A group of scientists from across the globe have unveiled a new plan to halt the decline of biodiversity of our freshwater ecosystems. Referred to as the ‘Emergency Recovery Plan’, it details the actions needed to bend the current downward curve of freshwater biodiversity loss. Published in Bioscience on February 19, the paper outlines a 6-point plan to tackle the threats facing biodiversity in rivers, lakes and wetlands. According to WWF’s Living Planet Report, the average abundance of freshwater species populations declined by 81% between 1970 and 2012.
The 6-point plan presented in the paper deals with the following issues: there are plans to accelerate implementation of environmental flows including river basin planning, water allocation and infrastructure design and operation all to restore and maintain the water flows to the freshwater systems. There are aims to improve water quality to sustain aquatic life, and this will be implemented by waste-water treatment and regulation of polluting industries to prevent the spoiling of the water sources and improved agricultural practices to reduce the amounts of pesticides and fertilisers making their way into the water systems.
In addition, critical habitats will be protected and restored via an introduction of protected areas of the water system, such as the entire 825,000 hectares of the Bita River basin where the Amazon River Dolphin is known to have its habitat, along with being a rare example of a completely free-flowing river. Habitat restoration is also occurring in places such as Eastern Europe along the Danube where 60,000 hectares of flood plain have been restored.
The plan will manage the exploitation of freshwater species and riverine aggregates through science-based fisheries management and community fisheries management, along with bycatch reduction to prevent the unnecessary deaths of species not intending to be captured and the overfishing of regions allowing populations to recover. Reducing aggregate demand and improved regulation of aggregate extraction will prevent the abstraction of rivers.
There will also be the prevention and control of non-native species invasions in freshwater habitats. This will be enforced through the identification and control on introduction pathways and the control and eradication of established invasive non-native species.
Safeguarding and restoring the freshwater connectivity will be carried out through system-scale infrastructure planning, including dam reoperation and removal and levee positioning.
Accounting for less than 1% of the Earth’s surface, wetland habitats are home to approximately one-third of all vertebrate species and around 10% of all species on Earth. Some species, like the Amazon River Dolphin, live only in freshwater habitats with no way of evolving quickly enough to colonise any other habitat. It is a relatively abundant freshwater dolphin but is classified as vulnerable due to human influences, including the contamination of the rivers and lakes and the building of dams that can fragment the populations.
Habitat loss is the major cause of the decline in freshwater populations as lakes, rivers and wetlands across the world continue to be fragmented, polluted and developed to follow human activities. In a section focussed on rivers, the Living Planet Report states that almost half of all river flows globally have been at one point subjected to alterations (abstraction – the removal of water from the river or channel modifications – altering the path of the river) or fragmentation by weirs and dams. Fragmentation of the rivers may be attributed as a cause for the 41% decline in migratory fish species which rely heavily on their natural migration routes along the river course to get back to breeding ground in breeding season.