David's blog posts tagged with 'wildlife'

The neonicotinoid saga continues



Yesterday saw publication of my review of the evidence for broader impacts of neonicotinoids on wildlife other than bees in the Journal of Applied Ecology. If you'd like to read it, please go to Goulson Lab publications page, scroll down, and click on the link to the pdf.

The key points are as follows:

1) Neonicotinoids are very widely used, and have extremely high toxicity to all insects and many crustaceans. They are commonly applied as a seed dressing to crops.

2) Most (<90%) of the active ingredient do NOT go into the crop, but get washed into the soil and ground water. They also leach into streams. Levels found in streams and California and the Netherlands commonly exceed lethal concentrations for aquatic wildlife. Data from UK waterways appear to be absent.

3) They have a half life in soil which commonly exceeds 3 years, meaning that they rapidly accumulate in soil if they are used annually. The effects of this on soil organisms and soil health are not understood.

4) Neonicotinoids have been found in field-margin vegetation, which is hardly surprising if they are accumulating in soils. Impacts of this on farmland wildlife such as butterfly caterpillars feeding on field margin vegetation have not been studied.

5) If dressed seeds are consumed by granivorous birds such as partridge, or by rodents such as voles, they need only eat a few seeds to recieve a lethal dose. During drilling, seed is inevitably spilled, but we do not know whether it is consumed by wildlife.

6) Evidence that neonicotinoid seed dressings actually increase yield is absent (or is not available for public scrutiny). Some US studies suggest that they have negligible benefit to farming. In short, modern farming practices do not seem to be EVIDENCE BASED, but are driven by marketing by the agrochemical industry.  

7) We seem to have forgotten all about Integrated Pest Management (IPM), an approach which emphasizes minimising pesticide use through monitoring of pest numbers, crop rotations, encouraging natural enemies etc... Instead we are simply using pesticides prophylactically.  

Although I supported the 2 year moratorium on use of neonics, which comes into effect in December 2013 (better than nothing), it is entirely unclear what it will achieve, or what will happen afterwards. Neonics will continue to be used extensively for non-flowering crops such as winter wheat. Even if we completely stopped using them they would be in soils for years to come. So any benefits from the partial moratorium will not be apparent in 2 years. In any case, there seems to be no plan to monitor the benefits, so if they did occur (which is unlikely) we wouldn't know.....

It is hard for most of us to make sense of what is going on here.....

 Dave Goulson's research lab website




Launch of the Worldwide Integrated Assessment (WIA) on the environmental impacts of systemic pesticides



On Tuesday this week I was in Brussels, for a press conference to launch a major series of scientific publications on the impacts of neonicotinoid insecticides on the environment. On the same day, press conferences were also held in Manila, Tokyo and Ottawa. The publications are the culmination of 5 years work involving more than 50 scientists from 4 continents, and together we reviewed evidence from >800 scientific papers. Our findings are being published as 7 papers in a special issue of the journal Environmental Science and Pollution Research. All have been accepted for publication following full, independent, scientific peer-review. The first of the seven is online now at http://link.springer.com/article/10.1007/s11356-014-3180-5; this deals with impacts on vertebrates. The rest of the papers will appear soon as the journal finishes processing them for publication.

The conclusions of our work, in brief, are that these systemic pesticides are accumulating in soils and polluting waterways and natural vegetation across the world, leading to widespread impacts on wildlife inhabiting farmland and aquatic habitats. There is also growing evidence that much of their use is unnecessary and ineffective. But you can read all about this over the coming months as the papers come out: all of them are to be open access.

On Monday, the day before the press conference and before anyone could have seen the full set of documents, I received a rebuttal of our work from Croplife, an organisation that represents the agrochemical industry. It was quite clear that they hadn’t read any of it. Their criticisms were: that the work was selective in what it reviewed (we looked at 800 papers, everything that we could find); that we looked only at lab studies (a bizarre claim, and completely untrue); that we ignored the economic importance of neonicotinoids and didn’t consider how farmers would cope without them (there is a whole paper in the WIA just on this topic).

We have also been criticised because not all of our papers are yet available. Had this been a single report, just placed on the internet without scientific review, we could easily have made it all available. This is what industry usually does. But the scientific review and editing process is slow and not all of the papers were quite ready. On the plus side, they have the huge advantage that they have all passed independent scrutiny.  

On Wednesday, Syngenta launched a request to the UK government for an exemption to the European moratorium. They want to treat 186,000 hectares of oilseed rape woth a neonicotinoid – 30% of the UK crop – because they say that otherwise there is a “danger to production”. There appears to be no scientific evidence to back up this claim. Indeed, just a week ago on 18 June an industry spokesman appeared before the UK’s Environmental Audit Committee and was asked to provide a single scientific study showing that neonicotinoid seed dressings increased yield of any arable crop. Embarrassingly, he could not. They’ve been selling neonics for 20 years, but can provide no evidence that they work!? How do they differ from the quack doctors of days gone by, who peddled cure-alls on street corners with their slick patter?

One can read Syngenta’s request another way – they seem to be conceding that 70% of the UK’s oilseed rape doesn’t need treating with neonics. Why then was 100% treated before the moratorium?

This simply appears to be a ploy by industry to bypass the EU moratorium, which was based on sound scientific evidence, and recommended by the European Food Standards Agency. If you’d like to sign a petition against their request, go to: https://secure.38degrees.org.uk/a-ban-is-a-ban

Biodiversity v Intensive Farming; Has Farming Lost its Way?



[This blog was posted as a guest blog on the Journal of Animal Ecology website, 16 Jan 2015, duplicated here for those that check my Uni blog]

Modern intensive farming produces plentiful, cheap food but is reliant on heavy use of agrochemicals and is a major driver of the ongoing collapse of wildlife populations. Taxpayers pay billions each year to support this system, with the bulk of this money going to the biggest, richest farming operations. In this blog I examine how we got to this unhappy position, question the need to further increase food production given current food waste, and suggest that we need to move towards a more sustainable, evidence-based farming system, with a source of independent advice for farmers, rather than allowing the agrochemical industry to shape the future of farming.  

It is not politically correct to criticise farmers or farming. We are brought up on stories about the adventures of a playful piglet who lives on a farm with a sheepdog, half a dozen chickens and a smiling cow, all presided over by a rosy-cheeked farmer, his wife and their two children. Farmers might also be portrayed as custodians of the land, where the countryside that they look after is filled with the sound of skylarks singing, bumblebees buzzing amongst the hedgerows, and butterflies flitting across sunlit, flowery meadows. 

Farming is of course the most fundamentally important of human activities; without farms and farmers, we would quickly starve. Going back to hunter-gathering is not an option. What is more, the human population is growing, and therefore we must increase food production. The United Nations Food and Agriculture Organisation (FAO) declared in 2010 that we must double food production by 2050, and this rationale is used to justify the drive for ever-increasing yield. One might argue that we should focus all our research on increasing yield at all cost, else our grandchildren will starve.

These are two quite different views of farming, the former obviously wildly inaccurate, but in both the farmer is the hero. Of course there is a contradiction between the two, a fundamental conflict. The drive to increase food production has resulted in an intensive farming system that is scrubbing wildlife from the face of the land. In Europe, we have good long-term data on populations of birds, butterflies and moths, and the overwhelming pattern is that most species are in retreat (e.g. Fox et al. 2014 J Appl. Ecol. 51: 949-957; Inger et al. 2015). Rather few larks are still singing, and most of the butterflies are gone.  A recent study by Inger et al estimates that bird populations in Europe have fallen by 420 million in the last 30 years. Groups for which we have less precise data, such as bees and beetles, also seem to be going the same way. For the UK this depressing pattern is summarised nicely in RSPB’s 2013 “State of Nature” report, which makes bleak reading. In short, farmland wildlife underwent massive declines through the twentieth century and in the twenty first century is still in rapid decline. Indeed, recent data for butterflies suggest that declines in many farmland species are accelerating

This continued decline is, on the face of it, puzzling. In Europe very large sums of tax-payers money are spent on agri-environment schemes: money paid to farmers to implement mechanisms to increase wildlife[1]. On the whole, farmers do not grub out hedgerows any more, or plough up ancient hay-meadows. They are more likely to replant hedgerows and attempt to restore flower-rich grasslands. Yet this does not seem to be working, for wildlife continues to disappear. What has gone wrong?

I would argue that there are two explanations. The first is that much of the funding for agri-environment schemes is wasted. The basic entry-level greening measures are so unambitious that a lot of farmers have to do next to nothing to qualify. There is little policing of what they actually do, and implementation of some schemes often fails. Wildflower strips on field margins are a good example – intended to support pollinators, they often don’t establish well, and end up containing nothing but coarse grasses. There are some shining examples of farmers who have successfully implemented a range of such schemes with measurable benefits for wildlife, but they are few and far between. [Note that these schemes have recently been revised in Europe, but overall funding has been cut and many farmers currently in the higher level schemes will soon find themselves getting no agri-environment subsidies at all, so it is unlikely that there will be a net improvement]  

The second relates to the way crop production systems have developed. Forty years ago there was substantial government funding for agronomic research. In the UK, we had many state-owned experimental farms where scientists developed new crops and devised integrated pest management programs. Rachel Carson’s famous 1963 book “Silent Spring” had highlighted the potential dangers of over-reliance on pesticides, and there was great interest in biological control agents, trap crops, rotations, cultural controls, use of resistant varieties, and so on. Today, most of those experimental farms have gone, or become essentially privatised, in attempts at cost-saving by successive governments. Industry has stepped in to fill the gap, shaping agriculture to its own ends. Now, agronomic funding comes almost entirely from the private sector – particularly the big companies that manufacture pesticides and develop GM crops. Most of the agronomists that advise farmers work for agrochemical companies (the figure is 71% in the UK[2]). Most arable farms in the UK use a minimal rotation –wheat, wheat, oilseed rape. Crops are commonly treated with ~20 different pesticides in a season[3], many of them applied prophylactically. [Ask yourself this: if you were growing veg in your garden for your family to eat, would you be comfortable spraying them with a cocktail of 20 different insecticides, fungicides, herbicides and molluscicides? If the answer is no, why are you happy buying food from the supermarket?]. The principles of IPM seem to have been discarded along the way. We have allowed current farming systems to be moulded by industry, and their goal is not to feed poor people in developing countries. Nor is it to look after wildlife, or worry about the long-term sustainability of production systems. It is to make the biggest profit that they can. Minimising pesticide use would be good for the environment, good for the long-term sustainability of farming, good for the farmer, and good for the consumer. But it won’t make big agrochemical companies rich.

Consideration of the current risk assessment procedures for new agrochemicals sheds some light on the failure of the current system. Typically, the safety of agrochemicals is examined by conducting acute toxicity tests for each compound on non-target organisms such as rats and bees, and comparing the response to plausible exposure scenarios in the field. So long as the animals are unlikely to receive a dose in the field anywhere near that which produces harm in short-term lab tests, all is regarded as well. These data are generally not made public, so they cannot be inspected or evaluated by independent scientists. There is currently no requirement to demonstrate that the new product provides a significant improvement in yield; such trials are presumably conducted by industry (well, one would like to think so), but are not made public. Under the current system, once a new product is on the market, farmers have little in the way of reliable, independent information available to them as to either the environmental risks posed or the efficacy of each product. They are largely reliant on the companies that manufacture the chemicals to advise them as to which ones they should use, with competing manufacturers providing conflicting advice, and all with a strong incentive to prescribe more use than may be necessary.

The current agrochemical regulatory system is clearly woefully inadequate.  In the real world, non-target organisms living in farmland are chronically exposed to multiple agrochemicals throughout their lives, not one at a time in a single dose. We know that these chemicals do not always act additively; for example some fungicides, while being of very low toxicity to insects in themselves, can greatly increase the toxicity of insecticides when an insect is simultaneously exposed to both. Such interactions will only be discovered when the chemicals have been approved and are in widespread use, which is far too late if one wishes to prevent environmental harm.

Interactions between agrochemicals, and the consequences of chronic rather than acute exposure, are just two important aspects that the current regulatory system fails to capture. Complex interactions also occur between agro-chemicals and other stressors. For example, low doses of pesticides which would produce no measurable effect in a lab toxicity trial can impair the immune system of honey bees, rendering them susceptible to viruses. Hungry animals (such as bees in flower-poor intensive farmland) are also more susceptible to both toxins and disease than well-fed lab stocks.  In short, our current regulatory system does not come anywhere close to approximating the complexities of the real world, and as a result we have failed to adequately protect biodiversity from the many stressors imposed by modern farming.

Of course it would never be possible to conduct realistic, long-term tests on every plausible combination of chemicals and other stressors. Perhaps we simply have to accept that modern, intensive farming is necessary if we don’t want to starve, and that loss of our wildlife is an unavoidable price that we have to pay?

I would suggest that there is a way forwards, but that we need a radically different, holistic and transparent approach based on scientific evidence. We need long-term farm-scale studies of crop production systems, comparing both the yield, profitability and the consequences for biodiversity and ecosystem services of different systems (e.g. conventional versus a reduced input, “Integrated Pest Management” approach versus organic). Such studies need not be enormously expensive, for the farms would still be productive. Surprisingly few studies have simultaneously compared profitability and biodiversity benefits across farming systems, yet this is the fundamental trade-off in food production. Indeed, for most agrochemicals there is currently little publicly available evidence as to what yield benefits they individually provide[4]. If a new chemical, crop or farming system were to be proposed, and provided that it passed some basic safety tests, it could then by trialed alongside existing approaches. Only if a new product significantly increased yield, or was found to have positive benefits for biodiversity, or both, would it be approved. Such a system would evaluate new products in the context in which they would be used in the real world, rather than highly unrealistic trials as currently used. New agri-environment schemes could be evaluated using the same framework. All such studies should be open access. This has parallels to the laudable move to “evidence-based medicine” whereby new drugs or therapies are only approved following trials demonstrating that they provide a significant improvement over existing treatments. At present, our farming systems are not evidence-based, and what evidence that is available is hidden.     

I would also argue that we should question the drive towards further yield increases. People are not starving because we don’t grow enough food. In India, obesity is now a bigger problem than starvation. We grow more than enough food, but estimates suggest that nearly half of what is grown goes to waste, and many of us eat far more meat and many more calories than is good for us. In the developed world we spend less on food, as a proportion of income, than we ever did – food is cheap. It is a disgrace that anyone is still starving, but it has nothing to do with food production.  Indeed, if one could largely eliminate food waste then every farm in the world could go organic and, even with the concomitant reduction in yield, there would still be more than enough food to go around.    

Without a radical overhaul of farming systems, and of the way agronomic research is funded and conducted, there is no doubt that we will lose a significant portion of our biodiversity. Even for those that don’t give a damn about wildlife, this ought to be a major cause for concern because we depend upon wildlife to deliver the ecosystem services that underpin food production. We should be focussing on sustainable production of healthy food, not on producing more cheap, pesticide-laced food and then throwing half of it away. In our rush to increase yields, based on an ill-conceived notion that this is needed to feed the world, we run the risk of irrevocably damaging our environment and hence our food production system, so that our grandchildren really do starve. 


Dave Goulson

(twitter: @DaveGoulson)

[1] The EU gives out €59 billion per year in total in subsidies to farmers. Most of this is dished out as single farm payments, which are more-or-less payments simply for owning the land. There is currently no cap, so some major landowners receive millions in subsidies. For example in France, the 160 biggest farm holdings receive €123 million between them. The UK fought hard, and succeeded, in blocking EU proposals to cap subsidies at €300,000 per farmer. The vast majority of this money does not go to poor farmers in marginal areas who might be deserving of support. One might question why such extra-ordinary sums of tax-payers money should be given to rich people or corporations to enable them to continue to farm in a way that is destroying our natural heritage.  

[2] This figure was provided by an independent agronomist, Caroline Corsie, but I am unable to find official figures.

[3] I have quotes this figure before, and it has been heavily criticised. It was originally based on surveys of arable farms in East Sussex in south east UK, which applied between 18 and 21 different pesticides to each wheat or oilseed rape field in 2013 (some of them multiple times). I’ve heard it said that we must have found the most intensively farmed fields in England. However, Defra’s own statistics demonstrate that this is spot on – their PUSSTATS website is open access, and one can obtain information on the total area of arable crops in Britain, and the total area treated with pesticides. The latter is almost exactly 20 times the former, demonstrating that the average arable field receives 20 applications. This average includes organic farms, so the mean for conventional farms must be higher.  

[4] This was recently highlighted by an astonishing revelation from the USA Environmental Protection Agency. They revealed a number of studies showing that application of neonicotinoid seed dressings to soya beans has zero impact on yield. At the advice of agronomists, farmers had been routinely applying neonics to soyabeans over 30 million ha, at an annual cost of $240 million. This seems to refute the oft-used argument “Farmers aren’t fools – they wouldn’t waste money on pesticides they didn’t need”. 

Are neonicotinoids killing birds?



Philip Lymbery, chief executive of Compassion in World Farming, has just launched his new book “Dead Zone: Where the Wild Things Were.” In it, he suggests that neonicotinoid insecticides may be contributing to bird declines. This claim has come under heavy fire from NFU and the agrochemical industry. In a recent online article NFU’s Dr Chris Hartfield is quoted as saying:

Evidence from real life field situations did not back up the claims, which are based on research by Dave Goulson, Professor of biology at Sussex University. Professor Goulson has published a paper which claimed a grey partridge would be killed by eating five treated seeds, and a sparrow after two. He also said birds which ate insects were ‘declining more rapidly in areas which use neonics’.

            “Dave Goulson’s theories about neonicotinoids poisoning birds are simply that – theories – and are not backed up by evidence from real life”, he added. In the UK, poisoning of all animals is investigated by the Wildlife Incident Investigation Scheme. If seed-eating farmland birds were being poisoned as a result of eating neonicotinoid treated seed, you would rightly expect this scheme to be finding these incidents. There are no incidents of bird poisoning resulting from the use of neonicotinoids over the last ten years. Promoting theories without the evidence to back them up is only going to damage the cause of pollinators and wildlife, and damage the public perception of science in general.

The paper to which Dr Hartfield refers was a review I published in 2013 in Journal of Applied Ecology (Goulson 2013).  In it, I say the following:

Although neonicotinoids do show relatively low toxicity to vertebrates, we might expect seed-eating vertebrates to be exposed to lethal doses if they consume treated seeds spilled during sowing. Typically, maize seeds are each treated with ~1 mg of active ingredient, beet seeds with 0.9 mg, and the much smaller oilseed rape seeds with 0.17mg (Rexrode et al. 2003; Anon 2012; Krupke et al. 2012). A grey partridge, typically weighing approximately 390g, therefore needs to eat ~5 maize seeds, 6 beet seeds or 32 oilseed rape seeds to receive an LD50. A grey partridge typically consumes ~25 g of seeds /day (Liukkonen-Anttila et al. 1999), equivalent to ~600 maize seeds, so clearly there is the potential for birds to swiftly consume a lethal dose. By a similar calculation, 3 maize seeds treated with imidacloprid would deliver more than the LD50 to a mouse. The US Environmental Protection Agency estimate that ~1% of drilled seeds remain accessible to granivorous vertebrates (i.e. they are not buried during drilling), and this does not include spillages which may occur, for example when transporting grain or loading hoppers. With typical sowing rates of ~50,000 seeds/ha for maize and 800,000 seeds/ha for oilseed rape, we might expect sufficient seed to be available on the soil surface to deliver an LD50 to 100 partridge or 167 mice for every hectare sown. 

            Lopez-Antia et al. (2013) fed imidacloprid-dressed wheat seed to red-legged partridge (Alectoris rufa) for 10 days and obtained 58% mortality, with the survivors exhibiting a range of sublethal effects.  This mortality rate, although considerable, is less than we might expect from the calculations above.  Lopez-Antia et al. report anecdotally that partridge did not avoid dressed seed when offered both dressed and undressed, but speculate that treated birds ate less than control birds, and so received a lower dose than expected. This requires further investigation, in this and other species, to determine how much treated seed vertebrates actually consume in the field. De Snoo et al. (1999) describe incidents of poisoning of wild partridge, pigeon and duck by seed dressed with imidacloprid reported by members of the public in France in 1994-5 (a time when neonicotinoid use was very low), but other evidence for effects in the field is lacking and it is unclear whether public reporting is an efficient means of detecting such incidents.

Since 2013, there have been a number of other scientific publications linking neonicotinoids to declines of birds and other vertebrates, most of which are reviewed here. I would draw your attention to two in particular. Firstly, in a high profile paper in the journal Nature, Hallmann et al. (2014) demonstrate that geographic patterns of declines of insect-eating birds in the Netherlands are explained by local levels of environmental pollution with the neonicotinoid imidacloprid.  They conclude that this is unlikely to be due to direct toxicity, but that it is probably simply that in areas where insecticide use is high there are few insects for the birds to eat. Seems pretty plausible to me.

Secondly, a recent study of bird poisoning incidents in France shows that, between 1995 and 2014, there were 101 incidents involving 734 dead animals in which toxicological reports detected imidacloprid, and where the death is likely to be associated with agricultural use of seed treatments. 70% of these incidents happened during autumn cereal sowing. Grey partridges and various pigeon species were the ones most frequently killed.

According to Dr Hartfield, there have been no such incidents in the UK. This strikes me as very odd. Farming in France is very similar to the UK; most of the same crops are grown, and pesticide uses are very similar. I rang the UK Wildlife Incident Investigation Scheme to ask them whether they actually test dead birds for neonicotinoids. The person I spoke to did not know, and asked me to send in an email request, which I have done. When I get a reply, I’ll update the blog.

So, Dr Hartfield, my theories are more than “just theories”. “Real life” evidence from the Netherlands and France strongly supports them. The absence of direct evidence from the UK should not be interpreted as evidence of absence – if you don’t look for something, you won’t find it.   

The ongoing complacency of NFU, and their willingness to aggressively attack scientists who speak out against overuse of pesticides does them no credit. Farming bird populations are collapsing, along with most other farmland wildlife. Isn’t it time the NFU faced up to this, and took some responsibility?


Farmland bird population change (from JNCC)



Goulson, D. 2013. An overview of the environmental risks posed by neonicotinoid insecticides. JOURNAL OF APPLIED ECOLOGY 50: 977-987.