A harmful algal bloom (HAB) contains organisms (usually algae, hence the name) that can severely lower oxygen levels in natural waters, killing marine life. Some HABs are associated with algae-produced toxins. Blooms can last from a few days to many months. After the bloom dies, the microbes which decompose the dead algae use up even more of the oxygen, which can create fish die-offs. When these zones of depleted oxygen cover a large area for an extended period of time, they are referred to as dead zones, where neither fish nor plants are able to survive.

Algal toxins can cause diarrhoea, vomit, tingling, paralysis and other effects in humans, mammals or fish. Algal toxins are produced by various algae and are found both in seawater and fresh water. The algal toxins can be retained in shellfish or contaminate drinking water. They have no taste or smell, and are not eliminated by cooking or freezing.

A series of such marine algal toxins are known, and among them are okadaic acid and the dinophysistoxins, saxitoxins, brevetoxins, domoic acid, azaspiracids, pinnatoxins, yessotoxins, pectenotoxins and cyclic imines, and most of them are found all over the world.

Types of Algal Toxins

There are three main types of algae which can form into harmful algal blooms: cyanobacteria, dinoflagellates and diatoms. All three are made up of microscopic floating organisms which, like plants, can create their own food from sunlight by means of photosynthesis. That ability makes them an essential part of the food web for small fish and other organisms.

Causes

The causes of algal blooms are chemical wastes, primarily nutrients—phosphorus and nitrates—from fertilizers or human waste, climate change with its resultant global warming, thermal pollution from power plants and factories and low water levels in inland waterways and lakes, which reduce water flow and increases water temperatures.

Climate change, according to NOAA scientists, contributes to warmer waters which makes conditions more favorable for algae growth in more regions and farther north. Global warming is also considered a key factor for algal blooms in the Southern hemisphere, acknowledged by scientists in Australia. In general, still, warm, shallow water, combined with high-nutrient conditions in lakes or rivers, increases the risk of harmful algal blooms.

While many varieties of cyanotoxins exist, the one believed to be the most widespread of these toxins is microcystin. Microcystin is a potent liver toxin and possible human carcinogen. Cyanotoxins can also kill livestock and pets that drink affected waters. Fish and bird mortalities have also been reported in water bodies with persistent cyanobacteria blooms.

There is much still to be learned about algal toxins in lakes, rivers and bays. Their presence tells us that a waterbody is most likely stressed by high levels of nutrients such as nitrogen and phosphorus, that risks to the recreational uses of the waterbody and to human and animal health are possible and that related problems, such as low dissolved oxygen due to the decomposition of algal blooms, are likely to also occur.

The Journal of “Clinical Pharmacology and Toxicology Research” is using Editorial Tracking System to maintain quality and transparency to the author in the peer-review process. Review processing will be performed by the editorial board members of the Journal of “Clinical Pharmacology and Toxicology Research” or by Reviewers (outside experts in the field). Two independent reviewer’s approval (Minimum reviewer’s approval) followed by editor approval is obligatory for acceptance of any manuscript excluding an editorial.

On the occasion of its 3 years, Successful Journey, Journal of Clinical Pharmacology and Toxicology decided to provide a partial waiver on its article processing charges to promote quality research from across the nations of the globe to encourage the latest research in the field of Infections, Diseases and Medicine. Journal of Clinical Pharmacology and Toxicology is also planning to release a special issue on its new approaches.

Regards,

Mary Wilson,

Editorial office,

Clinical Pharmacology and Toxicology Research

E-mail: pharmatoxicol@eclinicalsci.com