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

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

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
  1. 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