Biometry, Stat 412
Fall 2007

Warning: read handout completely before field exercise!!!

Purpose: Collect replicated data on stream water quality using several variables.

Equipment needed (for 60 students):

6-12 – thermometers

6– writing slates w/pencils

60 - data sheets

Problem:

1)        Mill Creek drains the urban and rural areas of  Battle Ground upstream of campus and thus is impacted by a variety of stressors, especially lack of stream vegetation.

2)        The goal of this study is to take measurements of one measure of water quality,  temperature, and estimate how it varies along different segments of the stream on campus and between the surface and bottom. We will also examine water clarity and flow rate.

3)        In addition, we will be collecting additional data on factors that can influence water temperature, including the type and amount of stream vegetation.

4)        Will test the following initial hypotheses:

H₀: Water temperature is not different between upstream and downstream areas

H_A: Water temperature is different between upstream and downstream areas

Another related hypothesis is that temperature would vary between surface and bottom waters, with the surface predicted to get cooler than the bottom as it moves downstream

H₀: Water temperature is not different between surface and bottom areas

H_A: Water temperature is different between surface and bottom areas

We will test this hypotheses by collecting data on at least six different locations on the WSU campus.

 Procedure: Surveyors will be divided into six groups of 8-10 people/group.

1)        Each student should fill out their own data sheet and observations but work together in their group.

2)        The Instructor and TA will guide teams to different areas on the stream for taking measurements. The areas will vary in habitat and stream water quality.

3)        Each team will collect similar but independent temperature data in the same area of the stream (replicate samples).

4)        Place the thermometer into the water at a standardized depth near the surface (1 cm). Let the thermometer calibrate with the water temperature until the reading is stable, then record this number on your data sheet. Repeat at the same spot near the bottom of the creek (at least 10 cm). Repeat until n=5 readings have been taken in three areas at each site

5)        Record who took the reading, the temperature, and time on your data sheet for each measurement.

6) Also record the following ordinal variables as they relate to water quality:

Water flow rate: 1 = low/still; 2 = moderate; 3 = fast (ripples).

Water clarity: 1 = Very turbid; 2 = moderately turbid; 3 = clear.

Vegetation overstory: 1 = none (sun); 2= some (partial sun); 3 = dense canopy (shade).

Reference Maps:

Salmon Creek Watershed

Study Areas: