Published online by Cambridge University Press: 11 May 2009
Flounders grew much more slowly in 1944 than during the previous 2 years. From October 1943 to October 1944 their mean size increased from 7·9 cm., 6·8 g., to 12·7 cm., 23·6 g., an increment which was if anything smaller than under normal conditions. The reason for the reduction in growth rate is attributed to the increasingly unfavourable hydrographic conditions resulting from the prolonged closure of the dam, in particular to the high H2S concentration, the high pH and the low oxygen concentration of the water.
In the autumn of 1944 the sluice gate of the dam was opened for several months. In 1945/46 the growth of stock III flounders was very rapid. They reached a mean size of 32·3 cm., 409 g., in March 1946 and 36·8 cm., 580 g., in March/April 1947. Native flounders reached a mean size of 30·6 cm., 353 g., in 2 years.