Many planktonic algae produce biotoxins that can affect grazer feeding, mortality and recruitment rates, or alter swimming behaviour and therefore predation risk. This report reviews the literature on the effects of algal biotoxins (excluding cyanobacteria) on pelagic copepod biology, focussing on copepod species that are important in Scottish waters.

Marine Scotland Science currently holds more than 10 years inshore coastal monitoring data on the occurrence of toxic phytoplankton and corresponding zooplankton species from the Stonehaven and Loch Ewe monitoring sites, and these data are summarised.

The relevant biotoxins that could influence copepod population dynamics in Scottish waters are identified as poly-unsaturated aldehydes from diatoms, and toxins associated with paralytic shellfish poisoning (Alexandrium spp.), diarrhetic shellfish poisoning (Dinophysis spp.) and amnesic shellfish poisoning (Pseudo-nitzschia spp.). There is potential for these Scottish field data and further experimental studies to provide insights into the way that interspecies relationships and energy flow in food webs can be affected by the production, transfer and effects of algal biotoxins.