Green yet Polluted: Demonstrating the Growth of Algae in Common Causes of Euthrophication

Abstract

Eutrophication is a common problem in most areas of the country, like the case of Laguna de Bay, where excess nutrients pollutions from its sources have caused the decline of its biological productivity. This study is important because it will generate information about the local community, particularly those surrounding our school, and will provide results that can help to prevent pollution of the nearby freshwater ecosystem. This study aims to demonstrate the growth of certain algae in pollutants that are commonly found in the Filipino community. Collection of the water samples was done within the vicinity of theschool. Water samples were divided evenly into 4 bottles. Baker's yeasts (2mg) were supplied to all samples and will supply carbon dioxide for algae's photosynthesis through fermentation. Pork Broth (2mg) is supplied as a protein source. Test substances were added (5mg), these were fertilizer (F), detergents (D), and poultry manure (M). One set up remained controlled (C). Observation was done every Friday for 5 weeks. Microscopy was done to identify algal species using the LPO and HPO. Identification was done using a field guide of freshwater algae. Ulothrix, Oscillatoria, and Euglena was found to be dominant in the set ups. Oscillatoria is a known algae that is bloom-forming. Images are under the High Power Objective (40x magnification). After the 5 observation weeks, the control set up (C) became slightly green, but still, no clumps or greenish mats were observed. The set up M remained cloudy and greenish. The green clumps got bigger and are all suspended on the bottom of the bottle. The set up F turned even greener and more clumps were observed. The set up D turned greenish and numerous green clumps were observed. The results supported the claim that the common sources of eutrophication (fertilizers, detergents, and manure) are responsible for the rapid growth of algal species. Using microscopy after the last observation, it was determined that Euglena is present in all of the water samples. Oscillatoria is very dominant in setups F and D. Set up M is characterized by a mixture of protozoans together with Euglena and Ulothrix. The control set up apparently has the least algal growth. This supports the idea that excessive nutrients cause rapid growth of these organisms, and if not controlled, blooms are more likely to occur.