Expert warns decline of pollinators could cause food-cost spike
From pesticide use to climate change, a number of factors are causing the populations of bees and other pollinators to decline, a University of Guelph researcher said Thursday at a conference in Ridgetown.
People should care about pollinator decline, first and foremost, because it has an effect on agricultural production, said Nigel Raine, the Rebanks Family chair in pollinator conservation at the university ’s school of environmental science.
“About one in three mouthfuls of food that we consume are dependent on the pollination services of insect pollinators,” he said during a presentation at the South West Agricultural Conference. “When we have excellent levels of pollination, we have abundant diversity of healthy, nutritious foods — lots and lots of fruits, vegetables and nuts,” he said, adding it’s also important for production of other crops that go into feedstock for livestock.
If pollinator decline continues on its current trend, food prices could “skyrocket,” he said, especially with some estimates that the world’s population could exceed nine billion by 2050. Pollinator decline also affects the biodiversity of plants, as about 90 per cent of flowering plants rely on pollination, he said. The issue is important to a region like southern Ontario, he added, because it’s home to about 420 of the 855 species of pollinators in Canada. Some bee species have declined by 96 per cent, though others are still common, said Raine. Canada, for example, hasn’t seen the rusty patch bumblebee for 10 years since it was last spotted in Pinery Provincial Park near Grand Bend, he said.
Raine said his lab has looked at the effect of insecticides on certain species of bees. It has found effects on their navigation, ability to find their hives, the flower choices bumblebees make, their learning performance and their ability to make pollen based on low-level exposure to these chemicals. “We see in bumblebees that low levels of exposure can affect the likelihood of a queen to set up a colony at the beginning of the spring,” he said.
“They can affect the reproductive output of colonies, the number of queens and males that are produced, and the success of which they mate.” Apples exposed to low levels of pesticides can also affect the success of pollination of those apples, Raine added.
Although he said these are “relatively subtle effects,” these changes in behaviour “may be affecting pollination services relatively widely.” As well, Raine said the rising of the April mean temperature, especially over the past 40 years, has been associated with an earlier emergence of certain bee species. He said data have shown butterflies are expectedly moving northward to stay within their “thermal zone,” but bee species are not doing the same and those at the southern part of their geographical zone are experiencing significant losses.
“We seem to be seeing their ranges being compressed, and they may be struggling to adapt as quickly as we thought they would to climate change,” he said. “What’s happening to other pollinators, we really don’t know because we don’t have good enough data to look at that yet.” Raine said a recent report showed about four per cent are at risk of extinction, but more than 1,000 bee species are considered “data deficient,” meaning scientists can’t say how their numbers are declining or improving. One way to stem the decline of pollinators is to support their habitats, he said, but this takes some careful considerations.
“We need to know which flowers we need to provide for them to provide the nectar and pollen they need,” he said, adding the distances between these flowers and nesting sites also need to be considered.
Habitat degradation itself is another cause of bee decline, said Raine, as well as exposure to pathogens and invasive species.