Baleen whale faeces in the Azores

Abstract

Cetacean faecal samples have been used to study diet, steroid hormones, exposure to parasites and biotoxins, individual genetic identification and assessment of microplastic ingestion in whales and dolphins. Baleen whale faecal samples are not usually easy to collect. However, as in the Azores whale watching platforms spend long time on the water and run trips year-round, they provide great opportunities to collect these samples. We review the baleen whale faeces records registered from whale watching platforms around São Miguel (Azores) between 2012 and 2018. During the seven years of the study, there have been registered 48 baleen whale faecal records, all of them between March and July. Of them, 77% were of fin whales, 17% of blue whales and only 6% of sei whales. These data support the Azores as a potential feeding ground for fin whales, blue whales and sei whales during the spring. During the spring, we have also registered krill patches on the surface in several occasions and feeding behaviour of the three species. The different colour of the faeces of each species may indicate differences in their diets: mostly red for blue whales, wider range of colour from orange, brown to red for fin whales; and even with a small number of records, yellow for sei whales. Furthermore, we create an appropriate protocol to collect and store faecal samples during the whale watching trips. In 2019 we start to use this non-invasive method as a new source of information here in the Azores. Nowadays we are looking for collaborators to go forward with the analyses of the faecal samples.

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Baleen whale faeces in the Azores
Víctor Ojeda1, Miranda van der Linde1, Maria R. Fonseca1, Marina C. Gardoki1, Miguel Soares1& Laura González García1,2
1. Futurismo Azores Adventures, Ponta Delgada, Azores, Portugal.
2. Applied Physics Department, University of Vigo, Spain.
victor.ojma@gmail.com
INTRODUCTION & STATE OF THE ART
Cetacean faecal samples have been used to study diet, steroid hormones,
exposure to parasites and biotoxins, individual genetic identification and
assessment of microplastic ingestion in whales and dolphins [1-4]. Baleen
whale faecal samples are not usually easy to collect. However, as in the Azores
whale watching platforms spend long time on the water and run trips year-
round, they provide great opportunities to collect these samples.
METHODS
Fig. 1. Location of São Miguel, Azores
(adapted from: naturalearthdata.com and
hidrografico.pt)
RESULTS
During the seven years of the study, we registered 53 baleen whale faecal records, all of them between March and October. The faeces of each species had different
coloration: mostly reddish for blue whales (8), wider range of colour from reddish to brown for fin whales (40); and yellow ochre for sei whales (5) (Fig. 2).
Blue whale / Balaenoptera musculus Fin whale / Balaenoptera physalus Sei whale / Balaenoptera borealis
DISCUSSION AND CONCLUSIONS
•Long-term data series and samples obtained from opportunistic sources like
whale watching tours are highly valuable.
•These data support the Azores as apotential feeding ground mainly during
spring time for fin whales and blue whales [5]. In case of the sei whales it is
mainly between late spring and mid-summer. We have also registered krill
patches (Fig. 3) on the surface in several occasions and feeding behaviour of the
three species.
•Different colours are probably linked with different diets; and different diets
are also suggested by different habitat preferences or even different routes [6].
LOOKING FORWARD
Furthermore, we created an appropriate protocol to collect and store faecal
samples during the whale watching trips. In 2019 we started to use this non-
invasive method as a new source of information in the Azores (Fig. 4). Nowadays
we are establishing new collaborations to go forward with the analyses of the
faecal samples.
AKNOWLEDGEMENTS.We would like to thank the Futurismo Azores Whale Watching team, biologists and guides who have collected data for this study, and especially, the skippers and lookouts who have
worked hard everyday with us. Also we would like to acknowledge the clients who choose this way to see the animals in their natural habitat.
REFERENCES. [1] de Vos et al. (2018). New determination of prey and parasite species for northern Indian Ocean Blue Whales. Frontiers in Marine Science, 5, 104.[2] Gillett et al. (2010). Molecular identification of individual North Atlantic right whales
(Eubalaena glacialis) using free‐floating feces. Marine mammal science, 26(4), 917-936. [3] Hermosilla et al. (2016). Endoparasite survey of free-swimming baleen whales (Balaenoptera musculus, B. physalus, B. borealis) and sperm whales (Physeter
macrocephalus) using non/minimally invasive methods. Parasitology research, 115(2), 889-896.[4] Hunt et al. (2019). Evaulation of fecal hormones for noninvasive research on reproduction and stress in humpback whales (Megaptera novaeangliae). General
and Comparative Endocrinology. [5] Visser et al. (2011). Timing of migratory baleen whales at the Azores in relation to the North Atlantic spring bloom. Marine Ecology Progress Series, 440, 267-279.[6] Gonzalez (2019). Cetacean distribution in São Miguel
(Azores): influence of environmental variables at different spatial and temporal scales. Tesis Doctoral. Física aplicada.
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Fig. 4. (A) Net to collect faecal samples.
(B) Collecting a sample with the net.
A B
OUR AIM: To review the baleen whale faeces records registered
from whale watching platforms around São Miguel (Azores) (Fig. 1).
Baleen whale faeces were registered between
2012 and 2019 around São Miguel (Azores) (Fig.
1), from whale watching tours with Futurismo
Azores Whale Watching. These records were
registered in areas where lookouts found
whales using powerful binoculars working from
strategic points along the coast. Once in the
whale area the specialized onboard observers
recorded the encounter identifying the defecator species and taking notes
about the colour of the faeces.
15% (8) 76% (40)
Fig. 3. Krill collected during a
whale watching tour.
9% (5)
Fig. 2. Percentages of records
from each species (number of
records). Bars indicate the
range of faeces coloration for
each species.
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