+ Most Popular
Cunninghamia lanceolata plantations in China
Mammalian lairs in paleo ecological studies and palynology
Studies on technological possibilities in utilization of anhydrous milk fat for production of recombined butter-like products
Should right-sided fibroelastomas be operated upon?
Large esophageal lipoma
Apoptosis in the mammalian thymus during normal histogenesis and under various in vitro and in vivo experimental conditions
Poissons characoides nouveaux ou non signales de l'Ilha do Bananal, Bresil
Desensitizing efficacy of Colgate Sensitive Maximum Strength and Fresh Mint Sensodyne dentifrices
Administration of fluid by subcutaneous infusion: revival of a forgotten method
Tundra mosquito control - an impossible dream?
Schizophrenia for primary care providers: how to contribute to the care of a vulnerable patient population
Geochemical pattern analysis; method of describing the Southeastern limestone regional aquifer system
Incidence of low birth weights in a hospital of Mexico City
Graded management intensity of grassland systems for enhancing floristic diversity
Microbiology and biochemistry of cheese and fermented milk
The ember tetra: a new pygmy characid tetra from the Rio das Mortes, Brazil, Hyphessobrycon amandae sp. n. (Pisces, Characoidei)
Risk factors of contrast-induced nephropathy in patients after coronary artery intervention
Renovation of onsite domestic wastewater in a poorly drained soil
Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot
Systolic blood pressure in a population of infants in the first year of life: the Brompton study
Haematological studies in rats fed with metanil yellow
Studies on pasteurellosis. I. A new species of Pasteurella encountered in chronic fowl cholera
Dormancy breaking and germination of Acacia salicina Lindl. seeds
therapy of lupus nephritis. a two-year prospective study

Nutrient inputs to the Choptank River estuary: Implications for watershed management

Nutrient inputs to the Choptank River estuary: Implications for watershed management

Estuaries 19(2B): 342-358

ISSN/ISBN: 0160-8347

DOI: 10.2307/1352455

Degraded water quality due to water column availability of nitrogen and phosphorus to algal species has been identified as the primary cause of the decline of submersed aquatic vegetation in Chesapeake Bay and its subestuaries. Determining the relative impacts of various nutrient delivery pathways on estuarine water quality is critical for developing effective strategies for reducing anthropogenic nutrient inputs to estuarine waters. This study investigated temporal and spatial patterns of nutrient inputs along an 80-km transect in the Choptank River, a coastal plain tributary and subestuary of Chesapeake Bay, from 1986 through 1991. The study period encompassed a wide range in freshwater discharge conditions that resuked in major changes in estuarine water quality. Watershed nitrogen loads to the Choptank River estuary are dominated by diffuse-source inputs, and are highly correlated to freshwater discharge volume. In years of below-average freshwater discharge, reduced nitrogen availability results in improved water quality throughout most of the Choptank River. Diffuse-source inputs are highly enriched in nitrogen relative to phosphorus, but point-source inputs of phosphorus from sewage treatment plants in the upper estuary reduce this imbalance, particularly during summer periods of low freshwater discharge. Diffuse-source nitrogen inputs result primarily from the discharge of groundwater contaminated by nitrate. Contramination is attributable to agricultural practices in the drainage basin where agricultural land use predominates. Groundwater discharge provides base flow to perennial streams in the upper regions of the watershed and seeps directly into tidal waters. Diffuse-source phosphorus inputs are highly episodic, occurring primarily via overland flow during storm events. Major reductions in diffuse-source nitrogen inputs under current land use conditions will require modification of agricultural practices in the drainage basin to reduce entry rates of nitrate into shallow groundwater. Rates of subsurface nitrate delivery to tidal waters are generally lower from poorly-drained versus well-drained regions of the watershed, suggesting greater potential reductions of diffuse-source nitrogen loads per unit effort in the well-drained region of the watershed. Reductions in diffuse-source phosphorus loads will require long-term management of phosphorus levels in upper soil horizons.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 009115006

Download citation: RISBibTeXText

Related references

Relating nutrient and herbicide fate with landscape features and characteristics of 15 subwatersheds in the Choptank River watershed. Science of the Total Environment 409(19): 3866-3878, 2011

Spatial Distribution of Dissolved Radon in the Choptank River and Its Tributaries Implications for Groundwater Discharge and Nitrate Inputs. Estuaries and Coasts 36(6): 1237-1252, 2013

A sediment budget for the Choptank River estuary in Maryland, U.S.A - Bilan des sédiments de l'estuaire de la rivière Choptank dans le Maryland, Etats-Unis. Estuarine, Coastal and Shelf Science 17(5): 555-570, 1983

Sources of nutrient inputs to the Patuxent River estuary. Estuaries 26(2A): 226-243, 2003

Assessing the seasonal influence of sewage and agricultural nutrient inputs in a subtropical river estuary. Estuaries 26(4A): 857-865, 2003

Long-term changes in watershed nutrient inputs and riverine exports in the Neuse River, North Carolina. Water Research 35(6): 1489-1499, 2001

A sediment budget for the choptank river estuary in maryland usa. Estuarine Coastal and Shelf Science 17(5): 555-570, 1983

The impacts of re-introducing Mississippi River water on the hydrologic budget and nutrient inputs of a deltaic estuary. Ecological Engineering 32(4): 347-359, 2008

From Watershed to Estuary: Assessment of Nutrient Loading, Retention, and Export from the Ipswich River Basin. Biological Bulletin 187(2): 277-278, 1994

Modeling of nutrient export and effects of management practices in a cold-climate prairie watershed: Assiniboine River watershed, Canada. Agricultural Water Management 180: 235-251, 2017

Temporal trends in wet-deposition of pesticides to the Choptank river watershed, Chesapeake Bay. Abstracts of Papers American Chemical Society 226(1-2): AGRO 80, 2003

Water quality and conservation practice effects in the Choptank River watershed. Journal of Soil and Water Conservation 63(6): 461-474, 2008

Water quality and conservation practice effects in the Choptank River watershed. Journal Of Soil And Water Conservation (ankeny): 6, 461-474, 2008

Nutrient mass balances for the watershed, headwaters intertidal zone, and basin of the Rhode River Estuary. Limnology and oceanography 26(6): 1142-1149, 1981

Assessing the effects of nutrient management in an estuary experiencing climatic change: the Neuse River Estuary, North Carolina. Environmental Management 37(3): 422-436, 2006