Laura González1,2, Clara Sardà1 & Miranda van der Linde1
1 Futurismo Azores Whale Watching, Ponta Delgada, São Miguel, Azores.
2 Department of Applied Physics, Vigo University, Vigo, Spain.
North Atlantic blue whales (Balaenoptera musculus)
are seen in tropical and warm temperate latitudes
during winter months, and further north in summer 1. In
the Azores they have been seen mainly during the spring
The aim of this study is to determine the temporal
distribution of blue whales off São Miguel (Azores) and to
photographically-identify individuals registered between
2006 and 2012.
We have analysed blue whale sighting data registered
between 2006 and 2012 off the south coast of São Miguel
(Azores), during commercial whale watching (WW) tours
with Futurismo Azores Whale Watching. From 2009
onwards, records are more continuous and more
complete than in previous years. Animals were spotted
from land and from WW vessels by specialised observers.
Photos were also taken during this period, and those of
sufficient quality to distinguish natural marks and the
shape of the dorsal region, were used for identification
• 45 blue whales, have been identified, 20 from both sides.
- 8 whales were resighted, but only on consecutive days
(maximum interval of 5 days).
•77 sightings were registered on 62 different days
between 2006 and 2012, most of them in the last three
years (Table 1).
•Blue whales pass the Azores every year, mainly between
March and May (92.3%) (Table 1, Fig.2).
Fig.1. Examples of identified whales: shapes, colour patches, unique marks.
The next step along this line of research would be to analyse
patterns in temporal distribution in relation to Chlorophyll A
measures and sea surface temperature, and to link these factors
with upwelling events and phytoplankton blooms.
In the framework of this photo-ID project we propose a
comparison analysis with other catalogues in the Atlantic Ocean,
especially with the eastern population one, in order to learn more
about the blue whale migration.
We would like to thank the Futurismo Azores
Whale Watching team, biologists and guides who have collected data for this
study, and especially, to thank the skippers and lookouts who have worked with
1) Reeves, R.R.; Smith, T.D.; Josephson, E.A.; Clapham, P.J. & Woolmer, G.
(2004). Historical observations of humpback whales and blue whales in the North Atlantic Ocean:
clues to migratory routes and possibly additional feeding grounds. Marine Mammal Science 20(4):
774-786. 2) Visser, F.; Hartman, K.L.; Pierce, G.J.; Valavanis, V.D. & Huisman, J. (2011). Timing of
migratory baleen whales at the Azores in relation to the North Atlantic spring bloom. Mar. Ecol.
Prog. Ser. 440:267-279.
Table 1. Monthly and annual % of blue whale sightings.
Fig. 2. Temporal distribution of Balaenoptera musculus off São Miguel (2006-2012).