2018年6月渤海大型水母分布特征

2018年6月使用渔业底拖网采样,对渤海大型水母进行了全面调查,调查船舶为"中渔科102"渔业科考船。本研究分析了渤海大型水母的种类组成、渔获密度与伞径大小,并对其源地进行了探讨。结果表明：本次调查共采集到海月水母、沙海蜇、海蜇、多管水母四种大型水母,其中海蜇、多管水母数量较少,各采集到一只。海月水母在渤海三湾均有分布,各海区伞径大小无显著差异且多为幼体（<10cm）,密度高值区出现在渤海湾东南侧海域,可达38-221.21ind./（net·h）,辽东湾海月水母出现于湾南,密度<5ind./（net·h）,湾北未见;作者推测,海月水母在渤海沿岸可能存在多个源头,诸如：莱州湾与渤海湾交界近岸海域、河北近岸、辽东湾大连近岸以及北部近岸。沙海蜇在渤海分布较广,辽东湾为密度高值区,均值为（35.32±21.64）ind./（net·h）,但伞径较小,均值为（12.15±6.52）cm;与此相对,渤海湾与莱州湾外侧海域沙海蜇密度虽小<20ind./（net·h）],但伞径要显著大于辽东湾,最大伞径均值可达（33.86±7.40）cm;作者推测,沙海蜇在渤海海域发源地主要集中于辽东湾近岸,渤海湾与莱州湾,外海出现的沙海蜇可能源于辽东湾,随海流运输至此。海月水母、沙海蜇在渤海发生时间要晚于黄、东海。本研究结果可为深入分析渤海大型水母的种群动态变化、暴发机理提供基础。

DISTRIBUTION OF GIANT JELLYFISH IN THE BOHAI SEA IN JUNE 2018

To explore the species compositions and distributions of large jellyfishes in the Bohai Sea, a comprehensive fishery survey was designed and conducted onboard R/V Zhongyuke in June 2018. Jellyfish were sampled using a bottom trawl at 47 stations. The dominant large jellyfish species, their diameter size, and biomass were recorded. The results show that the sources of jellyfish included Aurelia coerulea, Nemopilema nomurai, Rhopilema esculentum, and Aequorea sp., of which only one individual of R. esculentum and Aequorea sp. was collected. A. coerulea occurred frequently in the Bohai Sea, but the diameters were mostly <10cm in all sampling stations. The peak abundance of A. coerulea was in the southeast of Bohai Bay38-221.21ind./(net·h)]. A. coerulea in the Liaodong Bay occurred mainly in the south of the bay. We speculated that there may be multiple sources of A. coerulea in Bohai Sea, e.g., Laizhou Bay and the border coastal water of Bohai Bay, the offshore regions of Hebei Province and Dalian, and the northern Liaodong Bay. The peak abundance of N. nomurai was found in the Liaodong Bay(35.32±21.64)ind./(net·h)], while the mean diameter was only (12.15±6.52)cm. In contrast, although the abundance of N. nomurai between Bohai Bay and Laizhou Bay was <20ind./net·h, the diameter was significantly larger than that in the Liaodong Bay, and the maximum diameter was (33.86±7.40)cm. A. coerulea and N. nomurai in the Bohai Sea occurred later than in the Yellow Sea and East China Sea.