Toxic Algal Blooms, Red Tides and Heavy Metal Accumulation

This is a threat that has continually affected mankind. There are various types of algae that produced dangerous compounds and accumulations of chemicals lower down the food chain that accumulate to toxic levels in certain areas of those animals, eventually leading up by consumption to lethal levels higher up in the food chain.

A common occurrence is the one that occurs along Florida’s coast in summer. Some of these have been increasing in scope, but these harmful algal blooms or HAB’s have been worryingly increasing in numbers and occurring in other parts of the world. When the organisms die they can deplete the oxygen in the water, but some of the species are toxic, so even when they don’t die, ingesting large amounts can lead to a build-up of poisons. This concentration may not be apparent in the lower food levels, but some creatures accumulate these toxins.

High levels of Blue-green algae has now been found in many places around the UK.

For example, is the pufferfish or blowfish. The blowfish is not inherently poisonous, but what is does is eat plankton that contains small amounts of the neurotoxin, tetrodotoxin (TTX), a sodium channel blocker, that accumulates in its liver and ovaries that is said to be 1,000 times as lethal as cyanide. This toxin can also be found in balloon fish, toads, sunfish, porcupine fish, toadfish, globefish and shellfish such as oysters, clams, scallops, or mussels. In shellfish you can get a condition known as paralytic shellfish poisoning from a similar chemical called saxitoxin. What was once thought of as ‘shellfish poisoning’ and all lumped together has now been separated in 4 main types, depending on the type of effect the different chemical compounds tend to produce: Amnesic shellfish poisoning, Diarrhoeal shellfish poisoning, Neurotoxic shellfish poisoning and Paralytic shellfish poisoning.

Tetrodotoxin has no known antidote as yet and kills by paralysis, not interfering with the mental processes, but dampening and preventing the nerve signals getting through, eventually reaching the autonomous system that controls breathing. So, the person suffocates to death without being able to do anything about it. In lesser levels it may produce zombification, where the body is totally unresponsive, but the mind is not, and there is some evidence that a similar process may account for the Haitian tales of ‘zombies.’

There has been the concern about plankton species now found in warming UK waters that the puffer fish there eat that seem to contribute to their toxicity, probably coming from long distance shipping going between the two areas, hitching a ride, but so far there has been little evidence if any of the Psuedoalteromonas tetraodonia species arriving that may be the bottom end of the accumulation cycle, related to the Alteromonas species that may prove so useful in antibacterial and anti-cancer drugs. But we must assume that with warming waters this may not always be the case, and at some time in the future warming sea temperatures may cause the transfer of these organisms as well, so starting the cycle that may render the seafood areas unusable, toxic whelks, mussels, oysters, clams and scallops.

Toxic metal build-up, such as mercury has often been exaggerated by environmentalists and the press. Some areas where dumping has increased, large amounts have happened, but the levels are still very low, needing to consume in most cases ten times the normal levels to get even an effect. The notable levels of mercury are: for the blood, about 5 ng/mL and urine about 20 ng/mL, but mercury is common in the environment, 1 ng/mL in the blood not meaning you are dying 20% as fast, but meaning your body wouldn’t even notice it, various studies suggesting that 50ng/mL in blood would have a major effect and 100ng/mL having an effect of mercury poisoning. I tend to think in terms of equivalent pints of strong beer, so dividing the figures by 10. 10 pints a night showing signs of alcohol poisoning, 5 pints being of concern, but 1 pint having little effect, 1/10^th of a pint you would have little chance of tracing, so a move to limit stuff to 1/100^th of a pint as the standard being in the realm of the obsessive, not the logical, practical or pragmatic. Many health officials are tending to their ego’s and obsessing over alcohol in a similar way, 10 pints is bad and will kill you, 1 pint is also bad and will kill you 1/10^th of the amount. The only problem is that their thinking and reasoning is rubbish and psychologically fixated to that and nothing else.