Table 2.
Application of analysis workflow to fish gastrointestinal tract contents20.
| Step | Process | Number of items | Reason for change in numbers | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Affected by processing step | Taken to next processing step | ||||||||
| Total | Fibres | Particles | Total | Fibres | Particles | %b | |||
| 1 | Visual separation | — | — | — | 200 | 164 | 36 | — | — |
| 2 | Measurement and photography | 0 | 0 | 0 | 200 | 164 | 36 | 100 | — |
| 3 | Chemical characterisation | 11 (−5, −6) | 8 | 3 | 189 | 156 | 33 | 95 | missing, too small for ATR-FTIR; removed |
| 4 | Library interpretation of spectra | 12 | 8 | 4 | 177 | 148 | 29 | 89 | <60% match removed |
| 5 | Visual inspection of spectra | 5 | 3 | 2 | 172 | 145 | 27 | 86 | between 60 and <70% match, and very poor visual match; removed |
| 6 | Contamination check | 71 | 68 | 3 | — | — | — | — | ≥90% match to contaminant library |
| 7 | Visual inspection of photographs | 19 | 19 | 0 | 153 | 126 | 27 | 77 | visual match to contaminant; removed |
| 8 | Chemical type assignment | 38 | 14 | 24 | 115 | 112 | 3 | 58 | natural origin could not be excluded; removed |
| Number of marine microdebris items | 115 | 112 | 3 | 58 | |||||
The workflow is tailored to quantifying microdebris contamination, and applied to the gastrointestinal tract contents of 20 similarly-sized juvenile coral trout (Plectropomus leopardus and P. maculatus) collected on reefs around four reef islands in the Great Barrier Reef World Heritage Area, Australia, in 2011. The number of items affected by and taken to the next processing step of the analysis workflow, and the reason for a reduction in numbers is given; bpercentage based on total items separated using visual examination (n = 200).