Table 3.
Harbour porpoise abundance and density estimates, using g(0) = 0.364 [15], in the different sectors in Portugal during the study period. Survey effort (number of transects and length, in km), no. of harbour porpoise sightings and individuals, and expected group size. Coefficient of variation (CV, %) and confidence interval (CI) were estimated considering the 5-year sampling period.
| Survey Sector | Transects | Distance (km) |
Sightings | Individuals | Expected Group Size (CV) |
Density (ind/km2) (95% CI) |
Abundance (95% CI) |
CV |
|---|---|---|---|---|---|---|---|---|
| g(0) = 0.364 | ||||||||
| North | 58 | 6710.99 | 27 | 34 | 1.26 (7.44) | 0.140 (0.061–0.318) |
935 (409–2139) |
43.42 |
| Centre | 56 | 9145.15 | 17 | 26 | 1.52 (8.16) | 0.110 (0.051–0.237) |
1010 (470–2168) |
39.75 |
| Alentejo | 32 | 3424.86 | 4 | 5 | 1.14 (23.10) | 0.033 (0.012–0.092) |
113 (40–315) |
53.90 |
| Algarve | 49 | 5771.52 | 8 | 17 | 1.90 (24.79) | 0.071 (0.026–0.197) |
412 (150–1136) |
55.99 |