An algal bloom is a rapid increase in the population of algae (prolific growth of algae), which can occur in both freshwater (e.g. cyanobacteria/blue-green algae- Microcystis, Anabaena) and marine environments (e.g. dinoflagellates, diatoms). Environmental conditions that can promote algal blooms are temperature, nutrients (phosphorus and nitrogen) sunlight and other factors etc. A number of algae produce toxins such as cyanobacteria/blue green algae (e.g. microcystins) and dinoflagellates (e.g. paralytic shellfish poisoning- saxitoxins-STX; ciguatera fish poisoning- ciguatoxins-CTX).
Algal blooms of toxic cyanobacteria/blue-green algae can affect the water quality by causing peculiar tastes, odours, and discolouration. Irrigation with cyanobacterial toxin contaminated water may cause accumulation of toxins on the external surface of edible plant material or pastures. Algae are a regular component of food for fish and seafood organisms. Fish that don't feed on algae, may still receive toxins through the food web (such as from feeding on zooplankton and shellfish that have been contaminated with algal toxins). Algal toxins bioaccumulate in seafood (such as fish, shellfish), several studies reported accumulation of microcystins in freshwater seafood that are eaten by humans including fish, mussels and shrimps. A serious human poisoning due to cyanobacterial toxins caused the deaths of more than 50 patients who received cyanobacterial contaminated dialysis water in Brazil in 1996. Incidents of paralytic shellfish poisoning (PSP) have been reported throughout the world including human poisoning.Ciguatera fish poisoning (CFP) is one of the most common types of marine food poisoning, in particular in the tropical and subtropical Pacific and Indian Ocean regions.
Question: Will climate change (such as rise of temperature) enhance the frequency and intensity of algal blooms in freshwater and marine environments and thereby will it pose more risks to human health in the future?
Dear Thijs, Thank you for the very good review paper which shows that cyanobacteria blooms frequency may increase in a warming world since there is a competitive advantage for cyanobacteria to grow better in warmer temperatures. This will increase potential exposure of aquatic organisms and humans to cyanobacterial toxins under global warming. regards. Golam
Studying effect of cyanobacteria toxin on aquatic organism is a good work. Other than this may we also have see the algae of highly eutrophic waters. Climatic variable of such water body may indicate adverse condition.
Dear Soma, thank you for your inputs, the proliferation of cyanobacteria which is projected to increase due to climate change may cause severe water quality problem and a threat to human consumer. For example, in Uganda, a recent study found that microcystin concentration in fish harvested from a lake exceeded the WHO tolerable daily intake by several times
If we can use some biological method to control blooming it will be beneficial. May be some weed fishes. Again need lot of research to study harmful effect on the ecosystem. Can we think of a review on this topic or on a related topic? My email id: [email protected]. We can try.
Dear Soma,
I think there are many review papers already published in this field and a lot of research is going on!
Dear Ali Fade, Thank you
Researchers found that cyanobacteria grow better in warmer temperatures; therefore, bloom frequency may increase with the rising global temperature. In addition it is also reported that increased temperature promotes the growth of toxic Microcystis compared to its non-toxic strains. Some researchers also reported that temperature may also influence the type of toxin production in many species of cyanobacteria.
Hi
Article An Update on the Global Stressors and Constraints Affecting ...
Rise in thermal strata will enhance harmful cyanobacterial group and reduce population of other useful microalgal group. This phenomenan will certainly give rise to disbalance in ecosystem food chain and finally resulting into dwindling ecosysytem biomass. In this perspective modelling approach linked with climatic variables will aid as a better tool for ecosystem assessment and forecasting.
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