Measuring and Calculating Current Atmospheric Phosphorous and Nitrogen Loadings to Utah Lake Using Field Samples and Geostatistical Analysis

Jacob Olsen,Lavere Merritt,Gustavious Williams,A Miller

doi:10.3390/hydrology5030045

Abstract

Atmospheric nutrient loading through wet and dry deposition is one of the least understood, yet can be one of the most important, pathways of nutrient transport into lakes and reservoirs. Nutrients, specifically phosphorus and nitrogen, are essential for aquatic life but in excess can cause accelerated algae growth and eutrophication and can be a major factor that causes harmful algal blooms (HABs) that occur in lakes and reservoirs. Utah Lake is subject to eutrophication and HABs. It is susceptible to atmospheric deposition due to its large surface area to volume ratio, high phosphorous levels in local soils, and proximity to Great Basin dust sources. In this study we collected and analyzed eight months of atmospheric deposition data from five locations near Utah Lake. Our data showed that atmospheric deposition to Utah Lake over the 8-month period was between 8 to 350 Mg (metric tonne) of total phosphorus and 46 to 460 Mg of dissolved inorganic nitrogen. This large range is based on which samples were used in the estimate with the larger numbers including results from “contaminated samples”. These nutrient loading values are significant for Utah Lake in that it has been estimated that only about 17 Mg year−1 of phosphorus and about 200 Mg year−1 of nitrogen are needed to support a eutrophic level of algal growth. We found that atmospheric deposition is a major contributor to the eutrophic nutrient load of Utah Lake.

Highlights

With the increased focus on eutrophication of water bodies by nitrogen (N) and phosphorus (P), studies have found that atmospheric deposition is an important part of the total nutrient budget for many aquatic ecosystems [3,4,5,6]
We labeled a sample as contaminated (i.e., “contaminated sample”) if any of the following conditions occurred: overlapped samples, bulk deposition samples, samples with visible contamination, and samples that were collected longer than a week. Both contaminated and uncontaminated samples were used in analysis to describe a possible range of atmospheric loading to Utah Lake and we report both results
Many studies have indicated that atmospheric deposition can be an important component of the nutrient budget of a lake

Summary

Introduction

With the increased focus on eutrophication of water bodies by nitrogen (N) and phosphorus (P), studies have found that atmospheric deposition is an important part of the total nutrient budget for many aquatic ecosystems [3,4,5,6]. Shallow lakes such as Utah Lake might be even more susceptible to atmospheric deposition because of their large surface area to volume ratios. The objective of this work is to: (1) quantify the atmospheric loading of total phosphorous (TP) and dissolved

Objectives

Methods

Results

Discussion

Conclusion