Nonlinear time series analysis of snapping shrimp sounds

Abstract

Snapping shrimp produce sounds through cavitation bubbles generated by the rapid closing of their claws. These sounds are a primary source of ambient noise in sub-tropical, shallow water environments. Though seasonal and daily variations of snapping shrimp sound levels have been reported, comprehensive studies of short time series have been limited. We investigate the respective spectral characteristics from acoustic arrays recordings at various locations in Oahu, HI, over hourly, daily and weekly periods. Nonlinear time series analysis methods encompassing recurrence plots are used to investigate the acoustic time series together with bivariate and cross recurrence plot analysis with that of tidal and sunlight cycles. Signal entropy and determinism are investigated and transient acoustic ship sounds are located