Decline in pollinator population may hit food production, says a new study

Habitat destruction and heavy use of pesticide are among the main reasons for the loss of pollinator populations which are vital for the reproduction of three-fourths of food crops and flowering plants, according to a study appeared in the journal Nature Ecology and Evolution on Monday.

This was the first-ever global level study to index the causes and effects of the decline in “ecosystem services” provided by pollinator species such as bees, butterflies, wasps, bats, and hummingbirds across six regions including Asia Pacific, Africa and Latin America.

While the population of these pollinators is visibly diminishing, very little is known of the consequences of such a decline for human population, said the scientists.

“What happens to pollinators could have huge knock-on effects for humanity. These small creatures play central roles in the world’s ecosystems, including many that humans and other animals rely on for nutrition. If they go, we may be in serious trouble,” said Lynn Dicks, professor of zoology at the Cambridge University, who led the study, in a statement.

Top reasons

The study carried out by a team of 20 experts and indigenous representatives from different parts of the world showed that top three global causes of pollinator loss are habitat destruction, land management — primarily grazing, fertilisers and crop monoculture of farming — and widespread pesticide use. The effect of climate change comes in at number four, although data are limited, they said.

From India, Parthiba Basu, a zoology professor from the University of Calcutta, and Thingreipi Lungharwo from Naga Women’s Union in Manipur, contributed to the study.

The researchers found that the biggest risk to humans from the decline of pollinator population across all regions was what they called crop pollination deficit – that is the fall in quality and quantity of food and biofuel crops. The threat is much higher across two-thirds of the planet, where farmers with small holdings directly rely on pollinated crops.

“Crops dependent on pollinators fluctuate more in yield than, for example, cereals,” said Dicks. “Increasingly unusual climatic phenomena, such as extreme rainfall and temperature, are already affecting crops. Pollinator loss adds further instability — it’s the last thing people need.”

A 2016 report to which Lynn Dicks contributed suggested there has been up to a 300 per cent increase in pollinator-dependent food production over the past half century, with an annual market value that may be as much as $577 billion.

The researchers cautioned that not enough is known about the state of pollinator populations in the Global South, as evidence of decline is still primarily from wealthy regions such as Europe (where at least 37 per cent of bee and 31 per cent of butterfly species are in decline).

India, China

The scientists said China and India are increasingly reliant on fruit and vegetable crops that need pollinators, some of which now require people to pollinate by hand.

“We do not know much about the status of our pollinators because there was very little work on them. Secondly, since there is no historical records it is very difficult to know what is affecting them and so on so forth. It is really a black box,” said Hema Somanathan, professor of zoology at Indian Institute of Science Education and Research at Thiruvananthapuram, who was not part of the current study.

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