Abstract

The Magellan region (southern Chile) has been aware of the introduction and spread of Invasive Alien Species (IAS). For decades, it has been exposed to the impact by species from Argentina, which arrived in 1946 with 25 pairs of beavers that were released in the north of Lake Fagnano, and in 1948 75 males and 155 females of muskrat were released in lentic systems of Tierra del Fuego island. The presence of IAS on the island has become even more complex with the detection in 2013 of the invasive microalga Didymosphenia geminata (Didymo) in two connected freshwaters sources, the Grande and Blanco rivers (in Chile and Argentina respectively). This study aims to explain the possible relationship between wildlife mobility and Didymo cell transport within the Grande river watershed, proposing beavers as a target species. A total of 10 individuals of the beaver Castor canadensis were collected and analysed. The presence of viable cells of Didymosphenia geminata was identified on different parts of the body of the individuals obtained. This finding suggests that IAS such as beavers can act as vectors for Didymo in Tierra del Fuego and wildlife should be considered in management strategies to limit the spreading of D. geminata from one watershed to another.