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Lake Sampling Procedure -- main water body

Tasks:

Environmental samples may support the biotic collections in several ways:

  • Locate (GPS) the deep point, or deep enough point, and do a depth profile with the YSI sonde. Also, obtain secchi and chlorophyll a readings
  • Collect lake-water samples from the epilimnion, hypolimnion, and littoral zone where well--defined
  • Collect a gravity core for:
    surface-sediment diatom assemblage
    surface-sediment lithology and mineralogy
  • a few sub-interface sediment samples, mostly for diatom assemblages
  • Collect enough surface sediment at selected locations at selected sites for:
    ostracode analysis
    chironomid analysis (if only head capsules for later analysis)
    lithologic analysis (LOI and maybe mineralogy)

Procedure:

Preparation and paddle outward:

  • Upon arrival at the site, choose lake (or other site) name and ID number for labeling all samples.
  • Unpack and inflate canoe(s) and/or kayak. Begin with electric pump and finish with foot pump. Assemble paddles and gather other gear (ropes, PFDs, field packs, and sampling equipment). Find rocks or sediment to fill anchor bag, with 100' rope (or 50' or 75' rope...)
  • Prepare sample vials and some stick-on labels, if desired.
  • Paddle outward, taking GPS-located depth readings along the way (or just spot GPS readings). Locate maximum depth if possible, and anchor there (or hold position somehow)

At max depth location:

  • Do a YSI-sonde lake profile of T, SC, DO, and pH. Identify a hypolimnion, if any. Take a secchi reading and a chlorophyll a reading from the top 1-m layer (and maybe deeper layers...)
  • Collect 1-L (or maybe 0.5-L) water samples from the epilimnion (dipped by hand at 30-cm depth) and hypolimnion (if any, with a Kimmerer sampler).
  • Take gravity surface core; use turkey baster to pull off soupy sediment-water interface for diatom assemblage; collect vial (25-mL plastic scint vial) of remaining surface sediment for lithololgy (LOI) and mineralogy; collect a few subsamples at lower depths as available. Vial for LOI will have enough sediment remaining for pollen analysis, should someone want the material.
  • Take Eckman dredge sample of profundal (pelagic) sediment; place in large-mouth plastic 1-L jars for sieving by the ostracode and chironomid teams.

On paddle back to shore:

  • Collect Eckman dredge samples at selected depths during paddle back to shore. Aim for, e.g., 10 m, 5 m, 2 m, and 1 m depths (Mark's choice here). Subsample sediment for:
    -Diatoms
    -Ostracodes?
    -LOI?
    This was only rarely done…
  • Collect near-shore water sample, from middle of emergent zone if present (and possible). Include YSI readings, as usual, for each water sample.

Equipment and supplies:

  • Hip boots, or stocking-foot hip waders, or "wading pants"
  • Inflatable canoes and kayak, with rope bow (or stern) line(s)v
  • Pumps -- electric and foot
  • Paddles, T-handles
  • PFDs
  • Anchor bag and rope
  • Tupperware bins for holding equipment in canoe
  • Dry bags for some gear
  • GPS unit (connected to depth finder?)
  • Depth finder unit (connected to GPS?)
  • YSI sonde with T, SC, DO, and pH probes for sure, and a 30-m cable (or at least a 15-m cable). If possible, add chl a probe, and maybe depth (and maybe GPS...)
  • Secchi disk and depth-marked rope/cable
  • Kimmerer or van Dorn water sampler, depth-marked cord/cable
  • Field sampling bottles -- probably 1 L, but maybe only 500 mL. No smaller than that, I'd say.
  • Label tape and sharpies
  • Stick-on labels
  • Diatom sample vials, ~10 mL
  • Pollen sample vials, ~ 10 mL or less
  • Ostracode sample vials/jars, ~60 mL? -- for Emi and Koen separately?
  • Chironomid sample vials/jars, ~60 mL?
  • LOI vials/jars, ~20-60 mL?
  • Acid dropper bottle, hand lens
  • Gravity corer, either Wegener or mini-Glew, with extrusion equipment and sampling tools (little spatulas, etc.)