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SOP: Salt Marsh Coring

Materials (* not necessarily necessary; bold for safety):

  • 409 (to spray on boots to prevent spread of invasives)

    • Stakes with flagging* (to mark the entrance to the marsh or wayfinding)

    • Phone with GPS or handheld GPS

    • Small knife

    • Beveled core tubes (1.5-m or 3-m long, 10-cm diameter)

    • 2 blue core ‘heads’ (‘The Donald’)

    • Sledgehammer

    • Orchard ladder and small ladder board* (only for 3-m long cores)

    • Plywood boards (1 for vegetated marsh, 2 for mudflats)

    • Sawhorses* (2)

    • Earplugs

    • Measuring tape

    • Test plugs (1 for each cores)

    • Pipe clamp with large shackles (+ extra shackles)

    • Socket wrench (same size as bolts on pipe clamp)

    • Truck jack, handle, and noodle (for carrying)

    • Silicon spray

    • Rags

    • Metal spatula and metal tray

    • Red core caps (1 for each short core, 2 for each long core)

    • Blue core caps (1 for each short core, 2 for each long core)

    • Gorilla tape or electrical tape

    • Large sharpie(s)

    • Toolbox with extra tools (screwdrivers, extra shackles, extra tape, extra sharpies, etc.)

    • Pipe cutters (2)

    • Strap wrenches (2)

    • Lots of cord and bungees for securing to stake truck, more flagging

Paperwork:

  • Permit

  • Maps of core locations

  • List of previous GPS coordinates

  • Tide table

Personal Marsh Gear:

  • First aid kit

  • External charger for phone (GPS purposes)

  • Muck boots (2 pairs of socks)

  • Hat, sunglasses, sunscreen, sun shirt

  • Water

  • Notebook and pen

  • Work gloves

Salt Marsh Coring SOP:

  1. Before entering the marsh, everyone should spray their boots with 409 to prevent the spread of invasive species.

  2. Once you’ve chosen a location, push aside tall vegetation and cut dense surface vegetation away with the small knife. You shouldn’t be disturbing the sediment or below ground root systems. Line up the beveled side of the core barrel with the exposed sediment.

  3. Make sure everyone has ear protection in at this point!

  4. If collecting a 3-m long core, you’ll need to place the orchard ladder to the side of the core. Depending on how hummocky the ground is, you may need to place the small wooden ladder board under the extended leg of the ladder. Have someone hold the ladder steady at its widest base while someone is hammering.

  5. Place the blue plastic “The Donald” on the top of the core barrel and begin tapping it down with the sledge hammer. You should have someone else hold the core barrel to keep it stable. Before the core barrel has been pounded in a few cm, have people standing around make sure that the core barrel is straight. Continue to have someone hold the barrel for the first ~50 cm to reduce reverberation and shaking of the core following each hammering.

  6. Pound the core in until only ~ 40 cm is exposed.

  7. Measure and record the height between the top of the core barrel and sediment surface on both the inside and outside of the barrel. The difference is the amount of compaction.

  8. Place a yellow test plug inside the barrel as close to the sediment surface as possible. Once within the barrel, tighten the test plug using the notched end of the sledge hammer. If the test plug is spinning, you might have to remove and expand it. Tighten the plug until it is snug, but be careful to not tighten it till the wingnut breaks. If it breaks, it will still work but will be unusable in the future.

  9. Clean the outside of the barrel with a rag until the core is clean and dry. Fit the metal pipe clamp onto the barrel and tighten the two bolts using the socket wrench. If the socket wrench is sticking, grease it using the silicon spray. You can use this on the clamp if it sticks as well but make sure not to get it on the rubber inside of the clamp!!

  10. Place the plywood board next to the core with the rope handle positioned on the furthest side from the core. Place the truck jack onto the board lined up with the bolts on the pipe clamp. Attach the shackle on the clamp to the shackle on the truck jack. Make sure the lever is engaged on the side of the jack.

  11. Jack the core up as much as possible. As you jack up the core, the jack will want to tilt forward so one or two people should push back on the steel bar frame of the jack (watch out for hands getting pinched by the jack as it climbs up the pins!!). Also be careful that the tongue on the runner doesn’t get pressed into the PVC pipe, deforming it and possibly causing a crack. If the jack sticks, you can also spray silicon spray into the jack runner.

  12. Once you cannot lift the core anymore with the jack, remove the handle so it does not fling out and hit someone. Anytime you take your hand off the handle of the jack, you should remove the handle!

  13. Disengage the lever on the side of the jack. Using the socket wrench, loosen the bolts on the pipe clamp. Use a rag to clean the newly exposed core barrel. This is important so the pipe clamp does not slide while you jack up the core. Watch your fingers as you work near the jack – do not get them caught under the runner on the jack! At this point you need to lower both the runner on the jack and the pipe clamp keeping them shackled together (if this doesn’t seem to work then just unshackle them and reposition everything). Because the jack has been wedging itself against the ground, you can make this step much easier by first pulling out the wooden board under the jack, causing the jack to fall forward and release tension. Now you can slide the clamp and jack runner down while sliding the board back under the jack, and repositioning the jack upright and near the core.

  14. Tighten the bolts on the clamp, reengage the lever, and keep jacking up the core as before.

  15. Once the core is almost to the surface and can be lifted out by hand, have someone (who is strong) slide a metal rod, long screwdriver, or the end of the socket wrench through the shackle attached to the pipe clamp. While this person (maybe use two people) holds the core up, another person should disengage the lever of the truck jack and unshackle the bolt attached to the jack. Don’t lose the shackle! Have someone ready with a red endcap placed on the plywood ready for the bottom end of the core. Once the core is detached from the jack, the core should be lifted out of the ground and placed into the red endcap as quickly as possible. Use the gorilla tape to secure the endcap.

  16. If placing the core into the red endcap proves too challenging, you may lift the core so it is parallel with the ground, all the while having someone hold a metal spatula or tray against the end of the exposed core so as to not lose any sediment. Quickly remove the metal spatula and place the red endcap on the bottom of the core. Use the gorilla tape to secure the endcap.

  17. While two people hold the core up and parallel to the ground, use the socket wrench to loosen the core clamp and slide the clamp off of the top of the core.

  18. Place the blue end cap on the top of the core and tape it on using gorilla tape.

  19. Label the core clearly using a large sharpie and draw an arrow pointing toward the top of the core.

  20. If you’ve collected 3-m long cores, you will have to cut them in half to transport them. Once out of the marsh, lay the core parallel with the ground, using either the truck bed, ladder, sawhorses, picnic table, etc. to support either side. Use the pipe cutter to cut the core into two 1.5-m long sections. Once the PVC is cut, use a metal spatula to cut the sediment and cap both ends with the blue (top) and red (bottom) end caps.

Labeling:

When storing the cores at the OSU MGR, the cores should be labeled with two letters to abbreviate the salt marsh (e.g., NT for Netarts), the abbreviated state (e.g., OR for Oregon), the year and month abbreviated to 4 numbers (e.g., 1806), underscore, the number of the core you’ve collected that month (e.g., 01 for the first), PU to designate push core, underscore, and the section number (i.e., 1 for the top section, 2 for the second section, and so on). Thus, your first core is NTOR1806_01PU and when you section it, these should be labeled NTOR1806_01PU_1, etc.