Abstract of the Research
Aquatic plants need two essential nutrients for growth: phosphorus and nitrogen. They receive these nutrients through a process known as eutrophication, in which water bodies accumulate plant nutrients, typically from nutrient-rich land drainage (Smith 2003). In a healthy lake, both nutrients occur in limiting amounts, restricting plant growth. However, anthropogenic (human) factors can dramatically increase the concentration of plant nutrients in water bodies, a phenomenon known as “cultural eutrophication” (Hasler 1947). Human-induced pollution through the impacts of excessive fertilizer use, untreated wastewater effluents, and detergents significantly increases nutrient loading into lakes, accelerating eutrophication beyond natural levels and generating deleterious changes to the natural ecosystem (Litke 1999). Over the past 50 years, a large body of literature has been developed to identify the principle impacts and sources of increased nutrient levels on the quality of receiving waters (Smith 2003). It is now generally accepted that cultural eutrophication can stimulate the rapid growth of plants and algae, clogging waterways and potentially creating toxic algae blooms. Hypoxic (very low oxygen) conditions may result when these plants and algae die and decompose stripping water of dissolved oxygen, leading to fish kills and degrading the aesthetic and recreational value of the lake (ESA 2008). Cultural eutrophication is an increasingly global problem as the deterioration of water quality and excessive biological productivity in lakes inflicts significant environmental and societal damage. In identifying sources of eutrophication, studies have observed a strong relationship between algal biomass and nutrient loading, with phosphorus being the primary limiting nutrient in freshwater bodies. Therefore, most efforts to control algal biomass in lakes concentrate on reducing phosphorus levels in water (Smith 1999). Of the strategies developed to mitigate eutrophication, I propose that an integrated approach focusing on nutrient loading restrictions should be the essential cornerstone of effective management in lakes. This approach would incorporate nutrient loading restrictions with bio manipulation to limit the levels of phosphorus and nitrogen in lakes as well as to alter the food web to control phytoplankton populations, the major contributor to eutrophication.
Contents
1) Overview of Cultural Eutrophication |
2) Sources of Cultural Eutrophication |
3) Eutrophication Management Strategies: Control of Major Eutrophicated Sources |
4) Eutrophication Management Strategies: Nutrient Loding Restrictions |
5) Eutrophication Management Strategies: Biomanipulation |
6) Conclusion |
Download the complete Research material as a PDF |
|