In this introduction to common algae and cyanobacteria (blue-green algae) in lakes, learn what characteristics are used to identify and distinguish algae and cyanobacteria from each other. We will focus on cyanobacteria and will review environmental conditions that promote the growth of cyanobacteria to nuisance bloom levels. We will discuss health impacts of cyanobacterial toxins on animals and people who ingest, inhale, or have skin contact with cyanobacteria. We will cover recreational guidelines for cyanobacterial toxins, and how to determine safer recreational levels of cyanobacteria in Wisconsin’s lakes. We will also review new tools for tracking and reporting blooms, including a remote sensing app and website. Please bring a hand lens or magnifying glass for hands-on identification practice. Due to the short duration of the workshop, we are unable to cover algal identification using compound light microscopes. This workshop is intended for water professionals, field staff, and citizen monitors.