Institute of Marine Research, Bergen, Norway.
PLoS One. 2012;7(3):e33050. doi: 10.1371/journal.pone.0033050. Epub 2012 Mar 22.
An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 0-60 m depths is calculated for the period 1980-2010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 9×10⁸ kg, with some years showing biomasses in excess of 5×10⁹ kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1°C<T<10°C, with peak densities at ca. 5.5°C, and the greatest proportion of the jellyfish occurring between 4.0-7.0°C. It seems that the ongoing warming trend may be favourable for Barents Sea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region.
为了估计鱼类种群的丰度，巴伦支海每年都会进行一次 0 组鱼类调查。自 1980 年以来，一直记录着水母兼捕数据，尽管该数据集从未经过分析。然而，近年来，水母水母体的生态重要性已得到广泛认可。本文计算了 1980-2010 年 0-60 米水深范围内的水母（水母体）生物量。在此期间，气候从冷变暖，浮游动物和鱼类的分布和丰度发生了变化。本文讨论了人们知之甚少的生态系统组成部分；腔肠动物门的水母水母体，以及它们的时空变化。长期平均生物量约为 9×10⁸kg，有些年份的生物量超过 5×10⁹kg。1980 年代生物量较低，1990 年代增加，21 世纪初达到最高，随后下降。大部分水母集中在巴伦支海的中心区域，该区域是大多数 0 组鱼类的核心区域。在西部区域，水母与黑线鳕有关，在中部和沿海区域与鳕鱼和鲱鱼有关，在巴伦支海北部区域与毛鳞鱼有关。水母存在于 1°C<T<10°C 的温度范围内，峰值密度约为 5.5°C，最大比例的水母出现在 4.0-7.0°C 之间。看来，巴伦支海持续变暖的趋势可能对水母有利；然而，在巴伦支海创纪录高温的年份里，它们的生物量最近出现了适度下降。水母无疑是巴伦支海生态系统的重要组成部分，这里提供的数据代表了该地区迄今为止发表的关于水母生物量和分布的最佳总结。
