Harmful algal blooms (HABs) impact marine ecosystems, aquaculture, and tourism industries, and can pose a risk to human health across the world. Within ICES region, the impacts of HABs are recorded on an annual basis. The most frequently recorded HAB events are closures of shellfish harvesting areas due to the accumulation of algal toxins in marine bi-valve molluscs exceeding regulatory thresholds. Additionally, mortalities of farmed and wild fish, benthic organisms, sea birds, and mammals can also be recorded. Water discolurations, scums, and foams can also cause problems for local tourism industries with some high biomass algal blooms resulting in mortalities of wild and farmed fish, and benthic organisms through the generation of anoxia.
The Intergovernmental Oceanographic Commission (IOC) of UNESCO has just published the first Global HAB Status Report (GHSR). The aim of this report is to provide the first assessment of the status of HABs around the world and look for the presence of global trends.
The study found that reported HAB events have increased in some regions and decreased or stabilised in others. This variability in regional trends was driven by differences in bloom species, type, and emergent impacts. A widely-stated view that HABs are on the rise, perhaps due to climate change, throughout the world is not confirmed. Instead, trends in HAB events need to be considered regionally, and at the species level to identify drivers at a more local scale. Regional assessments point at intensified monitoring efforts associated with increased aquaculture production and tourism, being responsible for the perceived increase in harmful algal events.
The full Global HAB Status Report consists of:
Toxin producing HAB species from ICES area.
The majority of HAB events in ICES area are closures of shellfish harvesting areas due to algal toxins above regulatory levels. Multiple algal toxins produced by different genera and species of phytoplankton are responsible:
There are other significant HAB events in ICES area:
Aerial photograph of a Karenia brevis bloom along the Texas coast. Photo: Texas Parks and Wildlife.
Marine harmful algal blooms (HABs) in the United States: History, current status and future trends.Anderson, D.M., Fensin, E., Gobler, C.J., Hoeglund, A.E., Hubbard, K.A., Kulis, D.M., Landsberg, J.H., Lefebvre, K.A., Provoost, P., Richlen, M.L. and Smith, J.L.
Three decades of data on phytoplankton and phycotoxins on the French coast: Lessons from REPHY and REPHYTOX.Belin, C., Soudant, D. and Amzil, Z.
Diversity and regional distribution of harmful algal events along the Atlantic margin of EuropeBresnan E., Arévalo F.,Belin C., Branco M., Cembella A., Clarke D., Correa J., Davidson K., Dhanji-Rapkova M., Fernández-Lozano R., Fernández-Tejedor M., Guðfinnsson H., Jaén Carbonelli D., Laza-Martinez A., Lemoine M., Lewis A. M., Maskrey B. H., Mamán Menéndez L., McKinney A., Pazos Y., Revilla M., Siano R., Silva A., Swan S., Turner A. D., Schweibold L., Provoost P. and Enevoldsen H.
Harmful algal blooms and their effects in coastal seas of northern EuropeKarlson, B., Andersen, P., Arneborg, L., Cembella, A.D., Eikrem, W., John, U., Joy-West, J., Klemm, K., Kobos, J., Lehtinen, S., Lundholm, N., Mazur-Marzec, H., Naustvoll, L., Poelman, M., Provoost, P., De Rijcke, M., Suikkanen, S.
Three decades of Canadian marine harmful algal events: phytoplankton and phycotoxins of concern to human and ecosystem health. McKenzie, C.H., Bates, S.S., Martin, J.L., Haigh, N., Howland, K.L., Lewis, N.I., Locke, A., Peña, A., Poulin, M., Rochon, A. and Rourke, W.A.
Nature Communications Earth & Environment
Perceived global increase in algal blooms is attributable to intensified monitoring and emerging bloom impactsHallegraeff, G.M., Anderson, D.M., Belin, C. Bottein M-Y., Bresnan E., Chinain M., Enevoldsen H., Iwataki M., Karlson B., McKenzie C. H., Sunesen I., Pitcher G. C., Richardson A., Schweibold L., Tester P.A., Trainer V. L. Yniguez A. and Zingone A.