东海区龙头鱼数量分布及其环境特征

Spatial distribution and environmental characteristics of Harpodon nehereus in the East China Sea region

以2005年东海区渔业资源监测调查资料为依据，研究分析了龙头鱼资源的数量分布、渔业生物学特征、分布海域生态环境特征和资源量状况等。结果表明，东海区龙头鱼主要分布在长江口渔场、舟山渔场、大沙渔场和鱼山渔场，这几个渔场全年的渔获量占全部渔获量的82．99％，但各季度分布情况有差异；春季平均体长197．77mm，平均体重43．83g，夏季平均体长220．00mm，平均体重57．10g，秋季平均体长168．51mm，平均体重49．70g，冬季平均体长171．53mm，平均体重59．52g；体长～体重的关系式为形=1．3195×10^-6L^3.3259；龙头鱼分布海域的底层水温分布范围为9．11～26．11℃，平均为14．80℃，底层盐度范围为31．36～35．26，平均为33．39，水深分布范围为27．00—101．99m，平均为58．96m；现存资源量为2125t，但潜在资源量估计在5千吨以上，属于有潜在价值渔业。建议加强该资源的监测和研究，并执行相应的开捕规格。

Based on the data obtained from the fishery resource monitoring in the East China Sea in 2005, the paper analyzed the status of Harpoclon nehereus in the East China Sea, including spatial distribution, biological characteristics, ecological environment characteristics and estimate of its biomass. The results indicated that Harpodon nehereus is distributed mainly in Yangtze River esturary fishing ground, Zhoushan fishing ground, Dasha fishing ground and Yushan fishing ground, and the yield of these four fishing grounds accounted for 82.99% of the total catch in 2005. The study also revealed that there were seasonal variations in the distribution characteristics of Harpodon nehereus. The average body length and weight of Harpodon nehereus in spring were 197.77 mm and 43.83 g, respectively, while 220.00 mm and 57.10 g in summer, 168.51 mm and 49.70 g in autumn and 171.53 mm and 59.52 g in winter correspondingly. The relationship between length and weight was expressed as： W = 1. 3195 × 10^-6 L^3.3259. The bottom temperature in distribution regions ranged from 9.11 to 26.11 ℃, with the mean value being 14.80 ℃. The bottom salinity range was from 31.36 to 35.26, and the mean value was 33.39. The water depth range was from 27.00 to 101.99 m, and the mean value was 58.96 m. The estimated biomass was 2 125 tons, but potential biomass should surpass 5 000 t. So Harpodon nehereus should be considered as a potential fishery stock. We propose that the related authorities strengthen the research and inspection of the stock and implement measures to ensure length of the catch is greater than that at first capture.