Australian Rivers Institute - Coasts and Estuaries, Griffith School of Environment, Gold Coast Campus, Griffith University, Southport, 4222, Qld, Australia.
Glob Chang Biol. 2014 Jan;20(1):28-37. doi: 10.1111/gcb.12408. Epub 2013 Oct 28.
Increasing ocean temperatures and strengthening boundary currents have caused the poleward migration of many marine species. Cubozoan jellyfish known to cause Irukandji syndrome have historically been confined to tropical waters but may be expanding into subtropical regions. Here, we examine the interactive effects of warming and acidification on the population dynamics of polyps of an Irukandji jellyfish, Alatina nr mordens, and the formation of statoliths in newly metamorphosed medusae, to determine if this jellyfish could tolerate future conditions predicted for southeast Queensland (SEQ), Australia. Two experiments, examining the orthogonal factors of temperature and pH, were undertaken. Experiment 1 mimicked the current, ca. 2050 and ca. 2100 summer temperature and pH conditions predicted for SEQ using A1F1 scenarios (temperature: 25, 27, 29 °C; pH: 7.9, 7.8, 7.6) and Experiment 2 mimicked current and future winter conditions (18 and 22 °C, pH 7.9, 7.8, 7.6). All polyps in Experiment 1 survived and budded. Fewer polyps budded in the lower pH treatments; however, patterns varied slightly among temperature treatments. Statoliths at pH 7.6 were 24% narrower than those at pH 7.8 and 7.9. Most polyps survived the winter conditions mimicked by Experiment 2 but only polyps in the 22 °C, pH 7.9 treatment increased significantly. The current absence of A. nr mordens medusae in SEQ, despite the polyps' ability to tolerate the current temperature and pH conditions, suggests that ecological, rather than abiotic factors currently limit their distribution. Observations that budding was lower under low pH treatments suggest that rates of asexual reproduction will likely be much slower in the future. We consider that A. nr mordens polyps are likely to tolerate future conditions but are unlikely to thrive in the long term. However, if polyps can overcome potential ecological boundaries and acidification proceeds slowly A. nr mordens could expand polewards in the short term.
海洋温度升高和边界流增强导致许多海洋物种向极地迁移。已知会引起伊鲁坎吉综合征的立方水母已被限制在热带水域，但可能正在向亚热带地区扩张。在这里，我们研究了变暖和酸化对伊鲁坎吉水母，即 Alatina nr mordens 的水螅体种群动态和新变态的幼水母中耳石形成的相互影响，以确定这种水母是否能耐受澳大利亚昆士兰州东南部（SEQ）未来预测的条件。进行了两项实验，研究了温度和 pH 的正交因素。实验 1 模拟了当前、约 2050 年和约 2100 年夏季预测的 SEQ 条件，使用 A1F1 情景（温度：25、27、29°C；pH：7.9、7.8、7.6）；实验 2 模拟了当前和未来的冬季条件（18 和 22°C，pH 7.9、7.8、7.6）。实验 1 中的所有水螅体都存活并出芽。在较低 pH 处理中，出芽的水螅体较少；然而，温度处理之间的模式略有不同。在 pH 7.6 时，耳石比 pH 7.8 和 7.9 时窄 24%。大多数水螅体在实验 2 模拟的冬季条件下存活，但只有在 22°C、pH 7.9 处理下水螅体显著增加。尽管水螅体能够耐受当前的温度和 pH 条件，但伊鲁坎吉水母的幼体目前仍不存在于 SEQ 中，这表明目前限制其分布的是生态因素，而不是非生物因素。在低 pH 处理下出芽率较低的观察结果表明，未来无性繁殖的速度可能会慢得多。我们认为，A. nr mordens 水螅体可能能够耐受未来的条件，但不太可能长期繁荣。然而，如果水螅体能够克服潜在的生态边界，并且酸化进展缓慢，A. nr mordens 可能会在短期内向极地扩张。
