Integrating underwater surveys, telemetry and citizen science to understand drivers of movement in sea snakes
Résumé
As reef meso-predators, sea snakes play an important role in reef ecosystems and are bio-indicators for
eel populations and overall reef health. Strong evidence suggests that marine snakes are able to identify
changes in environmental conditions (i.e. tide, lunar phase, water temperature, air pressure) and use
these as cues to alter behaviour to capture prey, avoid predators, find mates, and survive storm
conditions. However, research on this topic has been restricted to changes in the observed abundance of
snakes at different time periods, with few data on continuous movements and use of space of these
animals over extended periods. In this study, we incorporated mark-recapture data collected using
regular underwater surveys with passive acoustic telemetry methods and local citizen science initiatives
to study the ecology of sea snakes at a higher resolution and identify environmental factors that influence
their movements and home ranges in Noumea, New Caledonia. The increased resolution of movements
and habitat use gained from the combination of methods of data collection highlighted strong tidal and
seasonal patterns of residency in Olive-headed sea snakes (Hydrophis major). We also found strong
species-specific differences in dispersal capacities across three species of sea snake commonly found in
Noumea (Emydocephalus annulatus, Hydrophis major, Aipysurus duboisii), highlighting variable habitat
use patterns within a single site. Movement and habitat use information can provide an insight into how
sea snake populations may react to acute or chronic changes to the ecosystem.