A biologging technique for monitoring the egg-releasing behavior of Pacific abalone Haliotis discus hannai in the wild

Abstract

To examine causes of variation in the population dynamics of Ezo abalone Haliotis discus hannai, it is important to understand its reproductive behavior, but there have been no methods for analyzing behavior related to egg release in the field. Spawning is assumed to occur in response to stormy weather, but this hypothesis remains untested. In the laboratory (August 2014), the behavior of abalone from Iwate Prefecture, northeastern Japan (39°36’N, 142°2’E) was recorded using 3-axis acceleration data loggers. Egg-releasing behavior was characterized using the predominant frequencies and amplitudes of time series acceleration data. Subsequently (October 2015), the putative egg-releasing behavior of abalone in the wild was recorded at the collection site, using the 3-axis acceleration data loggers. Further field observations using this system on H. discus hannai and other abalone species are expected to facilitate identification of the principal factors stimulating abalone spawning.