Bee decline could push up food costs: researcher
Several factors - from pesticide use to climate change - are causing populations of bees and other pollinators to decline, says a researcher with the University of Guelph.
Nigel Raine, the Rebanks Family Chair in pollinator conservation inside the university’s School of Environmental Science, said people should care about pollinator decline, first and foremost, because it has an impact on agricultural production.
“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 last week in Ridgetown, Ont.
“When we have excellent levels of pollination, we have abundant diversity of healthy, nutritious foods - lots and lots of fruits, vegetables and nuts -and also production of other food that goes into feedstock for livestock, as well.”
Raine said that, if pollinator decline continues on its current trend, food prices could “skyrocket,” especially with some world population estimates exceeding nine billion people by 2050.
Pollinator decline also affects the biodiversity of plants as about 90 per cent of flowering plants rely on some sort of pollination, he said.
Raine said that the issue is important to southern Ontario because about 420 of the 855 species of pollinators in Canada call it their home.
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 after it was last spotted in Pinery Provincial Park, near Grand Bend, he said.
Raine said that, in his lab, he has looked at the effect insecticides have had on certain species of bees.
He has found impacts on their navigation, ability to find their hive, the flower choices made by bumblebees, 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 an increase in the average April temperature over the last 40 years has been associated with an earlier emergence of certain bee species.
He said research has shown butterflies are expectedly mov- ing northward to stay within their “thermal zone,” but bee species are not doing the same. And those bees 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,” said Raine.
“What’s happening to other pollinators, we really don’t know, because we don’t have good enough data to look at that yet.”
He said a recent report showed about four per cent of bees 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, he said.
One way to stem the decline of pollinators is to support their habitats, he said, noting that such a move takes 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 must be considered.
Habitat degradation itself is another cause of bee decline, said Raine, as well as exposure to pathogens and invasive species.
Nigel Raine is the Rebanks Family Chair in pollinator conservation at the University of Guelph.