Field Sampling


Biological monitoring is a relatively easy science, but one that takes time to learn well. SalmonWeb incorporates the components to build a good monitoring program: setting up a quality assurance plan, selecting sampling sites, collecting benthic invertebrate samples, sorting and identifying the organisms, and summarizing the data.

When to Sample: Because SalmonWeb is designed to investigate change from year to year, sampling occurs once a year. A Fall sampling season, from mid August to mid October, allows monitors to sample when stream levels are at their lowest AND before most salmon runs occur. Sampling should be completed before adult salmon return to spawn.



The workshop participants will:

Karr Benthic Macroinvertebrate Sampling Protocol

Checklist of materials:

___ Meter tape to identify location
___ 500 micron mesh Surber sampler
___ (2) 500 micron mesh sieve (or smaller)
___ Waders (for each person)
___ Flagged weight to identify sample location
___ Isopropyl alcohol
___ 1-liter squirt bottle for isopropyl alcohol; second bottle to refill the first
___ Garden trowel to disturb substrate
___ Stop watch
___ (2) White buckets to empty sample from Surber
___ Large cup with handle to rinse invertebrates off Surber
___ Forceps (Tweezers)
___ Plastic spatula
___ Waterproof ("Rite-in-the-rain") paper
___ Pencil, permanent marker (Sharpie), and grease pencil
___ Screw-top vials
___ Ziploc bags
___ Camera

Sampling Protocol for Benthic Invertebrates

Select site

Locate stream reach to be sampled. Find a riffle (fast moving water over rock or cobble substrate, surface water should be broken) near the middle part of the stream. Riffle should be long enough to accommodate three replicate samples. Ideal sampling locations consist of rocks 5 to 10 cm in diameter sitting on top of pebbles. Substrates dominated by rocks larger than 50 cm in diameter should be avoided.

Sample within main flow of the stream. Sample at water depths of 10 to 40 cm. Depth, flow and substrate type should be similar for the three replicate samples collected in the riffle. Begin sampling downstream and proceed upstream for the three replicates.

Avoid bridges and other large human-made structural features. If unavoidable, sample at least 50 meters upstream of a bridge and 200 meters (more would be better) downstream of a bridge.

Write down the exact location of the sample site. Use meter tape to measure distance from nearest landmark.

Collect invertebrates

Sampling teams may range from 2 to 4 people. Actual collection of macroinvertebrates requires 2 people. Others can assist with equipment, labeling collections and other duties.

  1. Place Surber sampler on the selected spot with the opening of the nylon net facing upstream. Brace the frame and hold it firmly on the creek bottom.

  2. Lift the larger rocks resting within the frame and brush off crawling or attached loosely organisms so that they drift into the net. After "cleaning" the rocks, place them in a bucket.

  3. Once the larger rocks are removed, disturb the substrate vigorously with a trowel or large spike for 60 seconds. This disturbance should extend to a depth of about 10 cm to loosen organisms in the interstitial spaces, washing them into the net.

  4. Lift Surber out of the water: Tilt the net up and out of the water while keeping the open end upstream. This helps to wash the organisms into the receptacle. Drop a piece of weighted flagging tape to mark the location of the first replicate sample.

  5. On the creek bank, empty contents of Surber into large bucket. Rinse Surber and empty into bucket until all animals are removed. Great care should be taken in this step to collect and preserve all organisms from the Surber sampler as well as from the rocks and water in the bucket. Use of a magnifying glass and tweezers is essential. Rinse bucket through sieve to remove water from sample. Pick out large debris (sticks and leaves) after carefully removing any invertebrates.

Archive sample

Use spatula to move sample from sieve into a plastic vial. Fill vial to the top with isopropyl alcohol. Put label on inside of vial with name of sampler, date, location, and replicate number. Write location and date on top of vial lid. Place vial in a Ziploc bag labeled with the same information.

Collect replicate samples

Return to the location of the first sample, walk upstream and collect another sample of invertebrates. Leave another flagged marker and process the sample as above. Repeat this process once more for a total of three replicate samples from each site location. Each replicate should be labeled (e.g., #1, #2, #3) and archived separately.

* Protocol furnished by L. Fore, 1997.

Download the Site Description Form in Word or PDF version to print.

Site Description Form

Date _________________________(day/month/year)

Site Location



Weather ___ Sunny ___ Cloudy ___ Partly Cloudy ___ Raining ___ Foggy

Longitude ________degrees __________minutes __________seconds

Latitude __________degrees __________minutes __________seconds

USGS map used ________________________(include height and width scale)_______________________

Elevation _________________(Meters)

Land Uses ___ Urban ___ Suburban ___ Agricultural ___ Grazing ___ Forest

Channelized ___ Yes ___ No


Upstream ___ No ___ Yes Approx. distance from sampling site____________(Meters)
Downstream ___ No ___ Yes Approx. distance from sampling site ____________(Meters)


Upstream ___ No ___ Yes Approx. distance from sampling site__________(Meters)
Downstream ___ No ___ Yes Approx. distance from sampling site __________(Meters)

Inorganic substrate ___ Boulders ___ Rubble ___ Gravel ___ Sand ___ Silt ___ Clay

Embeddedness _________________(%)

Sediment _________________(%)

Organic substrate ___ Mud/Muck ___ Detritus ___ Logs/Limbs ___ Pulpy Peat ___ Fibrous Peat

Bank Slope ___ Steep ___ Moderate ___ Slight ___ Other ________________________

Bank Stability ___ Stable ___ Slightly Eroded ___ Moderately Eroded ___ Severely Eroded

Bank Material ___ Clay ___ Rock ___ Dirt ___ Mud ___ Stones ___ Other__________________

Bank Vegetation

___ Barren ___ Grasses ___ Herbaceous ___ Brush ___ Deciduous
___ Evergreen ___ Other __________________

Stream Shading _________________(%)

Channel cross-section

___ Rectangular ___ U-Shaped ___ V-shaped ___ W-Shaped ___ Other__________________

Undercut Banks ___ No ___ Yes

Air Temperature _________________(C)

Water Temperature (at site)_________________(C)

Water Temperature (1 mile upstream) _________________(C)

Surface Oils ___ None ___ Some ___ Lots

Water Odors ___ Normal ___ Sewage ___ Petroleum ___ Chemical ___ Other__________

Stream Width (at sampling site) _________________(Meters)

Surface Velocity _________________(Meters/second)

Water Depth _________________(Meters)

Riffle Length _________________(Meters)

Riffle Width _________________(Meters)

Distance between replicates within riffle _________________(Meters)

Additional Notes on this form

Document below any information or observations you made that are not included.

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Contact the SalmonWeb at Saturday, 16-Dec-2000 14:28:23 PST