Screening for biological activities and toxicological effects of 63 phytoplankton species isolated from freshwater, marine and brackish water habitats

► We screen 63 phytoplankton isolates for their toxicity and biological activity potential. ► Several species show antibacterial, anticanobacterial and antialgal properties. ► The highest toxicity is found in the marine dinoflagellate Amphidinium carterae. ► The employed toxicity tests show distinct differences, whereupon the acetylcholinesterase test is much more sensitive than the LUMIStox and brine shrimp assay.