Through global shipping and trade, mankind has inadvertently spread marine organisms to such an extent that many are now considered cosmopolitan. Further aggravated by changes in the foodweb structure (overfishing), eutrophication and climate change, this has led to a substantial increase in the occurrence of harmful algal blooms (HABs). Next to the large potential for environmental damage, these recurring events have become a global public health concern as many species produce potent marine toxins that may lead to shellfish poisoning. To ensure food safety, the mouse bioassay has long been used to screen seafood for the presence of these toxins. Due to ethical concerns, however, this test is now being replaced by alternative chemical analyses.