Honeybees and other pollinators declining

Source ENS Photo courtesy ENS

Bees, bats and other vital pollinators are declining across North America, placing crops and other plants at risk, according to a new report by the National Research Council. The report finds that shortages of pollinators already exist and warns that continued decreases in wild populations could disrupt ecosystems and agricultural production. "Despite its apparent lack of marquee appeal, a decline in pollinator populations is one form of global change that actually has credible potential to alter the shape and structure of terrestrial ecosystems," said committee chair May Berenbaum, an entomologist at the University of Illinois, Urbana-Champaign. Pollinators are vital to the environment as they spread pollen, enabling plant fertilization to occur. Three-quarters of all flowering plants–including most food crops and some that provide fiber, drugs and fuel–rely on pollinators for fertilization. The committee cautioned that there is little or no population data for many North American pollinators and urged increased monitoring efforts. But there is ample evidence that long-term population trends for some key North American pollinators, including butterflies, bats, hummingbirds and several wild bee species are "demonstrably downward," the committee said. The report sounds a specific warning for the honeybee, which is vital to US agriculture, pollinating more than 90 commercially grown crops. It can take a massive amount of bees to ensure a crop is suitably pollinated. For example, it takes about 1.4 million colonies of honeybees to pollinate 550,000 acres of almond trees in California. US honeybee populations have declined at least 30 percent since the 1980s, when a non-native parasitic mite was introduced. The committee said that the full extent of the decline is unclear because of problems with the way the federal government collects statistics on the beekeeping industry. Antibiotic-resistant pathogens and encroachment by Africanized honeybees also are hurting North American honeybee levels, the committee said, and there is clear evidence of a honeybee shortage. Last year farmers imported honeybees from outside North America for the first time since 1992. Importing bees raises serious concerns, the committee said, as they can bring new pests and parasites. It recommends that US Department of Agriculture and relevant agencies in Canada and Mexico take steps to prevent the introduction of new pests, parasites and pathogens if bees are imported. Like the honeybee, the bumblebee has been hurt by the introduction of a non-native parasite, the committee said, and many pollinator declines are associated with habitat loss–particularly native bat populations. The committee noted that its findings reflect a global decrease in pollinators. In Europe, where much more data has been gathered on pollinators, researchers have definitively documented declines and even extinctions. The report recommends the United States work closely with Canada and Mexico to form a network of long-term monitoring projects as well as a rapid, one-time survey should be conducted to establish baseline data to which future assessments can be compared. The study was requested by the North American Pollinator Protection Campaign, an organization that represents several agencies and organizations in the United States, Canada, and Mexico dedicated to raising awareness of this issue.