Very short-lived substances (VSLs) are known to play an important role in ozone depletion in the troposphere and stratosphere. Environmental factors that influence the production of these compounds by marine phytoplankton, which is known to be the source of these compounds in open oceans, have not yet been well studied. Here we examined the effects of light intensity on the production of VSLs by the marine diatom Ditylum brightwellii. Bromodichloromethane (CHBrCl₂), dibromochloromethane (CHBr₂Cl), bromoform (CHBr₃), chloroform (CHCl₃), and dibromomethane (CH₂Br₂) in cultures incubated under full spectrum daylight intensities of 30, 60, and 120 µmol photons m^− 2 s^− 1 were measured using purge and trap gas chromatograph–mass spectrometry. Phytoplankton growth was monitored by measuring chlorophyll-a concentration and cell density. Both the chlorophyll-a concentration (the cell density) and the production rates of VSLs increased with increasing light intensity. The maximum production rates of CHBrCl₂, CHBr₂Cl, CHBr₃, CHCl₃, and CH₂Br₂ were observed during the exponential or stationary phase, with the exception of CH₂Br₂ incubated under 30 µmol photons m^− 2 s^− 1. The chlorophyll a-normalized (or cell-normalized) production rates of VSLs increased with increasing light intensity, e.g., the maximum of chlorophyll a-normalized production rates of CHCl₃ under light intensities of 30, 60 and 120 µmol photons m^− 2 s^− 1 were 0.06, 0.46 and 1.84 µmol (g chlorophyll a) ⁻¹ day^− 1, respectively. Our results suggest that marine diatoms are one of the significant sources of VSLs and that light intensity is a significant factor in estimating VSLs emissions from the open ocean.

众所周知，极短寿命物质 (VSL) 在对流层和平流层的臭氧消耗中起着重要作用。影响海洋浮游植物产生这些化合物的环境因素尚未得到充分研究，海洋浮游植物已知是这些化合物的来源。在这里，我们研究了光强度对海洋硅藻Ditylum Brightwellii 产生 VSL 的影响。溴二氯甲烷 (CHBrCl ₂ )、二溴氯甲烷 (CHBr ₂ Cl)、溴仿 (CHBr ₃ )、氯仿 (CHCl ₃ ) 和二溴甲烷 (CH ₂ Br ₂) 在全光谱日光强度 30、60 和 120 µmol 光子 m ^{- 2}  s ^{- 1}下培养的培养物中，使用吹扫捕集气相色谱-质谱法测量。浮游植物的生长通过测定叶绿素监测一个浓度和细胞密度。无论是叶绿素一个浓度（细胞密度）和浮动利差的生产速率随着光强度的增加。CHBrCl ₂、CHBr ₂ Cl、CHBr ₃、CHCl ₃和CH ₂ Br ₂的最大产率在指数相或固定相期间观察到，CH ₂除外Br ₂在30 µmol 光子m ^{- 2}  s ^{- 1}下培养。VSLs的叶绿素a归一化（或细胞归一化）生产速率随着光照强度的增加而增加，例如，在30、60 和 120 µmol 光子 m ^{− 2}  s 的光照强度下，CHCl ₃的叶绿素a归一化生产速率的最大值^{- 1}分别为 0.06、0.46 和 1.84 µmol (g 叶绿素a ) ^-1 天^{- 1}。我们的研究结果表明，海洋硅藻是 VSL 的重要来源之一，光强度是估算来自公海的 VSL 排放量的重要因素。