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Grabowski T.B., V. Thorsteinsson, & G. Marteinsdóttir. 2104. Spawning behavior in Atlantic cod: analysis by use of data storage tags. Marine Ecology Progress Series 506:279-290. doi:10.3354/meps10787

Images of Atlantic cod captured by a dual-frequency identification sonar (DIDSON) deployed approximately 1.0 km off the coast of Iceland at Knarrarós on 15 April 2009. In panels a-d, the DIDSON is positioned approximately 10 m off the bottom and is oriented at a 30° angle off perpendicular to the substrate. The Atlantic cod shown in these panels (a-d) are swimming up into the water column. The DIDSON is the same distance above the substrate in panels e-h, but oriented at approximately a 60°-angle to it. These cod seem to have reached the depth that the fish in panels a-d were ascending to and are swimming parallel to the substrate. Arrows indicate two individuals that may be coupling and engaged in a spawning event.


Electronic data storage tags (DSTs) were implanted into Atlantic cod captured in Icelandic waters during 2002-2007 and the depth profiles recovered from these tags (females: n=31, males: n=27) were used to identify patterns consistent with published descriptions of cod courtship and spawning behavior. The individual periods of time males spent exhibiting behavior consistent with being present in a spawning aggregation, i.e., periods consisting of a clear tidal signature in the DST depth profile associated with an individual remaining on or near the substrate, were longer than those of females. Over the course of a spawning season, male cod spent approximately twice the amount time in spawning aggregations than females. Despite spending less time in spawning aggregations per season than males, female cod visited more aggregations per unit time. On average, males participated in approximately 57% more putative spawning events, i.e., vertical ascents potentially corresponding to gamete release, than did females. However, males less than 85 cm total length participated in the same number of putative spawning events as females of comparable size. In both sexes, larger individuals and/or individuals that spent a longer period of time within an aggregation participated in a larger number of putative spawning events. Although further validation and refinement is necessary, particularly in the identification of putative spawning events, the ability to quantify cod spawning behavior offered by DSTs has the potential to aid in the development of management and conservation plans.


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June 2014


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Texas Cooperative Fish and Wildlife Research Unit Cooperators

  1. Texas Parks and Wildlife
  2. Texas Tech University
  3. U.S. Fish and Wildlife Service
  4. U.S. Geological Survey
  5. Wildlife Management Institute