烟台四十里湾浅海养殖生物及附着生物的化学组成、有机净生产量及其生态效应

对四十里湾养殖海区一些双壳贝类和藻类收获时的化学组成和有机净生产量进行了分析，不同双壳贝类软体有机碳含量差别不大，而N含量差异较大，栉孔扇贝软体N含量最高（12．36％），而牡蛎，毛坩相对较低（8％－9％），贻贝和菲律宾蛤仔贝壳N含量最高，为0．55％和0．56％，而栉孔扇贝壳则较低（0．1％），且贝壳，C，N，P在扇贝C，N，P总含量中所占的比例分别为6．2％，7．5％和6．9％，海带和石莼元素组成说明海区营养元素N的不足，海带的不同部位N含量差别很大，且在不同海区有较大变化，贻贝贝壳C，H，N和P含量在整个贻贝中占有相对大的比例，分别为30．4％，30．2％，31．8％，29．6％，菲律宾蛤仔，长牡蛎和中国蛤蜊等贝类贝壳中这些元素的相对含量也较高，布扇贝贝壳却较低，四十里湾海区每年因贝类和藻类的养殖，海区将至少减少850tN和78tP，其中贝壳的营养损失占据着相当比例，在海水交换受到一定限制，营养不很丰富，海区，养殖生物收获本身也会对海区的营养状况产生影响，根据贝壳N，P的含量，笔者认为在营养不很丰富的沿岸海区，贻贝，牡蛎最好不养或尽可能少养。

Chemical composition and net organic production of cultivated and fouling organisms in Sishili Bay and their ecological effects

Chemical composition and net production of cultured bivalves and seaweed (the kelp Laminaria japonica), and fouling organism in the Sishili Bay, were determined. The investigated cultured bivalve species involved the scallop Chlamys farreri, the mussel Mytilus edulis, the oyster Grassostrea gigas, the clam Ruditapes philippinarum and Mactra chinensis, and the Ark shell Scapharca suberenata. The investigated fouling animals involved the clam Trapezium liratum, the ascidian Styela clava, Ciona intestinalis, Cnemidocarpa chinensis, Molgula manhattensis and Botrylloides violacens, and the seaweed Ulva pertusa. Samples were collected from different farming zones in the Sishili Bay in late May, 2000. All the investigated cultured bivalves and seaweed had reached commercial size. C content of soft tissue of bivalve species was similar, with the range 42.2 to 46.0% of soft tissue dry weight; while N content was significantly different. The N content of the soft tissue of C. farreri was the highest (12.36%), while that of G. gigas was much lower (8.19%). Chemical composition of shells varied with different bivalves. N content of M. edulis and R. philippinarum shells was the highest, 0.55% and 0.56% dry weight respectively. C, H, N and P in mussel shells accounted for 30.4%, 30.2%, 31.8% and 29.6% of the total C, H, N and P respectively. In contrast, the shells of C. farreri contained only 0.1% N, and C, N and P in the scallop shells accounted for only 6.2%, 2.5% and 6.9% of the total C, H, N and P respectively. In different part of kelp, N content was also significantly different. The C/N atomic ratios in L. japonica and U. fascita were relatively high, possibly suggesting deficient N origin. In different farming zones, the C/N ratios in the kelp were also different, indicating different nutrient conditions of the farming zones. In the Sishili Bay, about 850t N and 78t P were removed every year just through the harvest of the cultured bivalves and seaweed, and the lost of fouling organisms, indicating the effect of aquaculture on the ecosystem. Because a considerable amount of N and P was apportioned in mussel and oyster shells, it is suggested that large quantities of mussels and oysters should not be cultivated in oligotrophic coastal region.