Cooperative Fish and Wildlife Research Units Program: Hawaii
Education, Research and Technical Assistance for Managing Our Natural Resources

Grabowski TB, BJ McAdam, V Thorsteinsson, & G Marteinsdottir. 2015. Evidence from data storage tags for the presence of lunar and semilunar behavioral cycles in spawning Atlantic cod. Environmental Biology of Fishes 98:1767-1776.


Understanding the environmental processes determining the timing and success of reproduction is of critical importance to developing effective management strategies of marine fishes. Unfortunately it has proven difficult to comprehensively study the reproductive behavior of broadcast-spawning fishes. The use of electronic data storage tags (DSTs) has the potential to provide insights into the behavior of fishes allowing for data collection over relatively large spatial and temporal scales that can be correlated to predicted environmental conditions and ultimately be used to refine predictions of year class strength. In this paper we present data retrieved from DSTs demonstrating that events putatively identified as Atlantic cod spawning behavior is tied to a lunar cycle with a pronounced semi-lunar cycle within it. Peak spawning activity occurs around the full and new moon with no evidence of relationship with diel tidal or day/night cycles.