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）在对流层和平流层臭氧消耗中发挥着重要作用。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，而海洋浮游植物已知是公海中这些化合物的来源。在这里，我们研究了光强度对海洋硅藻Ditylum Brightwellii产生 VSL 的影响。在 30、60 和 120 µmol 光子的全光谱日光强度下培养的培养物中的溴二氯甲烷 (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 ) m ^{− 2}  s ^{− 1}使用吹扫捕集气相色谱-质谱法测量。通过测量叶绿素-a浓度和细胞密度来监测浮游植物的生长。叶绿素-a浓度（细胞密度）和 VSL 的生产率都随着光强度的增加而增加。 CHBrCl ₂、CHBr ₂ Cl、CHBr ₃、CHCl ₃和 CH ₂ Br ₂的最大生产率在指数期或稳定期观察到，但在 30 µmol 光子 m ^{− 2}  s ^{−下孵育的 CH} ₂ Br ₂除外¹ . VSL 的叶绿素a 标准化（或细胞标准化）生产率随着光强度的增加而增加，例如，在 30、60 和 120 µmol 光子 m ^{− 2}  s的光强度下，CHCl _3叶绿素a 标准化生产率的最大值^{- 1}分别为 0.06、0.46 和 1.84 µmol（克叶绿素a）^-1 天^{- 1}。我们的结果表明，海洋硅藻是 VSL 的重要来源之一，并且光强度是估计公海 VSL 排放量的重要因素。