An Overview of the Impact of Climate Change and Acidification of the Oceans on the Growth and Bloom of Marine Algae with Emphasis on Harmful Algae Blooms (HABs)

Climate change resulting from anthropogenic activities and subsequent increase in greenhouse gases with the potential to directly affect temperature, light, salinity, changes in wind and precipitation patterns, changes in organic matter and water pH, and rise of sea levels is one of the most important and challenging topics in oceanography and biology. Therefore, it seems necessary to study the effects of climate change on marine aquatic organisms especially microalgae as primary producers in marine ecosystem. Research shows that global warming and rise of sea temperatures have negative effects on photosynthetic microalgae, however, increase the density and the bloom of harmful algae. The study of harmful microalgae as a potential of environmental hazard for aquatic organisms and even humans has a special interest because some of these microalgae are toxic to the marine organisms and cause a lot of damage on the fisheries and aquaculture industry. Research shows that the rate of growth and blooms of harmful microalgae has reached its highest level in the last 4 decades as the result of significant climate change and further warming, and their pattern of accumulation, life strategy, distribution have changed under the probable influence of climate change. The present study has reviewed effect of climate change on marine environments and especially on microalgae; and has aimed to evaluate the challenges and consequences of increased blooms of harmful algae, algae toxins on marine ecosystem and human health.