Toxic Algae and Effects of Algal Poisoning in Animals and Human Beings
1 Department of Botany, Faculty of Life Sciences, Wazir Ram Singh Government College Dehri, District Kangra (H.P.) INDIA- 176022.
Algae include primitive thalloid plants having enormous uses. Despite of many beneficial activities, some algae cause sickness or death to the living organisms, called 'toxic algae'. Not only fresh water algae are toxic but marine algae are also toxic. A species may have different strains, some of which may be toxic and other non-toxic. Toxic algae affect different body parts of an organism. Algal blooms which generally appear in green, blue or brownish colour in warm seasons for longer duration, can look like foam, scum, or mats or like paint floating on the surface of water, contain a large numbers of pigmented cells and hence composed of bio-toxins. These toxins are secondary metabolites which are produced by a varity of algal species and harmful to organisms. The present paper describes the toxic algae belonging to Cyanophyceae, Dinophyceae, and Chlorophyceae groups; toxins produced by algae, and the effects of algal poisoning on animals and human beings.
Keywords: Algae, Toxins, Poisoning, Cyanophyceae, Dinophyceae, Chlorophyceae
Freshwater algae being a natural part of the aquatic ecosystem, when growing out of control under suitable environmental conditions like stagnant, warm water and in nutrient-rich level, may be due to the addition of fertilizers and its runoff in to the water bodies, if not managed effectively; sometimes produces toxic or harmful effects in the life of other organisms like fish, marine mammals, birds, and even human beings (Amasha and Aly, 2019; Alshehri, 2020). Harmful algal blooms promoted by human activities as well as climate change (Sinha, et al., 2017; Gobler, 2020; Trainer, et al., 2020; Burford, et al., 2020). Mostly toxic algae belonging to Cyanophyta and dinoflagellates have been reported. The toxicity depends on the ecological and developmental conditions of the algae. Environmental conditions influence the biosynthesis of toxin production in algae (Boopathi and Ki, 2014). Secondary metabolites play role in the colonization and bloom formation (Kurmayer, et al., 2016). Algal poisoning has been reported from Argentina, Australia, Bermuda, Brazil, Britain, Canada, Central America, Finland, Israel, Morocco, New Zealand, North America, Russia, South Africa, and U.S.A. (Kamat, 1982). It may be noted that Microcystis aeruginosa is a common alga throughout India. In temple ponds, it is probably the most common alga, but no toxic effects are recorded. Anabaena flos-aquae is also not rare in India. It is customary and religious also for the devotees to wash their feet and hands and even gargle with water from the temple ponds. This is a sort of ritual and it is certainly unhygienic when the water contains bloom (Kamat, 1982).
MATERIALS AND METHODS
An analysis of various toxic algae reported from the literature was carried out and an account belonging to different algal groups and their effects on animals and human beings were included in the results.
rESULTS AND DISCUSSION
Anabaena circinalis, A. flos-aquae, A. inequalis, A. limnetica, A. nadsonii, A. scheremetievi, Aphanizomenonflos-aquae, Aphanothececyanea, A. nidularis, Gloetrichiaechinulata, Lyngbyabizgei, Microcystis aeruginosa, M. toxica, Nidulariaspermigena.
Gymnodinium brevis, G. flavum, G. mikimotoi, G. veneficum, Gonyauloxcatenella, G. monilata, G. tamarensis, Prymnesiumparvum, Pyrodiniumphoneus.
Chlorella and Scenedesmus
Toxins may be produced according to the strains of the different species. According to Gorham et al. (1964) toxin of Anabaena flos-aquae, A. lemmermannii, is a polypeptide. The toxin of Microcystis is a non-volatile, acidic component with great absorption qualities and is a neurotoxin. It is a cyclic peptide composed of about 10 amino acids; some of them are D-serine, L-ornithine, aspartic acid, and glutamic acid. Gorham et al. (1964) isolated 28 strains of Microcystics aeruginouaout of which less than 1/3 rd produce FDF. He also found that different strains of this alga are genetically heterogeneous for toxin production.
The toxin of Prymnesium pervum is nondialyzable, thermolable, and Acidlabile. The endotoxin of Gonyavloxis retired to as Ichthyosarcodin with a chemical formula C16 H31 NO16.
It is an alkaloid, nonvolatile, water-soluble, and acid-stable. It can be stored for many months without losing its strength. The poison is thought to be ten times more potent than strychnine and its effects are more like those of Botulina poisoning. One millionth of a gram injected is sufficient to kill a mouse.
The toxin of Gymnodiniumveneficium is water-soluble, ether soluble, acid labile, of high molecular weight, and acts on the nervous system.
Algal toxins have been found poisonous to fishes, shell fishes, mussels, live stocks, cattles, horses, swines, water fowls, ducks, chickens birds, etc and even human beings. Symptoms and survival time vary from case to case. Cases of the death of a full grown cow and other cattle in ½ an hour or less are known (Kamat, 1982).
Besides death, the harmful effects of algae (e.g. Microcystistoxica) include loss of weight, weakness, liver pathology, abortion, etc. Some pigments like phycocyanin are sensitive to light and when they are in blood capillaries, cause internal burning and peeling of the skin.
The toxin extracted from Microcystis when given to animals shows an enlargement in of the liver tissue, a failure of blood to clot, and congestion within the spleen (Kamat, 1982).
The toxin produced by Gymnodiniumaffects both nerves and muscles and inhibit the response of skeletal muscles to acetylcholine by depolarizing membranes over which nerve impulse pass.
Symptoms produced by toxins of Gonyavlaxare dizziness, nervous disorders, and death within 30 minutes and 24 hours respectively.
Dogs and livestock account for majority of cyanotoxin poisoning in animals (Wood, 2016). An overview of cyanobacterial poisoning in livestock, wild mammals and birds has been studied by Stewart et al. in 2008. Poisoning of fish and other animals have been reported by a large number of workers as under:
The toxin of Gymnodiniumis enough to kill whole schools (school) of fish within many square miles particularly in the gully of Mexico, and the New Jersey coast where the alga forms the Red tide (Kamat, 1982).
Many a time’s fish deaths on a large scale are reported from different parts of India, almost always these deaths are due to depletion of the oxygen during nights and mostly during cloudy days, which may be mistaken for toxic effects (Kamat, 1982). Infact, according to some, mortality is partly caused by O2 deficiency and partly by a toxin produced by algal bloom of Microcystis aeruginosa, Anabaena flos-aquae, Aphanizomenonflos-aquae.
There are some indications that algae are occasionally toxic to human beings. Recreational activities are responsible for approximately half of the cyanotoxins poisoning in human beings (Wood, 2016; Vidal, et al., 2017)
Algae grow abundantly in water reservoirs where an excess of nutrients are available to them. This algal growth floats on the water surface and looks like foam or soap/other. In warmer season these blooms progress and persist for longer duration (Moore, et al., 2015; Grifith’s, et al., 2019). It is called water bloom. The harmful algal blooms responds to climate change (Huisman, et al., 2018; Ralston and Moore, 2020). Bloom forming algae release certain toxins. Although all the algae poisons mentioned cause considerable economic losses, the ones that have caused human deaths and sickness are of great public health importance in certain areas are the poisons from certain toxic algae that have causes shellfish poisoning in humans (Das and Sarkar, 2012; Trevino, et al., 2015). The trend toward the use of more products from the sea as food for man and the culturing of various algae for food makes it important that we know more about various toxic algae and the toxins that they produce. Proper management of nutrients ending up in water bodies, to stop excessive use of fertilizers and limiting erosion are the steps necessarily required for the solution.
It can be concluded from the present study that algal members mostly belonging to cyanophyaceae are more toxic followed by dinophyceae and Chlorophyceae. Environmental factors like light intensity and temperature leading to more accumulation of algal biomass and hence algal toxin production which ultimately have harmful effects in aquatic life as well as in the animals and human beings on land directly or indirectly.
ACKNOWLEDGMENTS: The author is thankful to the Principal and the staff of W.R.S. Govt. College Dehri, District Kangra (Himachal Pradesh) India for constant support and encouragement during the study. The author is also thankful to the reviewers for their constructive comments, thorough feedback and rapidly replies.
CONFLICT OF INTEREST: None
FINANCIAL SUPPORT: None
ETHICS STATEMENT: N.A.
Alshehri, M. A. (2020). Identification of Algae Species Using Advanced Molecular Techniques. International Journal of Pharmaceutical Research&Allied Sciences, 9(1), 142-159.
Amasha, R. H., & Aly, M. M. (2019). removal of dangerous heavy metal and some human pathogens by dried green algae collected from Jeddah coast. Pharmacophore, 10(3), 5-13.
Boopathi, T., & Ki, J. S. (2014). Impact of environmental factors on the regulation of cyanotoxin production. Toxins, 6(7), 1951-1978.
Buratti, F. M., Manganelli, M., Vichi, S., Stefanelli, M., Scardala, S., Testai, E., & Funari, E. (2017). Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Archives of toxicology, 91(3), 1049-1130. https://doi.org/10.1007/s00204-016-1913-6
Burford, M. A., Carey, C. C., Hamilton, D. P., Huisman, J., Paerl, H. W., Wood, S. A., & Wulff, A. (2020). Perspective: Advancing the research agenda for improving understanding of cyanobacteria in a future of global change. Harmful Algae, 91, 101601. 10.1016/j.hal.2019.04.004
Das, S., & Sarkar, N. S. (2012). Fish poisoning events in india vis-à-vis harmful algal blooms: a review. Eco Chronicle. 13(1), 36-42.
Gobler, C. J. (2020). Climate change and harmful algal blooms: Insights and perspective. Harmful Algae, 91, 1-4.
Gorham, P., McLachlan, J., Hammer, U. T., & Kim, W. K. (1964). Isolation and culture of toxic strains of Anabaena flos-aquae (Lingb.). Verhandlungen des InternationalenVereinLimnologie. 15(2): 769-780.
Griffith, A. W., Doherty, O. M., & Gobler, C. J. (2019). Ocean warming along temperate western boundaries of the Northern Hemisphere promotes an expansion of Cochlodinium polykrikoides blooms. Proceedings of the Royal Society B, 286(1904), 20190340. https://doi.org/10.1098/rspb.2019.0340
Huisman, J., Codd, G. A., Paerl, H. W., Ibelings, B. W., Verspagen, J. M., & Visser, P. M. (2018). Cyanobacterial blooms. Nature Reviews Microbiology, 16(8), 471-483. https://doi.org/10.1038/s41579-018-0040-1
Kamat, N. D. (1982). Topics in algae. Sai Kripa Prakashan, Aurangabad. 338pp.
Kubickova, B., Babica, P., Hilscherová, K., & Šindlerová, L. (2019). Effects of cyanobacterial toxins on the human gastrointestinal tract and the mucosal innate immune system. Environmental Sciences Europe, 31(1), 1-27.https://doi.org/10.1186/s12302-019-0212-2
Kurmayer, R., Deng, L., & Entfellner, E. (2016). Role of toxic and bioactive secondary metabolites in colonization and bloom formation by filamentous cyanobacteria Planktothrix. Harmful algae, 54, 69-86.
Moore, S. K., Johnstone, J. A., Banas, N. S., & Salathe Jr, E. P. (2015). Present-day and future climate pathways affecting Alexandrium blooms in Puget Sound, WA, USA. Harmful Algae, 48, 1-11.
Ralston, D. K., & Moore, S. K. (2020). Modeling harmful algal blooms in a changing climate. Harmful algae, 91, 101729. DOI: 10.1016/j.hal.2019.101729
Reddy, M. R. K., & Mastan, S. A. (2015). Algal Toxins and their Impact on Human Health. Biomedical and Pharmacology Journal, 4(1), 129-134. http://biomedpharmajournal.org/?p=1768
Schwimmer, D., & Schwimmer, M. (1964). Algae and medicine. In: Algae and man. Edited by Jackson DF. New York: Plenum Press. 412pp.
Sinha, E., Michalak, A. M., & Balaji, V. (2017). Eutrophication will increase during the 21st century as a result of precipitation changes. Science, 357(6349), 405-408.
Stewart, I., Seawright, A. A., & Shaw, G. R. (2008). Cyanobacterial poisoning in livestock, wild mammals and birds – an overview. In: Hudnell H.K. (eds) Cyanobacterial Harmful Algal Blooms: State of the Science and Research Needs. Advances in Experimental Medicine and Biology, vol 619. Springer, New York, NY. https://doi.org/10.1007/978-0-387-75865-7_28
Trainer, V. L., Moore, S. K., Hallegraeff, G., Kudela, R. M., Clement, A., Mardones, J. I., & Cochlan, W. P. (2020). Pelagic harmful algal blooms and climate change: Lessons from nature’s experiments with extremes. Harmful Algae, 91, 101591. 10.1016/j.hal.2019.03.009
Trevino-Garrison, I., DeMent, J., Ahmed, F.S., Haines-Lieber, P., Langer, T., Ménager, H., Neff, J., Van der Merwe, D., & Carney, E. (2015). Human illnesses and animal deaths associated with freshwater harmful algal blooms—Kansas. Toxins, 7(2), 353-366. https://doi.org/10.3390/toxins7020353
Vidal, F., Sedan, D., D’Agostino, D., Cavalieri, M.L., Mullen, E., Parot Varela, M.M., Flores, C., Caixach, J., & Andrinolo, D. (2017). Recreational exposure during algal bloom in Carrasco Beach, Uruguay: A liver failure case report. Toxins, 9(9), 267. https://doi.org/10.3390/toxins9090267
Wood, R. (2016). Acute animal and human poisonings from cyanotoxin exposure—A review of the literature. Environment international, 91, 276-282.https://doi.org/10.1016/j.envint.2016.02.026
Young, N., Sharpe, R. A., Barciela, R., Nichols, G., Davidson, K., Berdalet, E., & Fleming, L. E. (2020). Marine harmful algal blooms and human health: A systematic scoping review. Harmful Algae, 98, 101901. https://doi.org/10.1016/j.hal.2020.101901