Finding effective solutions to the threats facing agricultural pollination
Yesterday, the agroecology All-Party Parliamentary Group (APPG) met in the Palace of Westminster to discuss the scientific and political progress being made to protect England’s pollinators. In recent years, this has been a key discussion amongst scientists, politicians, farmers and conservationists due to the evidenced declines of pollinators in the UK. The decline of pollinators is multifactorial and has resulted from a combination of factors including reduced habitat, undermanaged pesticide use, the spread of disease and climate change. As such, it has been recognised that steps need to be taken to prevent pollinator decline due to their essential contribution to the agricultural industry and wild ecosystems. Just under two weeks ago the National Pollinator Strategy was released by Defra for review and this strategy was the main topic of conservation at the meeting. Speaking at the event was Dr. Lynn Dicks (NERC Research and Knowledge Exchange Fellow, University of Cambridge), Peter Lundgren (Farmer in Lincolnshire growing combinable crops) and Professor Mark Brown (Professor in Evolutionary Ecology and Conservation at Royal Holloway, University of London).
Dr. Lynn Dicks evaluated and assessed the complex circumstances we are facing and the recent strategy proposed by government. Currently, bumblebees, who make up a large proportion of wild pollinators, are in overall decline; this is, however, species dependent. Because in Britain wild pollinators contribute more to pollination services than the managed honeybee, they are a crucial asset. However, there are now around 40% fewer bumblebee species per 20 x 20km square compared to the 1950s and 60s.
The task of measuring and providing for declining pollinators is difficult as different species require different habitats and resources which is why reduced habitat and increased monoculture has had such a negative impact. Because there is no single cause of the decline, a clear solution is also proving challenging to cultivate. Furthermore, it is difficult to assess the economic impact of pollinator loss and the resulting loss of services. As such it is evident that information gathering and scientific assessment needs to be encouraged and facilitated so evidence-based solutions can be presented and implemented to account for varying threats and varying needs of different species. The strategy addresses the urgent need for more research to be performed and the arrangement of a knowledge exchange network by Defra is a big step towards this. Missing from the strategy is a clear timeline to reduce the use of pesticides or increase the planting of habitat for pollinators.
Peter Lundgren, a farmer who campaigns for sustainable farming practices argued that, “ignoring the crisis we are facing would result in consequences too great to ignore”. Lundgren also highlighted his misgivings with the calculations produced by the Humboldt Forum over the costs of the EU neonicotinoid ban to British farmers. He was surprised at how large the costs were estimated at, especially once he compared them to the realistic damage of the ban to his own business. Working with an agronomist, he concluded that per hectare of oil seed rape, loss of neonicotinoid pesticides would cost his farm £2.20 a year, not £230 – as estimated by Humboldt. In conclusion, he found that loss of neonicotinoids was far less risky to his business than the potential loss of pollinators and that the next step would be implementing alternative practices, such as integrated pest management, as a means of controlling pests.
Farmers are calling for more information on neonicotinoids and need Defra to support them through dissemination of peer-reviewed scientific evidence, cooperative discussions and effective actions.
Finally, Professor Mark Brown presented his study on the ways in which pyrethroids impact bumblebee colonies. Results currently indicate a reduction in bumblebee worker size by 16% in the presence of these pesticides. This is particularly concerning because of the way in which bumblebee colonies function. Bumblebee colonies have to achieve a colony of a certain size (have a large enough number of workers) before they have suitable resources to produce new queens and males (gynes) – reproductive bees. Because larger workers can carry more food, a reduction in the average worker size means achieving a high enough level of resources for the colony becomes more challenging. As a result there is a risk of there being less bumblebee queens to produce colonies the following season. Additionally, larger workers are better foragers as their antennae are more sensitive and their vision is better, therefore, they can seek out flowers more effectively. As such, they are more efficient pollinators and more productive workers. By reducing worker size to such a large extent, pyrethroids are potentially reducing pollinator efficiency and their capacity to reproduce.
Overall, the meeting concluded that more information needs to be available to all groups, more studies need to be carried out and funded, chemical companies should be legally obliged to share all their scientific findings and have their studies peer-reviewed and that the resources and access to knowledge needs to be more accessible to farmers so they can make informed decisions.
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