X-FILE ON ALGAE - Will algae take over the world?

January 1954....Scientist researching for the U.S. Department for the interior reported that algae in contact with submerged concrete blocks caused their complete disintegration.

At one point the safety of the Manhattan bridge in New York was in jeopardy as engineers were being confounded bywhat was causing the disintegration of the foundations. It was algae.

Algae is a term that covers a vast range of relatively simple plants. They come as a single cell, a colony of cells in a filament, tube, strand or within a membrane. They are plants since they have chlorophyll within their cell structure. In the presence of carbon dioxide and, absolutely essentially, sunlight a process of photosynthesis is activated producing starch and related substances. Given phosphorus, nitrogen and someDifferent sorts of freshwater pollution algae other substances they can also build up proteins. During this process carbon dioxide is absorbed and oxygen is released.

All plants and animals 'respire'; that is absorbing oxygen and releasing carbon dioxide. During the action of
Photosynthesis in plants, the production of oxygen exceeds by far the normal respiration of the organism. Algae as plants also naturally produce oxygen in sunlight. This oxygen is utilised by all the other inhabitants of the environment. In the pond environment, aerobic bacteria are the first in the chain of living things to utilise oxygen. They use it to process decaying organic matter back into compounds that are accessible for nutrition by plant life and are not toxic and non-polluting non-polluting to fish and even to man. It is estimated that the algae that lives in the sea provides 90% of the oxygen for the planet.

This alone makes algae one of the keystones to the existence of life on earth. Combine this with the essential role within the food chain of life in water we will see that the presence of algae is an essential ingredient to every water world from ocean to puddle, and as it happens, even every polluted ditch to everysceptic lagoon.

Photosynthesis allows plants to produce material such as the starches and oils from the inorganic elements in the environment to build the structure for the cell walls of the plant. Animals cannot do this but need carbohydrate for their own cell growth and structure. If were a very, very small animal then the basic ingredients of your larder will be algae, algae and more algae and you in turn will be meat for a larger animal.

Our usual mental pictures of algae are through the problems they cause. We only 'see' them when they 'bloom'. At various times of year and during certain conditions different species thrive to such an extent that they discolour water, usually green, or float in mats on the surface of the water in jelly like blobs or like green soggy candy floss. These are indicative of very particular conditions in that environment to cause that effect and it when they are causing a problem. But like a headache, algae growth is generally a symptom of some other underlying cause.

Algae are everywhere, even floating as desiccated dust in the air waiting for a nice damp spot to settle in. They range from species that exist in attached colonies growing to a size comparable with land plants in the varieties of kelp seaweeds and lakeland weeds, to microscopic free floating organisms only visible with a magnification of 5000 times.

Some algae with very specific characteristics Some that we can see and are familiar with, we might regard as distinct species but in fact we give them common names that covers a large groups or even genus. Spirogyra ("Blanket Weed"), for instance can exist in many specific forms like Spirogyra varians and Spirogyra ellipsospora. Other common names for visible algae include "water net" (Hydrodictyon), "green felt"(Vaucheria), "sea lettuce"(Ulva), and "stonewort"(Chara).

The free floating organisms number over 20,000 in distinct species and even these get subdivided when they are found to have adapted to varying environmental factors. These are generally referred to under more general headings such as diatoms, desmids, armoured flagellates, euglenoids, greens, blue-greens, yellow-greens, browns, golden-browns and reds, otherwise we use their latin names.
Some, like the diatoms, are stiff, hard structures with silicon cell walls, others have whip like appendages and can project themselves around moving like simple animals. The Euglena is the most common example. When you see these beasties; their variety of shape and design; the success of their existence in every nook and cranny
of the damp world, the microscopic world of algae just blows away the fiction of sci-fi, fantasy and horror.

PROBLEMS CAUSED BY ALGAE

Enthusiastic Koi carp keepers and water works engineers alike regard algae as the bane of their lives. They are all too familiar with the stress that algae creates on their filtration systems. Algae proliferation can cause significant quantities of organic matter in the form of dead and living organisms clogging up screening systems and filter systems. According to C. Mervin Palmer in his excellent book, "Algae and Water Pollution", 130 tons of algae a day flow into the Fox River in Winsconsin from Lake Winnebago. In Chicago, the water from Lake Michigan has shown counts of over 4000 algae per ml. In the White River in Indiana there have been counts of 100,000 algae per ml -that's what you call 'pea soup'.

But algae do not need to be in large numbers to cause problems. Synura, for instance, produces quite an obnoxious odour in moderate quantities described as 'cucumber' or 'spicy'. When it becomes abundant the smell is 'fishy' and the water has an acrid bitter taste and a dry metallic slick sensation on the tongue.

Other algae produce smells of 'musty nasturtiums'that deteriorates to 'sceptic' (Anabaena - Blue-green algae);
Asterionella smell of geraniums but 'fishy' in abundance; Chara smells of skunk or garlic; Closterium smells 'grassy' and Cryptomonas of violets !

ALGAE AND pH

There is an obvious chemical effect of algae in water with the continuous removal of carbon dioxide from the water in the daylight hours as a result of photosynthesis. This process brings about an alteration in the relative amounts of carbonic acid in the water, also some of the bicarbonates and even the nearly insoluble monocarbonates, often causing the latter to precipitate. The result is a change in water hardness. SomeA new pond already green with single celled algae: The reason is obvious. There are no plants.Blanket weed rampant in December, the water gardener's sign of 'global warming' vigorous growths of algae can reduce the water hardness by one third.

This affects the pH of the water. The pH rises as the algae photosynthesise more vigorously during the day and decreases at night as carbon dioxide is released back into the water. It is the 'depolarising' action of the oxygen in this process that has this corrosive effect on the metal tanks and concrete blocks mentioned at the beginning of the article. A problem that has an easy solution if you can think ahead -just cut out the light or coat it.

DANGEROUS ALGAE

There are both marine and freshwater algae that produce toxins. The serious danger of the poisonous 'Red Tides' that have killed marine life on the shores of the Americas and Europe are caused by armoured flagellates of the Gonyaulax and Gymnodinium geni.
In fresh water, Anabaena has been related to cases of dermatitis and Anacytisus and Lyngbya contorta to hay fever.

In 1954 scientists W.M. Ingram and G.W. Prescott reporting in "The American Midland Naturalist" linked the fatal poisoning of many horses, sheep, pigs, cattle, dogs, rabbits and poultrywith the blue-green algae genus Anacystis. The first specific alga reported as toxic was Nodularia spumigena. The reported symptoms being "prostration and convulsions followed by death". In human beings the toxic effects have been reported as severe
headache, high fever, nausea, vomiting, diarrhoea, pains in muscles and joints and exhaustion. These have been as a result of just swimming in water polluted by these algae.

Unexplained outbreaks of intestinal gastroenteritis in human populations have been linked with blooms of blue-green algae in water supplies. This may be indirect since the blooms of algae as they deteriorate on the floors of the sand filter beds may have overloaded the system to the extent that other toxins have been 
allowed to filter through. The outbreaks generally occur in the summer months when the problems caused by the bloom of any algae can affect the balance of their environment.

FISH DEATH CAUSED BY ALGAE

High water temperature, high pH and length of exposure to sunlight are all significant factors that lead to algae population explosions. If there has been a heavy algal growth in a pond or lake and the sunlight that has augmented that growth is suddenly reduced, either by weather conditions, nightfall or a thick blanket of algae, then photosynthesis of the algae in the water is reduced. Thus their production of oxygen is brought to 
a halt. At best it is reduced but their respiration continues. This uses up the oxygen content of the water and releases more carbon dioxide. If the situation is prolonged, eventually the fish and the algae die through oxygen starvation.

All the factors have to be prettily heavily weighed against the fish for this to persist and the ecosystem of the pond or lake not to revert to some balance which is tolerable to the fish. If the fish are stressed by overcrowding or some other exterior factor, then what would normally be a benign population of algae might effectively be detrimental. The beautiful Blagdon Lake in North Somerset, one of the most popular trout fishing lakes in the
country. During the second half of every March, Bristol Water adds new stocks of trout to replace those fished out during the previous summer. The young fish are healthy and have been extremely well fed and they are introduced so early on in the season in order that they can build up well coloured succulent muscle tissue by the start of the fishing season.

In the spring of 1995 the cool long drawn out end to the Winter did not create very favourable conditions for the introduction and settling in of these valuable fish. The conditions however were perfect for one of the most common algae of lakes and large ponds, Asterionella, a rigid star shaped cluster of cells. This has a tendency to bloom as temperatures are rising at the beginning of the year and it was blooming
strongly in March 1995. The fish, traumatised from their move from the growing tanks, would have had a damaged or much reduced protective mucous layer and so to them swimming around in a bloom of Asterionella was like slithering through a liquid version of carborundum. It would have damaged gills and further exacerbated
the stress the fish had already suffered. This in turn would make them susceptible to any disease under the sun. Two weeks later most of the fish were dead and the fishing season had to be postponed for a month whilst stocks were replenished again.

ALGAE Population AND pollution

With this total of convictions do algae have anything to commend them apart form being the keystone to all life on the planet?
As I have said, the problems that algae cause are really only a byproduct of some other state of affairs that has caused that algae to be there. This is so pertinent that scientists can take a count of the numbers and varieties of genus and species in anyone particular place and use that as indicator of various factors in that environment. Pollution is the obvious example and there are algae that love various sorts of pollution and the organic compounds in many forms of pollution is what causes them to proliferate. Many of the Euglenas love the high acid conditions of raw sewage; Chlorella indicate that there is a change and the sewage is oxidising. On the basis of this Scientists use the relative quantities of organisms that are present together with which organisms are present as an index as to the quality of that water. This scale of pollution is called the Saprobity index.

Algae are indicative of some industrial wastes by their tolerance of it and therefore their presence in the absence of other algae. Some species indicate the presence of oil, hydrogen sulphide, iron, chromium, copper and papermill waste. Ascertaining the identity of the algae population and its number is easier than chemical tests in calculating the degree of pollution from these chemicals.

The algae that survive sewage can be used to help break it down. The oxygen added to the water by algae photosynthesis can be used by bacteria to decompose raw organic sewage. The waste products produced include ammonia, nitrates and phosphates, which immediately serve as additional nutrients for the algae. The algae increase, the bacteria flourish. As the water becomes cleaner different algae begin to populate and the process works towards cleaner more stable conditions.

This process seems alright in theory but in practice with the overloading of pure organic and inorganic compounds into a waterways the different species of algae cannot cope with the 'witches brew' of pollutants and give up in favour of the moulds, anaerobic bacteria and yeasts that flourish in these conditions. There is no doubt however that in the future under controlled aerobic conditions lagoon systems for the breakdown of some industrial wastes will be developed.

AND FINALLY...............

The Japanese are researching into the use of algae for food for us. And if the worst comes to the worst then algae as food for human beings maybe what saves the planet from starvation.

For many years now the development of breeding algae for fish food has been very successful. The idea is to shorten the food chain between algae and higher animals. Take this idea to the extreme, you feed algae to people. It seems that Chlorella, Scenedesmus, Ankistrodesmus and others are particularly amenable to cultivation under controlled industrial conditions. Chlorella is already used in Japan as a dried product for speeding up the fermentation of milk. The growth rate of Chlorella is so rapid that if one were to draw comparisons of yield in lbs of protein per acre per year, it far exceeds the yield one could obtain from any other higher plants. The yield for grass is 600lb of protein, for beans it is 370, for chlorella it 14,000lb per acre per year. It contains all the 'essentials' for human nutrition apart from calcium and sodium and in its dry weight form consists of 50% protein, 20% carbohydrates and 10% ash. There is nothing of it that is inedible - therefore no waste, and it said to taste, smell and look rather like powdered green tea. In 1980 the Japanese estimated we would need less than 1,000,000 acres to feed the existing population.

"OK, two cheese and Chlorellaburgers on rye to go, please !"