Physical Sciences and Mathematics Commons^™

Spatial And Temporal Variation Of Nutrients In The Great Lakes-St. Lawrence Basin: Implications For Primary Production In Stream Ecosystems, Nolan Pearce

Electronic Thesis and Dissertation Repository

Growing human populations and associated land use activities has increased the amount of nutrients delivered to surface waters. Eutrophication from the over-enrichment of nitrogen and phosphorus has degraded ecosystem conditions in streams, lakes, and coastal areas worldwide. Thus, the management of anthropogenic nutrient loading is a global concern. This thesis employed a combination of field and experimental research to provide watershed managers with information on the spatial and temporal patterns in stream nutrient enrichment, and the associated ecological effects of anthropogenic nutrient loading in the Great Lakes-St. Lawrence basin. Four studies were completed to address this research goal. First, I …

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …

The Effect Of Soil Ph On Phosphorus Content Of Clover Pasture, David Weaver, Robert Summers, David Rogers, Peta Richards

Resource management technical reports

Testing of pasture soils from 2009 to 2018, as part of DPIRD’s Whole Farm Nutrient Mapping (WFNM) project in the coastal catchments of south-west Western Australia (WA), indicated that soil pH was so low it could be limiting plant access to nutrients. Observations by some farmers who had been involved in the soil testing were that lime application had not increased pasture production, even when pH_Ca (pH measured in calcium chloride) tests indicated that phosphorus (P) should become more available by increasing soil pH. Farmers also wanted to know if they needed to apply more P than soil testing …

Soil Amendment And Soil Testing As Nutrient Reduction Strategies For The Peel Integrated Water Initiative, Robert Summers, Peta Richards, David Weaver, David Rowe

Resource management technical reports

The Transform Peel program focuses on 42 000 hectares (ha) due east of Mandurah called the Peel Food Zone, 75 kilometres (km) south of Perth in the shires of Murray and Serpentine Jarrahdale and includes an assessment of intensified and enclosed agriculture and a business park. The Peel Integrated Water Initiative was developed through Transform Peel to identify water sources and minimise the effect of these projects on water quality by reducing the nutrient loads discharged into the Peel–Harvey Estuarine System, which has been suffering from poor water quality for this reason.

The mineral sand miner MZI Resources Pty Ltd …

Impacts Of Human Recreation On Nutrient Availability And Periphyton Abundance On The Niobrara River, Matthew Chen, Jessica Corman, Sydney Kimnach, Kayla Vondracek

UCARE Research Products

In freshwater ecosystems, eutrophication can create many problems. Excess nutrients, like nitrogen or phosphorus, promote algal or cyanobacterial growth. This growth also leads to increased organic matter production and decomposition, a process that can reduce oxygen concentration in the water. When this happens, species diversity declines, transparency of the water declines, and anoxia may lead to fish kills . Of particular concern is the possibility of cyanobacteria blooms that create compounds toxic for humans. Many of the waters across Nebraska receive excessive nutrients from human activities, largely related to agriculture (Dickey 1982). However, there is one river, the Niobrara River, …

Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang

Electronic Thesis and Dissertation Repository

Freshwater systems worldwide are threatened by excessive nutrient (nitrogen and phosphorus) loading. This study evaluated the contribution of septic systems to stream nutrient loads in nine subwatersheds. Stream sampling was conducted during low and high discharge conditions, with samples analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), nitrate (NO₃-N), and acesulfame (ACE; wastewater tracer). Higher septic effluent reached the subwatershed outlets during high discharge conditions. Subwatersheds with newer households had a lower percentage of septic effluent reaching the stream compared with subwatersheds with older households. Seasonal and event-based ACE concentration-discharge relationships revealed that the hydrological pathways delivering …