What Are Biological Organisms?

Lampert, Winfried; Sommer, Ulrich (2007-07-26). Limnoecology: The Ecology of Lakes and river streams. OUP Oxford.

Table 1 on page 651 presents the population densities for a number of species. The statement is made “small organisms usually have higher population densities than larger organisms”. What are TWO different reasons why you might expect this to be true? (R)

The Chesapeake Bay is the largest estuary in the United States. About half of the Bay’s water volume comes from salt water from the Atlantic Ocean. The other half drains into the Bay from its enormous 64,000-square-mile watershed. Estuaries are among the most productive environments on earth, creating more organic matter each year than similarly-sized forests and agricultural areas. Estuaries also provide diverse habitats for wildlife and aquatic life, protect our communities against flooding, reduce pollution of waterways, and support local economies through commercial and recreational activities. Thousands of species

Through our research we aimed to determine if there were any differences in water quality of both the north and south forks of Strawberry Creek. As time progresses and the environment changes it is important to keep track of how certain species are being impacted by these features, and how they cope with change. We hypothesized that due to the lack of pollution, the south fork will promote a greater diversity of macroinvertebrates. This was due to the fact that there was less runoff and trash that could be introduced to the water in the south fork, than there was in the north fork. We gathered data by analyzing the different organisms living in both forks. We collected a total of fifty vials composed of five organisms from each fork, and inspected them under microscopic view. After gathering data and identifying the different kinds of organisms living in the different forks we assessed whether the organisms from the samples could live in high or low resolution water. We also took a t-test to assess the probability of these differences being due to relevant factors or by chance. Our major findings suggest that organisms in the south fork showed a higher demand to living in cleaner water indicating that our hypothesis was correct.

An estuary system is “the resulting collisions of sweet and salt-fresh river water flowing seaward and ocean water inland.” It is an aquatic system where salt and freshwater are constantly mixing. An estuary system is one of most active systems of the planet; it is a hybrid system that contains the best and worst qualities of the ocean, river, and lake systems it conglomerates. Estuaries are unique in nature because of their ability to be the most productive ecosystem on the entire planet; humans have attempted and failed to reach the productivity that estuaries naturally grant. There productivity lies it the constant change that occurs from the conflicting flows of fresh and ocean water. Ocean and freshwater are measured largely based on salinity, or the level of parts of salt per thousand. Ocean water usually

There are two main componetns to population change, in this case population growth. These are natural increase and migration.

At this station, we had to go into the creek, pick out rocks, and observe and identify the animal life living on that rock. Animals that live in the water need dissolved oxygen so they can breathe under the water. The more turbulent the water is, the more dissolved oxygen can be found in it. The amount of dissolved oxygen in a body of water will determine the type and number of macro-invertebrates that may live there. There are three groups of animals that you could find in the Conodoguinet Creek. Group one is called stream insects and crustaceans. These are pollution sensitive organisms, which means they cannot exist in polluted waters. Group one organisms are only found in good quality water. Some examples of these organisms are mayflies, gilled snails, water penny, or a stonefly(shown in figure 8.) The next group is the organisms that are somewhat pollution tolerant, which means they can be found in good or fair quality water. Crayfish, dragonflies, and clams are all examples of group two organisms (shown in figures 3, 6, and 9.) Group three organisms are pollution tolerant organisms. This means they can be found in any quality water. Some examples of group three organisms are pouch snails, pond snails, orb snails, and leeches. When I conducted this experiment, I found seven group one organisms, seven group two organisms, and five group three organisms. Macroinvertebrate is another word for organism.

An estuary system is “the resulting collisions of sweet and salt-fresh river water flowing seaward and ocean water inland.” It is an aquatic system where salt and freshwater are constantly mixing. An estuary system is one of most active systems of the planet; it is a hybrid system that contains the best and worst qualities of the ocean, river, and lake systems it conglomerates. Estuaries are unique in nature because of their ability to be the most productive ecosystem on the entire planet; humans have attempted and failed to reach the productivity that estuaries naturally grant. There productivity lies it the constant change that occurs from the conflicting flows of fresh and ocean water. Ocean and freshwater are measured largely based on salinity, or the level of parts of salt per thousand. Ocean water usually has around 35 parts per thousands of salt water, while freshwater

Without oyster reefs, animal habitats are lost because the current is pushing against the shore, endangering the animals. Oyster reefs allow marsh grass to grow. Oyster reefs also provide habitats for oysters, shrimp, and crabs. Oyster castles help prevent shore erosion and water clarity. In addition, oysters exist here in the Lynnhaven River for many reasons. Oysters can SURVIVE in 5-35 ppt( parts per thousand), but they especially thrive in 12-25 ppt. Salinity levels also impact the presence of diseases. For example, at 10 ppt oysters can get diseases such as MSX or Dermo. If the salinity is below 10 ppt for 10 or more days, MSX will be eliminated. In places with lower salinity,around 12 ppt, oysters grow slower. In places with higher salinity, around 25 ppt, oysters grow faster. Their growth can also be affected by tempreature, food, and disease. The Lynnhaven River has high salinity, lots of food, and minimal diseases in most locations,ideal conditions for an oyster. Equally important is the roles other animals play to oysters and their ecosystem. Bioturbators are animals that dig up sediments and particles while making their burrows. Mud crabs are dominant

Sediment collected from the riverbank as the river flows downstream is also a problem; it increases the turbidity of the river, and this makes it difficult for plants to receive the necessary sunlight needed for survival. When these plants die, there is less food for fish and other river animals. Bacteria levels also rise in the water, because it can cling to sediment very easily. When there is more sediment, there are more places for the bacteria to collect. (Helsel & Mueller, 2009). All of these problems are occurring as the water is flowing along the river banks, collecting even more sediment, and pollutants as it travels downstream and deposits into the Gulf of Mexico. When all of this sediment, nitrogen and bacteria flow into the Gulf of Mexico, it causes changes in the water there. The increase in the level of nitrogen causes plankton to grow faster. When the plankton decomposes it takes a large amount of oxygen out of the water. The bacteria break down the decomposed plankton, which releases carbon dioxide, taking increasing levels of oxygen out of the water in the Gulf. Eventually the level of oxygen decreases to a point where most living organisms cannot survive. Some animals flee while other plants and animals that cannot leave usually die. This is referred to as the Dead Zone in the Gulf of Mexico. (Gulf of Mexico; NOAA, 2009). With an expected increase in the size

There are many factors that can contribute to a population's overall size. Four of the

In its simplest form, an estuary is a body of water formed where freshwater from a river flows into the ocean. This creates a mixture of salt and freshwater that a variety of organisms rely on for survival (U.S. Environmental Protection Agency, 2012). In my paper I will only be looking at the United States’ estuaries under the protection of the National Oceanic and Atmospheric Administration (NOAA). This will include 221 estuaries located throughout the United States.

The Increasing Growth Stage is when an area has a high birth rate a low death rate, which would lead to a great increase in an area’s population. The Moderate Growth Stage is when the birth rates are gradually decreasing along with a previously low death rate, causing the population to increase at a more gradual rate. The Stationary Stage is

First the exponential growth model is the the accelerating increase that occurs when growth is limited. The exponential models predicts that the larger a population becomes, the faster it grown. Exponential growth in nature is generally a short-lived consequence of organisms being introduced to a new or underexploited environment. Logistic growth model occurs when growth is slowed by limiting factors. The logistic model predicts that a population’s growth rate will be small when the population size is either small or large, and highest when the population is at an intermediate level to the carrying capacity. Finally regulation of population growth is limited by a mixture of density independent and density dependent factors (Simon, Dickey, & Reece, 2013

This is the second stage of the Theory of Demographic Transition. In this stage, birth rate does not come down from the High Stationary Stage but death rate gets very much declined, which triggers very rapid growth in the population change. In this stage, the nation provides the better public health services to the people so that the people will not depart from the life so rapidly, and the declining in infant