Taking on the invaders

01 October 2012 | Article

With invasive alien species posing a major threat to native biodiversity, progress in tackling the problem is among the topics at the UN biodiversity conference that starts 8 October.

Shyama Pagad, Programme Officer with IUCN’s Invasive Species Specialist Group, explains the ‘invasives’ problem, what’s being done about it and how she got involved.

Invasive species are organisms that have been transported from their native environment, accidentally or intentionally, to a new environment, where they can have devastating impacts on native species and habitats.

In many areas of the world, invasive mammals such as rats, mice, cats and mongoose have devastated bird populations even to the point of extinction. Introduced herbivores like goats, sheep, deer and cattle damage vegetation, altering entire ecosystems, while introduced pigs root and dig and destroy habitats, sometime carrying disease from place to place.

Prevention is key

Some success in removing invasive species has been achieved with sustained action, but this is expensive and requires vast resources. Preventing the introduction of alien and potentially invasive species is key to stemming biodiversity loss.

As a member and Programme Officer of IUCN’s Invasive Species Specialist Group, I focus on raising awareness of the impacts of invasive species on native species and natural areas and promoting information exchange both through networks and our online resources. This is the mission of our group.

My love for nature and growing plants was nurtured by my parents especially my mother, an avid gardener. I had my own little vegetable patch when I was six growing coriander and okra. I remember spending endless hours with my siblings watching dung beetles make progress, ants building anthills and, chasing lizards.

A passion for nature

Parthenium hysterophorus was introduced to India as a seed contaminant in the early 1950s. I recognised and understood biodiversity loss for the first time when parthenium and other invasive plants overtook all our open spaces. We could not find the cassia plant, the leaves of which we used to make a curry with coconut milk. Gone also were the lovely blue convolvulus plants. We also saw fewer lizards and the big showy grasshoppers that sat on the milkweed plants.

I went on to complete a degree in Horticultural sciences at the University of Agriculture Sciences in Bangalore. My first job was working on a project that focussed on the transfer of agricultural technology - the ‘Lab to Land’ project. After some years spent in designing landscape and environmental projects, I went on to settle in New Zealand. Here I realized not only the extent of the impact of invasive species on native biodiversity and their habitats, but more importantly that timely conservation action can bring success. Removal of introduced predatory mammals on our off-shore islands has created havens for our native birds and restored native species. Some of these islands are home to native species that have become extinct on the mainland.

High hopes

At the Convention on Biological Diversity conference in Hyderabad in India, my home country, I am looking forward to seeing recognition of the severe impact that invasive species have, not only on biodiversity, but also on food security and livelihoods. I also hope to see greater recognition of the fact that preventing the introduction of new alien species and managing pathways of spread is critical to turning the tide of biodiversity loss.