Recurrent jellyfish blooms are a consequence of global oscillations
Recurrent jellyfish blooms are a consequence of global oscillations
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DOI：
10.1073/pnas.1210920110
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发表时间：
2013-01-15
影响因子：
11.1
通讯作者：
Graham, William M.
中科院分区：
文献类型：
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作者：
Condon, Robert H.;Duarte, Carlos M.;Graham, William M.
据认为，最近全球水母数量增加，这被描述为海洋退化的症状。这种看法主要基于一些案例研究和轶事证据，但对水母种群全球时间趋势的正式分析一直缺失。在这里，我们分析了多个沿海站点水母丰度变化的所有可用的长期数据集，使用线性和逻辑混合模型和效应大小分析，以表明全球水母数量增加的证据。虽然自20世纪70年代以来，水母的数量出现了小幅线性增长，但这种趋势并未得到效应量分析的证实，效应量分析显示，在所有研究的时间段内，水母数量的增加与减少的比例没有差异。相反，最强的非随机趋势表明，水母种群经历了更大的，全球范围内的振荡，大约20年的周期，包括在20世纪90年代的上升阶段，有助于水母丰度的全球增加的看法。需要在今后十年中持续监测，以统计学的置信度阐明1970年后水母的微弱线性增长趋势是基线的实际变化还是振荡的一部分。无论增长的性质如何，考虑到水母大量繁殖对渔业、旅游业和其他人类产业造成的潜在损害，我们的研究结果预示了社会应该准备面对的水母种群的周期性上升和下降阶段。
A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is norobust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.