Description

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Context:

The study co-authored by species experts from all geographical regions of the world also revealed that a staggering one-quarter of the freshwater fauna are threatened with extinction.

The research reveals 35% of wetlands vanished between 1970-2015, with 65% of remaining habitats under significant threat.

About Multi-taxon Global Freshwater Fauna Assessment

The first-ever multi-taxon global freshwater fauna assessment for the IUCN Red List of Threatened Species has identified the Western Ghats as a key location with the greatest abundance of threatened freshwater species.

Key Findings

Aspects	Details
Main Foci	Lake Victoria - Kenya, Tanzania & Uganda. Lake Titicaca - Bolivia & Peru. Wet Zone - Sri Lanka. Western Ghats - India.
Key Threatened Species	Crabs, crayfish, and shrimp face the greatest risk of extinction. Freshwater fish are also significantly threatened.
Number of Species at High Risk	At least 4,294 species out of 23,496 freshwater animals are at high risk of extinction.
Other Observations	Areas with high water stress (high demand and low supply) do not host more endangered species compared to areas with lower water stress.
Eutrophication Impact	Eutrophication, caused by excess nutrients in water, leads to overgrowth of algae and plants but is not correlated with higher numbers of endangered species.
The threat in Western Ghats	It harbours over 300 freshwater fish species of which more than 1/3^rd face extinction.

The Western Ghats is the only region in Asia with 2 endemic families of freshwater fishes that occur exclusively in groundwater and underground systems.

The iconic humpback mahseer, a critically endangered megafish that can grow up to 60 kg, has been found in the Western Ghats.

Among Indian states, Kerala has the highest number of threatened freshwater fish, with 74 of the 188 fish species for which Red List assessments are classified as threatened.

The Periyar River is a critical conservation priority due to its high concentration of endemic and endangered freshwater fish species.

Threats	Impact on Freshwater Species (Decapods, Fishes, and Odonates)
Pollution	54%
Dams and Water Extraction	39%
Land Use	37%
Invasive Species and Disease	28%
Habitat Loss and Degradation	84%

Threats	Impact on Tetrapods
Agricultural Practices	74%
Logging	49%
Climate Change and Severe Weather	Poses a substantial risk, impacting nearly 1/5th of threatened freshwater species.

About freshwater landscapes

Status: Home to 10% of all known species on Earth.
Significance: Provides safe drinking water, livelihoods, flood control, and climate change mitigation.

Facing the threat

Mainly from agriculture and forestry.
Degradation: E.g., land conversion for agricultural use, water extraction, and construction of dams.
Others: Overfishing and introduction of invasive non-native species.

About the International Union for Conservation of Nature (IUCN) (1948)

It aims to provide public, private, and non-governmental organizations with the knowledge and tools to enable human progress, economic development, and conservation to move forward together.
Membership: This is a membership union composed of government and civil society organizations.
Headquarters: Gland, Switzerland.

Source:

https://www.downtoearth.org.in/wildlife-biodiversity/a-quarter-of-freshwater-fish-species-are-at-high-risk-of-extinction-report

PRACTICE QUESTION

Discuss the significance of the Multi-taxon Global Freshwater Fauna Assessment in understanding biodiversity and the conservation challenges faced by freshwater ecosystems. Highlight the key findings from the assessment and suggest measures to mitigate the threats to freshwater species. (250 words)