Monitoring inadequacies hamper bee population analysis

Declining bee populations are causing considerable concern for food security, since they play a fundamental role in pollinating many plants and crops that we rely on for food.

Agence française de sécurité sanitaire des aliments (AFSSA), the French food safety body, carried out the research into the bee problem, with funding help from the European Food Safety Authority (EFSA). The goal of the study was to evaluate existing monitoring systems, analyse existing data and critically the literature on possible causes of population loss.

Surveillance systems​

Its investigation into the bee mortality problem in Europe revealed that very few systems for monitoring colony loss are of an adequate standard.

Two countries, Ireland and Portugal, had no surveillance systems in place, and only 6 of the 24 systems surveyed were considered capable of producing representative figures of the true colony loss situation for their countries.

“This generally low level of compliance reflects a broad margin for improvement in most of the European surveillance systems considered within the project,”​ stated the report.

One the basis of this conclusion, the report drew up a set of 20 recommendations, designed to enhance honey bee surveillance in Europe.

In the meantime, AFSSA set itself the task of evaluating the existing data but found that trends were difficult to interpret because of the wide variation in the quality of monitoring systems.

Data on colony loss​

Nevertheless, the report did estimate that the baseline colony loss rate is around 10 per cent each year at the European level.

To go beyond this broad finding and compare different countries accurately, the report said the harmonisation of surveillance procedures and epidemiological indicators is needed on a European level. The report also exposed various ways of defining colony loss, and therefore called for further research to clearly categorise and quantify expressions of colony losses in the field.

Harmonisation of approach, and more rigorous monitoring systems, could help scientists better understand the causes of bee mortality and ultimately, identify strategies to curb declining bee numbers.

Currently, the scientific community is agreed that there are many causes of colony losses that include beekeeping and husbandry practices, chemical factors, and biological agents.

However, the respective role of each factor is poorly understood. The report said biological agents like parasites, viruses and bacteria have clearly been identified as important factors but further investigation is needed to better understand, and rank different causes.