Copepods drive large-scale trait-mediated effects in marine plankton

Area of Science:

• Marine biology
• Chemical ecology
• Oceanography

Background:

• Nonconsumptive predator effects are understudied in marine plankton.
• Predator cues can significantly alter prey behavior and physiology.
• Understanding these effects is crucial for marine food web dynamics.

Purpose of the Study:

• To investigate chemically induced predator effects in marine plankton.
• To identify the role of copepodamides in phytoplankton defense.
• To assess the ecological impact of copepodamides on a basin-wide scale.

Main Methods:

• Identifying copepodamides as chemical cues.
• Measuring toxin production and bioluminescence in dinoflagellates.
• Assessing defensive trait induction in diatoms (Pseudo-nitzschia seriata).
• Conducting a year-long field study in the northeast Atlantic.

Main Results:

• Copepodamides induce toxin production and bioluminescence in dinoflagellates.
• Copepodamides increase toxin production 10-fold in Pseudo-nitzschia seriata.
• Copepodamides reduce colony size in other diatoms by 50%.
• Natural copepodamide concentrations correlate with phytoplankton defense induction.

Conclusions:

• Copepodamides are a general mechanism for chemically induced predator effects in marine plankton.
• These effects can lead to harmful algal blooms and altered phytoplankton community structure.
• Copepodamides significantly influence marine plankton on basin-wide scales, favoring smaller, defended organisms.