Present problems in the culture of the larvae of Ostrea edulis

Abstract

1. The large-scale routine culture of the larvae of Ostrea edulis for 31 consecutive weeks in 1969 showed marked fluctuations in the growth rate of the larvae. 2. In the first 20 weeks the periods of reduced growth coincided with those times when the sea water was highly turbid. 3. The concentration of dissolved zinc in the sea water varied between 0.5 and 470 μg/1. Laboratory experiments showed that the higher levels would be sufficient to reduce growth. 4. A bloom of Phaeocystis pouchetti in the river reduced larval growth at the end of May. 5. In July an outbreak of a bacterial disease caused a number of larval cultures to collapse. 6. The use of mixed species of algae as food gives a more rapid growth of the larvae, an enhanced proportion metamorphosing, and more vigorous spat compared with feeding on one species of alga. © 1970 Biologischen Anstalt Helgoland.