Coral reef fish larvae: Patch size estimation and mixing in the plankton1

The daily pattern of settlement of larvae of the bluehead wrasse, Thalassoma bifasciatum, onto a number of coral reefs was reconstructed with the daily otolith increment aging technique. Larvae settled simultaneously onto reefs within an area of about 1,000 km2. The planktonic patch size of bluehead wrasse larvae is inferred to be at least 46 km wide. Larvae settling onto a reef at the same time were not the same age, indicating that planktonic dispersal results in mixing of cohorts of larvae.