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-IBYCYSI2003.01
Dataset Title:Year 2003, 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:Charles
Last Name:Hopkinson
Address line 1:Ecosystems Center
Address line 2:MBL
Address line 3:7 MBL
City:Woods Hole
Zip Code:02543
Associate Investigators:Hap Garritt
Keywords:PIE LTER, primary production, disturbance, temperature, oxygen, conductivity, salinity, depth, turbidity, saturation, gas, Plum Island Sound, monitoring
Abstract:15 minute readings of water column temperature, salinity, oxygen, depth, and turbidity 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-IBYCYSI2003
Beginning Date 5/14/2003
End Date 12/23/2003
Number of Data Records 21371
Other Files to Reference
Availability Status Type 1
Quality Control Information
Maintenance Description
Log of Changes:
Geographic Description 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 42.70899  
Longitude -70.79658  
Taxonomic Protocols
Organisms studied
Methods:Measurements are made using a YSI 6600 water quality sonde and YSI 6200 Data Collection Platform (DCP) with data radio telemetered to the PIE LTER Rowley field station. YSI Sonde sensors consist of 6562 dissolved oxygen probe (rapid pulse Clark type,polarographic), 6560 conductivity/temperature probe (thermistor), vented level depth sensor (stainless steel strain gauge), 6026 wiping turbidity probe(optical, 90o scatter) and 6025 wiping chlorophyll probe (optical fluorescence).
NOTES AND COMMENTS: Chlorophyll and fluorescence data typically does not calibrate well and data should only be used for relative purposes of looking at highs and lows of phytoplankton blooms not real concentrations.

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: Fouling of Clark style DO probe where membrane gets a brownish bacterial? film affecting DO sensor readings/calibration checks.
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.

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 millisiemensPerCentimeter ratio   real     blank cell
Salinity Salinity of water partsPerThousand interval   real     blank cell
DO% Percent dissolved oxygen saturation of water percent ratio   real     blank cell
DO Conc Dissolved oxygen concentration of water milligramsPerLiter ratio   real     blank cell
DO Charge Dissolved oxygen sensor charge dimensionless ratio   real     blank cell
Depth Water column depth above sonde pressure transducer meter ratio   real     blank cell
Turbidity Turbidity of water nephelometricTurbidityUnit ratio   real     blank cell
Chlorophyll Chlorophyll concentration in water microgramsPerLiter ratio   real     blank cell
Fluorescence Fluorescence of chlorophyll in water percent ratio   real     blank cell
Comments Comments about specific data   nominal         blank cell