Global study shows pesticides are fuelling biodiversity crisis

Experts say government must assist farmers to work more sustainably, and enable the reduction of pesticides through initiatives such as regenerative agriculture 

A study assessing the impacts of pesticides across all types of species in land and water habitats, has revealed that pesticides are inadvertently causing overwhelmingly negative effects on hundreds of species of microbes, fungi, plants, insects, fish, birds and mammals. Globally their use is a major contributor to the biodiversity crisis. 

The work was carried out by an international research team, led by East China University of Science and Technology, which included the UK Centre for Ecology & Hydrology (UKCEH) and the University of Sussex. 

Scientists analysed over 1,700 existing lab and field studies of the impacts of 471 different pesticide types – either insecticides, fungicides or herbicides – in agricultural, commercial or domestic use. 

Wide-ranging negative effects were seen for over 800 species found on land and in water, including impacts on how fast they grow, their reproductive success, and even behaviour such as their ability to catch prey, find plants to forage upon, move, or attract mates.

Pesticides can also affect organisms’ metabolism and damage cells. These negative effects can result in the premature death of wild organisms and reduce populations.  

“Our study provides an unparalleled insight into the consequences of pesticide use on the natural environment globally,” said co-author Dr Ben Woodcock, an ecologist at UKCEH. “Pesticides are a necessary evil, without which global food production and farmers’ livelihoods would likely collapse.

"However, our findings highlight the need for policies and practices to reduce their use. This could include bottom-up initiatives led by farmers such as regenerative agriculture, as well as government policies such as Defra’s Sustainable Farming Incentive, which pays farmers to reduce insecticide use on crops.”

Professor Dave Goulson of the University of Sussex, who was also part of the research, added: “It is often assumed that pesticides are toxic primarily to the target pest and closely related organisms, but this is clearly not true. Concerningly, we found pervasive negative impacts across plants, animals, fungi and microbes, threatening the integrity of ecosystems.”

Overuse of pesticides not only threatens beneficial species they are not intended to target but can also enable pests to develop resistance to the chemicals, rendering them ineffective.

“We are already facing a biodiversity crisis in the UK and globally…until pesticide use and its impact is dramatically reduced, biodiversity will continue to suffer.”

Nick Mole, UK Policy Manager, PAN UK said the organisation is “not at all” surprised by the finding that pesticides are harming and destroying biodiversity. “Since the publication of [environmental science book] Silent Spring in 1962 it has been very clear that pesticides have an adverse impact on biodiversity – sadly nothing has changed since then.” 

He added, “We are already facing a biodiversity crisis in the UK and globally, unless and until pesticide use and its impact is dramatically reduced, biodiversity will continue to suffer.” 

Alternative options for farmers include planting wildflowers and beetle banks to support species that eat pests. Other measures include adjusting the timing of planting to avoid pests and rotating crops to break the species’ life cycles and reduce their numbers. 

Mole agrees that solutions to the problem do exist. “The government needs to support, encourage and assist farmers to farm more sustainably. There is a lot that can be learned from organic and agroecological farming systems that could help reduce the use of pesticides. 

“Similarly, there is a growing realisation amongst ‘conventional’ farmers that reducing their inputs, such as pesticides, can help protect and restore biodiversity on their farms and improve their incomes.”