Drivers of variability in surf zone habitat use by sandy beach fish: Unwitting citizen scientists reveal detailed spatiotemporal patterns

Surf zones of sandy beaches are among the most heavily impacted aquatic ecosystems, yet are of critical
ecological importance for inshore fish and fisheries. Knowledge of the drivers of fish habitat use in surf zones is
needed across broad scales to advise conservation and fisheries management, but sampling capabilities can be
limited in spatio-temporal extent and resolution. The lesser weever Echiichthys vipera is a small, benthic,
venomous fish that dominates surf zone fish assemblages in Northwest Europe and inflicts painful stings on
beachgoers. This study capitalises on an extensive record of E. vipera sting incidents to characterise variations in
surf zone habitat use in relation to key physical environmental factors. Sting incidents, standardised by water
user numbers, are used as a proxy for E. vipera abundance across 77 beaches throughout Southwest England, with
2 h resolution, from April–November 2018. General Additive Models indicated a clear peak in E. vipera abundance at spring low tides, in the afternoons of summer months, under calmer wave conditions and at higher
levels of solar irradiance. Although the order of significance differed, human water users were also driven by the
same variables, compounding sting interactions over time. Key physical variables did not explain spatial variation in E. vipera abundance, although there was a weak relationship with sea surface temperature, and some
evidence that reflective beaches are unsuitable. Physical factors explained more spatial variation in human water
users, who gathered at more dissipative beaches with greater wave heights. This detailed study of an important
surf zone fish reveals clear drivers of temporal variation in habitat use, yet infers wide suitability of beaches
varying in the key physical drivers of sandy shore ecology