it has a few animals living in it as well as many plants growing on its sides. The only problem is the fact that there is a caution sign up saying that it may have leptospirosis. This could be a problem, so we need to make sure that we are careful when examining our ecosystem.

Assigned Journal Entry #1 At the stream we found a few different organisms, all of which seemed to be living in different niches. The first organisms that caught my eye were the dozens of what looked to be tiny guppies swimming around in the stream. These small guppies looked to be on average about a centimeter long and were a grey-brown color. They had fat, oval shaped torsos, and thin tails. On average the length of the tail was slightly longer than the length of the torso. The guppies tended to stay in the more shallow and calm parts of the stream. These parts were normally ½-1 inches deep and were calm because of rocks or other abiotic things, which were redirecting the water around a certain area and allowing only a slow, trickle of water. This caused these areas to be much calmer. Because of the calm waters, the guppies were able to hover against the current of the stream easily, and with a quick wriggle of their body, dart around. They ate a brown-green alga that was growing on the submerged areas of the rocks. I suspect that this algea is really green and it is soil on top of it that gives it its brown color. The fish never rested on the rocks but only pecked at them as they ate the algae. In the deeper areas with stronger currents I also noticed what looked to be the same type of fish, but larger and more mature. These guppies ranged anywhere from slightly over a centimeter, to half an inch. They were swimming at a constant pace against the current in order to stay in one place. Occasionally one would dart away or peck at algae on a rock. Another organism could be found at the bottom of the stream. This organism was a much larger and fatter fish. It had large pectoral fins that laid horizontal the stream floor. It was a dark brown color and had hundreds of white dots on it. These dots made patterns across its back, tail, and fins. This fish was normally found on the floor of the stream as long as it was deeper than a half inch. They barley moved at all, and were obviously feeding on the same green-brown algae that the guppies were eating. The interaction between the guppies and this larger fish was minimal. It was obvious there was no competition for the recourse of algae, because that was found in abundance and there weren't that many fish. There were plenty of ducks swimming around on the surface of the stream. These ducks were brown with green or brown heads and orange or brown feet. They bathed themselves in the water and possibly drank from it. It was impossible to tell when natural thing they ate though, because there were only eating the pieces of bread that people were throwing to them. When flustered these ducks would take off flying back towards the valley.

Day 1 relevant pics

Free Journal 2 The second time I visited the stream it seemed like the stream was lower and the current was a little slower than the first time. I found this funny because it rained a little in the valley earlier in the day. When we were there around 4:00 pm, the East bank of the stream was receiving sunlight while the west was in shade. This partially confirms my hypothesis that the West bank would get the light in the morning and the East bank would get the light in the afternoon. I also noticed that the west bank had a wider variety of vegetation than the East bank and its vegetation was also more robust. I believe that this is because the sun is brighter in the mornings than the afternoons. This means that the West bank plants get stronger and more effective sunlight allowing then to grow much better. This time I brought tools with which I could measure things like current, water depth and temperature. The width of the stream was 28 feet 2 inches and its deepest depth was 1 foot but in most places it is more like a few inches. I wonder if the very shallow bottom of the stream affects the animal life in it. I would guess that such a shallow stream would not be a good place for many large fish to live and that all of the fish in the stream would be small. I also timed how long it took a tennis ball to float 25 feet down the stream. I did this experiment three times and the average time was 1 min 30 sec. This comes out to about 0.28 feet per second. I wonder if the speed of the stream affects the strength and size of the fish in it. Another set of measurements I conducted was measuring the temperature of the soil at certain distances away from the stream. I found that the water was 75.5o F and the soil directly adjacent to the stream was 77.1o F on the West side and 75.9o F on the East side. The soil 3’ 9” from the stream was 83.3o F on the West side and 77.9o F on the East side. The soil 7’ 7” away from the stream was 82.4o F on the West and 78.8o F on the East. I wonder if the soil and water temperatures have an effect on the vegetation that grows there. Day 2 relevant pics

Assigned journal entry #2 On our second visit to the stream, I was able to find more fish than the first time. Here I noticed a community interaction between the types of fish in the stream. I noticed that the large bottom feeder type fish were always on the very bottom of the stream where it was deepest and strongest, the guppies were found in the medium level depth, and the tadpoles were always found in the shallowest parts of the stream, especially the areas where rocks and dirt had created a shallow, calm pool of water. This would be an example of competition for space and food. The bottom feeders probably stayed in the deeper and stronger areas of the stream because they are larger and stronger than any of the other fish. Here they used their strength and a large suction cup like mouth to stick to rocks. Because they were the only animals in this nitch, they had plenty of food and because they were so deep, they were probably safe from any of the stream predators like the ducks. They are also hard to spot because of the depth of the water and their camouflage like back. The guppies likely stayed in the medium level areas of the stream because they are medium size. And unlike the bottom feeders, they are much more mobile, allowing them to quickly escape from predators like ducks. The tadpoles, being the smallest and weakest were likely pushed to the shallower areas of the stream because anywhere else they wouldn’t be able to keep up with the current. Their nitch is the worst if you want to avoid predators because they are slow moving, in shallow water, and easy to see. I believe that competition has spread these species out to live in different nitches, and here they have adapted to their nitch. The bottom feeders by getting larger, suction cup like mouths, and camouflage coloring, the guppies by becoming more mobile, and the tadpoles by shrinking. Many of the plants living along the banks of the stream appear to be invasive, especially two particular types of weeds. These weeds appear to be slowly taking over the banks, and it even seemed like there were more of them the second time.

Free Journal 3

I have noticed that the stream can tend to get going pretty fast after days of heavy rain. This can cause natural selection because the bottom feeder fish need to stick on to algae covered rocks in order to get their food. I’ve also noticed that the bottom feeders use their large, suction cup like mouths to stick on to the rocks. This would cause the bottom feeders with stronger mouths to survive better because they can hold onto the rocks during times of rapid current. A bottom feeder who cannot hold on would not be able to get as much food because its food comes from the rocks. This would cause it to not survive and reproduce as well. Another environmental pressure that is causing natural selection is the height of the plants along the streambed. Because the plants along the streambed seem to be unkept and uncut, many of them have grown to very tall heights. This drives natural selection because the plants that can grow taller, faster would survive better because they can then soak up all of the sunlight. The shorter plants on the other hand would be smothered by the taller ones and would not receive as much sunlight and survive less. Over time this would lead to taller plants, because the taller ones would have a better fitness.

Another environmental pressure that could be driving natural selection would be the predation of the bottom feeders. It is quite obvious that there has been pressure acting on the bottom feeders because all of them are about the same color and the bottom of the stream. This similarity in color likely came from predation where the bottom feeders who stuck out in the water tended to get eaten and the ones who blended in were not seen and thus survived. I have never actually seen an animal come up with a bottom feeder in its mouth in the stream but I do know that there are always ducks patrolling the stream and I know that some species of ducks eat mainly fish. I have also seen an occasional dog going through the water. Mitchell from my group also has said that he has seen cray fish hiding in the stream. I know these animals are carnivores and might eat a bottom feeder if they spot one. I have also seen children trying to catch fish in the stream with nets. Often these children take the bottom feeders because they do not move and so they are easier to catch. But like anyone these children only go for the fish they can see, so the ones who blend in well would not be caught and taken away from the stream. This would cause the better-camouflaged fish to survive better and be more likely to stay in the stream rather than being taken away to be experimented on or put in a tank.

Assigned journal entry #3 At our third visit to the stream I noticed that the vegetation on the west side of the bank had gotten even taller, and more robust than the last time I was there. I also noticed that the East bank’s vegetation had grown, but not nearly as much as much as the West bank. I also saw that once again the East bank was getting the afternoon sun, for we were there at around 4:20pm and the West bank was in the shade while the East bank was in the sun. Given this information I believe that the reason the West bank has a wider and more robust variety of plant life is that the sun seems stronger in the mornings when the West bank is in the sun and weaker in the evenings when the East bank is in the sun. Because of this the plants on the West bank would be able to photosynthesize more than the ones on the East side.


 * Hypothesis: If two plants of the same species were observed, one on the East bank and one on the West bank, then the plant on the West bank would grow more because it would receive stronger sunlight in the mornings than the East bank in the evenings.** (My control would be to observe another of the same species of plant, one on each side, but cover that plant to make sure it is in fact the sun that is affecting the growth of the plants and not a difference in soil.) [I brought an electric pH tester to the stream but it didn’t work so I was not able to collect any data on that]

Because we were at the stream’s slightly later today (4:30 instead of 4:00) the shadows cast by the tall vegetation were longer and seemed to go a little farther out into the stream than they did last time. In these shady areas of the stream, the large, dark-brown (with white dots) bottom feeders were harder to see because of their dark color. Even though the bottom feeders were harder to see in the shaded part of the stream, it seemed to me that there were more hanging out in those spots than there were in the sunny areas. My guess would be that the reason there were more bottom feeders in the shaded areas is that the fish stay in dark areas is because it is harder for them to be spotted by predators there. So the fish that always stayed in the darkness were eaten less, and had more offspring’s who tended to stick to the darkness more.


 * Hypothesis: If shade or darkness is cast over certain areas of the stream, then more dark bottom feeders will be found in the dark areas because they have evolved to keep to the darkness so as to stay away from predators.** (I would conduct this experiment by finding dark areas of the stream and counting how many fish I could find in those areas, and then I would look in light areas of the stream that were equal in size and count how many fish I could find in those areas)

Today at the stream you could tell that the water was flowing faster than the last time we came. The data we took also backed that up, for when we did the test of timing how long it took a tennis ball to float 25 feet down stream at a certain spot the times were 59 sec, 1min 12 sec, and 1 min 4 sec. These were on average 25 seconds faster than the prior time. I also noticed that the bank of the stream seemed to be a little bit wetter. This leads me to believe that when the current is faster in the stream, more water washes up on to the bank. This water would likely bring more nutrients with it. More evidence that the strong water is affecting the soil would be that the soil along the stream tended to be colder. The soil on the West bank was an average of 78.97oF degrees where as last time it was an average of 80.93oF (a 1.96oF decrease from last time.) The soil on the East bank was an average of 77.03oF where as last time it was an average of 77.53oF (a 0.5oF degree decrease from last time.) I believe that it was the stronger current that caused the decrease in soil temperature because even though the measurements were taken about 25 min later than last time, the water temperature was only 0.3o colder.


 * Hypothesis: When the current is stronger, the soil directly adjacent to the stream will have more nutrients (ph) because the current will bring more and more will wash up on the soil. The temperature will also tend to be colder because more cold water will wash up on the bank.** (I could not test ph because the electronic ph tester I bought at Home Depot did not work, but I will get one in time to conduct the experiment.)

As a little thing to note, I noticed that since we were at the stream last time, someone has used the rocks that used to be scattered thorough the water to build an enclosed area but it does not affect most of my observations because I make most of them up stream from the area. The only observation that was effected was water depth because the area was right where I had measured depth the previous times.

Day 3 relevent pics

Free Journal 4: Today my group and I went at about 11:00 A.M. instead of our normal 4:00-4:30 P.M. We did this because it was the only time that we could get to the stream. It had rained almost all day the day before so the stream was going quite fast. This could be seen when I did the water current test I always do, where I drop a tennis ball in the stream in a certain spot and time how long it takes to the ball the travel 25 feet. I did this three times and it took the ball 40, 45, and 44 seconds to travel the 25 feet. That means that the tennis ball floated down stream the 25 feet an average of 22 seconds faster than the last time I came. Not only was the stream going faster, but it was also visibly higher and the water was a little murkier than it has been in past visits. I also noticed that today the banks of the stream were much muddier than they have been before. This is most likely the reason that the soil was a little colder today. On the West Bank the soil was 70.7°F adjacent to the water, 71.9°F 3’9” from the water, and 72.3°F 7’7” from the water. On the East bank it was 70.9F adjacent to the water, 72.0° 3’9” from water and 72.2°F 7’7” from the water. This is defiantly colder than it has been in past times, I also notice that the East bank was warmer than the West bank today, this is out of the ordinary for my observations. I believe the reason it is different is because I came in the morning instead of the afternoon so the sun would be at a different position in the sky meaning it would warm different parts of the stream. In my previous observations I noted that the bottom feeder fish had a dark brown back with small white dots that made them hard to see when there were shadows being cast over the water. I also thought that I saw more of the bottom feeders hanging out in the areas of the stream that were in shadows than there were in areas in the light. I guessed that this was because the fish were harder to see in the dark areas and therefore the ones that tended to hang out in the dark areas got eaten by predators less than the ones in the light areas and would have had more offspring who tended to stay in the dark areas.


 * Hypothesis: If shade or darkness is cast over certain areas of the stream, then more dark bottom feeders will be found in the dark areas because they have evolved to keep to the darkness so as to stay away from predators.**

I tested this hypothesis by finding areas in the stream that were 2’x2’. I found 4 areas that were completely bright and sunny, 4 areas that were dappled with light and dark, and 4 areas that were completely dark and shady. I then counted the number of fish in each of these areas (my partners and I all counted. My results strongly supported my hypothesis because I found very few fish in the light plots of stream (2.5 per plot on average), quite a bit more in dappled areas (5.5 per plot on average), and even more in dark areas of the stream (6 per plot on average.) Also the average number of fish per dark plot would have been higher (10 per plot instead of 6) if it weren't for one outlying bit of data, where I found only 4 fish in a dark plot. From this data I can conclude that more of the bottom feeder fish are found in the darker areas than the lighter ones. This is likely because the fish were harder to see in the dark areas and therefore the ones that tended to hang out in the dark areas got eaten by predators less than the ones in the light areas and would have had more offspring who tended to stay in the dark areas.

__Data__





__Type of fish being counted__



Assigned Journal #4 Like all ecosystems, Manoa Stream has a carbon cycle, where carbon is taken in and given off by different abiotic and biotic sources. If I had to describe the carbon cycle I would say it goes something like this: the weeds, tall grass, and trees take in a great deal of carbon dioxide through photosynthesis but also give some back through cellular respiration, any dead plant would also give off carbon dioxide through the process of decomposing. Animals like ducks and the occasional stray dog would give of carbon dioxide into the air through cellular respiration, and the under water creatures like the fish would give off carbon dioxide into the water. The water itself would also absorb carbon dioxide just like the earth’s oceans, but it would also give some of that CO2 back into the air. Dead animals would give off CO2 through decomposition and any animals living in the dirt like ants, and worms would give off CO2 through cellular respiration that would eventually be released by the soil, into the air. As you can see there are probably slightly more ways that CO2 is given of in the Manoa Stream carbon cycle, but I think that it would be a net consumer of CO2 because of the huge amounts of plants growing on each bank and the high rate that they seem to be growing.