Abstract:
The golden cuttlefish (Sepia esculenta) is an important cephalopod species with a lifespan of approximately one year. The species plays a crucial role in marine ecological support services and is commercially valuable in fisheries. In the seas around China, this species has emerged as the main target for cuttlefish fisheries, replacing Sepiella maindroni since the 1990s. Variations in oceanographic conditions associated with global warming could significantly impact the temporal-spatial distribution of the species. In this study, we performed bottom trawling surveys with four cruises during 2018-2019 in the East China Sea region to determine the current resource status and seasonal-spatial variations in S. esculenta. We found that the average individual weight (AIW) values were 4.87 and 519.00 g/ind at stations located at 30.50° N, 124.00° E and 30.50° N, 124.50° E, respectively, with the aggregation of larvae and parent groups in spring. The species was not distributed north of 32.00° N in summer. The catch per unit effort by weight (CPUEw) value decreased in the order of 2772.50→2575.20→503.29→124.36 g/h, corresponding to latitudes of 34.50° N→34.00° N→33.50° N→32.50° N 121.50° E in autumn. The most suitable fishing areas were the south of the East China Sea region in spring; the south of the East China Sea region extending to the center and outer parts of the East China Sea region in summer; the south of the Yellow Sea close to the Haizhou Bay fishing ground and the forbidden fishing line region of the Lusi and Dasha fishing grounds in autumn; and the south and center of the East China Sea region in winter. The most suitable sea bottom temperature (SBT) values from spring to winter were 14.76-20.53 °C, 19.54-22.98 °C, 11.79-17.64 °C, and 16.94-20.36 °C, respectively. The most suitable sea bottom salinity (SBS) values were 31.53-34.80‱ in spring, 32.95-34.68‱ in summer, 31.51-34.77‱ in autumn, and 33.82-34.51‱ in winter. We concluded the following: (1) the southern and northern areas of the East China Sea region are spawning and nursery grounds, respectively, in spring; (2) the central distribution is located at a latitude of 28.00° N in autumn and winter; and (3) the southern area of the Yangtze River to the north is a spawning ground in spring, and the areas located at 29.00-34.50° N, 124.00-124.50° E, and 28.00-30.50° N, 125.50-126.50° E are nursery grounds. The results of this study provide useful guidance for appropriate fisheries management, thereby avoiding a collapse in the S. esculenta population, which has been experienced in other species in this area.
摘要:
金色墨鱼(Sepiaesculenta)是一种重要的头足类物种,寿命约为一年。该物种在海洋生态支持服务中起着至关重要的作用,在渔业中具有商业价值。在中国周围的海域,该物种已成为墨鱼渔业的主要目标,自20世纪90年代以来取代了沙门菌。与全球变暖相关的海洋学条件的变化可能会显着影响该物种的时空分布。在这项研究中,我们在2018-2019年期间在东海地区进行了四次巡游的底拖网捕捞调查,以确定S.esculenta的当前资源状况和季节空间变化。我们发现,在位于30.50°N的站点上,平均个人体重(AIW)值为4.87和519.00g/ind,124.00°E和30.50°N,124.50°E,分别,随着春季幼虫和亲本群体的聚集。该物种在夏季未分布在32.00°N以北。按重量计算的单位努力捕获量(CPUEw)值下降了2772.50→2575.20→503.29→124.36g/h,对应于秋季34.50°N→34.00°N→33.50°N→32.50°N121.50°E的纬度。最适宜的渔区是春季东海地区的南部;夏季,东海地区的南部延伸到东海地区的中部和外部;秋季,黄海的南部靠近海州湾渔场和卢斯和大沙渔场的禁渔线区;冬季,东海地区的南部和中部。春季至冬季最适宜的海底温度(SBT)值为14.76-20.53℃,19.54-22.98°C,11.79-17.64°C,和16.94-20.36°C,分别。春季最适合的海底盐度(SBS)值为31.53-34.80分,夏季32.95-34.68,31.51-34.77秋天,和33.82-34.51冬天。我们得出以下结论:(1)东海地区的南部和北部地区是产卵场和育苗场,分别,春季;(2)秋季和冬季的中心分布位于北纬28.00°;(3)北部的长江南部地区是春季的产卵场,以及位于29.00-34.50°N的区域,124.00-124.50°E,和28.00-30.50°N,125.50-126.50°E是托儿所。这项研究的结果为适当的渔业管理提供了有益的指导,从而避免了S.esculenta种群的崩溃,这在这个地区的其他物种中已经经历过。