Streams within approx. 40% of the global land surface are at risk from the application of insecticides. These were the results from the first global map to be modelled on insecticide runoff to surface waters, which has just been published in the journal Environmental Pollution by researchers from the Helmholtz Center for Environmental Research (UFZ) and the University of Koblenz-Landau together with the University of Milan, Aarhus University and Aachen University. According to the publication, particularly streams in the Mediterranean, the USA, Central America and Southeast Asia are at risk.
Unlike other chemicals, agricultural pesticides are intentionally applied to the environment to help farmers control insects, weeds and other potentially harmful pests threatening agricultural production. They can therefore affect land ecosystems but also surface waters from runoff. According to estimates, ca. 4 million tons of agricultural pesticides are applied annually, equating to an average of 0.27 kilograms per hectare of the global land surface.
Use of insecticides in the West Bank. The investigation showed that with higher average temperatures even more insecticides are used and therefore streams are more at risk in warmer regions
Photo: André Künzelmann/ UFZ
„We know from earlier investigations for example that pesticides can reduce the biodiversity of invertebrates in freshwater ecosystems by up to 42 percent and that we can expect an increased application of pesticides as a result of climate change“, explains Prof. Dr. Matthias Liess from the UFZ, who was recently appointed to a term of five years on the scientific advisory board "National Action Plan on Sustainable Use of Plant Protection Products" where he advises the Federal Ministry of Food and Agriculture.
Liess warns of an increase in the application of pesticides in many developing countries as farmers increasingly switch from traditionally extensive agricultural practices to more intensive ones. Until now the global extent of the potential water pollution from the application of insecticides has remained largely unknown.
The international team of scientists therefore came up with a global model with a raster of ca. ten kilometres, into which agricultural data from FAO and land use data from NASA among other data were entered. Annual average temperatures and monthly maximum precipitation measurements from around 77,000 weather stations were also taken into account. Following that, the researchers then estimated the so-called runoff potential (RP), in other words the amount of insecticides that enters streams and rivers through the rainwater from agricultural land.
„In this respect, daily rainfall intensity, terrain slope, and insecticide application rate play an equally important role as well as the crops cultivated“, explains junior professor Dr. Ralf B. Schäfer from the University of Koblenz-Landau. „In order to test such complex models, we therefore carried out control measurements of insecticide contamination in freshwater ecosystems from four different regions“.
Several world maps were produced: the vulnerability map only takes into account the geographic and climatic background. The risk map on the other hand shows the risks from this natural vulnerability through anthropogenic land use. In Central Europe, scientists largely assessed the risk for water bodies as medium to high. In the northern hemisphere, insecticide runoff presented an overall more significant latitudinal gradient.
„The risks of insecticide exposure to water bodies increased significantly the further South one travelled on a North-South gradient in Europe, North America and Asia, mainly driven by a higher insecticide application rate as a result of higher average temperatures“, Dr. Mira Kattwinkel reports, who is now conducting research at the Swiss Federal Institute of Aquatic Science and Technology (Eawag). Because the economy and the population are growing rapidly in many countries of the southern hemisphere, scientists expect a higher insecticide application rate in those countries in the future to cover an increase in agricultural production. The map could therefore still change colour considerably in other parts of the world. At the moment it is water bodies in the Mediterranean, the USA, Central America and Southeast Asia that are particularly vulnerable.
In Southeast Asia, countries such as the Philippines or Vietnam are greatly affected for example. UFZ researchers are looking into solutions for such regions within the framework of the LEGATO-project together with the International Rice Research Institute (IRRI), in an attempt to reduce pesticide application rates. One approach for example could be to revitalise the functioning of ecosystems so that the natural competitors of rice pests can help to avoid their mass reproduction and subsequent harvest yield losses.
„Our analysis provides a global map of hotspots for insecticide contamination that are a major risk for biodiversity in water bodies. To our knowledge this is the first study that assesses insecticide contamination of water bodies on a global scale“, Prof. Dr. Matthias Liess summarizes the significance of the new investigation. The researchers intend to use the global map to sensitize citizens and authorities about this issue in vulnerable regions and to incite local investigations. Buffer zones along the edge of water bodies can significantly reduce negative impacts for example.
Efficient environmental management and conservation efforts in the future should focus on informing authorities and farmers about the costs, impacts and alternatives. Ultimately, mitigation and management takes place at the local level, determining the extent to which a water body will be affected under the application of such chemicals.
Alessio Ippolito, Mira Kattwinkel, Jes J. Rasmussen, Ralf B. Schäfer, Riccardo Fornaroli, Matthias Liess (2015): Modeling global distribution of agricultural insecticides in surface waters. Environmental Pollution, Volume 198, March 2015, Pages 54-60, ISSN 0269-7491, http://dx.doi.org/10.1016/j.envpol.2014.12.016
J.H. Spangenberg, J.-M. Douguet, J. Settele, K.L. Heong (2015): Escaping the lock-in of continuous insecticide spraying in rice. Developing an integrated ecological and socio-political DPSIR analysis. Ecological Modelling, Volume 295, 10 January 2015, Pages 188-195, ISSN 0304-3800, http://dx.doi.org/10.1016/j.ecolmodel.2014.05.010
Helmholtz Centre for Environmental Research (UFZ)
Prof. Dr. Matthias Liess
Phone: +49 (0)341-235-1263
Institute for Environmental Sciences / University of Koblenz-Landau
Jun.-Prof. Dr. Ralf B. Schäfer
Phone: +49 (0)6341 280-31536
Tilo Arnhold, Susanne Hufe (UFZ press office)
Phone: +49 (0)341-235-1635, -1630
Kerstin Theilmann (press office of the University of Koblenz-Landau)
Phone: +49 (0)6341 280-32219
Pesticides significantly reduce biodiversity in aquatic environments (Press release, 17 June 2013):
Study: Pesticide authorisation procedures fail to adequately protect biodiversity in rivers (Press release, 31 May 2012):
Insecticides an increasing problem in future for streams in Europe (Press release, 6 December 2011):
LEGATO - a major international project on sustainable development of rice ecosystems in Southeast Asia (Press release, 14 June 2011):
Pesticides - Easier detection of pollution and impact in rivers (Press release, 4 September 2009):
First forecast of the ecological risks associated with plant protection products in Europe (Press release, 2 October 2007):
In the Helmholtz Centre for Environmental Research (UFZ), scientists conduct research into the causes and consequences of far-reaching environmental changes. Their areas of study cover water resources, biodiversity, the consequences of climate change and possible adaptation strategies, environmental technologies and biotechnologies, bio-energy, the effects of chemicals in the environment and the way they influence health, modelling and social-scientific issues. Its guiding principle: Our research contributes to the sustainable use of natural resources and helps to provide long-term protection for these vital assets in the face of global change. The UFZ employs more than 1,100 staff at its sites in Leipzig, Halle and Magdeburg. It is funded by the federal government, Saxony and Saxony-Anhalt. http://www.ufz.de/
The Helmholtz Association contributes to solving major and urgent issues in society, science and industry through scientific excellence in six research areas: Energy, earth and environment, health, key technologies, structure of matter as well as aviation, aerospace and transportation. The Helmholtz Association is the largest scientific organisation in Germany, with 35,000 employees in 18 research centres and an annual budget of around €3.8 billion. Its work is carried out in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894). http://www.helmholtz.de/
Tilo Arnhold | UFZ News
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences