Italy’s drying lakes imperil rare shrimp species found only here

22 June 2017

By Lou Del Bello

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.

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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.

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UK fairy shrimps under threat from recent dry autumn

Fairy shrimps threatened after dry autumn

Britain's endangered fairy shrimps are under threat as a dry autumn has affected the ponds they live in, a charity says.


Fairy shrimps are tiny translucent crustaceans, which usually hatch near Christmas.

But charity Pond Conservation says many of their pools may dry out completely.

Another problem is that some "transient" ponds are beginning to hold water permanently, allowing predatory fish to colonise them.

Pond Conservation's Dr Jeremy Biggs said: "With only a handful of sites across the whole of Britain, the future of these beautiful creatures is balanced on a knife-edge."

It is that hoped fairy shrimps (Chirocephalus diaphanous), which are protected by the Wildlife and Countryside Act, will return to their "strongholds" this Christmas in Hampshire's New Forest, on the edge of Dartmoor in Devon, on Salisbury Plain, in parts of the Sussex Weald, as well as in Oxfordshire, East Anglia and South Wales.


They complete their life-cycle during the coldest part of the year, hatching as water returns to their shallow ponds, which dry out in summer.

They reach maturity over winter, then lay eggs, which can survive long periods of drought. The adults die when their ponds dry out in spring.

Dr Biggs said: "They are facing a double-whammy from pollution and changing weather patterns.

"We don't know whether they can survive in their existing habitats, so we have also been making special new seasonal clean water ponds for them to try to increase their numbers.

"We're hoping that by providing more habitat, we will increase their chances of surviving in the British countryside."

He says that, although Britain has half a million ponds, 80% of those in England and Wales are polluted.

Dr Biggs added: "We'd ask people to look out for them on their Christmas day walk, especially if they are walking past small pools in more natural parts of the countryside - in woods, or on heathland, for example."

http://www.bbc.co.uk/nature/16303086