Various news sources have reported Cyanobacteria, more commonly known as Blue-green algae is increasing in UK lakes. These microscopic organisms can pose serious threats to human health and local ecology
Cyanobacteria are unicellular aquatic and photosynthetic microorganisms. Although they are small, they often grow in colonies large enough to see, these are known as algal blooms. Interestingly enough they have the distinction of being the oldest known fossils, with some specimens being more than 3.5 billion years old. They are one of the largest and most important groups of bacteria on earth but they have gained a negative reputation lately due to the effects algal blooms have on local aquaculture and health.
Blue-green algae are highly opportunistic and grow exponentially in high nutrient areas. Local lakes and ponds are typically high eutrophic due to their proximity to farms and other sources of nutrient run-off. Blue-green algae secrete a harmful substance known as cyanotoxin, which in the presence of a bloom can accumulate in harmful quantities. The cytotoxin can upset the balance in an ecosystem in several ways. Microsystems may accumulate toxins through trophic levels, or levels in the food chain such as zooplankton and small invertebrates, bringing to higher more dangerous levels in smaller to medium sized fish. By the time it reaches the levels of larger fish the toxicity can reach levels lethal to small mammals and birds. They may even pose a significant health risk to humans that would unwittingly consume contaminated fish and water fowl.
Therein lies the danger. If these bodies of water, containing these dangerous algal blooms, are in close proximity of a human environment, at some point they will find their way into the equation.
Chao Hu lake is a massive body of water that is the largest lake in the Annan province and one of the largest lakes in all of china. Situated some 400km west of the bustling city Shanghai, it is one of the most extreme examples of how blue-green algal blooms can grow. Intense eutrophication or nutrient enrichment, from surrounding farms and industry has caused a biological explosion of immense proportions. These blooms are so extensive they can be clearly seen from space. However, it is not only in China that we see these worrisome water based woes.
Linlithgow Loch in West Lothian Scotland UK is a popular site of leisure and recreation. Since the early 2000s scattered reports have emerged that blue-green algal blooms have sickened family pets and water sports enthusiasts that may have accidentally swallowed small amounts of water. Sports fishermen report that they frequently fish the loch but any catches are promptly thrown back or discarded, never eaten or even offered to the family cat for fear that it would bring harm to them.
Linlithgow Loch is not a municipal water source but the same opportunities exist in those lakes that are used. It is imperative that greater care is taken to avoid the nutrient enrichment of water sources, from farming and industry, by utilizing the best and most effective wastewater treatment techniques available.