题型分类：否定事实信息题

题干分析：定位词metabolites secreted by phytoplankton；利用定位词定位到第四段的第二句至最后，包含较多信息，需要结合选项逐一排除。

选项分析：

A选项说They have a less significant effect on the dominant species of phytoplankton than they do on other species of phytoplankton，而第四段的最后一句But the effect of secretions by all the individuals of the dominant species can be significant both for themselves and for other species，因此该选项与原文描述不符，可选。

B选项说They affect the growth of phytoplankton living in seawater，对应第三句These metabolites can have an effect on the organisms living in the seawater；不选。

C选项说They are secreted in small amounts by individual phytoplankton，对应第四句For any individual organism, the amount of metabolite secreted is small；不选。

D选项说They cause changes in seawater that result in species succession of，对应第一句Yet another explanation is that species succession is a consequence of changes in seawater brought about by the phytoplankton living in it；不选。