黄、东海典型渔业海域鱼鳞沉积信息及其空间分布

Fish-scale-deposition information and spatial distribution in typical fishery area of the Yellow Sea and East China Sea

对黄海中部、长江口邻近海域和闽浙沿岸海域47个站位的表层沉积物样品及6个站位的柱状沉积物样品的鱼鳞沉积量(SDA)进行了调查,揭示了我国典型渔业海域鱼鳞沉积信息及空间分布,并证明了应用鱼鳞沉积速率(SDR)追溯鱼类种群动态变化的方法在我国海域的可行性。结果表明,黄海中部的鱼鳞组成种类比较单一,主要由鳀和小黄鱼组成,以鳀占绝对多数。平面分布中鳀占75.0%,小黄鱼占25.0%,发现鱼鳞的站位基本处在黄海中部的西北与东南边缘,10594站位(34°59.9′N,122°29.9′E)、12694站位(33°59.9′N,123°59.0′E)鱼鳞沉积量较高。黄海中部3个站位的鱼鳞沉积量随深度增加表现出不均匀的垂直分布,具有较为一致的变化趋势,并出现了明显而统一的高峰段。长江口单位体积的鱼鳞沉积量低于黄海中部,鱼鳞组成种类复杂。平面分布中有68.1%的鱼鳞被甄别出,数量较多的鱼种分别为小黄鱼29.2%,发光鲷12.5%,鳀8.3%。发现鱼鳞的站位基本沿舟山渔场中心延伸并与海岸平行分布,以H-28站位(28°09.1′N,122°55.3′E)鱼鳞沉积量较高。长江口3个站位的鱼鳞沉积量垂直分布由较多的鱼种组成,呈不规则变化,但未出现具有连续变化趋势的优势鱼种和相似的变化趋势。相比较而言,黄海中部是更理想的研究区域。

Fish-scale-deposition amount （SDA） of 47 surface sediment samples and 6 sediment cores from the central Yellow Sea, Changjiang Estuary, Fujian and Zhejiang coastal areas have been investigated in this study, to reveal fish scale-deposition information and spatial distribution in typical fishery sea areas. This study proved the feasibility of applying fish-scale-deposition rates （SDR） to trace fish population dynamic changes in China typical fishery sea areas. Results showed that the species composition of fish-scale deposition in the central Yellow Sea was simple. Anchovy （Engraulis japonicus） and small yellow croaker （Pseudosciaena polyactis） were the major fishes in Yellow Sea. In surface sediment, anchovy made up 75.0% and small yellow croaker made up 25.0%. The positions where found scales, distributed on northwest and southeast edges of the central Yellow Sea approximately, and SDA was high around 10594 position （34°59.9′N, 122°29.9′E） and 12694 position （33°59.9′N, 123°59.0′E）. The vertical distributions of SDA of 3 positions in central the Yellow Sea were inhomogeneous with depth increasing. The same change trend and an obvious identical abundance peak of SDA appeared in the vertical distributions of 3 positions in the central Yellow Sea. In Changjiang Estuary, SDA per unit volume was lower than that in the central, Yellow Sea, and the species composition of fish-scale-deposition was complex. 68. 1% scales were identified in Changjiang Estuary surface sediment; small yellow croaker, Acropoma japonicum and anchovy were the major fishes, made up 29.2%, 12.5% and 8.3% respectively. The positions where found scales, distributed along central Zhoushan Fishing Ground and paralleled to the coastal line approximately. SDA was high around H-28 position （28°09. 1′N, 122°55.3′E）. The vertical distributions of SDA in Changjiang Estuary were irregular, but the same change trend and the major fish that had continuous change trend, did not appear in the vertical distributions of 3 positions. Compared with the Changjiang Estuary, the central Yellow Sea is the more appropriate study area for applying SDR to trace fish population dynamic changes.