Sediment Collections
GSI Protocol #04
Published: February 2023
Prepared by: Stephen G. Hesterberg, Ph.D., Executive Director; Betsy Potter, M.S., Staff Scientist
SEDIMENT COLLECTION FOR BENTHIC CHLOROPHYLl
MATERIALS
5 mL cut syringe marked at 2 cm depth
Rubber stopper
15 mL centrifuge tube
1 L amber HDPE bottle or aluminum foil
Permanent waterproof marker and chemical labels
Cooler with ice
INSTRUCTIONS
1. Label the 15 mL centrifuge tube (e.g., MM/DD/YYYY, Site, Replicate).
2. Place colored tape around the syringe barrel 2 cm from the bottom edge.
3. Remove the plunger from the barrel of the pre-cut 5 mL syringe.
4. Push the syringe barrel into the sediment until the surface of the sediment is flush with the bottom of the colored tape, keeping the barrel vertical. Do not tilt the barrel; only twist while pushing the syringe into the sediment.
5. Insert the plunger or an appropriately sized rubber stopper at the top of the syringe barrel.
6. Carefully remove the syringe from the sediment and use your finger or another rubber stopper to cap the bottom of the barrel.
7. At the processing location, open the 15 mL centrifuge tube, remove the rubber stopper, and use the plunger to push the sediment sample into the centrifuge tube. Remove any excess water.
8. Keep on ice and in the dark until the sample can be frozen. Samples can be safely kept in the dark in a dry wide mouth 1 L HDPE Amber bottle or wrapped in foil. Samples should be processed within a year of collection.
SMALL VOLUME SEDIMENT COLLECTION
MATERIALS
60 mL cut syringe marked at a depth of 2 cm
Rubber stopper
Sterile 118 mL (4 oz.) Whirl-PakTM bag
Permanent waterproof marker and chemical labels
Cooler with ice
INSTRUCTIONS
1. Label the 118 mL (4 oz.) Whirl-PakTM (e.g., MM/DD/YYYY, Site, Replicate).
2. Place colored tape around the syringe barrel 2 cm from the bottom edge.
3. Remove the plunger from the barrel of the pre-cut 60 mL syringe.
4. Push the syringe barrel into the sediment until the surface of the sediment is flush with the bottom of the colored tape, keeping the barrel vertical. Do not tilt the barrel; only twist while pushing the syringe into the sediment.
5. Insert the plunger or an appropriately sized rubber stopper at the top of the syringe barrel.
6. Carefully remove the syringe from the sediment and use your hand or another rubber stopper to cap the bottom of the barrel.
7. At the processing location, open the sterile, 118 mL Whirl-PakTM bag, remove the rubber stopper(s), drain excess water, place the sediment sample into Whirl-PakTM, and close.
8. Keep on ice until the sample can be frozen. Samples should be processed within a year of collection.
LARGE VOLUME SEDIMENT COLLECTION
MATERIALS
Coring tube (e.g., aluminum, PVC)
Hammer
OateyTM plastic mechanical test plug
Plastic endcaps (×2)
Permanent waterproof marker
Dive slate and pencil
Plastic folding meter stick
INSTRUCTIONS
1. Label the coring tube with a unique identifier (e.g., MM/DD/YYY, Site, Replicate) and mark the maximum depth the tube should be inserted into the sediment.
2. Insert the coring tube into the sediment as deep as possible by hand.
3. If necessary, hammer the remainder of the coring tube into the sediment to the maximum depth mark.
4. Measure and record the distance from the top of the coring tube to the sediment surface inside and outside the coring tube to account for any sediment compaction.
5. Insert the OateyTM test plug and tighten the wing nut.
6. Extract the coring tube from the sediment and immediately place the plastic endcap on the bottom.
7. At the processing location, remove the OateyTM test Plug and replace it with another plastic endcap.
8. Keep core samples in the shade until they can be frozen. Samples should be processed within a year of collection.
REFERENCES
Protocols adapted from Dr. Ashley Smyth, Department of Soil and Water Sciences, Tropical Research and Education Center, University of Florida.