Acceptance and utilization of LTER data requires that:
(1) The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
(2) The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
(3) A copy of any resultant publications should be sent to:
Principal Investigator
Ecosystems Center
Marine Biological Laboratory
7 MBL St.
Woods Hole, MA 02543
| Dataset URLs: | METADATA: HTML, Rich Text, XML(EML compliant) DATA: Comma Delimited, Excel file with Metadata and data |
| Dataset ID: | WAT-VA-Load.01 |
| Dataset Title: | Annual Nutrient Loading and Yield to Plum Island Estuary, As Measured at the Ipswich and Parker Dams |
| Investigator 1: | |
| First Name: | Chuck |
| Last Name: | Hopkinson |
| Address line 1: | Marine Biological Laboratory |
| Address line 2: | The Ecosystems Center |
| Address line 3: | 7 MBL Street |
| City: | Woods Hole |
| State: | MA |
| Zip Code: | 02543 |
| Country: | USA |
| Investigator 2: | |
| First Name: | Hap |
| Last Name: | Garritt |
| Address line 1: | Marine Biological Laboratory |
| Address line 2: | The Ecosystems Center |
| Address line 3: | 7 MBL Street |
| City: | Woods Hole |
| State: | MA |
| Zip Code: | 02543 |
| Country: | USA |
| Investigator 3: | |
| First Name: | Emily |
| Last Name: | Gaines |
| Address line 1: | Marine Biological Laboratory |
| Address line 2: | The Ecosystems Center |
| Address line 3: | 7 MBL Street |
| City: | Woods Hole |
| State: | MA |
| Zip Code: | 02543 |
| Country: | USA |
| Associate Investigators: | W. McDonald Lee, Corey Lawrence, John Logan, Josh Goldstein, Greg Peterson, Nat Weston, Ishi Buffam |
| Keywords: | Ipswich, Parker, dam, loading, yield, nutrient, Plum Island Estuary |
| Abstract: | Nutrient concentrations for various forms of N, P, C, as well as suspended sediments, are determined from monthly grab samples taken at the Ipswich and Parker dams. These nutrient concentrations are then used in conjunction with USGS discharge data (recorded at gages in the Parker River at Byfield, MA and the Ipswich River at Ipswich, MA) to calculate annual nutrient loading to the Estuary, coming over each dam. Annual yield is also calculated for both dams. |
| Contact: | Plum Island Ecosystems LTER Information Manager The Ecosystems Center Marine Biological Lab 7 MBL St Woods Hole, MA 02543 Phone (508) 289 7485 Email: pie_im@mbl.edu Online URL: http://ecosystems.mbl.edu/PIE/ |
| DATA FILE INFORMATION: | |
| Data File Name | WAT-VA-Load |
| Beginning Date | 9/5/1993 |
| End Date | 9/16/2004 |
| Number of Data Records | 22 |
| Other Files to Reference | WAT-VA-Inputs |
| Availability Status | Type 1 |
| Quality Control Information | Loading is calculated using measured nutrient concentrations and USGS-reported discharge values. Nutrient concentrations are determined from monthly grab samples, and are measured using various chemical methods. Error (accuracy and precision) is generally less than 5%. USGS applies its own quality control methods to its discharge data. |
| Maintenance Description | Nutrient samples continue to be taken monthly. Monthly nutrient concentrations are updated annually in WAT-VA-Inputs. Every 2-3 years, WAT-VA-Load is updated with loading calculated from concentrations in WAT-VA-Inputs. |
| Log of Changes: | |
| RESEARCH LOCATION: | |
| Geographic Description | Ipswich Dam, Sylvania Dam, Ipswich, MA (Lat:42.6777, Long:70.8378), Parker Dam, Central St., Byfield, MA (Lat:42.7501, Long:70.9290) |
| Location Bounding Box | |
| West Bounding Coordinate | |
| East Bounding Coordinate | |
| North Bounding Coordinate | |
| South Bounding Coordinate | |
| OR if single point location | |
| Latitude | |
| Longitude | |
| Methods: | Sample Collection: Grab samples are collected monthly at the Parker and Ipswich dams. Water is filtered and/or partitioned for analysis for suspended solids, particulate organic nitrogen (PON), total dissolved nitrogen (TDN), ammonium (NH4), nitrate (NO3), dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON), particulate phosphorus (PPO4), total dissolved phosphorus (TDP), phosphate (PO4), particulate organic carbon (POC), dissolved organic carbon (DOC). Analyses are conducted according to PIE-LTER protocols (http://ecosystems.mbl.edu/pie/data/method.htm). Discharge: Discharge data is mined from the USGS website (http://waterdata.usgs.gov/nwis) for the Parker River gage at Byfield, MA and the Ipswich River gage at Ipswich, MA. Since the gages are NOT located directly at the dams where nutrient sampling occurs, the USGS discharge data is multiplied by a correction factor (1.1812 for the Parker data, and 1.1964 for the Ipswich data) to obtain discharge over the respective dams. Loading/Yield Calculations: Monthly nutrient concentrations are multiplied by total monthly discharge over the dams to estimate nutrient loading on a monthly timescale. Monthly loading numbers are added together to obtain annual loading per water year. Water years are determined according to USGS data updates, and generally start in September. The numerical year given to a water year is the new year reached in January during the September-September cycle (i.e. Sept 2003 - Sept 2004 is water year 2004). Yield calculations are derived from the loading calculations by dividing the nutrient loading by watershed area upstream of the dam (at Parker this is 65.2km2, and Ipswich this is 387.4km2). Total N and P loads and yields reflects organic and inorganic forms of nitrogen. Total C loads and yields reflect only organic forms of carbon, ie dissolved inorganic carbon was not measured and is not included. |
| Variable Name | Variable Description | Units | Measurement Scale | Code Infomation | Number Type | DateTime Format | Missing Value Code | Missing Value Code Explanation |
| Water Year | USGS-assigned water year | datetime | YYYY | |||||
| Year Start | Start date of the given water year | datetime | DD-MMM-YYYY | |||||
| Year End | End date of the given water year | datetime | DD-MMM-YYYY | |||||
| Days | number of days in water year | number | ratio | whole | ||||
| Dam | Dam site (Ipswich or Parker) | nominal | ||||||
| Annual Discharge | Total water discharge over the dam per year | cubicMetersPerYear | ratio | real | ||||
| Mean Daily Discharge | Average water discharge over the dam per day | cubicMetersPerDay | ratio | real | ||||
| Total N Load | Annual loading of total nitrogen as N | tonnesPerYear | ratio | real | ||||
| Total N Yield | Annual yield of total nitrogen as N | kilogramsPerHectarePerYear | ratio | real | ||||
| PON Load | Annual loading of particulate organic nitrogen as N | tonnesPerYear | ratio | real | ||||
| PON Yield | Annual yield of particulate organic nitrogen as N | kilogramsPerHectarePerYear | ratio | real | ||||
| TDN Load | Annual loading of total dissolved nitrogen as N | tonnesPerYear | ratio | real | ||||
| TDN Yield | Annual yield of total dissolved nitrogen as N | kilogramsPerHectarePerYear | ratio | real | ||||
| NH4 Load | Annual loading of ammonium as N | tonnesPerYear | ratio | real | ||||
| NH4 Yield | Annual yield of ammonium as N | kilogramsPerHectarePerYear | ratio | real | ||||
| NO3 Load | Annual loading of nitrate as N | tonnesPerYear | ratio | real | ||||
| NO3 Yield | Annual yield of nitrate as N | kilogramsPerHectarePerYear | ratio | real | ||||
| DIN Load | Annual loading of dissolved inorganic nitrogen as N | tonnesPerYear | ratio | real | ||||
| DIN Yield | Annual yield of dissolved inorganic nitrogen as N | kilogramsPerHectarePerYear | ratio | real | ||||
| DON Load | Annual loading of dissolved organic nitrogen as N | tonnesPerYear | ratio | real | ||||
| DON Yield | Annual yield of dissolved organic nitrogen as N | kilogramsPerHectarePerYear | ratio | real | ||||
| Total P Load | Annual loading of total phosphorus as P | tonnesPerYear | ratio | real | ||||
| Total P Yield | Annual yield of total phosphorus as P | kilogramsPerHectarePerYear | ratio | real | ||||
| PPO4 Load | Annual loading of particulate phosphorus as P | tonnesPerYear | ratio | real | ||||
| PPO4 Yield | Annual yield of particulate phosphorus as P | kilogramsPerHectarePerYear | ratio | real | ||||
| TDP Load | Annual loading of total dissolved phosphorus as P | tonnesPerYear | ratio | real | ||||
| TDP Yield | Annual yield of total dissolved phosphorus as P | kilogramsPerHectarePerYear | ratio | real | ||||
| PO4 Load | Annual loading of phosphate as P | tonnesPerYear | ratio | real | ||||
| PO4 Yield | Annual yield of phosphate as P | kilogramsPerHectarePerYear | ratio | real | ||||
| Total C Load | Annual loading of total organic carbon as C | tonnesPerYear | ratio | real | ||||
| Total C Yield | Annual yield of total organic carbon as C | kilogramsPerHectarePerYear | ratio | real | ||||
| POC Load | Annual loading of particulate organic carbon as C | tonnesPerYear | ratio | real | ||||
| POC Yield | Annual yield of particulate organic carbon as C | kilogramsPerHectarePerYear | ratio | real | ||||
| DOC Load | Annual loading of dissolved organic carbon as C | tonnesPerYear | ratio | real | ||||
| DOC Yield | Annual yield of dissolved organic carbon as C | kilogramsPerHectarePerYear | ratio | real | ||||
| Total N:P | Ratio of annual total nitrogen moles-N to annual total phosphorus moles-P | dimensionless | ratio | real | ||||
| Total C:N | Ratio of annual total organic carbon moles as C to annual total nitrogen moles as N | dimensionless | ratio | real | ||||
| Susp Sed Load | Annual loading of suspended sediment (dry weight) | kilogramsPerYear | ratio | real | ||||
| Susp Sed Yield | Annual yield of suspended sediment (dry weight) | kilogramsPerHectarePerYear | ratio | real |