Plum Island Ecosystems LTER Database

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:MON-SO-IBYCYSI2010.01
Dataset Title:Year 2010, 15 minute interval, water quality measurements of water column temperature, salinity, oxygen, and depth near the mouth of Plum Island Sound, Massachusetts
Investigator 1: 
First Name:Chuck
Last Name:Hopkinson
Address line 1:Georgia Sea Grant
Address line 2:University of Georgia
Address line 3:229 Marine Sciences
Zip Code:30602
Associate Investigators:Hap Garritt
Keywords:PIE LTER, primary production, disturbance, temperature, oxygen, conductivity, salinity, depth, saturation, gas, Plum Island Sound, monitoring
Abstract:15 minute readings of water column temperature, salinity, oxygen and depth in Plum Island Sound at the Ipswich Bay Yacht Club.
Contact: Plum Island Ecosystems LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7485
Online URL:
Data File URL
Data File Name MON-SO-IBYCYSI2010
Beginning Date 4/20/2010
End Date 11/15/2010
Number of Data Records 20085
Other Files to Reference
Availability Status Type 1
Quality Control Information
Maintenance Description
Log of Changes: Version 01: February 23, 2012, updated data and metadata. Used MarcrosExportEML_HTML (working)pie_excel2007.xlsm 2/9/12 1:33 PM for QA/QC to EML 2.1.0
Geographic Description Near mouth of Plum Island Sound, on Ipswich Bay Yacht Club pier, Ipswich, Massachusetts.  
Location Bounding Box    
West Bounding Coordinate    
East Bounding Coordinate    
North Bounding Coordinate    
South Bounding Coordinate    
OR if single point location    
Latitude 42.708995  
Longitude -70.796577  
Taxonomic Protocols
Organisms studied
Methods:Measurements are made using a YSI 6600 water quality datalogging sonde. YSI Sonde sensors consist of 6150 optical dissolved oxygen probe , 6560 conductivity/temperature probe (thermistor) and vented level depth sensor (stainless steel strain gauge).

Missing data or blank values are caused by maintenance time periods or where sensor measurements are obviously wrong in the context of what would be expected. For example, the conductivity sensor has a relatively small opening and chamber for the conductivity electrodes, the estuary can have varying suspended sediment/detrital loads moving in the water column which enter the conductivity cell shorting out the electrodes making a faulty conductivity measurement (lower than expected). Oxygen measurements are dependent upon the conductivity measurements so the oxygen also becomes erroneous. Obvious measurements/data errors have been removed from the data set however the user of this data should also conduct their own data analysis to determine if the data are suitable for their particular situation.

Typical sensor/data problems are:
For oxygen: Poor/inaccurate conductivity measurements will affect the dissolved oxygen accuracy
For conductivity: Conductivity cell can have detrital material stuck in it, shorting out cell, resulting in lower than expected conductivity.
For depth: Depth strain gage pressure sensor may come out of the water at low tides resulting in many "zero" depth readings or sometimes negative values.

YSI Dissolved oxygen % saturation reporting can vary depending upon how the oxygen is calibrated.
For this data set two Oxygen percent saturation values are reported.
ODO%YSI variable name represents a YSI calibration in air, from Standard Methods, refers to calibration at a particular ATM pressure which allows DO% for calibration to fluctuate above/below 100% when ATM is above/below reference 760 or 1 ATM
ODO%Local variable name represents an oxygen calibration in air at a particular ATM pressure but it forces the DO% to be 100%, does not allow it to be under or above if ATM is above/below 760.
ODO%Local data should be used for metabolism studies when correcting for diffusion based on gradient deviations from 100% which by definition is the % saturation of oxygen in air.
ODO%YSI should not be used since it would require a known ATM pressure at each interval to calculate the ATM % saturation of oxygen to be use for that interval, probably a small correction anyway.
Concentration of DO remains the same for either calibration.

Data Table

Variable Name Variable Description Units Measurement Scale Code Information Number Type DateTime Format Missing Value Code Missing Value Code Explanation
Date Date of sampling   datetime     dd-mmm-yyyy   blank cell
Time Time of sampling (eastern standard time EST, 24 hour)   datetime     hh:mm:ss   blank cell
Station Name of sampling station   nominal         blank cell
Temp Temperature of water celsius interval   real     blank cell
SpCond Specific conductivity of water millisiemenPerCentimeter ratio   real     blank cell
Cond Conductivity of water millisiemenPerCentimeter ratio   real     blank cell
Salinity Salinity of water partPerThousand interval   real     blank cell
ODO%YSI Percent dissolved oxygen saturation of water percent ratio   real     blank cell
ODO%Local Percent dissolved oxygen saturation of water percent ratio   real     blank cell
ODO Conc Dissolved oxygen concentration of water milligramPerLiter ratio   real     blank cell
Depth Water column depth above sonde pressure transducer meter ratio   real     blank cell
Comments Comments about specific data   nominal         blank cell