Flatfish: causes of variability in larval settlement

The flatfish Plaice (Pleuronectes platessa) spawns in the southern and eastern North Sea, and the English Channel. Developing larvae drift towards nursery areas - such as the Wadden Sea - where they settle. Yearly measurements of arriving juveniles on Balgzand show a strong inter-annual variability.

Modelling causes of larval settlement variability

A numerical model is used to study the causes of this variability. Model results show significant inter-annual variability where (i) changes in wind speed & direction cause current variability which strongly influences the direction and distance of the particle drift, (ii) low temperatures reduce the rate of development and (iii) settlement success varies over time and space. Future studies will include modelling of active behaviour (vertical migration) during the later development stages of plaice juveniles and identification of specific spawning grounds and periods.