Australia (Commonwealth Union) – Human activity continues to have a devastating impact on nature, from highways going through natural forests to human encroachment into animal habitats. Meanwhile, a new genetic study by the University of New South Wales (UNSW) researchers found large dams limiting platypus movement, with significant consequences for their conservation.
The platypus is an extraordinary species usually found in eastern Australia. They have unique mixtures of characteristics, including egg-laying even though their mammals, venomous spurs in males, electroreception for finding prey, biofluorescent fur, multiple sex chromosomes, and have DNA from reptiles, birds, and mammals.
The decline of platypuses has been a serious concern for environmentalists. The study appearing in the international journal Communications Biology evaluated the genetic makeup of platypuses in free-flowing and rivers close by with large dams in New South Wales, including the free-flowing Ovens River, together with the dammed Mitta Mitta River, the free-flowing Tenterfield Creek, and the nearby Severn River regulated by a large dam.
The findings indicated that large dams are obstacles to platypus movements. They further indicate greater genetic differentiation between platypuses above and below large dams contrasted with rivers without dams. Significantly, this genetic differentiation was elevated over time since the dam was built, demonstrating the long-term consequences of the dam.
Lead author Dr Luis Mijangos, a former UNSW PhD student presently at the University of Canberra said: “We extracted the DNA from the blood collected by our Platypus Conservation Initiative researchers at UNSW. By using thousands of molecular markers, we were able to identify a strong signal indicating that genetic differentiation increased rapidly between platypuses below and above these large dams.”
Recommendations made by the authors is that water conservation and management planning look into alternative solutions to large dams. Factors to consider may be storing water in off-river reservoirs and applying strategies to minimize the effects of dams, such as the artificial relocation of individual platypuses between groups above and below dams, or the construction of passage structures that raise dispersal.
