General procedures for grab sampling

1. Determine the positon of the station using a compass.
2. Record the ambient parameters, location, date, time, depth, gear(type of grab used), replicate number and other data on a data sheet or field notebook.
3. Take 5 replicate sample at each station.
4. Set up a series of sieves of 5mm, 2mm, 1mm and 0.5mm mesh sizes.
5. Place the hopper on its base with the spout positioned above the sieves.
6. Lower the grab vertically, at low steady speed, to the seafloor from a stationary boat. Additional weight may have to be added to the grab when the water currents are strong and when penetration of the sediment is difficult.
7. Contact with the seabed triggers the buckets to close.
8. After the grab is triggered, slowly pull it up onto the deck of the boat.
9. Once on the deck, place the sample on the hopper and hose down gently with running seawater.
10. The run-off or tailings are directed through the series of sieves.
11. Large organisms can be removed during the washing process and placed directly in properly labelled wide-mouthed plastic preservation containers.
12. Preserve the polychaetes in 10% buffered formalin.
13. Label the samples according to the station, position, grab number, time and date. Further information such as tidal and weather conditions should be noted. The waterproof label should be placed inside the container and distinguishing details can be marked on the exterior of the container of the container for quick identification.
14. All sieved material are kept in this condition until it is sorted out in the laboratory where the specimens can be identified using taxanomic keys.

Laboratory sorting

1. The samples collected are rinsed with water first to facilitate sorting. Pour formalin through the 0.5mm sieve to prevent possible loss of specimens, then rinse the sample with freshwater before pouring out into large white sorting trays.
2. Put a subsample from the tray into the petri dish for examination up to family level under a low-powered stereo dissecting microscope. The polychaetes specimens are sorted directly into parallel sided 50mm x 12mm flat bottom glass vials containing 70% alcohol.
3. To this is added a label(size about 35mm x 8mm) with the sample identification code and the name of the taxon.
4. After all samples have been sorted to family level, the vials for each family are grouped together to enable further identification to another level.

Note : Each person involved in the identification of polychaetes require the following tools:

• stereo dissecting microscope (magnification of 100x)
• compound microscope (magnification of 1000x)
• a focusable high intensity lamp for use with the stereo microscope
• two pairs of forceps
• two mounted needles
• a small scapel
• small petri dishes
• a fine drafting pen (Rotring 0.35-0.4 mm)
• immersion oil
• a small bottle containing half glycerol and half 70% alcohol
• flat slides and cover slips
• water to ensure specimens are completely submerged during examination.