Diatom‐produced allelochemicals trigger trophic cascades in the planktonic food web

摘要: Diatoms produce a series of cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA) in response to cell injury or stress. However, little information exists on the PUA effects pelagic food web. A set experiments was conducted Chesapeake Bay and coastal Atlantic waters using dissolved (2E,4E-octadienal 2E,4E-heptadienal), natural assemblages phytoplankton microzooplankton, copepod Acartia tonsa. The results demonstrate that primarily acts deterrent for microzooplankton herbivory diatoms, while enhancing picophytoplankton. This switch should favor PUA-producing diatoms by simultaneously reducing direct grazing losses competition. Additionally, stimulated predation particularly ciliates. Combined, these have potential disrupt growth-grazing equilibrium web create an opportunity bloom development.