A recovery of harbour porpoises (Phocoena phocoena) in the southern North Sea? A case study off Eastern Frisia, Germany

Table 3 Densities of harbour porpoises in the study area 2003/2004

Date	Altitude (m)	g(0)	esw (m)	Density (Ind./km²)	Density CV	Area size (km²)	N ±SE
02/17/03	183	0.24	169	0.85	0.19	1.438	1,232 (239)
05/07/03	183	0.24	169	0.39	0.25	1.438	569 (145)
06/07/03	183	0.24	169	0.52	0.28	1.438	762 (213)
07/10/03	183	0.24	169	1.00	0.28	1.438	1,449 (409)
02/16/04	183	0.24	169	0.79	0.18	2.588	2,058 (387)
02/16/04	76	0.36	106	0.75	0.17	2.588	1,937 (332)
03/03/04	76	0.36	106	1.26	0.28	2.588	3,274 (943)
03/18/04	76	0.36	106	0.63	0.27	2.588	1,636 (450)
04/14/04	76	0.36	106	1.15	0.20	2.588	3,000 (625)
05/03/04	183	0.24	169	1.62	0.27	2.588	4,211 (1,158)
05/28/04	76	0.36	106	0.48	0.28	2.588	1,265 (357)
07/21/04	76	0.36	106	0.38	0.36	2.588	999 (362)
07/22/04	183	0.24	169	0.57	0.27	2.588	1,483 (409)

g(0) Probability of detection at distance 0 from the transect-line, esw effective strip half-width, CV coefficient of variation, N estimated number of animals present in the study area, ±SE standard error

ISSN: 1438-3888