John Nguyen Lake Merritt Nitrogen Project May 9 2005 Lake Merritt Nitrogen Project Pinpointing Nitrate Contributions to Lake Merritt John Nguyen Abstract High quality golf courses and cemetery landscapes require substantial pesticide and fertilizer applications leading to concerns about their environmental impacts Anthropogenic sources of nitrogen coming from highly fertilized lawns of the Claremont Country Club golf course and the Mountain View Cemetery both located in the upper urban watersheds of Oakland California were hypothesized to be the major contributors of the nitrogen loading A study was conducted to locate the origin of nitrogen loading into Lake Merritt from its contributing waterways Runoff from the Claremont Country Club and the Mountain View Cemetery flows into Glen Echo Creek the adjacent waterway that drains into Lake Merritt This study includes monitoring nitrate levels above and below these sites in order to evaluate and locate the source of the nutrient load further downstream and in Lake Merritt The golf course and cemetery management practices did not appear to be the main contributors of nutrient loading into Lake Merritt High upstream concentrations of nitrate in Glen Echo Creek indicated contamination above these locations However monthly sampling also revealed increases in downstream nutrient concentration below these sites Therefore fertilizer applications and management practices at the Claremont Country Club and the Meadow Wood Cemetery appear to contribute some N loading but much of the N loading above these two sites appear to contribute more to long term stream and lake nutrient enrichment Further research above the locations is needed to conclusively identify the major nutrient contributor to Lake Merritt p 1 John Nguyen Lake Merritt Nitrogen Project May 9 2005 Introduction For as long as humans have lived near waterways they have used them to wash away their wastes and pollutants With the growing population and increased production and consumption this tradition of flushing wastes downstream has overwhelmed the cleansing capacities of the Earth s water Carpenter et al 1998 As a result water quality in rivers lakes and coastal oceans has degraded over recent decades This degradation is demonstrated by the disruption of aquatic ecosystems and the decimation of the various inhabiting species as well as the amenities that those ecosystems once provided to society Carpenter et al 1998 The most common impairment of surface waters in the United States is eutrophication caused by excessive inputs of phosphorous and nitrogen Caraco and Cole 1998 There are three forms of nitrogen dissolved organic nitrogen dissolved inorganic nitrogen and particulate organic nitrogen Dissolved inorganic nitrogen consists of ammonium NH4 nitrate NO3 or nitrite NO2 which fosters the growth of bacteria algae and higher plants Seitzinger and Kroeze 1998 Lake Merritt known as the Jewel of Oakland suffers from excessive nutrient loading from urban runoff Low oxygen levels within the lake have classified the lake as an impaired body of water by the Environmental Protection Agency The amount of nutrients drained into lakes in general is significant when the rainfall flows over the creeks and into drainage lines that are discharged directly into the lake Klessig et al 2004 It is speculated that increased urban development and recreational usages in the upper regions of Lake Merritt s watersheds has increased the nitrogen and phosphorus load into the lake The increased production and accumulation of these nutrients stimulates eutrophication of the lake and its waterways Unfortunately water quality and general upkeep of the Lake has suffered in recent years due to Oakland s declining budget and from the increasing pressures of an urban environment As a result the City of Oakland s Public Works Agency created a non profit organization that now oversees upkeep of the lake the Lake Merritt Institute Plearn 2000 Since its inception in 1992 the Lake Merritt Institute has supported research funded by grants and public donations to improve the environment of the lake and as a result aeration fountains tidal gates flood dams and weekly clean ups have contributed to a healthier lake and preserved the habitat for many migratory birds and aquatic species The Lake Merritt Institute has continued to support several p 2 John Nguyen Lake Merritt Nitrogen Project May 9 2005 water quality studies to pinpoint sources of additional pollution This particular study is focused on point sourcing nitrogen contributors to the lake Second only to phosphorous nitrogen is a limiting nutrient for plant and algae growth and may enter the lake through an array of sources Studies have shown that precipitation may be the main N source for seepage and some drainage lakes Klessig et al 2004 As excessive plantalgal growth dies aerobic bacterial decomposers proliferate and break down the dead and decaying plant matter In this decomposition process the aerobic bacteria consume dissolved oxygen from the water leaving oxygen shortages that causes fish kills Carpenter and Ludwig 1999 Alterations to the natural environment may decrease species population size growth rates reproductive success and survival rates while others sky rocket disturbing the fragile balance of ecosystem processes Thus overabundance of N loading plays a tremendous role in causing potential ecological destruction and the subsequent loss of biodiversity Vitousek et al 1997 The contribution of N from these watersheds into Lake Merritt has not been identified in the past This study was designed to obtain this data NO3 levels and turbidity levels were monitored for a full seasonal year beginning in February 2004 through February 2005 from the Glen Echo and Trestle Glen Watersheds The main creek in focus for this project is Glen Echo Creek found in the Glen Echo Watershed whose banks are parallel to both the golf course and cemetery These two recreational areas are hypothesized to be the major nitrogen contributors to Lake Merritt because of the potential for fertilizers containing N compounds spilling over into the creek By comparing the NO3 levels from the cemetery and golf course both upstream and downstream the primary focus of this study will identify the amount of N loading from these two locations to test our hypothesis that there is more N loading after the cemetery and golf course Our secondary objective is to analyze Trestle Glen Creek a creek
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