Report of a cetacean survey in the Western Approaches of the ...

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During the 2005 survey, the Beaufort sea state averaged 3.48 (n=318, SD 1.51). During transectwatches (T) it averaged 2.75 (n=46, SD 0.53) and during High Effort (S) it averaged 2.54 (n=92, SD0.8). During the 2004 survey, the Beaufort sea state averaged 3.61 (n=522, SD 1.72). However, duringtransect watches it averaged only 1.85 (n=43, SD 0.86) and during High Effort 2.91 (n=55, SD 0.9).The analysis presented here will focus mainly on sightings during transect and high effort surveymodes made within the Survey Area only (e.g. within the box as outlined in Fig 1), unless statedotherwise. We pooled probable sightings and definite sightings but excluded possible sightings fromfurther analysis.Fig. 3. All cetacean sightings made during the expedition, common dolphins (in cyan); bottlenosedolphins (in dark blue), harbour porpoise (in purple), Risso’s dolphins (in red) and fin whale (in green).One dot presents one sighting.12
SpeciesFAST MODENumber of sightings (Individuals)T S T+S2004 2005 2004 2005 2004 2005Common dolphin 50 (356) 79 (403) 50 (284) 52 (237) 100 (640) 131 (640)Harbour porpoise 10 (21) 1 (4) 2 (2) 3 (3) 12 (23) 4 (7)Bottlenose dolphin 1 (2) - 1 (18) 1 (2) 2 (20) 1 (2)Risso’s dolphin 2 (17) - - - 2 (17) -Fin whale - - 1(2) - 1 (2) -Unidentified dolphin 13 (38) 4 (4) 7 (17) 2 (5) 20 (55) 6 (9)Unidentified whale 1 (1) - 1 (1) - 2 (2) -Unidentified cetacean 2 (2) - 3 (4) - 5 (6) -Total 79 (437) 84 (411) 65 (328) 58 (247) 144 (765) 142 (658)SLOW MODENumber of sightings (Individuals)SpeciesTS SLOW TS+SLOW2004 2005 2004 2005 2004 2005Common dolphin 7 (20) - 19 (129) 12 (69) 26 (149) 12 (69)Harbour porpoise - 1 (1) 4 (16) 1 (2) 4 (16) 2 (3)Bottlenose dolphin - - - - - -Fin whale - - - - - -Minke/bottlenose whale - - 1 (1) - 1 (1) -Unidentified dolphin 1 (1) - 5 (5) - 6 (6) -Unidentified whale - - - - - -Unidentified cetacean 1 (2) - - - 1 (2) -Total 9 (23) 1 (1) 29 (151) 13 (71) 38 (174) 14 (72)FISHERIES OBSERVATIONSNumber of sightings (Individuals)ALLNumber of sightings(Individuals)SpeciesFOF+ FOS FISHERIESRELATED2004 2005 2004 2005 2004 2005Common dolphin 30 (346) - 20 (124) 15 (52) 156(1,135)158 (761)Harbour porpoise 10 (15) - 11 (44) 1 (1) 26 (54) 7 (11)Bottlenose dolphin - - - 1 (8) 2 (20) 2 (10)Risso’s dolphin 1 (20) - - - 3 (37)Minke whale 1 (1) - - - 1 (1)Minke-like whale - - 1 (1)Fin - - - - 1 (2)Fin/Sei whale - - 1 (1)Unidentified baleen whale - - 1 (1)Unidentified dolphin 5 (37) - 10 (71) 3 (17) 31 (98) 9 (26)Unidentified whale - - - - 2 (2)Unidentified cetacean - - 4 (7) - 6 (8)Total 47 (419) - 48 (249) 20 (78) 228(1,357)176 (808)Table 3. Summary of sightings made within the survey area during different effort survey modes, withapproximate number of animals in brackets. ‘All’ is the total number of sightings during all surveymodes within the survey area, excluding incidental sightings. NB Fisheries related sightings are allincidental sightings, no sightings were made during either fast or slow dedicated fisheries observationsin 2005.13
Page 1 and 2: Report of a cetacean survey in theW
Page 3 and 4: EXECUTIVE SUMMARYThe Western Approa
Page 5 and 6: INTRODUCTIONLittle is known about t
Page 7 and 8: Two important assumptions of line t
Page 9 and 10: also to report the presence of dolp
Page 11: RESULTSPart 1. Cetacean distributio
Page 15 and 16: Initial sighting cuesDuring fast su
Page 17 and 18: Harbour porpoiseThe harbour porpois
Page 19 and 20: Part 2. Fisheries observationsFishi
Page 21 and 22: On the 23 rd of March, at 08:23, a
Page 23 and 24: Fig 7. Frequency distribution of si
Page 25 and 26: The estimates of abundance generate
Page 27 and 28: Proportion of sightings by perpendi
Page 29 and 30: Proportion of sightings by componen
Page 31 and 32: Fig. 18. Histograms of perpendicula
Page 33 and 34: DISCUSSIONThe estimated corrected d
Page 35 and 36: extrapolated total estimated mortal
Page 37 and 38: Tregenza, N.J.C. and Collet, A. 199
Page 39 and 40: Dolphin 2SPECIES: Common dolphin (D
Page 41 and 42: CETACEAN POSTMORTEM REPORTDolphin 7

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