The Healthy State of the Bear Swamp Brook - Lab Report Example

?Stream paper 0 INTRODUCTION 1 Background information Streams and rivers have been under extreme pressure from anthropogenic sources which have consequently affected the river or stream quality and thus terminologies such as ecological integrity, stream condition and river health have been coined to describe the status of river ecosystems in response to human activities (Allan, 2004). River health is measured by use of structural and functional characteristics of the river or stream. Structural characteristics of a stream measures the biotic and abiotic resources present within the river ecosystem and thus measures the water quality and the composition of invertebrate organisms. Functional characteristics on the other hand measures the services or functions provided by the water ecosystem and are measured by the rate of primary productivity and organic matter decomposition. Structural characteristics of a stream are mainly used in the day to day monitoring of stream health. The biotic factors used mainly include macroinvertebrate diversity. Analyses of macro invertebrates in water is important because they are a link to the aquatic food chain, have diverse sensitivity to pollution and is a relatively cheap method for analysis of the stream quality. Additionally, the macroinvertebrate diversity provides useful information on the long term quality of the stream unlike water analysis which provides information for the sampling time only. These invertebrates have differences in their susceptibility to pollutants in water with some being highly susceptible to pollution while others are moderately susceptible with others being tolerant to different levels of pollution. Those organisms which are highly susceptible will not live in polluted waters while the most tolerant can survive. Therefore they measure the levels of pollution in the water and thus by extension the health state of the river. Functional characteristics of an ecosystem when integrated with the structural characteristics help in giving a complete picture of the health state of an ecosystem. This is due to the fact that the ecosystem can respond to human stressors differently including changes to the structure of the ecosystem without changes in functional parameters or changes in the ecosystem function without change in the structure while in some cases there could be both structural and functional changes. The functional characteristics of a water ecosystem can be measured by a number of indicators including the rate of uptake of nutrients, benthic microbial respiration, nitrification, organic matter, invertebrate production and fish production. Abiotic factors are also important in the assessment of the functional characteristics of the water. The concentrations of dissolved oxygen, air and water temperature, conductivity, and the velocity of the water have been shown to affect the health status of a stream or river. This is because the interaction of these abiotic factors with the biotic factors in the water determines the survival and existence of the latter and also the rate of breakdown of organic substances such as leaves in water. The concentration of dissolved oxygen for example is used as a measure of the rate of metabolism in the water ecosystem with water temperature increasing the rate of decomposition. Additionally the increased demands for water for human use have also led to increased abstraction rates of water. This reduction in the water flow due to abstraction has possible impacts on the stream ecosystems (Deswon et al. 2007). 1.2 Main Objective To determine the health states of Molly Ann Brook, Ramapo River and Bear swamp Brook 1.2.1 Specific objectives 1. To determine the structural and functional characteristics of Molly Ann Brook, Ramapo River and Bear Swamp Brook. 2. To determine and compare the health states the Ramapo River upstream and downstream 3. To compare the health state of the Bear Swamp Brook relative to Ramapo River 2.0 STUDY AREA 2.1 Molly Ann Brook The Molly Ann Brook is a tributary of the Passaic River. It lies between the latitude and longitude coordinates of 40.9131543 and -74.1882004 at an elevation of 36 feet. It flows south between the First and second Watchung Mountain ranges and north through the city of Paterson and the boroughs of Haledon, Prospect Park, North Haledon and Franklin Lakes. Its name comes from the pioneer settlers in the area, Dirck and Molly Van Houten. The Molly Ann Brook is lined by concrete and rock lined walls at the lower reaches to protect against floods. This brook joins the Passaic River in Paterson as the last tributary before plunging over the geologic barrier. 2.2 Bear Swamp Brook and Ramapo River The Bear Swamp Brook is a tributary of the Ramapo River in the Bergen County. It is located between the following coordinates; Latitude: 41-03'56'' N and Longitude: 074-12'33'' W. This stream has an elevation of 72 meters of 236 feet. Sampling in these locations was done in the Bear Swamp Brook and also upstream and downstream of Ramapo River after being joined by the Bear Swamp Brook tributary. 3.0 Methods 3.1 Biotic indices 3.1.1 Collection of macroinvertebrates The collection of the organisms was done according to the protocol provided. Before collection the stream conditions were determined for suitability of the collection of organisms. Three riffles were then identified for collection of the macroinvertebrates and included a faster, moderate and slower rifle. A 1m2 kick net was supported in such a way that the water currents would carry the dislodged organisms from their substrates into the net. The bottom of the net was held tightly to the bottom of the stream. An area of 1 m2 of the substrate upstream of the net was vigorously agitated until all rocks and sediments to a depth of five inches had been scraped over each other to make sure that organisms were dislodged and carried by the currents into the net. All the large debris including the leaves rocks and sticks were removed and put on a different basin after removing the organisms attached to them. The basin with the debris was then checked for any macroinvertebrate that may have hidden in the debris. An ice cube holder was then filled with water and similar organisms carefully sorted out using plastic tweezers into different ice cube compartments. The macroinvertebrates were then identified using the key to the Macroinvertebrate life in the River and the Citizen Monitoring Biotic Index. The number of types of animals were then counted and recorded and multiplied by the group value. This same procedure was repeated for all the other groups of animals collected. The calculated values for all groups were then added and divided by the number of types of animals that were found to get the index score and the health state of the stream correlated with the Macroinvertebrate life in the River and the Citizen Monitoring Biotic Index. 3.1.2 Water quality rating Macroinvertebrate count was used to determine the water quality rating. The microinvertebrates were classified into sensitive, somewhat sensitive and tolerant species according to the Macroinvertebrate life in the River and the Citizen Monitoring Biotic Index. The index results for each group of microinvertebrates were calculated by multiplying the number of organisms in the group by a constant i.e. 1 for tolerant, 2 for somewhat tolerant and 3 for sensitive. The total index value was then interpreted using the water quality rating standards provided. The results for each sampling area were then recorded. 3.2 Abiotic indices/Physico-chemical parameters The physico-chemical parameters of water in all the sample sites were measured using the appropriate calibrated water quality instruments. Among the parameters measured were the concentrations of dissolved oxygen, water and air temperature, conductivity, pH, total alkalinity and water velocity. The physic-chemical parameters of the water were done on 10th March, 2012. 4.0 Results 4.1 Macroinvertebrate analysis The results of the macroinvertebrate analysis are presented in the table below. They indicate that the health state of Molly Ann Brook is fair based on the biotic index healthy state while being poor based on the macroinvertebrate count water quality rating. However, the Bear Swamp Brook had a good health state based on the biotic index and macroinvertebrate count water quality rating. Macroinvertebrate count Water quality rating Location Biotic index Healthy state Sensitive Somewhat sensitive Tolerant Molly Ann Brook 2.5 Fair 3 2 2 Poor Bear Swamp Brook 3.0 Good 12 4 2 Good 4.2 Physico-chemical characteristics 4.2.1 Molly Ann Brook Results of the Molly Ann Brook showed that the dissolved oxygen concentrations were very high with the water having significant conductivity and alkalinity in addition to a very low velocity. 4.2.2 Bear Swamp Brook and Ramapo River Results of dissolved oxygen concentrations showed that the Bear Swamp Brook had higher oxygen concentrations when compared to the Ramapo River, both upstream and downstream. There was also poor water conductivity in all the locations and relatively lower total alkalinity and velocity compared to the Molly Ann Brook. The velocity of the Ramapo River was however not determined. 5.0 Discussion From the results obtained it was evident that Molly Ann Brook had low water quality both in terms of biotic quality, measured by the macroinvertebrate count and the biotic index, and also physico-chemical characteristics. Due to the poor water quality in the Molly Ann Brook the sensitive macroinvertebrate types were four times lower compared to the Bear Swamp Brook. Indeed it has been shown that indicators such as the number of intolerant species types determine the water quality since sensitive organisms cannot survive in polluted waters. The habitat and diversity of a stream is dependent on the land form and use upstream (Allan, 2004) and thus it is possible that pollution due to agriculture related activities could be responsible for the decreased biodiversity in Molly Ann Brook compared to Bear Swamp brook. The quality of the water habitat is mainly evaluated by a combination of several variables either used independently or in combination. Physical and chemical characteristic of the water help in determining the health state of the water. The electrical conductivity of the Molly Ann Brook was found to be very high. The conductivity of water is measured in microsiemens per centimetre (mS/cm) and is obtained due to the presence of ions such as sodium, potassium and chloride which give water the ability to conduct electricity. This is used as an indicator of dissolved wastes. The amount of dissolved oxygen in water is used to determine ability of water systems to support aquatic organisms that are dependent on oxygen which is mainly dependent on the temperature of water and elevation. The higher the temperature the higher the amount of oxygen will dissolve. Molly Ann Brook had a lower temperature than the Bear Swamp Brook and thus had a lower percentage of dissolved oxygen. The process of organic material decomposition consumes the dissolved oxygen. The concentrations of dissolved oxygen were not significantly different in all the sites sampled. The temperature of the water determines the solubility of oxygen in water. The temperature in a stream is mainly dependent on the amount of solar energy, the surface area of the stream and also the volume of the water in the stream. The pH of the water was not significantly different in the locations sampled and thus could not be used as a measure for water quality. The alkaline pH observed in all the locations could be due to the utilization of fertilizers upstream. Streams which are on a steeper ground have a higher flow velocity. Streams with a higher velocity have lower water quality when measured by macroinvertebrate diversity. Allan, (2004) notes that the high flow rates of water in a stream can eliminate some taxa of organisms especially at the life sensitive stages or if the frequency of removal is high then only the resistant species and those that are rapidly dispersed can survive. This is because the organisms cannot attach to the debris in the water. The Molly Ann Brook had a higher velocity and thus helps to explain why the microbial quality of this brook was poor. 5.1 Conclusion The results obtained showed that several factors used in the determination of the healthy state of a stream or river should be used in combination. The structural characteristic of a water system and its functional characteristic when used together help in drawing appropriate conclusion of the healthy state of the river. The macroinvertebrate organisms in the water are important because they give a long term healthy state of the stream as opposed to physico-chemical characteristics which give the transient condition of the stream. The Molly Ann Brook was in poor healthy state and this was confirmed by both biotic and abiotic properties of the water system while the Bear Swamp Brook was in a good healthy state as confirmed by both biotic and abiotic factors. 5.2 Recommendations We recommend that healthy state of the Molly Ann Brook should be reinstated by controlling the anthropogenic activities The healthy state of the Bear Swamp Brook should be improved to a better quality Read More