Effects on eggs and larvae

Research on larval stages and juvenile stage of Atlantic Cod

Desender et al (2017) exposed three embryonic stages, four larval stages, and one juvenile stage of Atlantic Cod to a homogeneous electrical field of 150 Vpeak/m for 5 seconds, mimicking a worst-case scenario. The results:

  • No significant differences were detected in embryo mortality rate between control and exposed groups. However, for the embryonic stage exposed at 18 day postfertilization, the initial hatching rate was lower.
  • Larvae that were exposed at 2 day and 26 day post hatch exhibited higher mortality rates than the corresponding non-exposed control groups.
  • In the other larval and juvenile stages, no short-term impact of exposure on survival was observed. Morphometric analysis of larvae and juveniles revealed no differences in measurements or deformations of the yolk, notochord, eye, or head.

Although exposure to a worst-case electrical field did not impact survival or development for six of the eight young life stages of Atlantic Cod, the observed delayed hatching rate and decreased survival for larvae might indicate an impact of electric pulses and warrant further research.