Methane (CH₄) production in the ocean surface mixed layer is a widespread but still largely unexplained phenomenon. In this context marine algae have recently been described as a possible source of CH₄ in surface waters. In the present study we investigated the effects of temperature and light intensity (including daylength) on CH₄ formation from three widespread marine algal species Emiliania huxleyi, Phaeocystis globosa, and Chrysochromulina sp. Rates of E. huxleyi increased by 210% when temperature increased in a range from 10°C to 21.5°C, while a further increase in temperature (up to 23.8°C) showed reduction of CH₄ production rates. Our results clearly showed that CH₄ formation of E. huxleyi is controlled by light: When light intensity increased from 30 to 2,670 μmol m⁻² s⁻¹, CH₄ emission rates increased continuously by almost 1 order of magnitude and was more than 1 order of magnitude higher when the daylength (light period) was extended from 6/18 hr light‐dark cycle to continuous light. Furthermore, light intensity is also an important factor controlling CH₄ emissions of Chrysochromulina sp. and P. globosa and could therefore be a species‐independent regulator of phytoplankton CH₄ production. Based on our results, we might conclude that extensive blooms of E. huxleyi could act as a main regional source of CH₄ in surface water, since blooming of E. huxleyi is related to the seasonal increase in both light and temperature, which also stimulate CH₄ production. Under typical global change scenarios, E. huxleyi will increase its CH₄ production in the future.

中文翻译：

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温度和光照对海洋浮游植物甲烷产生的影响

海洋表面混合层中的甲烷（CH ₄）生产是一种普遍存在的现象，但仍然是无法解释的现象。在这方面，近来海藻被描述为地表水中CH ₄的可能来源。在本研究中，我们研究了温度和光强度（包括日长）对三种广泛分布的海洋藻类Emiliania huxleyi，Phaeocystis globosa和Chrysochromulina sp。CH ₄形成的影响。当温度在10°C至21.5°C范围内升高时，霍乱弧菌的发生率增加210％，而温度进一步升高（最高23.8°C）则表明CH _4的减少生产率。我们的结果清楚地表明，赫克斯利肠杆菌的CH ₄形成受光控制：当光强度从30增加到2,670μmolm ^-2  s ^-1时，CH ₄发射速率连续增加近1个数量级，并超过1。当日长（光照周期）从6/18小时的明暗周期延长到连续光照时，数量级增加。此外，光强度也是控制Chrysochromulina sp。CH ₄排放的重要因素。和P. globosa，因此可能是浮游植物CH ₄的物种独立调节剂生产。根据我们的结果，我们可能会得出结论，虎的大量开花可能是地表水中CH ₄的主要区域来源，因为虎的开花与光照和温度的季节性增加有关，这也刺激了CH ₄生产。在典型的全球变化情况下，赫黎E. huxleyi将来会增加其CH _4的产量。