Malta’s only amphibian has its Rabat home, a one-kilometre water channel, restored - via Herp Digest

Government agency Ambjent Malta planning to restore Wied Liemu valley channel to its original state after Painted frog populations suggested decline due to destruction of habitat

August 16, 2019, by James Debonno, MaltaToday

  

Urbanisation threats to an indigneous frog population has forced the environment agency Ambjent Malta to carry out rehabilitation works by hand at the Wied Liemu water channel in Rabat.

The painted frog is Malta’s only amphibian but the species has shown a worrying decline with the biggest threat coming from the destruction of its habitat.

Government agency Ambjent Malta is now planning to restore the one-kilometre-long Wied Liemu to its original state through the manual removal of silt, the repair of channel walls and the construction of arches using local globigerina limestone.

Wied Liemu is an upstream tributary that flows into the Wied il-Fiddien and Wied il-Qlejjgħa valleys

Due to lack of maintenance, the channel is silted up leading to localised flooding that results into exacerbated soil loss from the adjacent agricultural land.

Most parts of the channel walls are damaged and some sections of the walls have practically disappeared.

The channel is inhabited by ruderal plants and numerous specimen of the painted frog (Discoglossus pictus).

The presence of these frogs means that works have to be carried out in a meticulous manner to limit any impact on the amphibians.

  

(They didn’t ID this frog, but since it so different from the painted frog shown above I have to assume it is the Levant water frog, an invasive species threatening the painted frog.)

  

The biggest threat for the frog in Malta comes from the destruction of its habitat

The removal of material will be carried out manually and using handheld tools to lessen the impact on the fauna and limit damage to the existing structures.

Ambjent Malta will also ensure that interventions will be carried out during the summer period, when the channel dries out and the frogs retreat into damper places away from the exposed parts.

The rehabilitation of this valley will also include the replacement of various concrete bridges with arched limestone ones.

The painted frog inhabits several Mediterranean countries but the species found locally is only present in Malta and Sicily. This species is, however, showing a worrying decline.

The biggest threat for the frog in Malta comes from the destruction of its habitat.

The highest numbers of frogs occur at Chadwick Lakes.

Chadwick Lakes also provides the highest number of adjacent suitable habitats and a higher possibility for migration of the species to other locations.

The frog population at Tal-Wej in Mosta is the most vulnerable since the area and its catchment is almost totally surrounded by urbanisation, eliminating any possibility for the species to migrate to adjacent areas.

Lower precipitation is considered as a major threat to the species. Another probable threat is the use of pesticides that poison the creature and its food. The painted frog is also facing the threat of alien amphibian species that could push it out of its habitat.

This has happened in some sites in Gozo where an alien species, the Levant water frog, was introduced some years ago.