Kareniaceae is an accepted marine family of relatively small, toxic, unarmored dinoflagellates belonging to the order Gymnodiniales. Species in the Kareniaceae clade often cause harmful discolored green algal blooms (HABs) that pose a safety and health risk to humans and the surrounding regions. Such blooms also pose a risk to coastal aquaculture worldwide, especially in places like France, the Atlantic Ocean, the English Channel and the Mediterranean Sea.