PLANKTON NETS

WATER SAMPLERS

SEDIMENT CORERS

PLANKTON SAMPLERS

LABORATORY EQUIPMENT

Gravity Corer

• Paleoecological analysis
• Deep water sediments
• Benthic community analysis

Gravity Corer Unit Includes:

• core head with release mechanism
  • Delrin® and stainless steel construction
  • rubberball is held in the open or "free-flushing" position by a release pin during penetration thus preventing
    frontal wave disturbance of sediments
• bronze messenger
  • 300 gm
  • actuates release of ball (under tension from a latex band) and sealing of core head
  • vaccuum seal retaines
    sediments in core tube during retrieval
• ballast
  • plastic coated carbon steel weights (10 kg) slip tightly over core head to provide easy adjustment of corer weight.
• polycarbonate core tube
  • 7.5 cm I.D., 1.6mm or 3 mm wall thickness x 125 cm length
  • virtually unbreakable
  • chamfered cutting edge
  • 1.0 cm scribe marks
  • polyethylene tube caps for safe transportation of intact cores

Slide-Hammer Corer

Unit Includes:

• core tube: same as described above for Gravity Corers
• slide-hammer assembly
• aluminum, bronze, and stainless steel construction
• bronze hammer slides freely on a stainless steel rod (2.5 cm diam., 75 cm length)
• weight can be hoisted upwards and dropped to force corer through harder substrates
• corer head: same as described above for Gravity Corers.

Options:

• custom core tube diameters and lengths
• additional ballast
• core extruding apparatus
• custom modifications

Citations:

Blomqvist, S., 1991. Quantitative sampling of soft bottom sediments: problems and solutions. Mar. Ecol. Prog. Ser., 72:295-304. Aaby, B., Digerfeldt, G. 1986. Sampling techniques for lakes and bogs. In: Berglund, B.E. (ed.) Handbook of Holocen Paleoecology and Paleohydrology. John Wiley & Sons, Chichester, pp. 181-194. Downing, J.A. 1984. Sampling the benthos in standing waters. In: Downing, J.A., Rigler, F.H. (eds) A Manual on Methods for the Assesment of Secondary Production in Fresh Waters, 2nd edn. IBP handbook No.17. Blackwell Scientific Publications, Oxford, pp. 87-130.

GRAVITY CORER

• Polyethylene, polycarbonate and stainless steel construction
• rubber ball-type core retainer w/ latex band
• simple-all angle-release mechanism, solid bronze messenger (400 gm)
• 10m x 10mm diam. polyester lowering line, linereel
• three bronze gravity weights (4 kg ea, five ea. max. capacity) $90 each
• one-ea. thin-walled-clear polycarbonate core barrel (68 mm x 71 mm x 60 cm)
• core extruding plug
• poly end caps
• spares
• toolbox carry case
• hexdriver
• complete: $700.00

• Clear polycarbonate core barrel with poly end caps: 68 mm x 71 mm x 60 cm: $25
• Clear polycarbonate core barrel with poly end caps: 68 mm x 71 mm x 120 cm: $50

Notes: Sample disturbance and compression are minimized by the thin-walled, free flushing core barrels. Ball-type seal held in the open position during deployment, which ensures good flushing. Sediments are retained in the core barrel by a vacuum created by an excellent ball seal, not core-catchers.

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.