According to Britannica online, lake is an area filled with water, localized in a basin that is surrounded by land apart from any river; is not part of the ocean and is also larger and deeper than ponds. Lakes have numerous features namely the lake type, drainage basin or catchment area, inflow and outflow, nutrient content, dissolved oxygen, pollutants, pH, and sedimentation. Lakes can be categorized on the basis of their richness in nutrients. The richness in nutrients of a lake typically affects plant growth. The three types of lakes according to their richness in nutrients are oligotrophic, mesotrophic and eutrophic. Nutrient-poor lakes are said to be oligotrophic. Lakes that are oligotrophic are generally clear, having a low concentration of plant life. Lakes that are mesotrophic have good clarity and an average level of nutrients. Furthermore, lakes that are considered eutrophic are enriched with nutrients, resulting in good plant growth and possible algal blooms. .
According to Laguna Lake Development Authority (LLDA) on 2005, Laguna de Bay is the largest inland water body and is the largest lake in the Philippines. It covers 98,000 hectares, with an average depth of about 2.8 meters and an elevation of about 1 meter above sea level The lake is located east of Metro Manila between the provinces of Laguna to the south and Rizal to the north, bounded by six provinces, twelve cities, and forty-nine municipalities, of which are lakeshore towns. The inflow in the lake primary come from the twenty-one main tributaries, with the Pagsanjan-Lumban rivers system contributing to as much as 35% of the total inflow to the lake. The lake's primary outflow destination is the Pasig River. The river is considered eutrophic because of the lake's richness in nutrients and good plant growth. Moreover, Laguna de Bay is home to a variety of organisms that comprise its biodiversity pool. Of note are the 31 species of fishes, 154 species of phytoplankton, 36 species of zooplankton, and 24 species of macrophytes (Lecciones, n.