The bluebottle (Physalis physalis) is a colonial animal resembling a jellyfish that floats on the surface of the ocean with a distinctive blue sail. It is well known to beachgoers for the painful stings delivered by their subsurface tentacles. Despite being a common occurrence, the origin of the bluebottle before reaching the coastline is not well understood, and neither is the way it drifts at the surface of the ocean. Previous studies used numerical models in combination with simple assumptions to calculate the drift of this species, excluding complex drifting dynamics.
In this study, we provide a new model for calculating the drift of the bluebottle and implement this model by creating a bluebottle module in Python. We use this module with wind and current velocity outputs from the east coast of Australia to run simulations and analyse the effect of different variables on bluebottle drift including sail orientation, shape, and wind and current conditions. This is the first step towards understanding the drivers of bluebottle beachings in Australia.