Sur la mortalité exceptionnelle qui frappe les jeunes gryphaea angulata lmk. (portugaises) depuis quelques années. Ses conséquences pour l'ostréiculture

In a recent note I reported the high exceptional mortality which hit, in 1926, the young Portuguese oysters aged one month. I demonstrated that this mortality was caused by the high temperatures of August. The maximum was reached on the 25th of August, with 33°, and corresponds with the day the young oysters were affected. This temperature corresponded to a very high tide coefficient. In 1927, there was, as in any other year, a first fixation of the larvae on the collectors over the second fortnight of July and a second one around the 10th of August. At the end of this month, even if the temperature was not as high as the previous year and stayed constant, we still observed an abnormal mortality in the young oysters recently fixed and especially in those fixed in July. This time, the mortality is caused by the stormy weather.