GREEN HARBOR RIVER STUDY

MARSHFIELD, MASSACHUSETTS

2005

Laurie Bianchi, M.Ed

Whitman-Hanson Regional High

                  1    Drainage Basin

                  2    Site Map of the Green Harbor River

                  3    Water level marks

                  4    Turbidity tube

                  5          Photograph of YSI -85 in use  

                  6          Nekton Seining at Site SN2  August 26, 2005

                  7          Turbidity Measurements 2005 - Secchi disk

                   8          Turbidity Tube Measurements

         9          Surface Salinity 2005

        10        Surface Water Temperatures 2005

                  11        Dissolved Oxygen Content 2005

                  12        Comparison of Percent Saturation  Dissolved Oxygen 2005

                  13        pH 2005

         14       To be entered - photo of fish

         15        Sluice Boards

         16        2004 Turbidity Measurements                          

          17        High Turbidity after nine months of zero tidal induction

          18        2004 Salinity Profile

          19        Postcard of Everson’s Island circa 1920

         Tables

          1          Water Levels in the Green Harbor River

          2          Turbidity Table

          3          Physical Data

          4          Nekton Sampling Data

5                         Physical Data for Nekton Sampling

6                        Relative Abundance

7                       Bag Seine Catch per unit Effort (CPUE)

8                       Life Stages – Nekton Length

Appendices                                                                             

          I           Data Sheets arranged by date:  General and Nekton

II.      Fishes and Crabs - excerpt from A Volunteer’s Handbook for Monitoring  New England Salt Marshes

III.               Salinity – excerpt from A Volunteer’s Handbook for Monitoring New England Salt Marshes

IV        Rainfall data 2005

V.       Nekton Sampling Spreadsheet and Physical Data

VI.              Fish of the Estuary

VII.            Line transect map

VIII.         Summary of Massachusetts Water Quality Standards

          IX.      Ecological Role of Estuaries

Methods and Materials

    This investigation involved visits ranging from thirty minutes to five hours, approximately once per week, from June 30 to August 26, 2005 at sites along the Green Harbor and Green Harbor River (Figure 2).  The harbor is considered the reference site (control) and the river is the study site.  There were   preliminary visits on April 22 and June 10,  with Whitman-Hanson students on a Community Service Learning field trip.   Water quality was tested by taking hydrographic measurements such as temperature, specific gravity, salinity, pH, dissolved oxygen, and turbidity.  Not all tests were done each day as time constraints were larger this year due to the quantification and expansion of data collection. Biological (nekton) sampling was done on July 29, August 15 and August 26 according to CZM protocol (Appendix II).  Transects were set in the salt marsh of Green Harbor, and wells were placed to measure porewater salinity.  (Appendix III)

The drainage area map (Figure 1) is from a U.S. Army Corps of Engineers Report (1993).

Figure 2   Site Map of Nekton Sampling Sites

Rainfall  data was provided from Kevin Silva at the Town of Marshfield Wastewater Treatment Facility, located on Joseph Driebeck Way abutting Green Harbor (Appendix IV).

      This investigation was completed during three-hour visits, once a week, from June 23 to August 26, 2004 at sites along the Green Harbor River (Figure 1).  One preliminary visit with students on a Community Service Learning field trip occurred on May 25. Three follow-up visits were September 6, October 9, and November 14. Water quality was tested on each visit. Hydrographic measurements consisted of temperature, specific gravity, salinity, pH, dissolved oxygen, turbidity, and general observations such as color and suspended solids. Plankton tows and bottom sampling were done most days. Biological surveying was accomplished on certain visits, usually when students and/or adults were available to assist with nets.

Figure 3:  Water level in NAVD (mean ocean tide is 0)

June 10, 2005

Turbidity

A secchi disk was clipped onto a line with markings every quarter meter.   The disk was lowered over the side of the dike from road level until it disappeared from sight.  Then it was lifted slowly until just visible.  This process shows the depth to which light can penetrate and is an indicator of the turbidity of the water.  The secchi disk was used when the inflow or outflow of water was very slow, preferably around slack tide.  When the current was too fast, the disk was pulled laterally, not allowing an accurate reading.

A turbidity tube (GLOBE protocol transparency tube) was used to enhance the quality of turbidity data and to allow measurements even when the current was strong.  A clear 120 cm. plastic PVC tube was equipped with a small secchi disk at the bottom.  Water collected from a clean bucket or the water collection device was placed in a bucket.  With the person’s back to the sun and using a clean container, the water sample was slowly transferred into the turbidity tube, a small amount at a time, just until the secchi disk was not visible.  The collector waited for air bubbles to settle as each new amount of water was added. The tube was rotated slowly while viewing to make sure none of the pattern was visible.  The height of water in centimeters was recorded. 

Figure 4:  Turbidity Tube for measuring turbidity

Water Chemistry

          The collection bottle or water collection device was first rinsed with the river water. The water sample was collected.  A plastic 100 mL graduated cylinder was rinsed with a small amount of sample.  After being emptied, the cylinder was filled with 90 mL of the sample.  The hydrometer was gently placed in the graduated cylinder. Temperature was checked and recorded. The water was allowed to warm up to 70°F if below that temperature, and the reading was taken from the bottom of the meniscus.  The hydrometer was manufactured by Marine Enterprises International, Inc. in Baltimore, MD.

The salinity was determined by using the specific gravity data and a conversion chart.  A Sea Test Full Range Specific Gravity Meter manufactured by Aquarium Systems was used to verify the data. The procedure consisted of three steps: (1) Pour the sample to horizontal line, (2) tap the sides to release any air bubbles, and (3) read the salinity in parts per thousand from the pointer.  A YSI – 85 probe was used when available.  A refractometer was also used several times for equipment comparisons.

Two methods were used for taking the temperature, depending upon the circumstances.  For grab samples the method was to collect the sample in the water collection device, transfer the sample to a white bucket, and insert an alcohol thermometer into the bucket for one minute.   A YSI – 85 probe was used when available.

Figure 5:  YSI – 85 probe   August 26, 2005  Site SN2

Nekton sampling was done according to a protocol approved by Tim Smith (CZM) and adapted according to the circumstances from  A Volunteer’s Handbook for Monitoring New England Salt Marshes (Appendix II).

Four sites, each ten meters in length, along the harbor and river were marked with PVC pipe.  Starting the first seine (RN1) approximately two hours before low tide in the ocean, a bag seine and stop nets were used to capture fish and invertebrates such as crabs and shrimp.  Organisms were sorted by species into buckets, counted, massed in groups, and measured using standard length (SL) in millimeters for fish and carapace length (CL) for crabs.  When more than forty of a species were caught, a sub-sampling protocol was utilized, in which all fish were massed and a random sub-sample of forty were massed.  Only the forty were measured for SL.  The total mass divided by sub-sample mass gave an expansion factor for analytical purposes.  Organisms were identified by using Inland Fishes of Massachusetts and Marine Animals of Southern New England and New York.                       

                    Figure 6:  Nekton Seining at Site SN2  August 26, 2005           

Plant survey 

    Using the CZM protocol from A Volunteer’s Handbook for Monitoring New England Salt Marshes, a baseline was chosen, and nine randomly selected transects were marked and measured on the harbor salt marsh.  Transects were not installed on the river side yet.  Wells for porewater salinity were installed at two depths (20 cm. and 50 cm.) at the edge of the marsh and the upland border (18 wells).  Porewater salinity was measured by extracting water with a sipper (hollow metal tube attached to a syringe) and using a refractometer.

During the summer of 2005, the water level ranged from -1.8 (high) to -2.5 (low) and for the year ranged from 0 (high) to -3.45 (low).  The average water level for the year was -2.2 feet NAVD.  After large rainstorms, the water level rose.  (Table 1)

Biological survey

Nekton sampling results

List of species caught                                                                             Location

Fish                                                                                         Harbor(H) & River (R)

            Mummichogs                                         Fundulus heteroclitus            H R

            Three spine stickleback                          Gasterosteus aculeatus           H

            Fourspine stickleback                            Apeltes quadrucus                       R

            Inland Silverside                                    Menidia beryllina                       R

            Atlantic Silverside                                 Menidia menidia                     H R     

*Banded killifish                                      Fundulus diaphanous                   R

            Winter Flounder (juveniles)                   Pleuronectes americanus          H R

            American eels (juveniles)                        Anguilla rostrata                        R

            Northern Pipefish                                  Syngnathus fuscus                        R

            * Menhaden                                         Brevoortia tyrannus                   H

            White Perch                                         Morone americanus                      R

            Banded killifish                                    Fundulus diaphanus                      R

            *Unknown fish                                                                                    H

            *Unknown fish (sculpin)                                                                       H

            *Unknown fish                                                                                         R

Crustacea

            Green crabs                                          Carcinus maenas                        H R

            Grass shrimp                                         Palaemonetes sp.                        H R

            Sand shrimp (Sevenspine bay)              Crangon septemspinosa                 H R

Number of species caught in harbor: 10              Number of species caught in river: 14

*Not positively identified by an expert at this time

*  Sub-samples may not have been representative of entire sample.  Expansions do not fit well with averages.

Additional fish data can be found in the Data sheets for June 10, 2005 but since the spring scales used that day were not highly accurate and the seining was in different locations, the information was not presented here.

                                                Table 7  Catch Per Unit Effort

                                        Table 8 Life Stage:  Nekton Length