The contribution of the sea urchin to ambient sea noise

Abstract

An unusual component of the ambient sea noise field of coastal New Zealand waters has been recognized for some years. The phenomenon involves an increase in noise level at sunset and sunrise, predominantly in the range of 1 to 2 kHz, with seasonal trends varying the pattern. The effect was reported first in 1962 and tentatively attributed to the seaurchin Evechinus chloroticus Valenciennes (1846). A continuous study in the shallow waters of the Hauraki Gulf throughout 1973 has confirmed this hypothesis. The results of this study will be presented and the characteristics of the effect reviewed.