Table 3.
Concentrations of metals in Gull eggs by year
| Herring Gull | 2012 | 2013 | χ2 |
| Number | 49 | 50 | |
| Arsenic | 57.4 ± 13.4 | 49.7 ± 7.3 | 0.7 (NS) |
| Cadmium | 5.3 ± 0.7 | 0.5 ± 0.1 | 44.1 (<0.0001) |
| Chromium | 85.2 ± 12.8 | 16.4 ± 3.7 | 47.9 (<0.0001) |
| Lead | 138 ± 43.8 | 244 ± 34.0 | 17.6 (<0.0001) |
| Mercury | 706 ± 83.5 | 229 ± 35.8 | 32.8 (<0.0001) |
| Selenium | 1822 ± 63.0 | 1323 ± 49.1 | 30.2 (<0.0001) |
| Great Black backed gull |
2012 | 2013 | χ2 |
| Number | 11 | 14 | |
| Arsenic | 159 ± 42.8 | 98.2 ± 17.6 | 1.5 (NS) |
| Cadmium | 4.51 ± 1.7 | 3.16 ± 1.1 | 0.9 (NS) |
| Chromium | 55.3 ± 16.0 | 96.3 ± 27.7 | 1.0 (NS) |
| Lead | 62.7 ± 22.5 | 260 ± 55.6 | 10.3 (0.001) |
| Mercury | 1049 ± 172 | 504 ± 66.2 | 10.1 (0.002) |
| Selenium | 2164 ± 112 | 1864 ± 66.8 | 3.7 (0.05) |
Given are mean ± SE. Comparisons are made with Kruskal–Wallis one-way analysis of variance, yielding a χ2 statistic
All values are in ng/g (ppb dry weight.)
NS not significant