ECOLOGICAL STUDIES ON THE MARINE FOULING ORGANISMS AT SOME IMPORTANT PORTS OF CHINA

During the period from March 1959 to February 1963, an investigation of marinefouling organisms was conducted at some of the important ports of China--at Chin-wangtao, Dairen, Tsingtao, Shihpu and Yulin for a period of one year, two years and three years respectively.The marine fouling organisms were collected from three series of wooden test panelswith an area of 100 cm2 or 225 cm2, exposed under the sea water at 3 levels--slightlybeneath the water surface, at 2 m and at 4 m.The first series consist of twelve panels, of which only one was exposed at the beginning of the month at a time and then taken out and changed to another each month. The second series consist of four panels, each exposed at intervals of three month. The third series consist also of twelve panels immerged simultaneously at the beginning and removed one at each time at intervals of one month. All removed panels were preserved in 5% formalin solution.In the present report, the specific composition of the fouling community and the monthly relative abundance of the major fouling organisms were determined for each port. The quantity of the foulers settling on the panels at the three levels was also noted. Our results show that the panels at the middle level are most favorable for the attachment of fouling animals, whereas those at the upper level are more convenient for the attachment of algae. The variation in both quantity and quality of the fouling community from year to year is less pronounced in the northern ports than in the southern ports.The annual total weight of fouling organisms of each of these five selected ports indecreasing order is as follows: Shihpu--3,126.7 g., Tsingtao--2,777.3 g., Dairen--2,211.8 g., Yulin--368.5 g. and Chinwangtao--38.2 g. According to the variation ofthe monthly total weight of fouling organisms, we may divide these ports into two types. In the first type, seasonal variation is quite marked and the month of occurrence of peak settlement and the constituent elements of the fouling community for the three years tested are more or less the same. Heaviest fouling occurs during warmer months. Chinwangtao, Dairen, Tsingtao and Shihpu belong to this type. In the second type, variation in monthly total weight of fouling organisms is not marked as compared with that of the first type, and the month of occurrence of peak settlement for the three years tested is quite different. The port of Yulin belongs to this type.