My colleagues and
I are pleased to announce the publication of our paper "Underwater photo-identification of sperm whales (Physeter macrocephalus) off Mauritius"in Marine Biology Research.
The long-term monitoring of long-lived animals often requires
individual identification. For cetaceans, this identification may be
based on morphological characters observable from a boat such as shape,
spots and cuts of the back, fluke and dorsal fins. However, for some
species such as the sperm whales (
Physeter macrocephalus), this
approach may be challenging as individuals display a rather uniform skin
pigmentation. They also do not very often show their fluke,
complicating individual identification from a boat. Immature sperm
whales that usually have an unharmed fluke may be excluded from
photo-identification catalogues. Within the framework of the Maubydick
project, focusing on the long-term monitoring of sperm-whales in
Mauritius, passive underwater observation and video recording were used
to identify long-lasting body markers (e.g. sex, ventral white markings,
cut-outs of fins). A catalogue of 38 individuals (six adult males, 18
adult females and 14 immatures) enabled observers to record some
nearly-daily, and yearly resightings.
Advantages and disadvantages
of this method are presented here. Such catalogues represent a robust
baseline for conducting behavioural, genetic and acoustic studies in
social species. Benefits of such newly acquired knowledge are of primary
importance to implement relevant conservation plans in the marine
realm.