Sample Essay: Distribution VS. Density of California Mussel in South of California Abstract

Abstract

Mussels are animals under the phylum Mollusca. One unique aspect about this group of animals is that they can grow in both salty water and fresh water because different species have various mechanism of dealing with the different osmotic potential. They have a relatively simple anatomy compared to other Molluscs in that in basically their body is made up of two shells with some sort of a hinge at one end a characteristic which enables the two shells to open and close. They basically feed via filter feeding where water containing nutrients is passed between the two shells and the required substances are filtered and taken in, as a result it is essential that they maintain a constant flow of water. The trapped foodstuffs are then channeled into the mouth and digested. Molluscs mostly feed on planktons and other free floating organisms. However it is important to note that mussels come in different varieties in terms of size, shape and distribution. Molluscs are used to prepare various delicacies in different communities and apart from that their shells can also be used for decoration purposes or even in making of buttons. Freshwater Mussels can also be used to manufacture pearls where the Mussels are harvested, polished and used as nuclei in living Oysters to stimulate the growing of Pearls from a substance secreted by the Oysters.

Purpose of the research

The purpose of this research is to study the distribution of various species of mussels in the shoreline of South Carolina and to determine the population of the respective species in particular areas depending on the characteristics of the habitats. Distribution of Mussels can provide information of other essential factors especially the ones that provide the optimum condition for the growth of Mussels. For instance Mussels of different species may require different temperatures for growth or may prefer a particular species of planktons for food. This kind of information is very important to marine biologists when studying the factors that determine the distribution of Mussels and the optimum habitat for growth of the various species. The results might also be important to the government in determining how the consumption and use of bivalves for other purposes such as for decoration have affected the population of various species. The government can therefore place relevant measures to tackle such a situation in case it is present. The research can also be important to determine how temperature changes due to global warming have affected the distribution of the Mussels. The distribution in Mussels is also important because some species release toxins which may interfere with the ecosystem around the areas they are found.

Research Methodology

The first important factor to consider in a research is to choose the most efficient type of hypothesis that will provide us with the theoretical assumption about a particular population parameter that may be true or false and therefore the research will seek to prove or disapprove the laid assumptions. The most relevant hypothesis in this case is the alternative hypothesis of whether the intertidal Californian Mussel shows intertidal zonation with respect to density. Therefore the research will seek to determine if this statement is true or false. The hypothesis assists in choosing the most effective research methodology.

Since the purpose of this research seeks to analyze the distribution of different species of Mussels and compare this against the density, it is important to use a research methodology that allows inferences to be made concerning the population represented by the sample, which in this case are the species and their respective distribution densities. The most efficient sampling method is the stratified random quadrant sampling, which will enable one to obtain the variations in different species of mollusks just as it occurs in the entire population of the sampled area. Using this method, locations were randomly chosen that would act as representatives of a particular area. At first a series of transect lines were laid down oriented up and down the shore making sure that they were perpendicular to the shoreline. These lines were laid with respect to the topography of the shoreline. Samples were then collected from the high shore towards the low shore along the shore transect after every 2 meters. Bias associated with the transect location by marking out the exact locations of the samples at 2 meters interval determined by selecting a random number to displace the placement of the quadrant left and right of the transect line. The random number will then be used to represent the displacement in centimeters from the transect line. The sample was then taken using a quadrant of 50 x 50 cm which is the one normally used for intertidal mollusks. The quadrants were then placed on the surface with respect to the transect line as specified by the random number. The number of species in each quadrant was then identified, counted and recorded.

Results

The type of species that was found was the Californian Mussel known as Mytilus californianus. Its characteristics is that it was large than most of the other species of Mussel and it belonged to the family Mytilidae. Its shells were thick and like most other members of the family they were mostly found attached on rocky surfaces. From research we were able to find that true to our findings, it is the most common Mussel species in all the west coast of North America, found in the area stretching from North of Mexico to the Alaskan Islands of Aleutian. This species of Mussels are always found clustered together mostly on rocks in the upper section of the intertidal zone. The number of mussels found within the 50 x 50 cm quadrants greatly varied from the shore and as one moved towards the sea and because the area of the quadrant was held constant the density also varied with the same degree.

The results were as follows:

The results clearly show that the number of Mussels increase as one moves towards the sea, therefore the density of Mussels also increase as one moves from the shore towards the sea. From the hypothesis chosen the results have proven that the density of mussels increase as one goes towards the ocean.

Discussion

The experiment was successful in that the trends observed were tallying with the trends available from previous research as recorded in books. However there were a few problems encountered in the course of the research. It was risky to venture too much towards the sea because of various threats from harmful sea animals. It was also difficult to locate mussels that were submerged underwater.

These results clearly show that there are some factors affecting the distribution of Mussels and these factors vary as one move from the shore towards the sea. One inference that can be drawn is that the harvesting of Mussels is the most probable cause for this distribution because harvesting will most likely take place from the shore towards the sea because it is easy to harvest the ones near the shore. Another inference that can be drawn from the results is that the planktons and other tiny sea animals that Mussels feed on are found in higher population as one move towards the sea therefore a greater population of mussels is found in places where their source of food is also abundant. Temperature could be the other reason for this kind of distribution because temperature of the ocean reduces as one move towards the ocean and therefore it can be said that mussels prefer cooler temperature.

Conclusion

The distribution of the Californian Mussel provided greater insight how ecological and climatic factors affect the distribution of sea animals. This information can be of great relevance when looking into ways of protecting the sea as an environment for thousands of species of animals.

References

Zhang, C. Fundamentals of Environmental Sampling and Analysis. Wiley Interscience. 2007

Warren, E. Mussels of Illinois: In the collection of Illinois state museum, Human Uses of Freshwater Mussels. Retrieved on 23^rd April, 2009 from, www.museum.state.il.us/ismdepts/zoology/mussels.

Gaines, D. Distribution, abundance, size and recruitment of the mussel, Mytilus californianus, across a major oceanographic and biogeographic boundary at Point Conception, California, USA

Distribution, abundance, size and recruitment of the mussel, Mytilus californianus, across a major oceanographic and biogeographic boundary at Point Conception. University of California, 2006. Retrieved on 23^rd of April, 2006 from www.nking hub.elsevier.com

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