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Grab Sampling and Analysis

A description of how the pockmarks were sampled and the results of the species identification.

Fig. 8

Figure 8. Grab Sampling Analysis

Sampling was undertaken from the CCGS Pandalaus III with Captain Wayne Miner and crew/winchman Danny Loveless. All grab samples taken were precisely positioned by use of GAPS, a grab acoustic positioning system (McKeown et al, 2007).  The coordinates of all grab samples can be found in the accompanying table “Grab Sample Positions” [ Grab Sample Positions Table].

Each grab sample was sieved on deck through a 5mm and 1mm square mesh sieve and the contents stored in an individual pail with 5 – 10% formalin in seawater. Each pail was closed with an airtight lid and stored in a warm storage building until analysis.

Samples were transferred to 70% isopropanol and stained with eosin for initial identification to the lowest possible taxon at the Atlantic Reference Centre, Huntsman Marine Science Centre, by Mary Greenlaw. Gerhard Pohle and other experts he consulted checked final identifications.

Macrofauna Species/Samples Abundance Matrix

Species by abundance matrices are summarized in the table “Species vs Abundance Matrix” [ Species vs Abundance Table ]. All species identified during the three years of sampling are listed in the first column. “Field Book #” which corresponds to the second column of the table “Grab Sample Positions” labels each of the columns to the right of this species list. We took three replicate grab samples at the each location, so that each “Field Book #” had three replicates, labeled A, B and C. To find which grab samples correspond to which pockmarks consult the table “Grab Sample Positions”.

One grab sample, 12A, was inexplicably lost during analysis. Two sample sets, #35 and #36, each consisting of 3 pail samples, were not analyzed because of resource limitations but are still stored at the St. Andrews Biological Station.

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