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Thesis about Phytoplankton :) enjoy reading and hoping someday will help the other student that will study about it

Thesis about Phytoplankton :) enjoy reading and hoping someday will help the other student that will study about it

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  • 1. COMMUNITY STRUCTURE OF PHYTOPLANKTON IN SAMPALOC LAKE, SAN PABLO CITY, LAGUNA A Thesis presented to the Faculty of the Department of Biology College of Science Polytechnic University of the Philippines Sta. Mesa, Manila In Partial Fulfilment of the Requirements for the Degree Bachelor of Science in Biology by DE ASIS, HAIZEL ANNE T. ZUBIAGA, JAHZEEL G. 2011
  • 2. ii ACKNOWLEDGEMENT We would like to express our deepest appreciation and sincere gratitude to our adviser Prof. Armin S. Coronado, for his valuable advice and assistance through useful comments, expensive suggestions, guidance and very helpful and critical reading of the manuscript, without which it would not have been possible for us to shape the thesis in the present form. We are very grateful to him for putting at our disposal every facility that he had which we need during the course of our work. Our profound thanks and appreciation to Dr. Luisito Evangelista for his criticisms, suggestions and generous help especially during the analytical stage of our research. We wish to express our special thanks to him for his guidance in the identification of phytoplankton and for letting us to use his equipment that were used during our sampling. This work would have been rendered impossible without the assistance of various people; from the sample collection, storage and transportation to analysis. It is impossible for us to cite everyone who contributed to the success of this work. We are most convinced, they know themselves and are conscious of our gratitude. Finally and most importantly, we would like to express our most sincere and warmest gratitude to our family, our relatives and friends for their prayers, assistance and encouragement throughout our study. We think words can never express enough how grateful we are to our parents. Nevertheless, thanks to our mother for their prayers, patience and untiring support in every way.
  • 3. iii Community Structure of Phytoplankton at Sampaloc Lake, San Pablo City, Laguna, Philippines ABSTRACT Sampaloc Lake is being vulnerable by human abuse and mismanagement of both living resources and the environment that support them. This situation pushed the local government of San Pablo City to have the lake rehabilitated due to the extreme changes. This study focused in the composition of phytoplankton community in Sampaloc Lake, San Pablo City, Laguna to qualify the current water status after the rehabilitation attempt specified by the local government. Horizontal hauling was used to collect the phytoplankton in littoral zone and vertical hauling in limnetic zone. The phytoplankton community of Sampaloc Lake was represented by Bacillariophyta (55%), Cyanophyta (30%) and Chlorophyta (15%) with a total of 20 taxa. Community in Sampaloc Lake were characterized with high species richness (D=1.682), high dominance (d=0.534) but uneven(E=0.132) distribution of phytoplankton organisms. During the sampling period, the average measurements of the various physico-chemical parameters (pH=8.35±0.05; transparency=30.38±0.57in; DO=9.33±0.04 mg/L) signify eutrophic condition of the lake. Moreover, the occurrence of Melosira, Oscillatoria and Pediastrum supported the eutrophic condition of Sampaloc Lake.
  • 4. iv Table of Contents Page No. Acceptance and Approval sheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i ii iii iv v vi vii 1 Background Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Objectives of the Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Significance of the Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Scope and Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Review of Related Literatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Taxonomy and Distribution of Phytoplankton. . . . . . . . . . . . . . . . . . . . . . . 5 Ecological Factors Influencing Growth of Phytoplankton. . . . . . . . . . . . . . 6 Nutrient Uptake and Growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Phosphate and Nitrogen: Major source of Nutrients. . . . . . . . . . . . . . . Consequences of Eutrophication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Effects of Eutrophication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 12 13 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 A. Description of the Study Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Environmental Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Collection and Preservation of Specimens. . . . . . . . . . . . . . . . . . . . . . D. Assessment of Phytoplankton Community. . . . . . . . . . . . . . . . . . . . . . 16 19 D.1 Enumeration of Phytoplankton. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 E. Community Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Results and Discussions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Parameter of the Lake water. . . . . . . . . . . . . . . . . . . . . . . . . . Chemical Parameters of the Lake Water. . . . . . . . . . . . . . . . . . . . . . . Phytoplankton Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phytoplankton Community Structure . . . . . . . . . . . . . . . . . . . . . . . . . . Characterization of Phytoplankton Community. . . . . . . . . . . . . . . . . . . Summary, Conclusions and Recommendations. . . . . . . . . . . . . . . . . . . . . . . Literatures Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 22 25 26 39 44 46 48 Appendices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
  • 5. v List of Figures Figure No. Title Page No. 1 2 3 4 5 6 7 Different points in five (5) stations. . . . . . . . . . . . . . The five (5) sampling stations in the study site. . . . . . Different genera of division Chlorophyta (A) Stigeoclonium sp.; (B) Protoccocus sp. ;(C) Pediastrum sp. ; (D) Staurastrum sp.; (E) Spirogyra sp.; (F) Green Algae 1. . . . . . . . . . . . . . . . . . . . . . . . Different genera of division Bacillariophyta.(A) Nitzschia sp.; (B) Cyclotella sp. ; (C) Coscinodiscus sp.; (D) Mastoglia sp.; (E) Melosira sp.; (F) Odontella sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Different genera of division Bacillariophyta. (A) Navicula sp.; (B) Pinnularia sp. (C) Thalasiosira sp.;(D) Amphora sp.;(E) Berkeleya sp. . . . . . . . . . . . Different genera of division Cyanophyta.(A) Merismopedia sp.; (B) Lyngbya sp.; (C) Oscillatoria sp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distribution of the major phytoplankton taxa in Sampaloc Lake . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 17 30 33 35 38 41
  • 6. vi List of Tables Table No. Title Page No. 1 Physico-chemical parameters of Sampaloc Lake (November 2010). . . . . . . . . . . . . . . . . . . . . . . . . . 22 2 Composition, relative abundance and relative frequency of phytoplankton in Sampaloc Lake (November, 2010). . . . . . . . . . . . . . . . . . . . . . . . . . 40 3 Community characteristics of phytoplankton in Sampaloc Lake (November, 2011). . . . . . . . . . . . . 44
  • 7. vii List of Appendices Appendix No. Title Page No. A Nautical map of San Pablo City, Laguna . . . . . . . . 52 B Description of San Pablo City, Laguna. . . . . . . . . . 53 C D E F G H Preparation of reagents. . . . . . . . . . . . . . . . . . . . . Table for analysis of variance (ANOVA). . . . . . . . Different measurement of Physico-chemical Parameters on each station in Sampaloc Lake San Pablo City, Laguna, Philippines (November, 2010). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical structure of diatoms. . . . . . . . . . . . . . . . . . Typical structure of blue green algae. . . . . . . . . . . Typical structure of green algae. . . . . . . . . . . . . . . 54 55 57 58 59 60
  • 8. Chapter 1 INTRODUCTION Background Information Phytoplankton refers to the group of minute, autotrophic organisms that float in the water surface of rivers, lakes and oceans. Like any terrestrial plants, phytoplankton requires sunlight, water and nutrients for growth. Sunlight is most abundant near the water surface where phytoplankton remains. They acquire their food reserves from the fixation of carbon dioxide with the presence of light and built up within the protoplasm (Relon, 1988). Thus, organism occupying higher tropic level may both directly and indirectly dependent for energy supply. Aside from its important role in the food chain, phytoplankton performs vital role in the biogeochemical cycles necessary for biological metabolism. Plankters are capable of adapting to different environmental conditions and their distribution are affected by several factors such as pH, temperature, light intensity and carbon dioxide concentration (Jorgensen, 1996). Moreover, they need a wide variety of chemical elements but the two critical are nitrogen and phosphorus, which are used to make proteins, nucleic acids and other cell parts. Hence, the presence of elements in the water allows the phytoplankton to survive and reproduce. The population of phytoplankton is said to be sensitive to fluctuations in the environment. Temperature affects the uptake of carbon dioxide for photosynthesis and oxygen for respiration. As temperature reaches beyond optimal range, net carbon dioxide changes until the limits are reached and refer
  • 9. 2 to the hot and cold limits of net photosynthesis (Salisbury and Ross, 1992). Furthermore, extreme temperature may also inhibit subsequent photosynthesis at optimal temperature. Another condition that affects the growth of phytoplankton is eutrophication, which rejuvenated by an increase in plant nutrients. This would allow algae bloom on the surface that prevents penetration of light in the lake water (Round, 1981). Eutrophication leads to oxygen depletion thus, death of oxygen-dependent organisms. In recent times, Sampaloc Lake shows the sign of being eutrophic because the lake is extremely threatened by diverse human activities (i.e. illegal settlement along the shores, resulting pollution illegal fish-pens, overfeeding and crowded fish cages). The overuse of commercial fish feeding may resulted in high nitrogen levels, low dissolved oxygen and proliferation of water lilies that made the lake on its current trophic condition. Recently, the local government of San Pablo regulates the construction of fish cages within the lake. According to Mrs. Aleiga (personal communication) one family can only avail 10 x 10 m2 of fish cages to support their personal needs and other necessesities. It is in this premise that characterization of the phytoplankton community be done in Sampaloc Lake. This would verify the current trophic status of the lake by identifying indicator species present in the study site.
  • 10. 3 Objectives of the Study The main objective of this research is to determine the structural diversity of the phytoplankton in Sampaloc Lake, San Pablo City, Laguna. Specifically, this study aims to: 1. identify and classify the phytoplankton present; 2. compare the phytoplankton diversity in each station ; and 3. assess the diversity of phytoplankton in the study site. Significance of the Study This study dealt with the adoption of the different ecological parameters to determine the community structure and dynamics of phytoplankton present in Sampaloc Lake. The phytoplankton collection at different areas of the lake would increase the value of knowledge on their distributional data. Such data are essential in any phytoplankton studies by describing its structure as well as diversity. Furthermore, such data generated by describing species richness and structural adaptations are very useful in any attempt to various conservation management. Since phytoplankton depends upon certain conditions for growth, they are good indicators of change in their environment (Herring, 2010). For these reasons, phytoplankton are the primary interest to oceanographers and Earth scientists around the world because they can relate the distribution of phytoplankton on the climate (Herring, 2010). Moreover, data derived from the
  • 11. 4 physico-chemical parameters of this study will enhance the knowledge of the local government of San Pablo City by knowing the diversity of the phytoplankton in the lake and how these organisms can affect their daily life. This information would help them to create sustainable management planning for maintenance of the lake. This study is also useful for the student who wishes to study freshwater biology and are interested in algae. This would help them to identify common phytoplankton that is present in freshwater ecosystem that would give them a detailed description as well as their ecological importance. Scope and Limitations This study was limited in determining the community structure of phytoplankton present in Sampaloc Lake located at San Pablo City, Laguna, Philippines. Classification and identification of the collected phytoplankters were based using Patrick and Reimer (1966) and Prescott (1951) keys. Identification was done to the lowest possible level. The species distribution and its ecological importance were discussed. Phytoplankton investigation was done last November 21, 2010 from 11:00 a.m. to 3:00 p.m. This time was appropriate for sampling since phytoplankton is dependent upon the amount of sunlight. Moreover, the only physico- chemical parameters measured were temperature, pH, transparency and dissolved oxygen concentration.
  • 12. 5 Chapter 2 REVIEW OF LITERATURE Taxonomy and Distribution of Phytoplankton The factors affecting the distribution and growth of the freshwater phytoplankton are a complex of physical (light, temperature, viscosity, current, velocity, and turbidity), chemical (nitrate, phosphate, silicate, organic factors) and biological features (growth rate, interaction, grazing etc.) The gross correlation between nutrient status and organic production suggests that nutrients are a limiting factor particularly in tropical and semi-tropical regions (Round, 1973). Abundant freshwaters organisms are greatly dominated in Euglenophyceae and Chlorophyceae which are the blue green algae and green algae. There are 450 species in genus Chlamydomanas that found in freshwater lakes and ponds but only few in marine waters (Willen and Willen, 1955). The taxonomy of the phytoplankton of Balayan Bay was studied by a group of undergraduate students from De la Salle University (de la Cruz et al, 1992) and reported a total of 104 species of phytoplankton collected and found out that the dominant species were the following: Bacteriastrum, Chaetoceros and Rhizosolennia. In the succeeding year, Relon (1988) did the taxonomy of phytoplankton in the Northwestern Luzon. Her study included collections from Pagudpud, Ilocos Norte up to Balayan Bay in Batangas. She reported 108 species belonging to 39 genera and 19 families. She also noted a significant difference in the number of
  • 13. 6 cell counts in both seasons of the year and correlated some physico-chemical factors such as temperature, salinity, pH, nitrates and phosphates affecting the distribution of phytoplankton. In freshwater environment the desmid are strictly confined because this group is rich in species of genus Cosmarium ( Willen and Willen, 1955). Ecological Factors Influencing Growth of Phytoplankton Turbidity Turbidity caused by suspended matter such as clay, silt, and organic matter and by plankton and other microscopic organisms can interfere with the passage of light through the water (Andersson, 2003). Thus, turbidity measures the cloudiness of water- the cloudier the water, the greater the turbidity. Patrick and Reimer (1966) emphasized that the amount of incident light does not seem to be the limiting factor for growth, but rather the turbidity of water caused by turbulence. The magnitude of turbidity depends on the amount and grain size of suspended matter. They added that turbidity return sediments previously deposited on the bottom into suspension. The light-photosynthetic relationship was affected by temperature (Prescott, 1968) and other factors such as salinity and nutrient concentration. Since most of the incident light energy was transformed into heat, temperature conditions were usually dependent on the light regime. With respect to light intensity, photosynthetic pigments were the most affected part. In diatoms, cells growing at higher light intensities have a lower
  • 14. 7 chlorophyll concentration per cell and a higher maximum photosynthetic rate (Strickland and Parsons, 1972). Diatoms continue to synthesize their photosynthetic pigments when growing heterotrophically in the dark and were capable of photosynthesis immediately upon return to the light. In a study made by Frouin and Iacobellis, they argue that the impact of phytoplankton extends beyond its warming influence. Changes in Earth's surface reflection caused by increases or decreases in phytoplankton concentrations may significantly affect the interactions of the planet's climate system with human-produced concentrations of greenhouse gases and aerosols. They also argue that the climatological significance of phytoplankton increased or decreased from region to region, since the magnitude of phytoplankton concentrations ultimately will dictate the strength of their warming influence. In fishponds, turbidity reduces phytoplankton growth thus reducing fish production (Larsson, 1994). He added that erosion carries silt, sand and other materials into ponds where they settle and lead to filling in of the pond. This shortens the lifespan of the pond, creating problems with macrophytes, thus, reducing the productive volume and sometimes increases turbidity. Global warming has great influence on the growth and distribution of phytoplankton; light and nutrients are also greatly affected by changes in the environment (Behrenfeld ,2006).
  • 15. 8 pH According to Piat (2007), they had recently discovered that the basic chemistry of the ocean was being altered by excess carbon dioxide absorption, which threatens organisms by increasing acidification. Acidification was caused by a reaction between CO2 and H2O, which forms carbonic acid (H2CO3). Carbonic acid increases the acidity of waters by lowering the pH. With increasing acidity, every species that constructs skeletons and shells of CaCO3 will find it more difficult to survive in the future. The impact of such a widespread decline in shell-producing marine organisms could be disastrous for nearly all-aquatic ecosystems. Increasing acidity will also affect numerous reproductive and/or physiological processes in other species with unknown consequences. The pH of freshwater ecosystems can fluctuate considerably within daily and seasonal timeframes, and most freshwater animals have evolved to tolerate a relatively wide environmental pH range. Animals can become stressed or die when exposed to pH extremes or when pH changes rapidly, even if the change occurs within a pH range that is normally tolerated (Tucker and D’Abramo, 2008). Temperature Temperature influences oxygen solubility, photosynthetic rates, respiration and metabolism (Wetzel, 1983). It has a significant influence on the species of
  • 16. 9 fish that can be cultured, growth rates, the quality of fish flesh, food conversion efficiency, and the economics of a fish culture operation. In addition, the temperature of air and water has great influence in the growth and distribution of phytoplankton as they constantly change e.g. they change as tides and currents bring new water into the area, or as solar radiation heats up surface layers. Temperature affects the uptake of carbon dioxide for photosynthesis and the uptake of oxygen for respiration. As temperature increases or decreases beyond the optimal range, net carbon dioxide becomes steadily smaller until finally limits are reached where CO2 equals to intake. Those limits are the hot and cold limits of net photosynthesis, respectively (Salisbury and Ross, 1992). Furthermore, extreme temperature may also inhibit subsequent photosynthesis at optimal temperature. If the top layer of the water warms, it makes harder for the upwelling of nutrients to reach the surface, starving the phytoplankton. Researchers found that drops in the amount of chlorophyll as detected by the satellite closely corresponded to increases in surface water temperature, confirming the predictions of climate models (Brahic, 2006). In the Philippines, surface temperatures warm during summer and cool during the rainy season. As reflected in the temperature readings furnished by PAGASA, temperature of the water changed as the season changes.
  • 17. 10 Nutrient Uptake and Growth The size of phytoplankton will be reflected in the relationship between maximum specific rates of nutrient uptake and growth. Maximum nutrient uptake rates are typically higher than the maximum growth rates and steady. State growth rates are independent of nutrients concentration in chemostat cultures (Caperon, 1968). Assimilated nitrate can be stored (as nitrate, ammonia or low molecular weight organic compound)and utilized for growth at some future time (Antia et. al 1963) have shown theoretically that such intracellular nutrient reserves can have a marked influence on the relative abundance of phytoplankton species in a variable nutrient environment. Lags between uptake and growth make possible higher growth rates than could otherwise occur (Caperon, 1969). McCarthy and Goldman (1979) present evidence that small-scale variation in nutrient supply allow phytoplankton to grow at nearly maximum rates when nutrient concentration are undetectable. Cells with the capacity to store nitrogen when nitrogen supply exceeds the demand by growth should have advantage in a variable nutrient environment over cell that have smaller storage capacities (Lawas and Caperon 1976). Many phytoplankton species posses a large vacuole within which nitrogen reserves could be compartmentalized (Eppley and Coastworth 1968).This organelle is esp. characteristics of large dinoflagellates and diatoms its volume increasing as cell volume increases (Smayda 1965 and Paasche 1973). The
  • 18. 11 vacuole comprises of 30-90% of the cell volume in diatoms with mean spherical diameters greater than 5um (Smayda, 1970). An ability to store nutrients would provide a mechanism by which large cell could grow faster than small cells under non steady state condition. Phosphate and Nitrogen: Major source of Nutrients In addition to carbon, oxygen and hydrogen that plants can find directly from water, and carbon dioxide in the atmosphere, two major nutrients are necessary for the development of aquatic life: Nitrogen (N) and phosphorus (P). A third one, silica (Si), is necessary for the development of diatoms. During eutrophication, the concentration of nutrients in the water changes. In some cases one out of the three nutrients may be totally bound to the aquatic life and will not be available for further growth of algae. This nutrient is then called the limiting factor. The ratio of nitrogen to phosphorus compounds in a water body is an important factor determining which of the two elements will be the limiting factor, and consequently which one has to be controlled in order to reduce a bloom (Volterra, 2002). Generally, phosphorus tends to be the limiting factor for phytoplankton in fresh waters. Intermediate areas such as river plumes are often phosphorus- limited during spring, but may turn to silica or nitrogen limitation in summer. When phosphorus is the limiting factor, a phosphate concentration of 0.01 mg l-1 is enough to support plankton and concentrations from 0.03 to 0.1 mg l-1 or higher will be likely to promote blooms but may turn to silica or nitrogen limitation
  • 19. 12 in summer. When phosphorus is the limiting factor, a phosphate concentration of 0.01 mg l-1 is enough to support plankton and concentrations from 0.03 to 0.1 mg l-1 or higher will be likely to promote blooms (Volterra, 2002). Consequences of Eutrophication The major consequence of eutrophication concerns the availability of oxygen. Plants, through photosynthesis, produce oxygen in daylight. On the contrary, in darkness all animals and plants, as well as aerobic microorganisms and decomposing dead organisms, respire and consume oxygen. These two competitive processes are dependent on the development of the biomass. In the case of severe biomass accumulation, the process of oxidation of the organic matter that has formed into sediment at the bottom of the water body will consume all the available oxygen. Even the oxygen contained in sulphates will be used by some specific bacteria. This will lead to the release of sulphur that will immediately capture the free oxygen still present in the upper layers. Thus, the water body will loose all its oxygen and all life will disappear (Boualam, 2002). In parallel with these changes in oxygen concentration other changes in the water environment occur changes in algal population during eutrophication, macroalgae, phytoplankton (diatoms, dinoflagellates, chlorophytes) and cyanobacteria, which depend upon nutrients, light, temperature and water movement, will experience excessive growth (Boualam, 2002).
  • 20. 13 Ecosystem experience changes in zooplankton, fish and shellfish population when eutrophication occurs. Being most sensitive to oxygen availability, these species may die from oxygen limitation or from changes in the chemical composition of the water such as the excessive alkalinity that occurs during intense photosynthesis. Ammonia toxicity in fish for example is much higher in alkaline waters (Volterra, 2002). Effects of Eutrophication Lake eutrophication is now a world-wide concern. The main manifestation of this process is a very strong development of primary producers in the euphotic zone and very low oxygen concentration in deep layers of the lake. In highly eutrophic lake, phytoplankton is often dominated by cyanobacteria (Yasser Abdul Kader Al-Gahwari, 2007). These organisms form water blooms at the surface which strongly reduce light penetration in the water column most cyanobacteria species are toxic, their massive development compromise drinking water production and leisure activities (Yasser Abdul Kader Al-Gahwari, 2007). Cyanobacteria have been largely studied in fresh water systems, due to their ability to proliferate, to form massive surface scums, and to produce toxins that have been implicated in animal or human poisoning. Algae display varying degrees of complexity depending on the organization of their cells. Macroalgae, phytoplankton and cyanobacteria may colonize marine, brackish or fresh waters wherever conditions of light, temperature and nutrients are favourable. There is growing evidence that
  • 21. 14 nutrients, especially nitrogen, favour the duration and frequency of such toxic“blooms”, and concentrations of toxin in the cells
  • 22. 15 Chapter 3 METHODOLOGY A. Description of the Study Site Sampaloc Lake was located within the city proper of San Pablo, Laguna (Appendix A) with an area of 104 hectares, a maximum depth of 27 meters and a maximum width of 1.2 kilometers. Generally, Sampaloc Lake has muddy substrate. The lake was situated at latitude of 14.079°N and 121.33°E (Evangelista, 1987). During the sampling, the lake was divided into two (2) zones namely littoral and limnetic zone. The littoral zone was subdivided into four (4) stations (Figure 1) and designated as (1) commercial, (2) residential and fish cages, (3) tributary and (4) non-residential area. The various environmental conditions were the bases of assigning different stations of the lake. This include as having the presence of household’s waste, the milieu of having plants, along the fish cage and the natural environment of the lake. B. Environmental Parameters The following physico-chemical parameters were determined in this study namely transparency, temperature, pH and dissolved oxygen.
  • 23. 16 Figure 1. Shows the different station and their points. Red Dots- Point 1, Yellow Dots- Point 2, Green Dots- Point 3. The large number indicates the station for the water sampling both for Limnetic and Littoral zone (Map Source: http://www.openstreetmap.org). + 21 14°4.477 N 121°19.608 + 16 14°4.577 N 121°19.528 + 14 14°4.882 N 121°19.483 + 16 14°4.805 N 121°19.542 + 16 14°4.911 N 121°19.716 + 19 14°4.988 N 121°19.904 + 22 14°4.701 N 121°20.132 + 16 14°4.548 N 121°20.096 + 15 14°4.781 N 121°20.186 + 14 14°4.441 N 121°19.993 + 19 14°4.382 N 121°19.815 + 16 14°4.419 N 121°19.699 + 12 14°4.744 N 121°19.631 + 16 14°4.799 N 121°19.574 + 11 14°4.493 N 121°19.540 1 2 3 4 5
  • 24. 17 Figure 2. The different stations for water sampling for both littoral and limnetic zone in Sampaloc Lake, San Pablo Laguna. (A)Station 1-Commercial Area, (B)Station 2- Residential (C) Fish Cages Area, (D)Station 3- Tributary Area, (E)Station 4- Non Residential Area and (F) Station 5- Limnetic Area. A D B E FC
  • 25. 18 B.1 Transparency A circular metallic plate known as Secchi Disc was used having a 10 cm radius. The disc was lowered into the water and the distance of its first disappearance was noted. The plate was slowly raised and the distance when the plate reappeared was taken. The average distance (cm) between the two readings represented the turbidity of the water. The procedure was repeated three times in each station. B.2 Temperature and pH Temperature and pH were measured using Oakton pH tester 30. The probe was immersed in water for at least two (2) minutes before measurement was noted and repeated for three (3) times. B.3 Dissolved Oxygen (DO) Concentration Dissolved Oxygen (DO) concentration was measured at each sampling site using the Oakton DO 300 series. The probe was immersed at about six (6) inches below the water surface and performed three (3) times, which the average measurement was noted.
  • 26. 19 C. Collection and Preservation of Specimens Collections of samples were done using horizontal hauling for littoral zone and vertical hauling for limnetic zone. There were three (3) points considered for each sampling station. The water samples were collected by using plankton net, which has a diameter of 15 cm and height of 44 cm. In littoral zone, the collection of sample was done by throwing the net at about 5 meters and repeated for five (5) times. On the other hand, vertical hauling was used in limnetic zone. This was done by submerging the plankton net at 10 meters below the water surface. The collected water sample was transferred to 100 mL collecting bottle that was previously labeled with station identification and replicate number. Water samples were preserved in 4% buffered formalin (Appendix C). The buffered formalin was used as a preservative that prevents deformation of the cell (Azanza – Corrales et al, 1993). Identification of preserved samples was based on the keys used by Patrick and Reimer (1966) and Prescott (1951). D. Assessment of Phytoplankton Community D.1 Enumeration of Phytoplankton In order to calculate the density of phytoplankton present in water sample, a counting chamber and a microscope were used for this purpose. Since the size of the phytoplankton were small, haemocytometer was used (Neubauer Brand) as suggested by Martinez (1975).
  • 27. 20 One hundred (100) milliliter water samples were concentrated to 10 mL and 1 mL aliquot was taken and carefully placed in the trough of the haemocytometer. The organisms were observed under low and high magnifications of the microscope for identification and enumeration. The filled chamber was allowed to stand 1-2 minutes prior to counting in order to give enough time for cells to settle down. Observation follows under low magnification to check the distribution of the cells within the chamber. The haemocytometer comprises 5 quadrants and each quadrant consists of 16 squares. Large squares were used to count the phytoplankton present in the chamber to show the average organism present. Cambridge Microscope was used in order to examine the features of each specimen under LPO and HPO. Ocular Micrometer was also used to measure the length and width of each species. Each of the measurement (length and width) was multiplied by 0.255µm (HPO) and 1.02µm (LPO) to calculate the size of the specimen. Above measurement were calibrated to get the definite size of the species. Abundance is the number of species in an area. It was used to determine the abundance of the species on a particular environment and also used to calculate the number of species per cell present in the lake. In determining the species abundance in each sampling station the following formula was used (Odum, 1980). Density= N X V1 Vs
  • 28. 21 Where: N= Number of cell in 1 mL sample V1= Total Volume of the sample where 1 ml aliquot taken (mL) Vs= Volume of the water filtered by plankton net within a hauling depth (mL) E. Community Structure To asses the estimation of species diversity, dominance, richness and evenness of phytoplankton present in the study site, different diversity indices were used.Dominance is defined as the number of species that can be found in an area in frequent occurrence (Odum, 1980). Moreover, Shannon index as well as Simpson’s index emphasizes not only the number of species (richness or variety) but also the apportionment of the numbers of individuals among the species (Odum, 1971 and Reish, 1984). Evenness, therefore, takes into consideration the dominance or lack of dominance of one or a few organisms in the community. Lastly, Margalef’s is the number of different species in a given area. It was used in conservation studies to determine the sensitivity of ecosystems and their resident species. All the calculations to characterize the phytoplankton community was evaluated using the software Paleontological Statistics ver. 1.88.
  • 29. 22 Chapter 4 RESULTS AND DISCUSSIONS Physical parameters of the lake water The different environmental parameters measured in five stations of Sampaloc Lake during November 2010 were summarized in Table 1. Water temperature ranges from 25.86°C to 28.23°C with a mean of 27.33 ± 0.24°C. Surface water varied from pH 8.27 to 8.43 generating a mean value of 8.35±0.05. On the other hand, the measured water transparency were 20.08 in to 38.58 in giving a mean of 30.38 ± 1.568 in while dissolved oxygen concentration ranged from 8.75 mg/L to 10.22 mg/L with a mean of 9.33 ± 0.04 mg/L. Table 1. Physico-chemical Parameters of Sampaloc lake (November 2010). *values are reported as mean ± Standard Error (s/√n) *values with the same letters are not significantly different at α= 0.05 *values in parentheses are acceptable ranges for a healthy aquatic ecosystem Parameters Station Average 1 2 3 4 5 Temperature (13 0 C-31 0 C) 28.23±0.04 a 27.82±0.03 a 27.61±0.02 a 25.86±1.11 a 27.14±0.02 a 27.33±0.24 pH (6.5-9) 8.35±0.05 abc 8.32±0.05 abc 8.36±0.03 ac 8.43±0.05 b 8.27±0.09 c 8.35±0.05 Transparency (20-90 in) 28.50±1.32 ab 38.58±5.30 a 34.72±7.50 a 30.02±7.59 a 20.08±0.19 b 30.38±0.57 Dissolved Oxygen (9-10 mg/L) 8.75±0.05 a 9.06±0.02 ab 9.32±0.02 ab 10.22±.08 b 9.29±0.05 a 9.33±0.04
  • 30. 23 Temperature The highest temperature was obtained in Station 1 (28.23°C) and the lowest temperature was observed in Station 4 (25.86°C) during the sampling period. There was no significant differences (α0.05< 0.91) observed from among the five stations of the lake. Each station would imply different degree of stresses hence variation can be observed. Mean temperature of the lake has a value of 27.33 ± 0.24°C, which may maintain the development and production of phytoplankton present in the lake. The optimum temperature that enabled the phytoplankton to grow is about 130 C to 320 C (Boney, 1971). The temperature of a freshwater environment can directly affect the environment as a whole and the organism that occupy it. Phytoplankton as a photosynthetic organism can proceed their production even if the temperature rises up to 31 ºC (Boney, 1971). The condition that most blue-green algae seem to flourish is having warm water temperatures at 28°C-31ºC. pH During the sampling period the pH of surface water in Sampaloc Lake ranges from 8.27 ±0.09 to 8.43 ±0.05. The highest pH value was obtained in station 3 (pH=8.43 ±0.05) while lowest at station 5 (pH=8.27±0.09). The ideal pH of culture condition is 6.5 - 9.0 while about pH 8.0 in natural condition (Relon, 1988). Data showed that the surface water of Sampaloc Lake is
  • 31. 24 slightly basic (mean=8.35±0.05), which is better for phytoplankton development (Relon, 1988). Stations 4 showed significant differences in pH at stations 3 (α0.05>0.030) and station 4 (α0.05>0.013). The differences in pH for each station can be attributed to the presence of fish cages wherein Station 3 had fewer fish cages as compared to station 4 and station 5. By the presence of the fish cages, it has been recently discovered that water altered by excess carbon dioxide absorption, threatens organisms by increasing acidification. Acidification will tend to be higher because of the reaction of water and the carbon dioxide (CO2) released by the fish. Carbon dioxide dissolves slightly in water to form a weak acid called carbonic acid (H2CO3). After that, carbonic acid reacts slightly and reversibly in water to form hydronium cation, H3O+, and the bicarbonate ion, HCO3- (Shakhashir, 2008). pH of water will tend to be alkaline by having relatively low concentration of hydrogen ion. This condition is favorable for the growth and respiration uptake of phytoplankton (Moss, 1972). Transparency The highest measurement of transparency was recorded in station 2 with 38.58+5.26 in (3.22 ft) and the lowest measurement was observed in station 5 with 20.08+4.19 in (1.67 ft). Michigan Lake Institute (MLI) stated that water with less than 90 in (7.5 ft) transparency is considered to be
  • 32. 25 eutrophic. Significant differences in the transparency (α0.05> 0.015) were observed in the surface water among the different stations. This was observed in stations 2 and 5 (α0.05>0.014), 3 and 5 (α0.05>0.034) and in station 4 and 5 (α0.05>0.046). Station 5 was not directly disturbed by human’s organic devastation because this area was distant from the shoreline and the deviation in water transparency could be caused by suspended matters such as clay, silts and sand obtained in every stations (Andersson, 2003). By this condition, excessive suspended matters in the lake will cause water surface to be unclear. If these conditions happen the light coming from the sun prevent to pass through the water surface that would decline the photosynthetic rate of the phytoplankton (Boney, 1971). Chemical Parameters of the Lake Water Dissolved Oxygen The highest amount of dissolved oxygen was obtained at station 4 (10.22±.08mg/L) while lowest at station 1 (8.75±0.05mg/L). Results showed that there is significant difference (α0.05> 0.009) in the level of dissolved oxygen among different stations. Station 4 showed significant differences with station 1 (α0.05>0.006) and 5 (α0.05>0.047) that indicates the variation in the dissolved oxygen among the stations. The significant differences of dissolved oxygen in different stations was due to differences in the stresses that each station obtained. DO obtained in station 4 was due to reduced amount of stress it receives as
  • 33. 26 compared with station 1 and 5. On the otherhand, DO obtained from station 1 maybe due to the human effluents and improper disposal of their waste in the periphery of lake. Effluents have organic wastes that coming from the remains of any living organism. It is decomposed by the bacteria and eventually remove dissolved oxygen from the water when they breathe. If more food (organic waste) is available for the bacteria, more bacteria will grow and use oxygen, and the DO concentration will drop (Murphy, 2007). The mean value of dissolved oxygen observed in Sampaloc Lake was 9.33 mg/L. DO concentration ranging from 9 to 10 mg/L indicated a very healthy aquatic life (Mack and Cub, 2003). If dissolved oxygen levels are too low (3-5ppm), some fish and other organisms may not be able to survive (SIT, 2009). Levels of 5 to 6 ppm are usually required for growth and activity of aquatic organism (LaMOTTE Company, 2006). Phytoplankton Composition The algal composition of Sampaloc Lake was characterized by three major groups namely Bacillariophyta, Chlorophyta and Cyanophyta, which consist of twenty (20) taxa. Green algae collected was distributed into four (4) orders and six (6) genera (Figure 3). Five taxa were identified up to the genus level and 1 taxon was not identified but considered to be in Division Chlorophyta. Moreover, five (5) orders of Bacillariophyta were collected and it was distributed to eleven
  • 34. 27 (11) genera (Figure 4-5). In addition, Division Cyanophyta consists of two (2) orders and three (3) genera (Figure 6). Division Chlorophyta During the sampling period (November, 2010), 6 genera were determined under Division Chlorophyta namely Protococcus sp., Pediastrum sp., Stigeoclonim sp., Staurastrum sp., Spirogyra sp. and Green Algae 1. Algae belonging to this group are characterized by green color chloroplast, one or many in each cell or protoplasmic unit. The cell wall, which is firm in most genera, is composed of cellulose and pectic compounds. There may be, also, a mucilaginous outer layer. Sometimes it may be unicellular (one cell), multicellular (many cells), colonial (living as a loose aggregation of cells) or coenocytic (composed of one large cell without cross-walls; the cell may be uninucleate or multinucleate) (Prescott ,1951). Order Chaetoporales Family Chaetophoraceae 1. Stigeoclonium sp. (Figure 3A) Thorn-like branches; cell ranges up to 12-18 in diameter. Branches mostly alternate or opposite; branched filament; cells scarcely smaller than those or of man’s axis ending in bluntly pointed or setiferous cell; horizontal or prostrate portion of the thallus often present.
  • 35. 28 Family Protococaceae 2. Protoccoccus sp. (Figure 3B) Simple colony and simple filament; the colony of the cell ranges to 4-6 celled colonies; 1.275 µm in diameter; globular in shaped; cells are up to 8-12 in diameter. Order Chlorococcales Family Hydrodictyaceae 3. Pediastrum sp. (Figure 3C) Species form a colony; Shape like a human tooth; the colony of the cell ranges to 32-38 celled colony; colony cell size is 65µm in diameter; cells up to 12-20 µm in diameter; thallus flat, circular plate of polygonal cell; cylindrical cell arranged to form a macroscopic closed cylindrical net. Order Desmidiales Family Desmidiaceae 4. Staurastrum sp. (Figure 3D) Cells appear star shaped or triangular. H-Shaped; cells ranges to 1.507 µm; apex of cell extended into 3 or more arms or lobes, the arms usually extended radiantly so that the cell appears star-shaped or triangular when seen in vertical or end.
  • 36. 29 Order Zygnamatales Family Zygnamataceae 5. Spirogyra sp. (Figure 3E) Filaments are long and unbranched; cell are cylindrical and short; colony of the cell ranges to 55-90 µm in diameter; 40.8 µm in length. 20-30 cells diameter. Bright green in color and cotton growth. 6. Green Algae 1 (Figure 3F) Green algae; non filamentous; the size of the cell ranges 3- 10µm in diameter; semilunate in form; appears to be green.
  • 37. 30 Figure 3. Different genera of division Chlorophyta (A) Stigeoclonium sp.;(B) Protoccocus sp.; (C) Pediastrum sp. ; (D) Staurastrum sp.; (E) Spirogyra sp.; (F) Green Algae 1.
  • 38. 31 Division Bacillariophyta During the sampling period (November, 2010) 11 genera were determined under Division Bacilliariophyta namely Amphora sp., Berkeleya sp., Cosinodiscus sp. ,Cyclotella sp., Mastoglia sp., Melosira sp., Navicula sp., Pinnularia sp., Odontela sp., Nitzcha sp. and Thalossiosira sp. The external morphology of diatoms is based on the solid silica shell or frustule that they all have in common. All diatom skeletons are made of silica and consist of two parts or frustules that fit inside each other like a petri dish: the epitheca and the hypotheca. The shape of the frustule is the defining feature that is used to break the diatoms into two distinct classes: the centric or Centrobacillariophyceae and the pennate or Pennatibacillariophyceae. The pennate diatoms are usually radially symmetrical while the centric diatoms are generally bilaterally symmetrical (Alexopoulos, 1967). Order Bacillariales Family Bacillariaceae 7. Nitzchia sp. (Figure 4A) Frustules solitary; diagonally opposite one another; raphe on a keel or wing; occur both valves.
  • 39. 32 Order Centrales Family Coscinodiscaceae 8. Cyclotella sp. (Figure 4B) Cells drum-shaped; the length of the cell size ranges to 0.5- 3µm; valves with an intramarginal zone of costae; frustules circular in valve view and without spine-like thorns. 9. Coscinodiscus sp. (Figure 4C) Circular in shaped; species arises up to thousands of cells; the length of the cell ranges to 30-60µm; valves without intranargint profusion and every ornament; frustules of drum-shaped, rectangular in girdle view. 10. Mastoglia sp. (Figure 4D) Cell is solitary; bean shaped; the length of the cell ranges 1- 5µm; frustules with septa; rectangular in girdle view; naviculated in valve view; septum large. 11. Melosira sp. (Figure 4E) Cells closely united to more straight and arranged in filament; Bread like; short spines at the junction of the frustules, which are united into a filament; cells ranges to 0.5-1.5µm in diameter; frustules cylindrical in girdle view attached end to end in filament polar margin in often with denticulation; with intercalary band.
  • 40. 33 Figure 4. Different genera of division Bacillariophyta.(A) Nitzschia sp.; (B) Cyclotella sp. ; (C) Coscinodiscus sp.; (D) Mastoglia sp.; (E) Melosira sp.; (F) Odontella sp.
  • 41. 34 Family Eupodiscaceae 12.Odontella sp. (Figure 4F) Filamentous; cells ranges to 1-2 µm in diameter; colony composed of 4-6 cells; valves are thin-walled with ocelli on elevation; mantle rounded. Order Naviculales Family Naviculaceae 13.Navicula sp. (Figure 5A) Cells solitary; cells are longitudinal in form and elongated; axial field narrow and linear; transverse ornamentation composed of puncta. Family Pinnulariaceae 14. Pinnularia sp. (Figure 5B) Cell is elongated and elliptical; not filamentous; the cell size ranges to 1-3µm in diameters; composed of 2 valves, valves overlap like a petri dish; valves are covered by connecting band called cingulum. 15. Thallossiosira sp. (Figure 5C) Cells in colonies usually wide apart; solitary; the cell size ranges to 0.5-1µm in diameters; the length of the cell ranges to 1- 4µm
  • 42. 35 Figure 5. Different genera of division Bacillariophyta. (A) Navicula sp.; (B) Pinnularia sp. (C) Thalasiosira sp.;(D) Amphora sp.;(E) Berkeleya sp..
  • 43. 36 Order Thalassiophysales Family Catenulaceae 16.Amphora sp. (Figure 5D) Comb-like shaped; not filamentous; the cell size ranges to 3- 8 µm in diameter; ventral margin of curved frustules; cells usually with concave margin. 17. Berkeleya sp. (Figure 5E) Raphe are straight; the length ranges to 8-25 µm; composed of 2 cell; cells are long and elongated; optical ending terminate valves linear-lanceolate, broad with rounded apices. Division Cyanophyta During the sampling period (November, 2010), 3 genera were determined under Division Cyanophyta namely Lyngbya sp.,Merismopedia sp.,Oscillatoria sp..They are characterized by having poorly defined nucleus. Although individual organisms in this kingdom are for the most part microscopic, their colonies can reach great size. The cell component lack membrane and the protoplasm is gel- like without streaming characteristics of eukaryotes. The cell wall are distinct from those on other algae in consisting of two or more three layers in close association with the plasma membrane. They are unicellular colonial or filamentous. The photosynthetic apparatus is not bound in chloroplasts but rather on the surface of free floating thylakoids (Prescott, 1951).
  • 44. 37 Order Chroococcales Family Chroococcaceae 18.Merismopedia sp. (Figure 6A) Plate-like colony; quadriangular in cell shaped. 2-4 cells; colony cells ranges to 15-25 µm in diameter; consisting of more than 4000 cells in one colony; globose cell compactly or loosely arranged in rows both transverse and longitudinally . Order Nostocales Family Oscillatorialles 19.Lyngbya sp. (Figure 6B) Filamentous; diameter of the cell ranges to 1.5-3 µm ; size of the taxa ranges to 20-50 µm; composed of uniserate and unbranched trichomes of cell; more or less firm sheath. 20.Oscillatoria sp. (Figure 6C) Filamentous and elongate; 1-3 µm in cell diameter; solitary or matted trichomes ; length ranges to 50-80 µm diameter in long; distinct sheath like membrane the calyptras.
  • 45. 38 Figure 6. Different genera of division Cyanophyta.(A) Merismopedia sp.; (B) Lyngbya sp.; (C) Oscillatoria sp
  • 46. 39 Phytoplankton Community Structure The composition of phytoplankton community in Sampaloc Lake and their abundance during November 2010 is presented in Table 2. The algal composition of Sampaloc Lake was represented by three major groups namely Bacillariophyta (diatom), Chlorophyta (green-algae) and Cyanophyta (blue-green algae) which comprises a total of twenty (20) taxa. The taxa were distributed into 6 genera of green algae, 11 genera of diatoms and 3 genera of blue-green algae. Light microscopy was used to identify the phytoplankton species at high power magnification. This allowed to identify the morphological characters of each species. However, the highest possible level of identification is up to genus level only. The relative abundance for 3 major phytoplankton groups of Sampaloc Lake is summarized in Figure 7. The phytoplankton community is highly represented by Bacillariophyta (55%), Chlorophyta (30%) and Cyanophyta (15%), respectively. The highest number of taxa was obtained in Bacillariophyta which accounted for the presence of 11 genera. On the otherhand, low abundance of Cyanophyta (15%) in the different station of the lake can be attributed to the impacts of human activities such as household wastes, manure and industrialized effluents that directly manipulate the distribution of this group.
  • 47. 40 Table 2. Composition, relative abundance and relative frequency of phytoplankton in Sampaloc Lake (November, 2010). Taxa Abundance ( individuals/ m3 ) Mean RA (%) Rf (%) 1 2 3 4 5 Chlorophyta 1. Pediastrum sp. 76 0 0 0 116 131.20 0.180 40 2. Protoccocus sp. 0 0 0 139 0 139.00 0.191 20 3. Spirogyra sp. 182 8 0 0 0 44.40 0.061 40 4. Stigeoclonium sp. 0 369 0 0 0 369.00 0.507 20 5. Staurastrum sp. 0 0 58 0 0 58.00 0.080 20 6. Green algae 1 8 0 0 0 0 1.60 0.002 20 Bacillariophyta 7. Amphora sp. 0 0 0 0 152 152.00 0.209 20 8. Berkeleya sp. 0 0 0 0 3 3.00 0.004 20 9. Cosinodiscus sp. 3 0 1768 0 0 1768.60 2.43 40 10. Cyclotella sp. 245 240 104 328 53 774.00 1.06 100 11. Mastoglia sp. 0 0 0 0 18 18.00 0.025 20 12. Melosira sp. 2326 1374 859 902 12104 15704.20 21.56 100 13. Navicula sp. 48 0 33 5 0 47.60 0.065 60 14. Pinnularia sp. 3 0 0 0 0 0.60 0.001 20 15. Odontela sp. 0 0 0 0 1152 1152.00 1.582 20 16. Nitzcha sp. 35 10 13 0 73 103.00 0.141 80 17. Thalossiosira sp. 0 96 0 0 0 96.00 0.132 20 Cyanophyta 18. Lyngbya sp. 0 0 0 0 1323 1323.00 1.816 20 19. Oscillatoria sp. 533 78 0 0 0 184.60 0.253 40 20. Merismopedia sp. 0 116 46510 0 4242 50868.00 69.82 60 Legend: RA (Relative Abundance) Rf (Relative frequency)
  • 48. 41 Figure 7. Distribution of the major phytoplankton taxa in Sampaloc Lake (November 2010).
  • 49. 42 Among the five stations, Station 1 had the highest number of taxa (n=10) while station 4 obtained the least number of taxa (n=4). The difference is due to the amount of light received by both stations. This circumstance can cause obstruction of light penetration that is one of the requirements of phytoplankton to conduct photosynthesis (Boney, 1971). Station 1 was more likely receiving much light because this area does not have any impediment such as the presence of trees which station 4 obtained. During sampling, the dominant taxon was Melosira sp. that can be found in basic water (Prescott, 1951). It can tolerate at about a pH ranges from 8 to 9 and accompanied with low transparency (Prescott, 1951 and Relon, 1988). In this study, results of physico - chemical parameters coincide with the said condition. Melosira being dominant genera can be a proof that the water in Sampaloc Lake is in eutrophic condition. Melosira sp. being a dominant taxa would mean that diatoms respond quickly to environmental changes as well as for having specific tolerances for water quality (Dixit et al, 1999). Phytoplankters in the five stations with highest frequency (100%) were observed in Melosira sp. and Cyclotella sp.. Their presence would indicate the capability of the diatom to adapt to different kinds of environment. With a high sensitivity to environmental variables, a group of diatoms performs essential roles that include acting as a primary food source, oxidized the water and increased the available nutrients (Stone, 2005).
  • 50. 43 On the otherhand, members of Chlorophyta were found in the lake specifically Pediastrum sp., Protococcus sp., Spirogyra sp., Staurastrum sp., Stigeoclonium sp. and Green Algae 1. It has been reported that the presence of Pediastrum (18 %) species are more common in eutrophic waters than in oligotrophic waters (Turkmen, 2005). Therefore, Sampaloc Lake could be characterized with a eutrophic condition. Members of Cyanophyta were observed to be more abundant in all stations except in station 4. Merismopedia sp., Lyngbya sp. and Oscillatoria sp. belonging to Cyanophyta were observed. These species can tolerate a polluted water (Turkmen, 2005). Boney (1971) also stated that the presence of Oscillatoria species on the bodies of water would signify rapid eutrophication. Characterization of Phytoplankton Community The summary of diversity indices of the phytoplankton community along the study site is presented in Table 3. A total of 20 species of phytoplankters was observed in the study site, where the highest quantity of taxa was found in station 1 (S=10) whereas the least number was recorded in Station 4 (S=4). Station 1 (D=1.104) showed a high value of species richness as compared to other stations that is evidently supported by the occurrence of elevated number of taxa present in the said station. Likewise, low value of species richness in station 4 (D=0.415) would indicate the low number of taxa present. The variation between the species richness showed no significant relationship (α0.05< 1.680) among the different stations. This only shows that
  • 51. 44 Table 3. Community characteristics of phytoplankton in Sampaloc Lake (November, 2011). *values are reported as mean ± Standard Error (s/√n) *values with the same letters are not significantly different at α= 0.05 despite of different stresses that the lake is exhibiting, there would be less variation in terms of species richness and composition among them. Moreover, the computed dominance was highest in station 3 (d=0.89) and lowest in station 1 (d=0.048). The high value of dominance in station 3 indicated that there is a tendency of one (1) species to dominate the community, which was observed in the abundance of Merismopedia sp. while dominance(d=0.048) in station 1 would only mean that one (1) taxa will not strictly dominated the and that was observed in Melosira sp.. Inspite of great number of cell count in Melosira sp. (2326/ m3 ), it shows that abundance in cell count does not dominate the community as well as with Merismopedia sp.(46510/m3 ). Hence, high values of Shannon Wienner and Simpson’s Indices were found in station 2 (H’=1.302; 1-D=0.601) and lowest in station 3 (H’=0.274; 1- D= 0.11) (Appendix D). Data showed that there were no significant Station Diversity Indices Taxa Dominance Shannon Simpson Evenness Richness (S) (d) (H’) (1-D) (E) (D) 1 10 0.048a 1.113a 0.516 a 0.305 a 1.104 a 2 8 0.398a 1.302 a 0.601 a 0.409 a 1.033 a 3 7 0.890 a 0.274 a 0.110 a 0.188 a 0.555 a 4 4 0.498 a 0.871 a 0.502 a 0.597 a 0.415 a 5 9 0.453 a 1.092 a 0.547 a 0.298 a 0.912 a Average 20 0.534 0.973 0.466 0.132 1.680
  • 52. 45 differences between Shannon Wienner Index and Simpson index (H’= α0.05 < 0.384; 1-D = α0.05 < 0.334). This only proved that the overall diversity of the plankton community is greatly represented by the total quantity of species present in the area. Evenness was highest in station 4 (E=0.597). This only means that the phytoplankton species in station 4 are more evenly distributed than station 3 (E= 0.188). In addition, no significant differences (α0.05 < 0.718) were observed between species evenness in the different stations. This would indicate that there is little distribution of phytoplankton in each station. A total of 20 taxa was documented in Sampaloc Lake during the sampling period. High species richness (D=1.680) implies that despite the high dominance value (d=0.534) in the site, there is possibility that one taxon will dominate the phytoplankton community. Values near one (1) would indicate that there is a chance of one taxa to dominate the area. Moreover, values of Simpson Index (1-D=0.466) and Shannon-Wienner Index (0.973) would indicate that the general diversity of phytoplankton community in Sampaloc Lake is highly represented by the total quantity of species present in the study area but index of species evenness (E=0.1324) showed a little distribution within the community.
  • 53. 46 Chapter 5 SUMMARY, CONCLUSIONS AND RECOMMENDATIONS Phytoplankton plays an important role in determining the trophic status of freshwater systems. Their distribution, development and productivity are directly affected by the varying physical and chemical factors present in an environment. This study assessed the composition of phytoplankton community in Sampaloc Lake, San Pablo City, Laguna to qualify the current water status after the rehabilitation attempt specified by the local government. Different environmental parameters were measured, specifically temperature, pH, transparency and dissolved oxygen but only temperature did not showed significant differences. This may be due to differences in the stresses experienced by the lake. The values attained from the various physico-chemical parameters during sampling support the present status of the lake as eutrophic. In this study, the composition of phytoplankton community in Sampaloc Lake was determined as well as their relative abundance and frequencies for each species identified. The phytoplankton community was highly represented by Bacillariophyta (55%) followed by Chlorophyta (30%) and Cyanophyta (15%), respectively. Diversity indices of phytoplankton in Sampaloc Lake were characterized with high species richness (D=1.682), high dominance (d=0.534) but uneven(E=0.132) distribution of phytoplankton organisms. During the sampling period, some species indicated that the Sampaloc Lake could be eutrophic. This was ascertained by the dominance of Melosira
  • 54. 47 sp., which can also tolerate about pH 8 and low transparency of water. Merismopedia sp., Lyngbya sp. and Oscillatoria sp. (Cyanophyta) also indicated polluted water and rapid eutrophication. Based on the results obtained, the following conclusions were figured out: 1. the phytoplankton community in Sampaloc Lake was distributed to 3 major groups namely Division Chlorophyta, Bacillariophyta and Cyanophyta ; 2. a total of 20 taxa was present in Sampaloc Lake and dominated by Melosira sp. ; and 3. Sampaloc Lake is exhibiting eutrophic condition based on the presence of bioindicator species. Upon completion of the study, the following are recommended: 1. the trophic state of Sampaloc Lake be verified using other chemical analyses ; 2. continuous monitoring of the lake be done to improve the trophic condition of the lake; and 3. use (scanning electron microscope) SEM in identification of the phytoplankton at species level.
  • 55. 48 LITERATURES CITED Adeyemi, S.O., A. I. Adikwu, P. M. Akombu and J.T. Iyela. 2009. Survey of zooplanktons and macroinvertebrates of Gbedikere Lake, Bassa, Kogi State, Nigeria. International Journal of Lakes and Rivers. 2(1). 37-44. Andersson, G. 2003. Sea water composition. Marine Science. Behrenfeld, M. 2006. Global warming will reduce ocean productivity. Boney, A.D. 1975.Phytoplankton. London:Edward Arnold publishers limited,116p. Coronado, A. S., C. P. Dela Cruz, Y. C. Cabillon–Lagasca, and M. I. Millendez. 2010. Association of Phytoplankton and Zooplankton in Bunot Lake, San Pablo City, Laguna, Philippines. Unpublished Special Problem in Freshwater Zoology. University of the Philippines at Los Banos. Dela Cruz, R.T. E. Ladaga and l. Sacaban, 1992. Taxonomy of the phytoplankton flora in Balayan Bay, Calaca, Batangas. Unpublished undergraduate thesis. De la salle university, Manila 210p. Grover, James P. 2005. Sasonal dynamics of Phytoplankton in 2 warm temperature reservoirs Association of Taxonomic Composition with temperature. University of Texas, Arlington. Hallegraff, G., C. Bolch, B. Koerbin and J Bryan. 1988. Ballast water a danger to aquacultre. Australian fisheries journal 47(7):32 -34. Herring, D. 2006. Phytoplankton influence global change. Jorgensen, E.G. and N. Sterman.1966. Adaptation in planktonic algae. Primary productivity in aquatic environments. Proceedings of an J.B.P. pf symposium Psallanza, Italy. April 26-May 1, 1965. Edited by C.R.Goldman. University of California Press, Los Angeles. pp 37 – 46. Larsson, B. 1994. Environmental aspects of aquaculture in the tropics and sub- tropics. Alcolm field document number 27 Mann, A., 1925. Marine diatoms of the Philippine islands. Wash. Bot. Off. US Nat. Mus. Bull. 100. 6(1): 1 – 162. Martinez, M.R., H. Paul Chakroff and J.B. Pantastico, 1975. Note: direct phytoplankton counting techniques using the haemocytometer. Phil. Agri. 59: 43 – 50.
  • 56. 49 Martinez – Goss, M.R., 1995. A checklist of Nitzschia and Tryblionella (class Bacillariophyceae) of the Philippines. Phil. J Sci. 124(1): 75 – 99. Moss ,Brian 2007.The Influence of Environmental Factors on the Distribution of Freshwater Algae:An Experimental Study: II. The Role of pH and the Carbon Dioxide-Bicarbonate System.The Journal of Ecology, Vol. 61, No. 1. (Mar., 1973), pp. 157-177. Odum, E.P. 1980. Fundamentals of ecology. Philadelphia: W.B. saunders co. 501 pp. Patrick, R. And C.W. Reimer. 1966. The diatoms of the United States exclusive of Alaska and Hawai. Acad. Nat. Sci Philad. Monog 13, 688 pp. Piat, V. 2007. Carbon-carbon pilot project. sarcs.org Indonesia. Prescott, G.W. 1951. Algae. Michigan Granbrook: Institute of Science, 946p. Prescott, G.W. 1968. The algae: a review. Boston: houghton mifflin company. 435p. Relon, M.L, 1981. Analysis of phytoplankton ecosystem from freshwater to marine water in Talin Bay, Matuod, Lian, Batangas. Agham 8(2): 78 – 87. Relon, M.L. 1988. Taxonomy of the phytoplankton flora in Northwestern Luzon, Phil. With notes on their ecology. Phil. J. Sci 117(2) 131- 156. Relon, M.L., 2000. Centric diatoms (class Baccillariophyceae) of Talin Bay, Lian, Balayan Batangas province. Asia Life Science. 9(2): 155-180 Round, F.E. 1973. The biology of the algae. 2nd edition, London: Edward Arnold publisher ltd. 278p. Round, F.E. 1981. The ecology of the algae.: Cambridge University Press. Great Britain. 633p. Salisbury, F.B. and C.W. Ross. 1992. Plant physiology. Wadsworth Publishing Company, California. Shakhasir, 2008. Chemical of the Week (CO2). Science Fun Organization. Smith R.L. and T.M. Smith, 2004. Elements of ecology. Pearson education south Asia ltd. Singapore. 692p. Stone, Jeffery R. 2007.Using Diatoms as Ecological and Paleoecological Indicators in Riverine Environments . Department of Geosciences University of Nebraska-Lincoln 214 Bessey Hall Lincoln, Nebraska,
  • 57. 50 68506-0430 Paleontological Society Papers, Volume 13, Starratt, S. (Ed.). Copyright © 2007 The Paleontological Society. Strickland, J.D.H. and T.R. Parsons, 1972. A practical handbook of sea water analysis, Bull. Fish. Res. Bd. Canada. 167p. Thangaradjou, R. Shidhar T., (2006). Water Quality and Phytoplankton Characteristics in the Palk Bay, Southeast Coast of India Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai- 608502, India. Tucker, Craig S. (2008). Managing High pH in freshwater Ponds. Southern Regional Aquaculture Center. Turkmen, Mehmet, (2004). Phytoplankton Biomass and Species Composition of Lake Golbasi. Faculty of Fisheries, Mustaka Kemal University Hatay- Turkey. Volterra, Laura and Boualam, Marc Ph.D.,2002. Euthrophication and Health, Luxembourg: Office for Official Publications of the European Communities. Wetzel, R,G. 1983. Limnology. Saunders college publishing, Philadelphia, Newyork, Chicago. Willen E. and T. Willen.1976. About freshwater phytoplankton. 297 White, A. M. Anraku and K. Hoi, 1984. Toxic red tides and shelfish toxicity in Southeast Asia. Proceeding of a consultative meeting in Singapore. Sept. 11-14, 1984. pp. 1 – 13. Yasser Abdul Kader Al-gahwari, 2007. Physico-chemical parameters and Microorganisms as water quality indicators of Teluk Bahang reservoir and Batu Ferringhi treatment plant. Zafaralla, M.T. 1998. Microalgae of Taal Lake. National Academy of Science and Technology, DOST. 66 pp.
  • 58. 51 APPENDICES
  • 59. 52 Appendix A Nautical Map of San Pablo City Laguna (Source:blogspot.com/2010/02/sampaloc-lake.html)
  • 60. 53 Appendix B Description of San Pablo City, Laguna (GBLontok 2004) San Pablo City, Laguna's first city, is an important commercial and transportation hub linking the provinces of Laguna with Batangas and Quezon and is also on the southern rail line. San Pablo City is also known as the “City of the Seven Lakes.” There are actually 8 crater lakes of extinct volcanoes (including a very small one), each nestled in a depression created long ago by volcanic activity. All have scenic charm and are worth seeing. Total aggregate area is 210 hectares. The other lakes have an aggregate area of 34 hectares. The seven lakes are Sampaloc Lake, Calibato Lake, Bunot Lake, Mohicap Lake, Palakpakin Lake, Lake Pandin and Lake Yambo. Lake Sampaloc is an inactive volcanic maar on the city. The 105-hectare Sampaloc Lake is the largest of the city's lakes. It is also the most accessible being just in the vicinity of the City Hall. Considered one of the prime tourist spots in the city, Sampalok Lake is also home to numerous floating restaurants along its shoreline that serve Filipino food and Native Philippine cuisine. It used to abound with various types of fish tilapia, bangus, carp and several species of shrimps but not anymore. Today the fishpens in the lake are for growing fingerlings only. San Pablo City is 2 hours drive from Makati. It is a border city to the province of Quezon where the nearby town Tiaong has the storied Villa Escudero resort. Most of the bus lines servicing Laguna and Southern Luzon will have direct trips to San Pablo. Also, Lucena-bound buses pass through the city limits.
  • 61. 54 APPENDIX C Preparation of 3% buffered formalin The preserving solution (3% buffered formalin) was prepared by adding 54 mL (37%) of commercial formalin for every one liter and saturated with borax powder. This type of preservative affected the color and avoids the deformation of the cell (Azanza – Corrales, 1993).
  • 62. 55 APPENDIX D Table for Analysis of Variance (ANOVA) C.1 Analysis of Variance of Physico-chemical Parameters of Phytoplankton Community. Parameters F p-value Temperature 2.717 0.091 pH 5.288 0.015 Transparency 5.302 0.015 Dissolved Oxygen 6.283 0.009 C.1.1 Multiple Comparison of the Different Environmental Factors of Phytoplankton using Tukey HSD. Station Point s Temperature pH Transparency Dissolved Oxygen 1 2 0.982 0.908 0.364 0.589 3 0.925 0.662 0.657 0.103 4 0.075 0.238 0.765 0.006 5 0.641 0.372 0.266 0.664 2 1 0.982 0.908 0.364 0.589 3 0.999 0.984 0.979 0.679 4 0.166 0.067 0.939 0.058 5 0.901 0.824 0.014 1.000 3 1 0.925 0.662 0.657 0.103 2 0.999 0.984 0.979 0.679 4 0.244 0.030 1.000 0.391 5 0.972 0.980 0.034 0.605 4 1 0.075 0.238 0.765 0.006 2 0.166 0.067 0.939 0.058 3 0.244 0.030 1.000 0.391 5 0.512 0.013 0.046 0.047 5 1 0.641 0.372 0.266 0.664 2 0.901 0.824 0.014 1.000 3 0.972 0.980 0.034 0.605 4 0.512 0.013 0.046 0.047
  • 63. 56 C.2 Analysis of variance for the diversity indices Diversity Indices F Sig. (0.05) Dominance (D) 1.29 0.334 Shanon (H') 1.16 0.384 Simpson (1- D) 1.3 0.334 Eveness (E) 0.528 0.717 Margaleff (R) 0.478 0.751 Required t-value for significant at 0.05 level C. 2.2 Multiple Comparison of the Different Diversity Indices of Phytoplankton using Tukey HSD. Station Points (D) (S) (1-D) (E) (R) 1 2 0.566 0.685 0.272 0.805 1 3 1 0.999 0.873 0.675 0.8 4 0.955 1 0.866 0.831 0.921 5 0.44 0.73 0.171 0.899 0.991 2 1 0.566 0.685 0.272 0.805 1 3 0.628 0.533 0.068 0.999 0.804 4 0.91 0.677 0.758 1 0.923 5 0.999 1 0.997 0.999 0.991 3 1 1 0.999 0.873 0.675 0.8 2 0.628 0.533 0.068 0.999 0.804 4 0.976 0.999 0.372 0.998 0.998 5 0.497 0.578 0.061 0.989 0.961 4 1 0.955 1 0.866 0.831 0.921 2 0.91 0.677 0.758 1 0.923 3 0.976 0.999 0.372 0.998 0.998 5 0.812 0.722 0.575 1 0.995 5 1 0.44 0.73 0.171 0.899 0.991 2 0.999 1 0.997 0.999 0.991 3 0.497 0.578 0.061 0.989 0.961 4 0.812 0.722 0.575 1 0.995
  • 64. 57 APPENDIX E Table 9. Different Measurement of Physico-chemical Parameters on each station in Sampaloc Lake San Pablo City, Laguna, Philippines (November, 2010). Station Temperature pH Transparency DO 1 28.85 8.18 19.00 7.66 1 28.3 8.45 26.00 8.15 1 27.55 8.01 30.50 8.09 2 28.32 8.04 28.25 7.85 2 27.3 8.13 45.50 8.76 2 27.84 8.22 42.00 9.44 3 28.04 8.03 49.65 9.60 3 27.45 8.04 26.50 9.18 3 27.33 8.17 28.00 9.19 4 27.16 8.52 31.25 10.07 4 23.65 8.34 42.50 10.25 4 26.77 8.44 26.30 10.34 5 26.92 8.01 13.75 7.50 5 27.07 8.04 8.00 9.25 5 27.42 8.03 8.50 9.11 Ave. 27 8.18 28.38 9.00
  • 65. 58 APPENDIX F Typical Structure of Diatoms (Source:blogspot.com/2010/02/diatoms.html)
  • 66. 59 APPENDIX G Typical Structure of Blue Green Algae (Source:blogspot.com/2010/02/bluegreenalgae.html)
  • 67. 60 APPENDIX H Typical Structure of Green Algae (Source:blogspot.com/2010/02/Green Algae.html)