Harmful Algal Blooms in Benthic Systems Recent Progress and Future Research

Shallow, well-illuminated coastal waters from tropical to temperate latitudes are attractive environments for humans. Beaches and coral reefs have provided lodging and food to coastal communities for centuries. Unfortunately, tropical regions traditionally have been threatened by outbreaks of the toxic benthic dinoflagellate Gambierdiscus, which is associated with ciguatera fish poisoning. The ciguatoxins produced by Gambierdiscus bioaccumulate in reef fishes and are responsible for the most common algal toxin-related illnesses, globally affecting the greatest number of victims and often with significant long-term health effects. Recently, Gambierdiscus has been documented in subtropical and temperate latitudes. Blooms of another benthic and toxic dinoflagellate, Ostreopsis, have become more frequent and intense, especially in temperate waters. Ostreopsis produces palytoxins and analogues, and some outbreaks have been associated with massive benthic faunal damage and respiratory irritations in humans exposed to aerosols. The increased frequency of harmful events and the biogeographic extension of benthic microalgae incentivized the launch of the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Core Research Project on "Benthic Harmful Algal Blooms" in 2010. This article summarizes the main scientific advances and gaps in related knowledge as well as advances the project has made toward managing and mitigating the impacts of benthic HABs on human illnesses and marine resource losses.