For a deep-diving
cetacean species like the sperm whale, acoustics is a vital tool
for research. This need is especially pressing in the eastern
Caribbean, where the habitat of marine mammals overlaps with
heavy maritime traffic, leading to noise pollution and an
increased risk of vessel collisions. To mitigate this risk,
understanding their habitat use is essential. Mature males are
generally solitary and migrate over long distances, while
females and immatures form stable social units in subtropical
and tropical waters. In this study, we examined intraspecific
variation in distribution and habitat use among individuals
along the Caribbean coast of Martinique, using both visual and
acoustic data. Over the course of 24 surveys, 19 aggregations
involving a total of 74 individual sightings were characterised,
recognizing that some individuals may have been recorded
multiple times. Using the inter-pulse interval (IPI) of clicks,
we estimated individual size, which provided insights into the
age and/or sex of each individual. Habitat characteristics
included bathymetry, distance from the coast, and seabed slope.
Our results on social structure are in line with previous
literature: 37% of the aggregations were made up of females
and/or juveniles, immatures, with a mature male nearby, with
temporal changes in aggregations linked to male migration
patterns. Spatial distribution and habitat use appeared
consistent across aggregation types, regardless of group size,
average individual size, or the presence of immatures. However,
specific areas were identified for hunting and socialising based
on bathymetry. This study highlights the importance of
bathymetry and/or distance from the coast and temporal dynamics
related to variations in weather conditions and movements of
breeding males, in understanding habitat use by sperm whales in
the eastern Caribbean. The lack of observed influence of seabed
slope suggests that our spatial scale may have been too limited,
or that finer details regarding seabed characteristics are
needed. These findings could inform traffic management
strategies to reduce the risk of vessel collisions with sperm
whales.