“Traces of rare mussels sensitive to pollution and thought to be on the point of extinction in France have been discovered in the Seine in Paris, raising hopes that efforts to clean up the river that bisects the French capital might be succeeding,” reports The Guardian. This was discovered “after Olympic swimming events were held in the Seine last year – the first time swimming in the river has been deemed safe in a century.” Scientists took large water samples from eight points on the river near the city center. Then,
They uncovered the DNA of 23 different types of mussels – including three classified as near extinct – and 36 species of fish, 10 times more than in the river in the 1960s.”
“All organisms lose skin cells all the time and we recover the DNA of these cells from the environment,” said Vincent Prié, a hydrobiologist. “We filter the water and sequence it. This potentially gives us a list of everything that lives. And that’s what’s so interesting, because we didn’t expect to find them in Paris at all, because they’re under threat.”
The groundbreaking study of environmental DNA (known as eDNA) consists of identifying the presence of species in an environment based on the traces they leave.
The scientific team found traces of thick shelled river mussel, the black river mussel and the depressed river mussel, three species classified as almost extinct.
The depressed river mussel, also known as the compressed anodont, which can grow up to 8cm in length, had disappeared from almost all the country…
The survival of the mussels is a good thing, because they help purify water. Each mussel can filter over 10 gallons of water per day.
The snow leopard population has doubled in Kazakhstan. Mountain gorillas are making a comeback in the African country of Rwanda.
Bengal tigers are making a comeback in Bangladesh, as are Asian antelopes and olive ridley turtles, even though Bangladesh is one of the world’s most densely-populated nations, with nearly as many people per square mile as cities like Atlanta. (Bangladesh has more than 170 million people living in an area the size of Arkansas).
Crocodiles are making a comeback in Cambodia and in northern Australia. A giant fish believed to be extinct was found last year in the Mekong River.
The critically-endangered Siberian crane is growing more numerous.
Wild horses recently returned to Kazakhstan after being absent for two hundred years.
