Simple Plankton Nets
Closing Plankton Nets
Bongo Plankton Nets
Multi-Net (Tucker) Trawl
Student Plankton Nets
Stream Sampling Nets
Horizontal Water Samplers
Vertical Water Samplers
Student Water Samplers
Limnology Field Kits
Universal Percussion Corer
Russian Peat Borer
Piston Interface Corer
Large Bore Sediment Sampler
Extension Rods and Percussion
Core Extruding Apparatus
Discrete Point Piston Corer
Haney Grazing Chambers
Limnocorrals, Microcosms, Enclosures
Utermoehl (Phytoplankton) Sedimentation Chambers
Folsom Plankton Sample Splitter
Motoda Plankton Sample Splitter
Zooplankton Counting Trays
Piston Interface Corer
- Paleoecological analysis
- Lightweight piston sampler for soft lake deposits
- Long (2.0m long/drive), undisturbed cores of sediment- water interface from shallow lakes
- Ideal sampler for gyttja, clay, and fine sand sediments
Literature available on piston coring lake sediments for paleoecological analysis is extensive (see review by Blomqvist 1991). The corer shown here is a simplified composite of proven samplers described in the literature cited below.
ICELANDIC PISTON CORER
- Collects best quality core samples
- Piston sampler can be deployed on Aluminum Holobar Extension Rods (to max depth of 25 meters) or in deep lake with Cable Deployed Percussion hammer Assembly (see both options below)
- 68 mmid x 71 mmod aluminum and stainless steel construction
- Bolt on barrel attachment method
- Drives clear polycarbonate core barrel x (2 5/8" (68mm) x 2 3/4" (71mm)
- 10 m piston wire w/ attachment hardware
- Three (3) adjustable piston assemblies w/ "o" rings
- Ready to deploy
- Complete Unit $695 each
ALUMINUM HOLOBAR EXTENSION RODS
- 40 mm diameter aircraft aluminum holobar construction
- 7/8”- 9NC stainless steel threaded couplers, wrench flats (to aid uncoupling), lightweight, rigid and buoyant
- Available in two (2) lengths: 1.2 ($105) and 2.4 m ($140)
POLYCARBONATE CORE BARRELS
- Proven to produce the best quality samples with minimum amount of sample loss, 2 5/8” (68mmid) x 2 3/4” (71mmod) thin walled barrels with chamfered (sharpened) ends, poly end caps, core extruding plugs (optional $14 each).
- Available in standard lengths of: 60 cm ($35) 1.2 m ($55) and 2.4 m ($98).
DEEP WATER CABLE DEPLOYED SLIDE-HAMMER ASSEMBLY
- For Icelandic piston corer in deep lakes (greater than 25 meters)
- Piston wire travels “dead center” through stainless steel tube (100 cm long) that supports gravity weight and slide hammer assembly and attaches to adjustable piston assembly at distal end of wire.
- Sampler is lowered by a two (2) point bridle on slide hammer assembly while piston wire remains slack during deployment.
- Once mud water interface is reached; secure piston wire to decking to prevent downward movement of piston; release lowering line to allow gravity to begin coring action.
- Raise and drop slide hammer assembly to drive core barrel to desired stratum.
- Retrieve sampler to surface by hauling upward on both lowering line and piston cable
- 90 cm long x 8 kg SS tubing (piston cable runs (plumb) through tubing)
- One (1) each bronze gravity weight
- One (1) each bronze slide hammer assembly w/ 2-pt bridle (to lower sampler)
- Complete Unit $525 each
Some of these features include:
- polycarbonate core tubes
- (7.5 cm I.D., 3 mm wall; max 2.0m long)
- clear, unbreakable, non-metal sample containment
- 1.0 cm scribe marks, chamferred edges
- piston assembly;
- double, integral "O"-rings
- built-in vacuum breaker that allows the piston to be withdrawn from the core tube with minimal sediment disturbance and therefore enabling transportation of intact cores
- drive/extrusion rod
- designed to incrementally expell sediments (see Core Extruding Apparatus) and adjust the piston assembly tension at any point in the tube
- this feature allows cores to be extruded from the "top- down" or "bottom up" since the core head can be removed and attached to either side of core tube
- internal piston rod
- (not shown; see Cushing and Wright, 1965)
- deep (>2.0m), consecutive cores may be collected with use of an internal rod which slides through the the drive rods from the surface to the piston assembly
- this rod assures the piston remains at the bottom of the core tube until the sampling depth is reached
- rinse polycarbonate core tube and piston assembly with water
- loosen piston assembly and insert in core tube with cable attached
- slide core tube on to core head and tighten hose clamps on "no-hub coupler"
- use drive/extrusion rod to push piston assembly to the lower end of core tube and tighten piston assembly (tight enough to be difficult to move by hand) in core tube with the key on end of extrusion rod
- retract drive/extrusion rod and secure in place with retainer pin
- determine the depth of water and couple the necessary extension rods together
- lower the corer to just above the sediment-water interface with slack in the wire. (Figure 1, A)
- tie the piston wire to the coring platform.
- drivers should place their hands at various levels along the drive rod so that the push can be steady for a full meter without pause
- (note: a pause during a drive may prevent furthur recovery since internal core friction may cause plug formation and core compaction)
- if driving becomes difficult, it may be nessasry to use pipe wrenches or cross beams to provide mechanical advantages (Figure 1, B)
- pull the corer from the sediments while maintaining tension on the piston cable (if cable slips, part of the core may be lost) (Figure 1, C)
- cap the bottom of the core tube with polyethylene caps (or bottom piston when extruding from the "bottom-up") until the extrusion process begins.
Fisher, M.M., M. Brenner, K.E. Reddy., 1992. A simple, inexpensive piston corer for collecting undisturbed sediment/water interface profiles., Journal of Paleolimnology, 7:157-161. Wright, H.E., 1991. Coring tips., Journal of Paleolimnology, 6:37-49. Blomqvist, S., 1991. Quantitative sampling of soft bottom sediments: problems and solutions., Mar. Ecol. Prog. Ser., 72: 295-304. Wright, H.E., 1980. Cores of soft lake sediments., Boreas, 9:107-114. Wright, H.E., 1967. A square drive piston sampler for lake sediments., J. Sedim. Petrol., 37:975-976. Cushing, E.J. and W.E. Wright., 1965. Hand operated piston corers for lake sediments., Ecology, 46:3:380-384.
PISTON SEDIMENT SAMPLER
- Polyethylene, polycarbonate and stainless steel construction
- 10 m piston cable
- adjustable piston assembly
- 1.5m built-in extension/extruding rod w/key
- rubber coupler sleeve
- one-ea. Thin-walled clear polycarbonate core barrel (68 mm x 71 mm x 120 cm)
- core extruding plug
- poly end caps
- carry case
- 2-ea aluminum holobar extension rods w/ stainless steel couplers (40mm diam. x 2.4m)
- complete: $850.00
- Clear polycarbonate core barrel with poly end caps: 68 mm x 71 mm x 240 cm: $90
- Clear polycarbonate core barrel with poly end caps: 68 mm x 71 mm x 120 cm: $45
- Aluminum holobar extension rod w/ stainless steel couplers (40mm diam. x 2.4m): $130
- Aluminum Holobar extension rod w/ stainless steel couplers (40mm diam. x 1.2m): $80
Notes: The piston assembly and thin wall core barrels collect, high quality, uncompressed samples. Upon retrieval, one must plug the bottom of the core tube before breaking the air-water interface (with core extruding plug or poly end cap) to prevent loss of sample.
Clear polycarbonate core barrel material readily available at most plastic distributors. Core extruding plugs allow one to incrementally extrude sediments upward with aid of a Core Extruding Apparatus. Core barrels can easily be drilled/plugged (for pore water extraction), serrated, cut and split to meet the special needs of the investigation.