Assessment of artificial substrates for lumpfish: effect of material thickness and water current speed

This study assessed the use of different types of substrates (450 g PVC, 130 g plastic) and water speed (5.0, 10 and 20 cm s−1) on growth and substrate selection in lumpfish. There were no differences between the percentages of fish attached to both types of substrates as they grew for each of the three different water speeds. Substrate adherence was similar on both substrate types and for all water current speed as the study progressed and was between 25 to 30% in all groups at termination of the trial. Results from the present study show that increasing water speed did not affect attachment preferences in lumpfish as they grew. Larger specimens were observed attaching to both thin and thicker substrates equally. Water speed did not affect growth performance as there were no differences in growth observed at the end of the study period between the three groups of lumpfish. However, further studies are required to determine if higher water speeds affect both growth and attachment preference of lumpfish as they grow.