[Carrying capacity of shellfish culture in Dadeng Island sea area of Xiamen].

To fully and rationally exploit local living marine resources while have a sustainable, efficient and healthy development of shellfish culture in the Dadeng Island sea area of Xiamen, this paper determined and analyzed the related model parameters of this area, including chlorophyll a, primary productivity, phytoplankton organic carbon tent, wild filter feeder yields in subtidal and intertidal zones and suspension culture area, cultured shellfish filtration rate and organic carbon content, shellfish's total weight to fresh meat ratio, and adopted the Nutrient namic Model and Coastal Waters' Energy Flow Analysis Model to estimate the ecological capacity of shellfish this area, from which, the wild filter feeder yields were deducted for estimating shellfish carrying capacity. model established by Fang Jianguang was also used to estimate the shellfish carrying capacity. Statistics analysis was used to estimate the suitable culture area of shellfish and other species, aiming at limiting local shellfish ture and optimizing the culture of various species mollusks. According to the estimation of the three models, shellfish carrying capacity in this area should be 35,248-39,990 tons, with an average of 37,488 tons, 140,008 x 10(4) - 158,850 x 10(4) individuals, averaging 148,903 x 10(4). The theoretically suitable culture area 2 145 hm2, 1,900 hm2 for Ostreidae, 81 hm2 for razor clam (Sinonovacula constricta), 20 hm2 for blood (Tegillarca granosa), and 144 hm2 for musculus (Musculus senhousei). In 2000, the actual culture area of shellfish and other species in the waters around Dadeng surpassed the estimated suitable culture area. It is proposed that some measures should be taken to reduce the overexploited area.

[Fishery biology of Cyanea nozakii resources in the waters of Dongshan Island].

According to the investigations during April-September 1994, the peak date of Cyanea nozakii density of in the waters of Dongshan Island was from 25 June to 10 July, and that of its biomass was from 10 July to 5 August. The diameter of umbrella-part of the stock ranged from 15 mm to 580 mm, averaging 247.48 mm, and the body weight ranged from 0.4 g to 10,250 g, averaging 1,274 g. The growth of the diameter of umbrella-part and the body weight of Cyanea nozakii could be calculated using power equation and power exponential equation, respectively. Based on the bio-economics principles, the optimal opening date was 15 July, and the rational fishing umbrella-part was 360 mm.