Fact Check

Fact check: Is two-thirds of Australia's food production reliant on bee pollination?

Updated November 16, 2018 14:14:00

The claim

A joint Fairfax-ABC investigation recently reported on allegations that a number of well-known brands of honey contained substitute ingredients.

Featured in the report, screened on the 7.30 program, was fruit and vegetable magnate Robert Costa, who spoke on the viability of Australia's beekeeping industry and the important role played by bees in agricultural production.

"As a matter of fact, two-thirds of Australia's food relies upon bee pollination," he said.

"That's why we're particularly conscious of the viability of the beekeeping industry in Australia, which is under great threat."

Is two-thirds of Australia's food production reliant on bee pollination? RMIT ABC Fact Check investigates.

The verdict

Mr Costa's claim is overstated.

Experts told Fact Check that crops reliant on bee pollination represented closer to 35 per cent (about one-third) of total food production.

They said that although around 75 per cent of all crops get some benefit from pollination by bees, this was not simply a case of "all or nothing".

Rather, the pollination by bee species provided varying degrees of benefit.

Although honey bees and other bee species are an integral part of the pollination process for Australian crops and commercial pollinators, they are not the only insects involved in pollination.

Flies and beetles, among other insects, as well as birds and bats, play a larger role than is often acknowledged.

Also, some of Australia's most heavily consumed cereals — wheat, oats and rice, for example — are wind pollinated, whereby pollen is carried from plant to plant by the wind.

Experts also cautioned about using the word "rely". Although a lot of crops did experience increased volumes and quality of fruit or seed set when bees were present, this did not mean there would be no product without them.

The inference that removing bee species from the pollination process would see two-thirds of our food source disappear was misleading, they said.

How bees get involved

The most popular and well-known pollinator is the European honey bee, also known in the scientific world as Apis mellifera.

Honey bees are proficient workers that make frequent visits to a broad variety of plant species in search of nectar or pollen.

As bees forage, pollen attaches to the fine hairs on their bodies which is then transferred from site to site, leading to the pollination of plants and flowers. This facilitates plant fertilisation by taking pollen from a flower's male anther (where the pollen is released) and transferring it to the female stigma (where the pollen must be deposited).

While this process generally occurs naturally, professional beekeepers are also deployed to help with the process for commercial purposes. As an industry, honey bee pollinators are estimated to contribute around $6 billion a year to the Australian economy.

The extent of bee pollination

A 2014 Senate inquiry into the Future of Beekeeping and Pollination Services was told that 65 per cent of horticultural and agricultural crops grown in Australia require honey bees for pollination.

Saul Cunningham, a professor of Environmental Science at Australian National University, pointed out that while the figure refers to the number of different crops requiring bees for pollination, it did not reflect the importance of different crops to overall food production.

"The 65 per cent number in the Senate report is a reference to 'counting crops' rather than assigning the actual quantitative impact on production," he said.

"Not all of those crops are equally important to our food. You obviously wouldn't want to count every species equally … In other words, weighted by volume of trade, about one in three bites of food are influenced by bee pollination."

Are some crops more responsive to bees than others?

The Senate report on pollination awareness lists a variety of crop species and calculates what it terms as their 'dependency' on honey bee pollination.

For instance, almond crops have a 100 per cent dependency, according to the report, as do avocados and blueberries. Those with 90-100 per cent dependency include cucumbers, mangoes, apples and pumpkin.

Those least dependent are vine crops such as squash, and seed products such as beans and soy.

Professor Cunningham disputed whether labelling this responsiveness as 'honey bee dependency' was fair, because "we know for certain that most of these crops are pollinated by a wide range of species, not just honey bees."

According to Dr Romina Rader, a senior lecturer in ecology at the University of New England, a shortage of bees would not necessarily mean no crops altogether.

"It is likely that for some crops, the fruit will be smaller and lower quality, but it doesn't mean we're going to have no fruit ," she said.

"There are a number of food crops that don't require bees for pollination. Fruits benefit most from animal pollinators, but many vegetable crops only require pollination for seed production and breeding purposes.

"[But] for other crops, like apples and watermelon that require cross-pollination, you would get no high quality [fruit] at all if you don't have pollinators."

The consequence of poorly pollinated crops was low yields or fruit that was misshapen, meaning it could not be sold.

"We need to understand more about the different crop breeding systems and the pollinator dependency of different cultivars [a human-cultivated variety of food crops] and then synthesise the literature of studies that have witnessed the types of pollinators visiting flowers, and put them together."

She added that although a lot of crops relied on insect pollination, the proportion of production that depended on bee pollination was around 35 per cent.

Professor Cunningham said: "If you look at all the different species of crops we grow and eat that get some benefit from bees, based on trade figures, you'll get a number that's closer to two-thirds.

"However, that's very different to saying the amount of food that relies on bee pollination."

Plant ecologist Dr Margie Mayfield, of the University of Queensland, said although a lot of crops did rely on insect pollination, the exact proportion was not a simple calculation.

"It's actually a very hard number to calculate because it depends on whether you're looking at biomass or crop numbers."

She added: "If we're talking about total food biomass, two-thirds seems high. A lot of our crop species don't represent a large proportion of our food biomass. For instance, a lot of our tropical fruit are insect pollinated — but we don't eat a lot of them."

Dr Mayfield concluded that the common statistic of one in three bites was a more accurate representation of the proportion of Australian food that relies on bee pollination, given "much of our food is meat and grain."

The extent of the benefits of bee pollinators

Rough estimates of crops that rely on insect pollination can be deceptive since they might omit the various levels of pollinator dependency.

A 2007 report published by the Royal Society, Importance of Pollinators in Changing Landscapes for World Crops, categorises crops as pollinator-dependent, pollinator-beneficial or as those drawing limited benefits from pollination.

But this response to pollination varies between crop types and their stages of production.

For instance, some crops only benefit from pollination for breeding and seed production, while for others the benefits are through the amount or quality of fruit produced.

The report found that around 75 per cent of the main food crops do benefit from pollination.

"Not rely on pollinators," Dr Rader emphasised. "But benefit.

"It's not black and white — dependent on bees or not dependent. Pollinator dependency is different across all crops and even within crops for different types of cultivars.

"We need to understand this range for Australian crop cultivars to quantify exactly how much we actually benefit from animal pollinators."

In addition, the report found that a loss of insect pollinators would dramatically affect the viability of a diverse plant industry, and therefore the diversity of the human diet, but wouldn't have a major effect on the production of staple food products.


Other pollinators

There are a number of alternative pollinators that Australian crops rely upon, including birds, flies, beetles, butterflies, moths, bats and wasps.

For some species, pollination can occur naturally within the flower, through a self-pollination process.

For others, wind pollination is crucial. These include cereal crops wheat, corn and rice, which make up Australia's largest agricultural sector and are a major staple around the world.

University of New England's Dr Rader told Fact Check it was understandable that people tended to focus more on the honey bee as a pollinator.

"[The honey bee] is managed, it's everywhere, it's really easy to handle and it visits a lot of flowers. It's an amazing generalist pollinator — but we also need to be aware that other conditions influence pollination success as well, in addition to the honey bee.

"These include the timing of crop flowering, receptivity, the availability of compatible pollen, the behaviour of other pollinating insects, the surrounding management of farms, the conditions the plants are grown in and the environmental conditions, like the temperature, rain and hail.

"All of these conditions need to be managed effectively for optimal fruit production in horticultural systems.

"But we need to acknowledge that the honey bee is not the only pollinator. There are solitary and social bees that are native to Australia, as well as flies, beetles, all sorts of other insects."

ANU's Professor Cunningham said: "If you ask what portion of food production relies on managed honey bees, then you would end up with an even smaller number, because most pollination is done by unmanaged insects.

"The great majority of crops don't have those white-boxed managed honey bees.

"And it's quite difficult to say what proportion of food production comes from managed honey bees compared to what proportion comes from all the other bees and insects. But we certainly know for sure that it's a smaller fraction."

Principal researcher: Natasha Grivas

factcheck@rmit.edu.au

Sources




Topics: agricultural-crops, agricultural-policy, sustainable-and-alternative-farming, agribusiness, australia

First posted October 15, 2018 06:01:32