Bees and the web of life

23 05 2013

beesI’m happily planning what will be my new organic kitchen garden, and I keep thinking about agriculture and how it relates to Fritjof Capra’s statement that we are all part of a vast interconnected universe – one that is constantly in flux. And I also keep returning to the subject of how agriculture, as practiced in the “developed” world, impacts us.

Across the United States and around the world, honey bee populations are mysteriously vanishing. Honey bee colony losses are not uncommon, however, the sort of disappearance I’m talking about is unprecedented: This honey bee colony loss (called colony-collapse disorder, CCD) is due to uncharacteristic bee behavior: bees are failing to return to the hive. And we don’t know why.

Given how important honeybees are to the food that we eat — bees help pollinate crops that are worth more than $200 billion a year — the fact that they are dying in large numbers, and we can’t say why, is very, very worrying. And it’s not just honey bees that are dying: according to a study written by a team of scientists including entomologist Sydney Cameron of the University of Illinois, the relative abundance of four species of bumble bees over the past few decades has dropped by more than 90%—and those disappearing species are also suffering from low genetic diversity, which makes them that much more susceptible to disease or environmental pressures.

CCD was first reported in 2006, when commercial beekeepers began noticing that their adult worker honeybees would suddenly flee the hive, ending up dead somewhere else. This led to the rapid loss of the colony. During normal years, commercial beekeepers expect to lose 10% to 15% of their colony, but over the past five years, mortality rates for commercial operations in the U.S. have ranged from 28% to 33%. This could be disastrous for our food supply: according to a study released by the United States Department of Agriculture in May, 2013, “the consequences for the agricultural economy — and even for our ability to feed ourselves — could be dire.”(1)

How is this of such concern? In California, the almond crop (as one example) is so large and intensively grown these days that it has greatly surpassed the region’s inherent ability to supply pollinators. Decades ago, when there were fewer almonds, farmers could rely on pollination just from the beekeepers who lived in the Central Valley. Now, they have to import migrant apian labor.

And now, bees are big business: Scientific AG, a firm based in Bakersfield, California, helps broker pollination deals between local almond growers and apiarists from across America. Joe Traynor, the pollination broker who founded Scientific AG, says that in the 1960s there were 100,000 acres (40,000 hectares) of groves. Today, groves cover 700,000 acres and the industry claims it supplies 80% of the world’s almonds. In order to meet this pollination demand, more than a third of America’s beehives must be moved to California for the season. Such changes to the industry have been reflected in the prices for bee hives. In 1995 growers could rent a hive for $35. Today, says Mr Traynor, a strong colony would cost $150-200. Beekeepers truck their hives cross country to pollinate almond groves in California, field crops and forages in the Midwest, apples and blueberries in the Northeast and citrus in Florida.

But now the bees are dying and nobody has pinned down the precise cause for CCD.

A lot of things can kill a hive, but nothing has devastated beekeeping in America in the last half century more than the accidental introduction of Varroa destructor in the mid-1980s. A tiny parasitic mite, varroa reproduces fast, and mite populations can and do overwhelm colonies and kill them outright. Varroa is credited with wiping out the wild bee population in North America. Breeding a varroa-resistant bee is the holy grail of American beekeepers. And often varroa mites are cited as a cause of CCD, but varroa mites were present in North America 20 years before CCD.

Other types of fungus (such as Nosema ceranae, a parasitic fungus from Asia which impacts a bee’s ability to process food) have been mentioned. But there is almost certainly a further factor causing stress on the bees—a poor diet.

It is increasingly being recognized that managed bees need food supplements. In some places, a decline in the area of pasture land on which they can forage, the loss of weedy borders and the growth of crop monocultures mean it is hard for bees to find a wide enough range of pollen sources to obtain all their essential amino acids. In extreme cases they may not even find enough basic protein. Writing in Bee Culture, February 2009, Mr Traynor observes that places where crops with low-protein pollens are grown (such as blueberries and sunflowers) are also places where CCD has appeared.

The suggestion is that poor nutrition has weakened the bees’ immune systems, making them more vulnerable to viruses and other parasites. Feeding bees supplements, rather than relying on their ability to forage in the wild, costs time and money. Many beekeepers therefore try to avoid it. Anecdote suggests, however, that those who do fork out find their colonies are far more resistant to CCD.

New research suggests yet another potential contributor to CCD. The problem? We’ve been stealing the bees’ honey, which aids the bee’s “immune systems”—detoxification enzymes used to rid the body of foreign chemicals, like pesticides – and instead feeding them high fructose corn syrup. Commercial beekeepers feed bees high fructose corn syrup instead of honey for the same reason that commercial food manufacturers feed it to us: it’s cheaper.(2)

And of course, there are pesticides. Systemic pesticides like imidacloprid and clothianidin, so-called “neonics,” are persistent in soils for as long as two years, are water-soluble so they can travel far from their original application, and they’re taken up by plants’ roots and circulated throughout, so leaves, nectar, pollen, fruit – indeed, all of the plant is contaminated. The European Union recently instituted a two year ban on neonics. Research at Washington State University has found that pesticides embedded in old honeycombs is a major contributors to CCD.(3) They found traces of insecticides, herbicides, miticides and fungicides in honeycombs and bees raised in those hives had “significantly reduced longevity”.

Even more far-fetched concerns for CCD include cellphones and GMO crops.

But here’s the thing: Australia is one of the few nations in the world to have remained free of varroa mite (so far). And Australia – which has cellphones and towers, migratory and commercial beekeeping, neonic pesticides in agriculture, high fructose corn syrup for supplemental feeding, and environmental factors like drought and urbanization and all the rest – has had zero incidents of colony collapse disorder.
So, going back to Fritjof Capra and his insistence that the “web of life” is made up of a series of interconnected things, could it not be because of all of the above? Bees are stressed by loss of habitat, infection from fungus and mites, pesticides and poor nutrition – perhaps they’re just reaching the tipping point?

(1) http://science.time.com/2013/05/07/beepocalypse-redux-honey-bees-are-still-dying-and-we-still-dont-know-why/
(2) http://arstechnica.com/science/2013/05/feeding-bees-corn-syrup-may-leave-them-vulnerable-to-colony-collapse/
(3) http://researchnews.wsu.edu/environment/248.html

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