A quarter of freshwater fish species risk extinction by climate change, IUCN (GS Paper 3, Environment)
Why in news?
- About a quarter of the world’s freshwater fish species are at risk of extinction by climate change, a new International Union for Conservation of Nature (IUCN) Red List assessment revealed.
- Out of the 14,898 species assessed, 3,086 are at risk of extinction.
Threats:
- At least 17 per cent of the threatened freshwater fish species are affected due to decreasing water levels, shifting seasons and rising sea levels pushing the seawater up the rivers, influenced by climate change.
- The climatic change risks to fish compound threats from pollution that affects 57 per cent of the freshwater fish species, dams and water extraction that impact 45 per cent and overfishing that hurts 25 per cent, respectively.
- Disease and invasive species harm 33 per cent.
Atlantic salmon:
- New evidence received by researchers showed that the global population of Atlantic salmon (Salmo salar) dropped by 23 per cent between 2006 and 2020, pushing the species from the least concern category to near threatened.
- Atlantic salmon are now limited to a small portion of rivers across northern Europe and North America that were inhabited centuries ago.
- The population was reduced by multiple threats experienced during long-course migration between freshwater and marine habitats.
Impact of climate change:
- Climate change has affected the entire life cycles of the species, influencing its development at a young age, reducing prey availability and restrictions due to invasive alien species.
- For example, the Pacific pink salmon has expanded its range towards northern Europe, among others. Further, anthropogenic disturbances such as dams and other barriers prevented access to spawning and feeding bases.
- Water pollution and sedimentation, mainly from logging and agriculture, caused higher deaths among young salmon. The assessment also noted concerns and threats to farmed salmon and their lack of adaptability to climate change.
Green Turtle:
- The Red List assessment also revealed that the Central South Pacific and East Pacific green turtle (Chelonia mydas) populations in the areas have moved from the categories of endangered and vulnerable to extinction.
- The green turtles face threats from high temperatures that result in poor hatching success and increasing sea levels that threaten to flood their nests and drowning the young.
- The warming ocean temperatures and changes in currents due to climate change also affect the growth of seagrasses that the species consume, making them susceptible.
Big leaf mahogany:
- The big leaf mahogany (Swietenia macrophylla) is another example, which is one of the world’s most commercially popular timber trees and moved from vulnerable to endangered on the Red List.
- New information received by the researchers revealed that the number of big leaf mahogany has reduced by 60 per cent over the past 180 years across Central and South America.
- It is the most sought-after timber across the United States, China, and Western Europe for producing veneers, musical instruments, decorative and ornamental features and high-quality furniture.
- The drop in numbers has been attributed to unsustainable practices used to harvest the valuable timber from the wild and urban encroachment in tropical areas along with agriculture.
- Illegal logging and trade continue to be a threat to the species, despite having protection under national and international laws. Further, climate change threatens the habitat of the big leaf mahogany too.
Way Forward:
- It is imperative to safeguard our freshwater systems as they remain the sole home for precious, irreplaceable wildlife while offering humans with many services, he urged.
Urgent need to control use of e-cigarettes, says WHO
(GS Paper 2, Health)
Why in news?
- E-cigarettes as consumer products are not shown to be effective for quitting tobacco use at the population level. Instead, alarming evidence has emerged on adverse population health effects, the World Health Organization said recently.
- It added there is an urgent need to control e-cigarettes to protect children, as well as non-smokers and minimise health harms to the population.
Regulations:
- The WHO said that e-cigarettes have been allowed on the open market and aggressively marketed to young people.
- Thirty-four countries have banned the sale of e-cigarettes, 88 countries have no minimum age at which e-cigarettes can be bought and 74 countries have no regulations in place for these harmful products.
- In India, the possession of e-cigarettes and similar devices is a violation of the Prohibition of Electronic Cigarette Act, 2019.
Rising number of users:
- Even brief exposure to e-cigarette content on social media can be associated with increased intention to use these products, as well as more positive attitudes towards e-cigarettes.
- Studies consistently show that young people who use e-cigarettes are almost three times more likely to use cigarettes later in life.
- According to data, children in the age group of 13-15 years are using e-cigarettes at rates higher than that among adults in all WHO regions.
- In Canada, the rates of e-cigarette use among 16 to 19-year-olds has doubled between 2017 and 2022, and in the U.K., the number of young users has tripled in the past three years.
Impacts:
- The e-cigarettes with nicotine are highly addictive and are harmful to health.
- While long-term health effects are not fully understood, it has been established that they generate toxic substances, some of which are known to cause cancer and some that increase the risk of heart and lung disorders.
- It can also affect brain development and lead to learning disorders for young people.
- Foetal exposure to e-cigarettes can adversely affect the development of the foetus in pregnant women. Exposure to emissions from e-cigarettes also poses risks to bystanders.
Way Forward:
- The urgent measures are necessary to prevent uptake of e-cigarettes and counter nicotine addiction alongside a comprehensive approach to tobacco control, and in light of national circumstances.
