Brad's+Journals



Ecosystem: Plants

Location: Mcgrew Point (Aiea Recreation)

__Journal Entry 1__ the place that we chose is Aiea Recreation Park, more specifically we chose the small cove by the bridge. We chose this area because we felt that it would be a good place to observe different types of animal, plant, and other life. I first noted that there was a change in water level for there was damp soil about one and a half feet from the waters edge. there were also plants surrounding the cove, some in the water others on the higher elevations of land. the next thing that i noted is that the water, even in the shallower parts had a lot of life in them. there were small fish, big fish, and the occasional crab that kept moving in the water. this place i feel is a good place to study because it gives us a lot of variables to what we can study. because there is so many plant and animal life forms that make a living here it will give us more than one example from out sight. it also gives us the variable of tides and shows us that tides are a ever changing thing in our ecosystem. the plant life as well, houses different types of critters from baby moth like creatures to providing shade for small fish. in all we believed that this park, which is almost untouched by humans, was a great place to begin our study. __Assigned Journal Entry 1__ My topic is plants and i believe that the plants that grow along the edge of our cove play a very important role in the ecosystem. first of all i think that the plants provides a place for fish to get shade, for most of the plants are hanging over the water's edge. it also provides excellent protection for animals like crabs who don't want to be disturbed. the plants i believe also helps keep the ridge in a slope shape. i can come to this conclusion because the places where there is little or no plant growth is where there is flat land.

__**Journal Entry 2**__ The first thing that I noted when I visited my sight today is that it was high tide. The water level rose about a foot from when we went last time. Because of the tide change almost 65% of the plants that were on land the first time were submerged in the water. In a closer look I noticed that there were numerous little fish swimming around the roots of the plants. Also moth like bugs and mongoose use the plants (on land) for shelter and food (I believe). During the time that I was there, there were times when small fish would make a sudden dart and swim towards the shoreline. I believe this is because something is chasing the others for food. After watching about three of these happenings I saw that when the smaller fish did dart they swam directly to the roots of the plants. This is why I believe that the plants are also used as a “hideout”. the biggest question that arose during my second visit was, how does the plants affect the predator prey cycle if they are only in the water for half the time? __Assigned Journal Entry 2__ In our ecosystem I see two different types of interactions going on. The first is a predator prey cycle between the plants, fish and mongoose. When it is high tide the fish seem to use the plants as a place for food and shelter. I saw a lot of mongoose going in and out of the bush and I assumed that they were feed on the fish. And after they feed they take a number 2 which fertilizes the plants. The plants then grow and create a shelter for the fish. The other interaction is competition. The fish population seems to be abundant and still growing. There were many fish of all different sizes in the cove. However I think that competition for protection is the biggest. It seems that the smaller fish hang out near by shore where as the larger fish hang farther out. __Free Journal Entry 3__ Today was hot, humid and mildly rainy. The plants seemed to be suffering from the low tide when I went as they were kind of droopy and not perky. I noticed also that crabs during low tide were running in and out of the bushes by the water’s edge. Compared to my two other visits the plants seemed more droopy and less life was scurrying around the water’s edge. During today’s observation I came to ask the question, does the weather affect the amount of life that is active? Another question is, do the tides bring in bigger fish because it also brings “food” from the mountains? These questions arose after this visit was noticeably different than the other two. If the weather is HOT, then there will be less life on land. If it is low tide, then the plants surrounding the water will be less impacting on the ecosystem. If the water is at high tide, then the plants will affect the environment and ecosystem greatly. Some of the pressures that could be driving natural selection are the dirt, tide, and weather. I have only observed that there are two types of plants that thrive close to the water. These two plants must be suited better to survive in the brackish water and dry/wet mud. The process of cellular respiration, which takes place in all plants, is important with these plants. The plants give the little fish and crabs a place to hide and in turn they give them nutrition (manure). These plants are the reason that fish can get big in our cove, in the sense that they provide protection for fish until they are able to fend for themselves. They also provide food and an easy access route out of danger. **__Free Journal 4__** On the first day of my experiment it was low tide, but there was something different about the behavior of the fish. There were more fish around the edges of the pond and they were calm. So I decided that it wouldn’t be a good day to do the experiment. After a little fishing and some observation I noticed why. There was junk coming in from upstream so the fish had more to eat. The next day I went to do my experiment. It was low tide when I went and everything was jumping as normal. The plants were half submerged and there were little fish by the shore. I put a fake fish (the kind you can get from a fishing supply shop w/o the hook) on a line and attached it to a stick. I put the stick in the water around the edges of the reservoir. I had 4 lines set up 2 by the plants and two in the open without plants. I observed it for a half hour and looked for, how many fish inspected the fake fish and how the fish reacted to a bigger fish near them. The data I found was as follows.
 * __Assigned Journal Entry 3__**

|| Fish inspecting || Fish Scared || Fish w/plants || As soon as I put the fake fish in the fish started to swarm around the fake fish and nibbled on it. || After a while the fish started to avoid it and seemed to swim more around the fish than to it. they also seemed to go into the covering of the plants more || Fish w/plants || Same as test 1. || Same as test 1 except the fish off the bat started to be caucious of the fake fish. || Fish w/o plants || No fish came to see the fake fish. But some of the crabs tried to get the fish. || The fish darted away and never came back during the duration of the time. Seemed scared. || Fish w/o plants || Same as test 1 || Same as test 1 || I then did the same experiment when it was high tide. || Fish inspecting || Fish Scared || Fish w/plants || More fish seemed to inspect the fish and some of the bigger “kids” tried to eat the fake fish. || Didn’t seem as scared but were very cautious about the fish and seemed not to come out of the plant cover unless it wanted to inspect. || Fish w/plants || Same as test 1. || Same as test 1  || Fish w/o plants || Some larger fish seemed interested but the smaller guys left. || The fish darted away and never came back during the duration of the time. Seemed scared. || Fish w/o plants || Same as test 1 || Same as test 1 || I concluded with this that the plant cover is a way that the fish use for protection. I was able to conclude this because the fish near the plants were less cautious and seemed to use the plants to dart back into when there seemed to be danger.

**__Assigned Journal 4__** I think my eco system gives off more carbon dioxide than it takes in. there is minimal trees and a lot of wild life. The water is full of fish and crabs and the plants that are out side of the water aren’t full and hearty. The fish, since there are so many give off more carbon dioxide then the water can take in. Also the birds that hang around the outer sides of the pond give off more carbon dioxide than the 4 trees and bushes can take in. My ecosystem is a prime example of a place where carbon dioxide is given off more than taken in.