Summer Research Program for Science Teachers



Susan Vincent

Young Women’s Leadership School of East Harlem, New York

August 2005



Fieldwork Protocols for Sampling Nekton and Invertebrates



Marine Science Unit Plan


Objective: Students will learn how to set up a field experiment to answer the questions:

1.      What kinds of animals use the marsh habitat?

2.      What habitat conditions are necessary for survival?

3.      What are the strengths/weaknesses of our sampling protocols?


Project Description:  The unit of study will require approximately 1 week of class time: one class period to prepare for fieldwork; one entire day in the field; and 3 to 4 laboratory periods as a follow up to the fieldwork.  This unit of study is designed to follow a unit of wetland ecology of a river estuary, so the students will have an understanding of basic wetland functions, flora and fauna before performing the fieldwork.  Since the dominant vegetation in the study area is Phragmites australis, it is suggested that the wetland unit include a study of invasive species.


Students will deploy minnow traps in a salt marsh at Piermont Pier for the purpose of collecting samples for subsequent analysis in the lab.  A quantitative and qualitative comparison of the results found north of the pier with results collected south of the pier will allow students the opportunity to develop their ability to analyze, interpret and present data using technological tools.


Equipment and Supplies:

1.      36 (4mm wire mesh) Gee minnow traps

2.      40 meters cotton rope (for connecting sets of traps for each site)

3.      ball of heavy cotton string (for attaching minnow trap pins to transect rope)

4.      6 one-meter lengths of ¾ inch PVC pipe (for marking transects)

5.      depthometer: a two-meter length of ¾ inch PVC pipe marked in centimeters for measuring water depth and canopy height

6.      quadrat ( ½ m2 ) for standardizing vegetation stem count: constructed by joining 4-half meter sections of ¾ inch PVC pipe with corner joints

7.      100-meter measuring tape

8.      waders (at least 2 pair)

9.      YSI-85 meter for measuring DO, salinity, conductivity, temperature

10.  6 clipboards with data sheets (template attached)

11.  6 plastic containers with tight-sealing lids (~16 oz.) for preserving samples

12.  formaldehyde solution (10%) 2-3 liters

13.  gloves

14.  3 buckets (~5 gallon)

Laboratory identification of animals:

15.   microscope

16.  isopropyl alcohol (50%) 2-3 liters

17.  fish and invertebrate keys

18.  6 inch metric ruler (for measuring fish lengths)

19.  electronic balance (for weighing samples)





Teacher preparation for field trip: Prior to bringing the students to the field sites at Piermont Pier, six marsh sites are selected and marked, 3 north of the pier and 3 south of the pier, along a 500 meter transect parallel to the access road.  Site selection is based on quality of habitat (dense vegetation, inundation to a minimum depth of ~30 cm. at slack high tide, and easy accessibility for the students.  Each site is marked with a meter long PVC pipe pushed into the substrate.  One team of students will be responsible for collecting data at each site. (i.e. Blue Dolphin team will manage site 1 north; Diamond Back Turtles will manage site 2 north, etc.)


Classroom preparation: Teacher will demonstrate how to assemble the minnow traps and attach them to the transect rope.  A set of 6 traps (attached to 6 meters of transect rope) is needed for each field site:  

  1. Cut a 6 meter (plus ~ 20 cm.) length of rope.
  2.  Tie a loop in one end (to secure to the transect marker in the field).
  3. Mark the rope at 1 meter intervals.
  4. Attach the pins (supplied with the minnow traps) to the transect rope at each mark with string.
  5. Assemble 6 traps and attach to transect rope. Repeat for each set of 6 traps.
  6. Disassemble traps; leaving pins attached to rope, place 1 transect rope with each set of 6 traps to expedite deployment in the field.
  7. Students will select their groups and decide on a group name.  This project is designed to accommodate 6 teams of 4 students each.  Each group will be responsible for the following tasks at one of the six pre-selected sites at Piermont Pier: characterize habitat, deploy traps, retrieve traps, and record data.
  8. Teacher will assign a site to each group.



Fieldwork Protocols:

            I. Site Characterization:

1.      At each site, use the YSI-85 meter to measure and record water temperature, salinity, conductivity and dissolved oxygen (waders can be used, or students can wear old tennis shoes and shorts).

2.      Place the quadrat around a half-meter section of vegetation; count the stems; record.  Repeat at 3 places along the 6-meter transect (each end and middle).

3.      Using the depthometer, measure water depth and canopy height at 3 places along the 6-meter transect (each end and in the middle).  Record.

II. Trap Deployment (deploy ~1 hour before high tide)

     Check tide charts for Tarrytown, NY (near Piermont) at < >

4.      Assemble traps and attach to transect rope.

5.      Deploy traps in the marsh at the transect marker (PVC pipe).  The loop on the end of transect rope is secured onto transect marker and traps are submerged making sure that traps are spread out along the 6-meter transect within the vegetation.

III. Trap retrieval:

6.      Traps are deployed for a period of 3 hours.  Retrieve traps from the marsh; bring to the shore.

7.      Empty traps into a bucket.

8.      Transfer animals to container; pour formalin solution over animals; cover; mark lid of container with site number, date and time.

9.      Samples are transported back to the lab and left in formalin for a minimum of 24 hours to preserve tissues. 

Laboratory Protocols:

IV. Processing Samples:

10.  Using proper procedures for disposal of formaldehyde, decant formalin from each container.

11.  Rinse samples in de-ionized water; place in 50% isopropyl alcohol solution.

12.  Key out fish and invertebrates to species level.

13.  Record results on data sheets (attached).

14.  Enter data in excel spreadsheets and generate graphs to compare results obtained at each site.


Synthesis: Students will analyze, interpret and discuss their findings within each group.  Students are encouraged to pose questions and find solutions by analyzing the data.  The instructor may want to prompt questions such as:


  1. How does density of organisms compare across sites?  Is there a difference between north and south sites when data is combined?
  2. How does diversity of organisms compare across sites?  From north to south?
  3. Does habitat differ across sites?  From north to south?
  4. Does mean fish length differ among sites?  Total fish weight?
  5. What habitat conditions are optimum for the organisms?  Do those conditions exist at Piermont Pier?
  6. Did we get an accurate sampling of all the organisms that use the marsh at high tide?
  7. How might we vary our sampling protocols to get a more robust data set?


Each group will publish their data for comparison among groups.  Finally, each group will create a PowerPoint presentation of their work for the class.



Science Standards:

S1. Students will use mathematical analysis, scientific inquiry, and engineering design as appropriate to pose questions, seek answers and develop solutions.


S2. Students will access, generate, process, and transfer information using appropriate technologies.


S4. Students will understand and apply scientific concepts, principles and theories pertaining to the physical setting and living environment and recognize the historical development of ideas in science.


S6. Students will understand the relationships and common themes that connect mathematics, science, and technology and apply the themes to these and other areas of learning.


S7. Students will apply the knowledge and thinking skills of mathematics, science, and technology to address real life problems and make informed decisions.


Piermont Pier Data Sheet


Minnow Traps


Date/Time Deployed: _________________________


Date/Time Collected: _________________________





















Piermont Pier Data Analysis Sheet



Location ________________                           

Transect ________________   

Date       ________________