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:EST-PR-SO-ZoopSurv.01
Dataset Title:Zooplankton surveys using plankton tows along transects in the Plum Island Sound estuary
Investigator 1: 
First Name:Anne
Last Name:Giblin
Address line 1:Ecosystems Center
Address line 2:MBL
Address line 3:7 MBLSt
City:Woods Hole
Zip Code:02543
Investigator 2: 
First Name:Peter
Last Name:Milligan
Address line 1:School for Marine Science and Technology
Address line 2:University of Massachusetts Dartmouth
Address line 3:706 Rodney French Blvd
City:New Bedford
Zip Code:02744
Investigator 3: 
First Name:Charles
Last Name:Hopkinson
Address line 1:
Address line 2:University of Georgia
Address line 3:229 Marine Sciences
Zip Code:30602
Associate Investigators:Hap Garritt, Jane Tucker
Keywords:LTER, PIE, Plum Island Ecosystems, Massachusetts, Parker River, Plum Island Sound, population dynamics, zooplankton
Abstract:Zooplankton were collected in spring and late summer/fall at four stations representing the salinity gradient in the Parker River-Plum Island Sound estuary. Two size classes, >335 micron and >150 micron, were collected by net tows. Conductivity or salinty and temperature were recorded for each sample. Samples were concentrated to less than 250 mls and preserved in70% EtOH. For taxonomy, sample splits were taken such that a minimum of 250 individuals were present, and counted under a dissecting microscope. Individuals were identified to the lowest taxonomic level possible, generally to species. Adult copepods were additionally characterized by sex.
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 EST-PR-SO-ZoopSurv
Beginning Date 4/8/2001
End Date 8/23/2011
Number of Data Records 1762
Other Files to Reference
Availability Status Type 1
Quality Control Information
Maintenance Description On going collections
Log of Changes: Version 01: 30Sep2013, metadata and data created to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007_Sep2013.xlsm 9/30/13 2:57 PM for QA/QC to EML 2.1.0
Geographic Description Plum Island Sound, near Ipswich Bay Yacht Club (IBYC), Ipswich, MA Lower Parker River, near Old Town Landing (OTL), Newbury, MA Parker River, below Mill River confluence and above Railroad Bridge, Newbury, MA Upper Parker River, near Triton High School, Newbury, MA  
Location Bounding Box          
West Bounding Coordinate          
East Bounding Coordinate          
North Bounding Coordinate          
South Bounding Coordinate          
OR if single point location          
Latitude 42.706588 42.761663 42.755449 42.750348  
Longitude -70.789676 -70.836217 -70.87203 -70.914366  
Taxonomic Protocols
Organisms studied
Zooplankton samples are collected and processed by PIE researchers according to the following:

NOTE: Only data from the > 335µ and >150µ sample fractions are contained in this dataset.

Collections for plankton monitoring are done annually in the early Spring and late Summer, seasons of high and low discharge respectively. Collections are typically synchronized to occur during the same weeks as dawn/dusk whole system metabolism studies, sediment benthic flux studies and whole estuary nutrient transect water collections. Planktonic collections generally occurr during mid-low ebb tides.
Plankton are collected at four sites in the estuary representing varying salinities from near fresh water to near seawater.
The four site names were
P2 (MON-PLNKT-EST-PR-21.75), P5 (MON-PLNKT-EST-PR-14), OTL (Old Town Landing, MON-PLNKT-EST-PR-10.5) and IBYC (Ipswich Bay Yacht Club, MON-PLNKT-EST-SO-2.5).
Sample collection
Four plankton size classes are collected at each site, whole water, 20µ, 150µ and 335µ.
The 20u sample is collected from the surface water using a calibrated bucket and pouring known volumes of water through a Sea Gear, 25 cm diameter, 20 u student plankton net. The cod end sample is transferred into a 500 ml wide mouth Nalgene container.
The 150u and 335u samples are collected via plankton tow using Sea Gear, 50 cm diameter, 150 or 335u plankton nets with General Oceanics Inc. Model 2030R mechanical flowmeters for measuring water volumes. The cod end samples from the 150 and 335 u nets were transferred into 1000 ml wide mouth Nalgene containers. All samples were stored in a cooler for transport back to the field station for preservation.
Plankton nets were towed for 30 – 300 seconds to ensure enough material for identification without exceeding the maximum amount that could be preserved adequately in 250 ml bottles.
For the small 20u student plankton net, buckets of known water volume were poured into the net and recorded.

For the larger plankton net tows, 150u and 335u with General Oceanics Flowmeter attached across the diameter of the hoop (0.5m), Start and stop counts were recorded prior to and after the plankton tow.

Calculations using Model 2030R standard flowmeter rotor:

10 counts are equal to 1 rotor revolution on the graphic labels on all flowmeters.
The cts/sec. Is “counts per second” and must not be used as revolutions per second for calculations.
Standard Speed Rotor Constant = 26,873

A. DISTANCE in meters = (Difference in COUNTS X Rotor Constant) / 999999
(Example: Where the graph may indicate 100 cts/sec this is also equal to 10
revolutions/sec). Therefore please ensure the correct units are being used when
measuring and calculating.

B. SPEED in cm/sec = (Distance in meters X 100) / Time in seconds

C. VOLUME cubic meters =( (3.14 X (Net Diameter)^2 ) X Distance) / 4

Sample preservation
Whole water
25 ml was sub sampled, saved in a wide mouth 250 ml polyproplylene bottle and 75 ml of 95% EtOH added for final 70% EtoH sample solution.

20u, 150u and 335u samples
To decrease the volume, the 20u, 150 u and 335u plankton material was filtered through 20u mesh Nitex and the filtered material was saved in a labeled wide mouth 250 ml polyproplylene bottle and preserved with EtOH to make a final conc of 70% EtOH (ie. 25 ml sample and 75 ml 95% EtOH for 1:3 ratio water to EtOH). The samples were rinsed down on the 20 u Nitex using the corresponding ambient site water from the 20u filtrate fraction.

Taxonomy and counts of zooplanton samples from 2001-2011 were performed by Peter Milligan, in the laboratory o fDr. Jefferson Turner at UMass Dartmouth, as follows:

Samples were reduced to aliquots of at least 250 animals with a Folsom plankton splitter, and animals are counted under a dissecting microscope and identified to the lowest possible taxon. In most cases, this will be to species; adult copepods will be additionally characterized by sex. Counts of all copepodite stages of a given copepod genus will be combined. Copepod nauplii will not be identified to genus or species because nauplii species cannot be reliably identified to those levels by using a dissecting microscope. Meroplankters cannot be identified to genus or species in most cases, and such organisms will be identified to the lowest reliable taxon, such as barnacle nauplii, fish eggs, or gastropod veligers. Concentrations of total zooplankton and all identified taxa are calculated based on the number of animals counted, multiplied by the aliquot concentration factor, and divided by the volume of filtered by the net.  

For instance, if 400 animals were counted in a 1/256 split, and the volume filtered was 4.2 cubic meters, then the calculation would be 400 x 256 = 102,400, and 102,400 divided by 4.2 = 24,381 animals per cubic meter.

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 (dd-mon-yyyy)   datetime     dd-mon-yyyy NA NA = sample or value missing or lost
STATION ID location sampled, either specific station or bounding box   nominal       NA NA = sample or value missing or lost
STATION NAME KM station name indicating distance upstream from mouth of Plum Island Sound (km 0)   nominal       NA NA = sample or value missing or lost
SITE descriptive site names [IBYC = Ipswich Bay Yacht Club, OTL = Old Town Landing, P5 = Parker R. site 5(retired name), P2 = Parker R. site 2 (retired name)]   nominal IBYC = Ipswich Bay Yacht Club | OTL = Old Town Landing | P5 = Parker R. site 5(retired name) | P2 = Parker R. site 2 (retired name)     NA NA = sample or value missing or lost
LAT Latitude of sample location in NAD 83 geographic coordinates (decimal degrees) degree ratio   real   NA NA = sample or value missing or lost
LON Longitude of sample location in NAD 83 geographic coordinates (decimal degrees) degree ratio   real   NA NA = sample or value missing or lost
DIST distance upstream from the mouth of the estuary degree ratio   real   NA NA = sample or value missing or lost
SAMPLE NAME Zooplankton specific subsample name   nominal       NA NA = sample or value missing or lost
TIME time of sample collection   datetime     hh:mm NA NA = sample or value missing or lost
TEMP temperature (oC) celsius interval   real   NA NA = sample or value missing or lost
SAL salinity (ppt) partPerThousand ratio   real   NA NA = sample or value missing or lost
COND Specific conductivity (mS/cm) millisiemenPerCentimeter ratio   real   NA NA = sample or value missing or lost
COUNT START count of flowmeter revolutions marking starting point of net tow number ratio   real   NA NA = sample or value missing or lost
COUNT END count of flowmeter revolutions marking end point of net tow number ratio   real   NA NA = sample or value missing or lost
COUNT DIFF difference in start and end counts on flowmeter, used to calculate volume number ratio   real   NA NA = sample or value missing or lost
TOW TIME duration of tow (sec) second ratio   real   NA NA = sample or value missing or lost
VOLUME total volume of water filtered for analysis (L) liter ratio   real   NA NA = sample or value missing or lost
SIZE FRACTION either > 150µ or > 335µ size classes   nominal       NA NA = sample or value missing or lost
SUBSAMPLE FRAC fraction of entire sample volume counted dimensionless ratio   real   NA NA = sample or value missing or lost
TAXON taxon to lowest level identified (F=female, M=male, A=adult, J=juvenile)   nominal       NA NA = sample or value missing or lost
NUMBER COUNTED number of individuals counted in subsample number ratio   real   NA NA = sample or value missing or lost
NUMBERperTOW total number of individuals per tow number ratio   real   NA NA = sample or value missing or lost
ABUNDANCE number of individuals per volume (#/m3) numberPerMeterCubed ratio   real   NA NA = sample or value missing or lost