Table 2.
Number (N), relative frequency (%N) and frequency of occurrence (F.O.%) of each microplastic category for the analysed cetaceans (n = 38). The mean and median numbers of microplastics per individual are also presented. SD, standard deviation. IQR, interquartile range.
| Species | Type | N (%N) | F.O.% | Mean (±SD) | Median (IQR) | Range |
|---|---|---|---|---|---|---|
| D. delphis | Fibres | 100 (84.75) | 79.17 | 4.17 ± 5.75 | 2.5 (1.0–5.5) | 0–27 |
| Fragments | 10 (8.47) | 20.83 | 0.42 ± 1.02 | 0 (0) | 0–4 | |
| Films | 7 (5.93) | 20.83 | 0.29 ± 0.62 | 0 (0) | 0–2 | |
| Fibre clusters | 1 (0.85) | 4.17 | - | - | 0–1 | |
| Total | 118 (100) | 87.50 | 4.92 ± 5.76 | 3 (1.75–6.25) | 0–27 | |
| P. phocoena | Fibres | 66 (80.49) | 100 | 8.25 ± 6.27 | 5 (3.75–14.50) | 2–17 |
| Fragments | 11 (13.41) | 25.00 | 1.38 ± 2.88 | 0 (0–0.75) | 0–8 | |
| Films | 5 (6.10) | 25.00 | 0.63 ± 1.19 | 0 (0–0.50) | 0–3 | |
| Fibre clusters | 0 | 0 | - | - | - | |
| Total | 82 (100) | 100 | 10.25 ± 7.21 | 9 (4.0–14.75) | 3–22 | |
| S. coeruleoalba | Fibres | 29 (53.70) | 100 | 4.83 ± 4.49 | 3 (2.25–6.00) | 1–13 |
| Fragments | 23 (42.59) | 83.33 | 3.83 ± 6.97 | 1 (1–1.75) | 0–18 | |
| Films | 2 (3.70) | 16.67 | 0.33 ± 0.82 | 0 (0) | 0–2 | |
| Fibre clusters | 0 | 0 | - | - | - | |
| Total | 54 (100) | 100 | 9.00 ± 6.96 | 6.5 (5.0–11.75) | 2–21 | |
| All individuals | Fibres | 195 (76.77) | 86.84 | 5.13 ± 5.79 | 3 (1.0–7.0) | 0–27 |
| Fragments | 44 (17.32) | 31.58 | 1.16 ± 3.21 | 0 (0–1) | 0–18 | |
| Films | 14 (5.51) | 21.05 | 0.37 ± 0.79 | 0 (0) | 0–3 | |
| Fibre clusters | 1 (0.39) | 2.63 | - | - | - | |
| Total | 254 (100) | 92.11 | 6.68 ± 6.53 | 4.5 (2.25–9.50) | 0–27 |