A dramatic increase in what is commonly known as blue-green algae is causing the deaths of birds at the Vermont Saltpan.
At least 14 carcasses have been found and taken away to be destroyed – mainly shovelers, geese, teals and a couple of gulls, Club veteran Mike Ford said this week.
The death toll is expected to rise. “There are also several really sick looking birds resting on the rocks and I don’t think they’ll last much longer,” he said.
“The main problem is that the disease is spread by maggots from the carcasses, so it is very important to find and burn any dead birds – easier said than done as they tend to hide in the reeds to die.
“The problem is due to the rapid evaporation at the pan and dropping of levels at this time of year, plus heating of the water, especially round the edges. It’s not the first time this has happened. I remember around 2002 the pan was littered with dead waterfowl.”
‘Blue-green algae’ is the common name for cyanobacteria. They are so named because these organisms have characteristics of both algae and bacteria, although they are now classified as bacteria, according to the World Health Organization. The blue-green colour comes from their ability to photosynthesize, like plants.
Some species of cyanobacteria produce toxins that affect animals and humans. Under certain conditions, the cyanobacteria reproduce exponentially to form blooms. Blooming cyanobacteria can produce cyanotoxins in such concentrations that they poison and even kill animals and humans, according to Wikipedia.
The first published report that cyanobacteria could have lethal effects appeared in Nature in 1878. George Francis described the bloom he observed in the estuary of the Murray River in Australia, as “a thick scum like green oil paint, some two to six inches thick.” Wildlife which drank the water died rapidly and terribly.
The cyanobacteria have also been tremendously important in shaping the course of evolution and ecological change throughout earth’s history, says the University of California Museum of Paleontology on its website.
The oxygen atmosphere that we still depend on today was generated by numerous cyanobacteria during the Archaean and Proterozoic Eras. Before that time, the atmosphere had a very different chemistry, unsuitable for life as we know it today.
The cyanobacteria have the distinction of being the oldest known fossils, more than 3.5 billion years old. They are still around; they are one of the largest and most important groups of bacteria on earth.