Invasive alien species pose threat to our local biodiversity

Invasive Alien Species (IAS) are plants, animals or pathogens that establish themselves outside their natural habitat, spread and threaten ecosystems. According to the United Nations Development Programme (UNDP), invasive alien species are the second largest cause of biodiversity loss worldwide. 

They act as predators, compete for food, hybridize with native species, transmit parasites and diseases, etc. They can be as harmful to native species and ecosystems as habitat destruction and degradation. Invasive alien species have caused the extinction of hundreds of species. Their ecological damage is irreversible damage to native species and ecosystems. Invasive species can reduce or eliminate native species by competing with them for food, water, and space, by preying on them, or by spreading new diseases among them. 

Islands and highly restricted habitats are particularly vulnerable to ecological invasion by exotic plants and predators. In addition, climate change multiplies this threat, making habitats more vulnerable to invasion by exotic species and altering environmental conditions in ways that help these non-native species expand their range. Mitigating the impact of invasive alien species requires a multi-pronged approach, including strict quarantine laws, early detection systems, close monitoring of trade flows, and international cooperation for trans boundary ecosystem management. Educating the public and conserving natural habitats are equally important steps to protect global biodiversity from these environmental invasions.

Experts have identified more than 69 invasive alien plants and animals, with aquatic ecosystems and protected forest areas like the Sundarbans being hit the hardest. They degrade water quality, compete with native plants and animals for resources, and destroy local food chains and agricultural production.

This plant can double its population in just a few weeks, forming thick mats that cover rivers, canals, and ponds. This rapid spread blocks sunlight, depletes dissolved oxygen in the water, and severely harms native fish populations and aquatic biodiversity. Additionally, it disrupts water transport and blocks irrigation channels, creating major economic bottlenecks.Terrestrial forest ecosystems in Bangladesh-such as the hill forests of Sylhet and the Sundarbans-are struggling with invasive alien weeds. Micaniamicrantha, a fast-growing vine, covers native trees and shrubs and suffocates them by blocking sunlight. 
Similarly, Lantana camara forms dense, impenetrable thickets in protected areas, outcompeting native understory plants and severely reducing rangeland biodiversity. African sharptooth catfish (Clariusgaripinus) and tilapia. Several exotic fish species were introduced for farming purposes to increase initial productivity in the fisheries sector. Species such as the African sharptooth catfish (locally known as African magur) and various varieties of tilapia are highly prolific and predatory. When these fish escape into natural reservoirs or floodplains, they prey on native fish species, compete for food, and sometimes spread disease, leading to a decline in native fish diversity.   
Invasive alien species represent a profound and often irreversible threat to the natural heritage and economic stability of Bangladesh. As climate change and global trade continue to accelerate, the risks of biological invasions will only increase. Protecting Bangladesh’s rich ecosystems and sustaining its agricultural and fisheries sectors will require coordinated national policies, enhanced scientific research, robust regional cooperation, and active public participation.
Invasive alien species represent one of the most significant yet preventable threats to global biodiversity and economic stability. As international trade and global travel continue to expand, the pathways for these biological invaders will only multiply. Protecting our native ecosystems and ensuring food security requires a shift from reactive damage control to proactive, preventative measures.Addressing this issue requires cross-sector collaboration between governments, industries, and local communities. 

Only by implementing stringent biosecurity measures and investing in sustainable management can we safeguard our economies and ecosystems from these relentless biological threats. Protecting our planet's natural heritage depends on our collective willingness to prioritize ecosystem health over short-term human gain. By supporting robust conservation policies and raising public awareness, we can mitigate the devastating impacts of IAS and preserve the fragile balance of our natural world for future generations.