Formicki, K.; Korzelecka-Orkisz, A.; Tański, A. The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review. Int. J. Mol. Sci. 2021, 22, 1210. https://doi.org/10.3390/ijms22031210
The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.
5. Concluding Remarks
The interest in the effect of SMFs and EMFs on early developmental stages has been steadily increasing in recent years, since technological advancement contributes much magnetic and electromagnetic “pollution” in the aquatic environment, and the number of various electric facilities and industrial equipment in aquatic environment is growing. The effects of anthropogenic MFs on early development stages of fishes are varied and manifest both with a long-term and short-term exposure to an MF. The effect depends on the characteristics of the field (static vs. alternating), its magnitude, the time of exposure, and the advancement of ontogenesis during the exposure. The effect of long-term exposure to an SMF on, for example, the duration of the hatching period may be favorable because it reduces the duration of the process. Incubation in an SMF may increase survivorship of the hatchlings. Storing sperm in an MF prolongs its activation capacity. An alternating MF, depending on its characteristics, can increase the embryos’ mortality and can cause a heart rate disturbance or a developmental instability of the inner ear organ. The long-term impact of anthropogenic SMFs and EMFs on early developmental stages, which in consequence affects whole fish populations, should be considered, as they even offer the possibility of estimating the effect on whole fish populations. There is thus a need for standards for SMFs and EMFs that can be safely introduced into aquatic environments.