Don't be intimidated by the title, there will be no bloodshed on this post, I promise (?). What we're looking at today is an algal bloom phenomenon. Under right conditions algae population might increase over a specific area with harmful consequences.
Image from the Public Domain, source: commons.wikimedia.org
The Vegan Killer!
Ok, ok, I lied! This story is about an evil serial killer! You wouldn't believe that tiny little seaplants are capable of killing anyone, would you? I mean, they are so small, how would they ever manage to kill? Hellooooo! There is power in unity people, read on below...
Algae population can rise uncontrollably resulting in the release of harmful toxins in high amounts. In other cases this can just end up in oxygen depletion of the waters. Both effects seem deadly catastrophic for marine life (fish, birds and other creatures of the "afflicted" ecosystems) and unlucky people who may happen to consume affected seafood. The "killer's" nickname? Red tide. The term is not the most accurate naming, but it has prevailed in everyday language, especially in the USA. Its official name? HAB (Harmful Algae Bloom) [1].
The killer is nothing more than some phytoplankton species, dinoflagellates, which carry specific pigments resulting in the coloration of the waters they are found in. The colors range from red, brown and yellow [3], [4].
Dinoflagellate Karenia brevis - Image from the Public Domain, source: commons.wikimedia.org
The Execution Plan
This is not fully understood, but as the NOOA suggests after conducted studies, wind and water currents might lay the grounds for the overpopulation to take place. Another "accomplice" can be the nutrients (like phosphorus and nitrogen) from agricultural activities that end up in sea, river or lake waters. Other natural phenomena may also act supportively and they are floods, droughts, hurricanes. Moreover, unusually warm water temperatures caused by water pollution along the coasts and climatic changes are also thought to share part of the blame [1], [3].
The phenomenon is not limited to one region only and it is not uniform. In fact its appearance and intensity varies accordingly to the area due to the variability of geographical features and organisms that live in each place [1]. For example, in the Gulf of Main you will find the Alexandrium fundyense species taking over, whereas the Karenia brevis will rule over the Gulf of Mexico and make it all the way to Florida (therefore bearing also the name Florida red tide) [3], [4].
The Weapon
The algae kill with the toxins they release or by simply "eating out" the oxygen supplies of the waters. Either way, it's a bad, bad death. Karenia brevis produces powerful brevetoxins, these affect the nervous system and fish gills. They can be easily airborne affecting people breathing them in and causing respiratory problems that can persist for even several days. Toxin blooms may last from weeks to even months, whereas there have been rare reports when the toxins were present for a whole year (1995-1996 and 2005) [3], [4].
Some fish and sea animals die from poisoning, but there are others more resistant that end up to a poor fellow's dish. What if they eat contaminated fish or seafood? Neurotoxic shellfish poisoning is on its way. Gastrointestinal and neurological symptoms start occurring like diarhea, nausea, vomiting and even partial paralysis. The state of Florida has taken measures to prevent such incidents by monirtoring shellfish consumption and they have managed to prevent deaths by shellfish poisoning almost 100% [3].
You can check the wikipedia's list of the most important incidents recorded over the last 6 centuries in the relevant article.
Image source: pixabay.com - (CC0 license)
Where does it happen?
It is a worldwide phenomenon, but the US coasts seem to suffer more. Since we can end up mourning innocent victims (of the animal and the human kingdom), NOAA decided to work with NASA, the U.S. Environmental Protection Agency and U.S. Geological Survey in 2015. They have joined forces in order to collect satellite data, monitor and predict HAB occurrences. There is also the Phytoplankton Monitoring Network, along with a new technique asigned to test the waters with underwater devices and "ring the alarm" whenever the danger threshold is reached [1].
Are They All Sinister?
No! Not all algae work to smother or poison innocent sea creatures. In fact algal blooms are very very important and necessary in order to provide marine animals and fish with food [1].
References
[1] noaa.gov
[2] oceanservice.noaa.gov
[3] wikipedia.org
[4] accuweather.com
Thank you so much for your time!
Until my next post,
Steem on and keep smiling, people!
