Level 2 study procedures and documents

Last updated on December 11, 2025

Reminder

Do not go out if:

  • It's raining heavily (making it difficult to see the Secchi disk accurately)
  • There's abnormally high boat traffic, or
  • Your safety would be at risk

A clear, calm day is best.

Refer to the Level 2 program overview page for useful information before and after your sampling event.

Step 1: Getting to the site

  • Upon arrival, note any safety hazards or concerns and adjust plans as needed
  • It's important that the exact location of the predetermined station is found so that the measurements collected can be compared with the water quality data collected by the ministry
  • Before anchoring, check the lake depth with calibrated rope/tape or depth sounder:
    • Record the depth to the nearest 0.01 m or establish a permanent buoy
  • Record the date, time, volunteer names, weather, and water conditions

Step 2: Lake profile

YSI ProSolo ODO Meter

  • Calibrate the YSI
  • Refer to “How to Calibrate my YSI ProSolo ODO Meter” for step-by-step instructions:
    • To get accurate readings, the meter depends on Barometric pressure, which varies daily, so the meter must be calibrated each time you sample
    • Record the Post Cal Value % DO reading and the Barometer reading at the end of calibration in the field sheet to help us determine whether the YSI probe needs servicing
  • Lower the YSI probe until the probe is submerged just below the surface
  • Wait at least one minute before reading your results to allow the readings stabilize
  • Record:
    • Temperature (to the nearest 0.01°C)
    • Dissolved oxygen (to the nearest 0.01 mg/L)
  • Lower the YSI probe until the sensor is submerged just below the surface of the water (the '0 m' reading)
  • Continue to measure and record temperature and dissolved oxygen values at one metre intervals, until you reach a depth of 20 metres.  After 20 metres, measure and record at 5 metre intervals. The last measurement will be from a depth one metre above the measured lake bottom (to prevent sediments getting into the sensor) or until the probe cable has reached its maximum length. You may have to alter the final depth on your field sheet to include the depth 1 m off the bottom

Step 3: Secchi depth

  • Remove any hats and/or sunglasses – these will interfere with your measurement
  • Lower the Secchi disk over the shaded side of the boat
  • Slowly lower the disk until the black and white pattern is no longer visible. Note the measurement on the tape measure (in metres) at the surface of the water (estimate to the nearest 0.01 m). Record this as Distance A
  • Pull the disk up until the black and white pattern just appears again and note the measurement of the tape measure at surface of the water. Record this distance as Distance B
  • Average the 2 measurements [(Distance A + Distance B)/2] = Secchi depth

A graphical representation of conducting a secchi depth reading from a boat

Step 4: Check and fill in the remainder of the form

Fill in the entire form and note any observations while traveling to or while sampling at the site.

This may include:

  • Algae blooms
  • Surface slicks
  • Debris
  • Pollen
  • Zooplankton
  • Fish kills
  • Recent storm or high wind events
  • Fishing derbys
  • Water skiing competitions, etc.

The data form has space for one site on the same water body.

If you need more, use a separate copy of the data form.

Contact us if you need assistance with any of the above steps.

Step 5: Data entry and end of season responsibilities

  • After the final sampling event of the season, copy the field data into the standardized digital format provided and submit it electronically to the ministry within 30 days
  • Using the Purolator account number provided, return sampling equipment to the ministry for maintenance and storage within 30 days of final sampling event for the season, unless otherwise arranged
    • Phone: 250-649-2939
    • Ministry of Environment and Parks
      Attn: BC Lakes Stewardship and Monitoring Program
      1011-4th Ave, Suite 325
      Prince George, B.C.
      V2L 3H9
Field data submission

For current lake monitoring volunteers, send us your completed field data:

Submit your data

If you have questions: