Subject: Oceanography
Lesson Topic: Water quality
Author: Jeff Marshall
Grade Level: 9-12
Summary of Activity/Lesson: Students will use data visualization tools to look at relationships
that affect water quality.
Activity:
Visualizing Water Quality with Coastal Ocean
Research and Monitoring Project (CORMP) Data
Read “Ecology of the Cape Fear River” by Dr. Mallin who is head of the Lower Cape Fear
River Program (LCFRP). Discuss CORMP with students. Discuss how scientists are
monitoring the health of the river with sampling stations strategically placed throughout the
estuary and coastal ocean.
Link for introductory information:
http://www.uncwil.edu/riverrun/river_tutorial/CFRSystem.htm
The following vocabulary is available on the intro material and will be helpful background
information for students completing this activity.
Vocabulary: estuary, river mouth, coastal ocean, discharge, runoff, nitrate, orthophosphate,
turbidity, salinity, river plume, ammonium, turbidity, point source, non-point source,
micrograms/liter
Name:
Water Quality
1. On the map provided plot the locations of the following sampling sites.
Station #
CFP-1
CFP-2
CFP-6
CFP-7
CFP-5
CFP-4*
CFP-3*
CFP-8**
CFP-9**
Location
33° 53.281’ N -78° 00.473’ W
33° 50.683’ N -78° 02.355’ W
33° 52.5’ N -78° 05.00’ W
33° 50.4’ N -78° 06.8’ W
33° 53.201’ N -78° 08.71’ W
33° 48.241’ N - 78° 05.326’ W
33° 48.100’ N - 77° 59.400 ‘ W
33° 53.00’ N -78° 10.25’ W
33° 47.25’ N -78° 13.5’ W
Designation
lower estuary
river mouth
coastal ocean
coastal ocean
coastal ocean
coastal ocean
coastal ocean
coastal ocean
coastal ocean
Depth
14 m
11 m
10 m
10 m
10 m
14 m
10 m
8m
14 m
*discontinued as of 12/03
** new station as of 12/03
1A. Based on their location label these stations as either: lower estuary, river mouth, or coastal
ocean.
1B. Compare your results to those found at http://www.uncw.edu/riverview
Use the RiverView DVT to answer the following questions.
2. Based solely on location, which of these stations on average should have the highest and
lowest average surface salinity?
3. Calculate the average salinity over the 11 month period beginning on 12/12/01 and ending on
11/01/02 at each of the stations listed below. Provide answers to the nearest tenth. Also give the
maximum and minimum value for each station.
Average
Minimum
Maximum
CFP-1
CFP-3
CFP-5
CFP-6
CFP-7
3A. What is the trend in salinity with increasing distance from the river mouth? Was this what
you expected?
4. Average discharge at the mouth of the Cape Fear River is 5418 cubic feet per second (cfs) and
average salinity is 29 parts per thousand (ppt).
a) For CFP-1, list the dates when salinity was sampled to be less than 25 ppt.
b) After doing so, go to http://www.cormp.org/stream.php and record the largest river
discharge at the mouth of the river within two days of that date.
Date
Salinity
(ppt)
River Mouth
Discharge (cfs)
Number of Times Greater
Than Average Discharge
Hint: To calculate column four, divide the river mouth discharge for the specific date by the
average river discharge given above.
4A. On average, how do salinity and discharge compare at the CFP-1 sampling station?
4B. Describe when and why this might occur?
5. Minimum salinity values for each of the seven stations occurred in January and maximum for
each of the seven stations occurred in August.
Guess why this might be?
What kind of scientific data could provide evidence for your explanation?
Where might we obtain this data?
6. Besides decreasing the salinity and increasing river discharge, what other effects might major
precipitation events have on the river? Hint: Think about the different paths of the water going
into the river and what it might pick up along the way.
7. On the table below, use information from Question 4 to determine if it qualifies as a period of
both high river discharge and low salinity at the CFP-1 sampling station.
Also, record the appropriate values for nitrate, orthophosphate, and ammonium using the
RiverView DVT.
Date
High Discharge and
Low Salinity? (Y/N)
Nitrate
(g/L)
Ortho-phosphate
(g/L)
Ammonium
(g/L)
3/29/00
9/27/00
3/23/01
4/20/01
6/21/01
1/1/02
7A. Average nitrate value is 75.3 g/L at CFP-1. Is this value typically high during low salinity
and high discharge periods?
7B. Average orthophosphate value is 12.1 g/L and average ammonium values are 26.3 g/L at
CFP-1. Are these values typically high during periods of low salinity and high discharge at the
CFP-1 sampling station?
7C. Why are all these values typically positively correlated? Think about events upriver that
may lead to increased discharge and decreased salinity.
8. What are the significance of increased nitrate, phosphate, and ammonium in the river? Refer
to your reading for help.
9. What are some point source examples where these potential pollutants might enter the river?
10. What are some non-point source examples?
11. List potential solutions to limit the amount of this material from entering the river from both
point and non-point sources?
Disclaimer: These lesson plans were compiled, edited, written, and/or prepared by Erin Spruill,
UNCW Coastal Ocean Research and Monitoring Program (CORMP). CORMP is a NOAA grant
funded program, located at the UNCW Center for Marine Science, Wilmington, NC. Feel free to
update or adapt the existing lesson plans to fit your needs. We ask that you credit the authors
and editors of these activities. In addition, please contact us with new methods and activities you
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