Invasive alien species can spell doom to local species

Ishara Mudugamuwa

The introduction of invasive alien species can result in the extinction of local species and make irreparable changes to the habitat and biodiversity of ecosystems, Environment Ministry Secretary B. M. U. D. Basnayake said.

Basnayake was participating at a workshop of Global Environment Facility funded project on Strengthening Capacity to Control the Introduction and Spread of Alien Invasive Species in Sri Lanka held yesterday at Hotel Taj Samudra, Colombo.

"The Convention on Biological Diversity which was ratified by Sri Lanka in 1994 was inspired by the world community's growing commitment to sustainable development.

It represents a dramatic step forward in the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of benefits arising from the use of genetic resources," he said.

The Secretary also said this convention identifies invasive species as any foreign species that threatens the balance of an ecosystem through its introduction and proliferation. Such alien species generally can come into a community as either as an unintentional introduction or as an intentional introduction.

"The Convention on Biodiversity lists invasive species as one of the direct drivers of biodiversity loss. These species through predation, parasitism, disease and competition can affect biodiversity. Invasive and native species can also mate to form hybrid species, which can potentially displace the native species, leading to loss of stability among the native population and eventual extinction," he said.

Basnayake said that the economic impact of invasive species is derived from direct and indirect costs. Direct costs are those related to controlling the spread of invasive species, such as the use of pesticides applied in an attempt to contain the spread of pests.

Indirect costs relate to the ecosystem services lost through such destruction. Worldwide, billions of dollars are spent annually as a result of invasive species.

"Invasive species spread disease that can be devastating to humans. Increased transportation and accessibility have allowed for new interaction between diseases and human hosts. Other social concerns that stem from invasive species include food security and water depletion, which are significant concerns in developing countries," he said.

Global environmental change, chemical and physical alterations of ecosystems and increased globalization are three main factors contribute to the expansion of invasive species. Global trade also has become the single largest factor in the worldwide spread of invasive species by means of ships, planes and railroads. Environmental disruption has increased as transportation technology has allowed an amplified level of global trade.

"Invasive species are also closely connected with climate change. Invasive species present a global challenge and its contributing factors such as international trade and mobility increase, international regulations will increasingly necessary to limit the further introduction and spread of invasive species," the secretary said.

UNDP Country Director Razeena Bilgrami, University of Colombo Faculty of Science Prof. Lasantha Manawadu, University of Peradeniya Faculty of Agriculture Prof. Buddhi Marambe, University of Colombo Faculty of Science Prof. Dewaka Weerakoon and many others participated.