Observations sur la production du naissain dans le bassin d'arcachon en 1929

This year, the observations of the spat production were carried out in a more rational way and according to the agenda we had established. They were made easier by the A.O.B.A. which lent us its new pinnace, equipped with an Ostrea, thus enabling us to go out to sea about twenty times between May 11th and August 9th, and to carry out 71 dredgings in the different fair-ways of the Basin. Moreover, the temperatures were taken at the Eyrac station, following the same method as described last year. The average water density was also monitored on a daily basis over this period. Lastly, we recorded the rainfalls on the pluviometer of the weather station of the Arcachon Scientific Society. We gathered these four elements under the same graph; the amount of larvae and the densities are read using their weekly average. (See graph.)