Pollinator depletion: new threat to agriculture

Lazarus Sauti

The Southern African Development Community’s food security situation is facing a serious threat from the shrinking number of pollinators – living organisms that transfer pollen to the stigma of a flower.

Wild and managed pollinators, according to agronomist, Jonathan Rwodzi, have gone down over the last 50 years due to diseases, invasive species, the increasing use of pesticides as well as habitat loss, thereby reducing the abundance and diversity of floral resources as well as nesting opportunities.

“The intensification of agriculture and increasing reliance on pesticides mostly neonicotinoids means that pollinators are chemically exposed to cocktails of agro-chemicals," he said.

Echoing similar sentiments, Pride Machingauta, secretary of Bee Keepers Association of Zimbabwe Trust, says birds, bees, bats and other animals are increasingly threatened by an onslaught of harmful influences such as excessive use of toxins and bee-killing crop chemicals.

He added that this pollinator depletion, caused by modern farming techniques, is not only threatening the region’s agricultural security, but negatively impacting on the biosphere, such as the air and water pollution, leading to the growth of infectious diseases.

“Bees are the primary pollinators in agricultural systems. They are the most efficient pollinators of crops because they forage among the same plant types in a single visit, while others such as butterflies are more random in the flowers they visit.

“The depletion of bees as well as other pollinators is, therefore, a serious threat to SADC’s food security as well as health and wellbeing,” explained Machingauta.

Due to pollinator depletion, for instance, it is estimated that Zimbabwe’s maize production dropped by as much as 40 per cent in the 2014/15 cropping season with a likely cereal deficit of between one and 1.3 million metric tonnes.

The problem is not affecting Zimbabwe only as most countries in Southern Africa are struggling with food security and health issues caused by pollinator depletion, climate change in addition to other issues.

“Most countries in SADC are facing food and health challenges simply because modern agriculture techniques involving spraying crops with toxic chemicals are killing soils, which in turn are killing off the bees that feed on the plants that grow in these soils,” agreed James Tembo, a soil expert with Zimbabwe’s Ministry of Agriculture, Mechanisation and Irrigation Development.

A study of crops by the University of Zimbabwe, the oldest and largest university in the country, says: “Pollinators provide a key ecosystem service vital to the maintenance of both wild and agricultural plant communities; a healthy population of wild bees is key to the successful yields of crops ranging from pumpkins to grape fruit.”

Another paper titled “Pollinators in Africa: Understanding is the First Step to Protecting”, written by Daphne Mayes, Peace Corps Volunteer and Master’s International student, Zambia, 2009–2011, states:

“Pollinators are an integral part of our food supply as well as the many plants that other wildlife depends upon for food and shelter; they contribute to food security, biological diversity and the economy.

“It is, therefore, crucial to focus efforts on pollinator conservation.”

SADC countries need to improve pollinator biodiversity as well as the pollination of crops and wild plants through networking if the region is to feed its citizens and foster a society with a shared future that will ensure collective socio-economic growth, improved living standards and quality of life.

“Almost 80 per cent of world crops require pollination to set seed; thus, countries in Southern Africa need to promote farming techniques that do not harm soils as well as pollinator species such as birds and insects (bees and beetles),” he said.

Tembo again: “Grains are primarily pollinated by the wind, but the best and healthiest foods – fruits, nuts, and vegetables – are pollinated by bees. Seventy out of the top 100 human food crops, which supply about 90 per cent of the world's nutrition, are pollinated by bees.

“To protect bees and other pollinators, SADC countries need to fix their dysfunctional and destructive agricultural systems.”

Greenpeace, the leading independent campaigning organisation that uses peaceful protest and creative communication to expose global environmental problems as well as to promote solutions that are essential to a green and peaceful future, believes common sense actions can restore and protect the world's pollinators.

The organisation, thus, urges countries to ban dangerous pesticides, protect pollinator health by preserving wild habitat, and restore ecological agriculture.

“Pollinators are important players in agriculture. They must be considered when applying certain management strategies if countries are to protect them and improve their food security,” said Greenpeace.

The organisation added, “The health and needs of pollinators are vital for the future of sustainable agriculture, as is improved soil fertility, food security and productivity which are by-products of these methods.”

Greenpeace also said educating all stakeholders in the agricultural field about the importance of pollinators will be of great benefit to all as it will ensure a more productive and secure future.

The decline in the health and populations of pollinators pose serious threat to the integrity of biodiversity, regional food webs as well as human health.

As a result, policy decision makers in the SADC region need to recognise the 1999 convention on the Biological Diversity issued the Sao Paulo declaration on pollinators by recognising the critical role these species play in supporting and maintaining technical productivity, as well as the survival challenges they face due to anthropogenic change.