A tiny ancient shrimp found only in a single small lake tucked away in the mountains of central Italy could soon disappear, as a combined result of climate change and an earthquake that hit the area last year.
The fairy shrimp (Chirocephalus marchesonii) has evolved from a species native to the Himalayan region. Its ancestors are thought to have reached the Appennine range during the last ice age, after their eggs latched onto the feet of migratory birds.
“Over the millennia, the shrimp has adapted to the specific environment of Lake Pilato, and its reproductive cycle is in sync with the seasonal hydrologic balance of the basin,” says Maria Gaetana Barelli of the Sibillini Park authority. The species is unique among freshwater shrimps in the area for its Asian origins, offering clues on the movement of animal species in prehistoric times.
Barelli says that to hatch, the shrimp’s eggs need such a complex combination of environmental parameters that her five-year-long research project wasn’t enough to make them hatch in captivity. This is why she is concerned that the crustacean may go extinct if the small lake it inhabits undergoes significant environmental changes.
Big shock
“The major earthquake that struck the region last summer has certainly caused deep shocks in the water system of these mountains,” says Alessandro Rossetti, a biologist with the Sibillini Park authority. “The water levels in the basin are abnormally low this year, and we still don’t know if this is due to a disruption of the aquifer. If that was the case, the lake would permanently dry out and this unique shrimp would disappear.”
A group of scientists flew drones over the lake and analysed its biochemistry, looking at factors such as temperature and acidity to gain insight into the underground water system that feeds the basin. However, more research is needed to establish whether the earthquake has fatally damaged it.
The shrimp can survive long dry spells because it buries its eggs under the lake bed, where they can remain alive and intact for more than a year until conditions are right to hatch. Hikers are the most immediate threat to the eggs, because they kill most of them by walking on dry areas of the lake bed.
However, the scientists’ main concern is climate change. “From 1990 onwards, we recorded an increasing number of hot years with abnormally low water levels,” says Rossetti.
Uncertain future
“I am very worried about the shrimp’s fate – it’s a precious animal,” says Barelli. “My concern is that this year, because the water is already so low, the individuals present in the lake might not have the time to mature sexually and lay their eggs before the basin dries out.”
But this shrimp is not the only species here that sees its survival threatened.
In a valley not far from Lake Pilato, another endemic shrimp (C. sibyllae) depends on the regular seasonal cycle of the pond where it reproduces and goes idle for a few months every year. Like C. marchesonii, this crustacean’s survival is tied to the availability of water when it matures and lays eggs.
Barelli says the risk of extinction would turn into a certainty should the basin fail to replenish for more than a year.
Paolo Guarino, a geologist at the Italian National Institute for Environmental Protection and Research, says there is a need for more historical data to “verify whether the water balance is being tipped – namely, if more water leaves the area and its basins than enters them”.
Source: http://bit.ly/2tTKiK5
