The migration of viscous fish eggs in artificial reefs

Artificial reefs play a key functional role in marine ecosystem recovery and particularly in the rebuilding of fish populations. However, improving the reef design for viscous-egg-spawning fish is very challenging. Viscous eggs must adhere to a substrate to continue the hatching process, i.e., increasing the egg adhesion rate of the reef makes it a better fish spawning habitat. Therefore, the movement characteristics of viscous fish eggs in an artificial reef are a vital issue in marine ecology. In this study, a vertical two-dimensional lattice Boltzmann method was developed to simulate the complex hydraulic field in a reef zone and to predict the movement of fish eggs as affected by the hydrographic environment. A particle image velocimetry experiment on fish egg transportation was carried out to validate the model. These results revealed the effects of different hydrodynamic conditions on the migration of sticky eggs in the reef zone, to promote the sustainable development of fisheries and restore the marine ecology.