Records of harbour porpoise (Phocoena phocoena) in the mouth of the Douro River (northern Portugal) with presence of an anomalous white individual

Table 1 Survey effort and sightings of harbour porpoises (Phocoena phocoena) in the mouth of the Douro River

2017 Month	Number of surveys	Total hours of observation	Total Sightings	Total SPUE	Group Size (min-max; mean ± sd)	Number of sightings with AWI
July	13	36.58	06	0.46	2–3; 2.33 ± 0.52	06
August	02	5.98	00	0.00	–	00
September	05	15.88	04	0.80	1–3; 1.75 ± 0.96	03
October	06	32.43	12	2.00	1–3; 2.08 ± 1.00	04
Total	26	90.87	22	0.85	1–3; 2.09 ± 0.87	13

The table summarises total and monthly data for the surveys between July and October 2017. The measure of sightings per unit of effort (SPUE) is calculated as the total number of sightings per number of surveys; group size is presented with minimum (min), maximum (max), mean and standard deviation (sd) values; and the number of sightings with the presence of the anomalous white individual (AWI) is also compiled

ISSN: 1755-2672