December 2015 – Ecology Field Notes

Genetically modified insects and the precautionary principle

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Last week the Guardian newspaper reported on the findings from the UK House of Lords’ science and technology committee into the development and use of GM insects. According to the committee’s chairman, Lord Selborne:

“GM insect technologies have the potential not only to save countless lives worldwide, but also to generate significant economic benefits for UK plc, where we are an acknowledged world leader.”

No surprises there. The case for GM insects to be developed as a form of vector control has many proponents and seizing an economic opportunity is to be expected from the Lords. Apart from a cursory explanation of the means of developing GM insects, and a mention of the fact that the committee would like to see a reform of European Union regulation around GMOs (more on this later), the reporter fails to consider any environmental issues that may arise from the release of transgenic insects, in what seems to me to be a failure of research and the rehashing of the committee’s summary report.

Thankfully, in an attempt to provide a balanced argument the Guardian also published a piece that was more critical of the report, describing it as “an unsophisticated form of moral blackmail” and laying out the possible extinction risks associated with gene drive systems. The scientific knowledge gap is highlighted by these authors, who write:

“We are not against GM insects. Our point is that we do not know enough. Nobody knows enough.”

Though I commend these authors for responding to the Lords’report in a more critical way, there are still a couple of findings in the report that hadn’t been directly addressed and which I think need exploring further.

The first is the issue of EU regulations of GMOs that the Lords describe as “failing lamentably” and would like to see amended. This critique is aimed at EU Directive 2001/18/EC which states that “due attention be given to controlling risks from the deliberate release into the environment of genetically modified organisms”. This is to be conducted through case-by-case environmental risk assessments, public consultation, a requirement to consult all relevant scientific and ethical committees, and development of “a mechanism allowing the release of the GMOs to be modified, suspended or terminated where new information becomes available on the risks of such release” before consent will be granted. It is a very robust piece of legislation which, when linked with Regulation (EC) No 1946/2003 that restricts the release and transboundary movement of any GMO within EU member states, makes this not “lamentable” as the Lords would have us think, but sound legislation based on the Cartagena Protocol which states that products from new technologies must be based on the precautionary principle and allow nations to balance public health against economic benefits. And which allows countries to ban imports of a genetically modified organisms if they feel there is not enough scientific evidence that the product is safe. It seems to me that an attack on the governing EU legislation is also an attack on the Cartagena Protocol which environmentalists need to be aware of.

The international consensus of the definition of the Precautionary Principle is:

“When human activities may lead to morally unacceptable harm that is scientifically plausible but uncertain, actions shall be taken to avoid or diminish that harm.”

And this brings me to my second concern about the House of Lords report, wherein Professor Rosemary Hails states that:

“the Precautionary Principle properly applied would also take into account the risks of not developing a particular technology and the benefits forgone. It is a misuse of the Precautionary Principle that has led us to this place.”

This reconstitution of the Precautionary Principle is a matter of great concern and has already been discussed at some length by the House of Commons Science and Technology Committee in their Fifth Report: Advanced Genetic Techniques for Crop Improvement: Regulation, Risk and Precaution wherein Sir Mark Walport framed the precautionary principle not as a response to scientific uncertainty, but as a guide to evidence-based decision-making. He said:

“Decisions must be informed by the best evidence and expert advice. The application of the ‘precautionary principle’ can help to guide this. This simple idea just means working out and balancing in advance all the risks and benefits of action or inaction, and to make a proportionate response. All too often, people citing this principle simply overreact: if there is any potential hazard associated with an activity, then it should not be done, or, if it is already being done, it should be stopped.”

By removing the imperative for evidence and advice that is provided to governments to be based on the principles and rigour of scientific enquiry, the report is effectively providing ministers with a means of bypassing environmental legislation. A recent example of this is when George Eustice MP recently cited food security as a reason to maintain the use of neonicotinoid pesticides under this bastardised definition of the Precautionary Principle.

If it were as simple as Sir Mark maintains to identify and stop hazardous activities we would not be facing some of the world’s current health and environmental catastrophes. That is why we must legislate against them and that is why scientific evidence needs to be the basis for that legislation. And when that evidence is lacking or inconclusive, aren’t we safer not taking the risk in the first instance? If, as Prof. Hails maintains we need to consider the risks of not using certain technologies for their potential benefits we have to ask ourselves whose benefits are we talking about.

The Great Pottery Throw Down

The title of this blogpost is taken from the latest BBC television series that has just finished screening in the UK. The premise for this series is based on the model developed for the hugely successful The Great British Bake Off, in which contestants compete against each other day-after-day to produce a variety of baked goods that are then judged by experts. Replace baked goods for ceramics and you will have grasped the intricacies of The Great Pottery Throw Down in its entirety. But what, if anything, is the significance of this to the study of invertebrates?

Well, having recently read Animal Architecture by Ingo Arndt and marvelled at the complexity and ingenuity of animals to create structures such as the heaped nests of wood ants, the towering cathedrals of termites and the delicately partitioned nests of paper wasps; I was rather taken with the notion of insects as ‘makers’. Serendipitously, I stumbled across the website of naturalist and artist, John Walters – specifically across his marvellous illustrations and accounts of Heath Potter Wasps, Eumenes coarctatus.

wasp_november_2009-1 — Eumenes coarctatus. Source: Wikipedia

Potter wasps, Eumeninae, are the most diverse group of Vespidae, with over 3,500 species in 210 genera found throughout the world. Of these, 23 species in 9 genera are found in the UK. They derive their common name of potter (or mason) wasps from the fact that the females tend to construct nests from mud and clay. These nests can take multiple forms, but one of the most elegant (in my view) is the vase-shaped nest of Eumenes coarctatus, the solitary Heath Potter Wasp.

Using heather, gorse or dead grass stems as nesting sites, the female will build her clay vessel over the course of two to three hours. During this time she will repeatedly fly from a water source to a quarry site, where she will form a ball of mud in her jaws, which is then transported to the construction site where she builds the nest. Once she has shaped the neck and lip of the nest she lays a single egg in the chamber suspended on a strand of silk. She will then search for, sting and collect a number of small caterpillars, especially pug and horse chestnut moth larvae, from the heathland vegetation and then fills the pot with them. A final trip to the water source and quarry then provides enough clay to seal the pot with between 9 and 38 paralysed caterpillars trapped inside. A female heath potter wasp may produce up to 25 pots in her lifetime (2 to 3 months) and occasionally she will cluster pots as shown in the series of photographs below. It is possible that these clusters prefigure the development of eusocial colonies as seen in some other vespids.

index.php — Development of a cluster of clay nest cells built by a single Eumenes coarctatus. Bovey Heath, Devon. Photos by John Walters.

When the wasp larva hatches from its suspended egg it drops onto the paralysed prey on which it feeds for about a week before pupating. The emergence of the adult depends on the timing of the building of the pot. If the pot was built before the end of June, the adult wasp will emerge 2 to 3 weeks later; if the pot is built in early July, the adult will still emerge in the same year; however, if the pot is built after this date emergence will be delayed until the following April or May.

potterwasps19july2012boveyheath — Illustration of Heath Potter Wasps taken from the field notes of artist and naturalist John Walters.

Though the E. coarctatus larvae are predatory, the adults feed on the nectar of heathland plants such as gorse, heather, bramble, angelica and alder buckthorn.

nhmsys0000875934-1 — Distribution map of Eumenes coarctatus in the UK. Source: NBN

Found on lowland heaths in England (from South Devon to East Sussex, and north to Buckinghamshire) the Heath Potter Wasp is classified as nationally scarce, though not designated a BAP species.

I also love Jean-Henri Fabre’s description of Eumenes taken from The Wonders of Instinct:

“A wasp-like garb of motley black and yellow; a slender and graceful figure; wings not spread out flat, when resting, but folded lengthwise in two; the abdomen a sort of chemist’s retort, which swells into a gourd and is fastened to the thorax by a long neck, first distending into a pear, then shrinking to a thread; a leisurely and silent flight; lonely habits.”

John Walters has also made a video of a wasp building a nest.

Michael Archer’s Key to British Potter and Mason Wasps is a very useful resource for identifying the various UK species.

The Little Bombardier

Best stay out of the way.

There are more than 500 species of Bombardier beetle (a form of ground beetle – Carbidae) in the tribes Brachinini, Paussini, Ozaenini, or Metriini all displaying the highly effective defence mechanism of releasing a superheated pulsing jet of noxious chemicals sprayed directly at would-be predators. I have always been fascinated by the ammunition of Bombardier beetles – their highly accurate and violent chemical attack brought on whenever you touch them – but it was only on reading Eisner’s essay that I started to fully grasp the incredible complexity of these beetles.

These diagrams are reproduced from Thomas Eisner’s fascinating book For Love of Insects which explores the variety of ways in which insects use chemicals for defence, signalling and prey capture. I cannot recommend this book highly enough for anyone interested in the pursuit of entomology or study of chemical ecology.

Screen Shot 2015-12-04 at 07.33.26 — Diagram of a bombardier beetle with its 2 glands in place. R = reservoir; r.ch = reaction chamber; gl = glandular tissue; dt = duct

Screen Shot 2015-12-04 at 07.38.01 — The mechanism of operation of the bombardier glands. E = enzymes in the reaction chamber; R indicates that either a hydrogen (H) atom or a methyl group (CH3) can occur at that site on the hydroquinone or quinone molecule.

The chemical process involves hydrogen peroxide rapidly decomposing into oxygen and boiling water, while the hydroquinones oxidize into benzoquinone in the beetle’s reaction chambers. This mix explodes out of the beetle with an audible popping sound, in a volley of rapid-fire blasts – in a manner likened to the pulsing propulsion system of Germany’s V-1 “buzz bomb” in WWII. The consequent foul chemical burn (at 100°C) incapacitates smaller attackers like ants, and deters larger predators such as the unfortunate frogs in one of Eisner’s experiments.

By examining the propulsion mechanism using high-speed synchrotron X-ray imaging Eric Arndt from MIT confirmed Eisman and his colleagues’ qualitative passive ‘pulse jet’ model. This research shows that a flexible membrane and a valve passively control the spray pulsation – as pressure increases in the reaction chamber because of the chemical explosion, the membrane stretches and the valve closes. The membrane then relaxes and the valve reopens once the pressure has been reduced following the ejection of the liquid, and so the process repeats.

The only UK resident species of bombardiers are Brachinus sclopeta, the streaked bombardier beetle, and Brachinus crepitans, the common bombardier beetle, and both are rarely seen. B. sclopeta is so rare that it has only recently been accepted as a native species (past records were thought to be of rare migrants) and prior to 2005 had been presumed extinct since 1928. Because the beetles prefer habitats with thin soil, rubble and bare ground they tend to favour brownfield sites and have been found in east London; but with the continuous and unrelenting development of this area, these beetles’ futures are very precarious despite being listed as UK BAP priority species, and considered critically endangered by the IUCN. However, insect charity Buglife worked with developers to secure a site near London City Airport that is now the only known intact colony of the species in the UK. You can read Richard Jones highly informative blog about the relocation and conservation of this species.

Brachinus crepitans, though more common than B. sclopeta, is restricted to Southern England and Wales and especially the coastal areas of the South-East where it is considered nationally scarce. It is more commonly found in continental Europe, central Asia, the Middle East and North Africa, with central Sweden being the northernmost extreme of its range.

Brachinus crepitans. Image source: Wikipedia

Distribution of Brachinus crepitans. Source: NBN Gateway

Usually seen in May and June, the beetle favours calcareous grasslands, arable field margins and chalk quarries. It is usually found in dry, sunny areas – typically under stones. Little is known about its life-cycle, but it is thought that the larvae are external parasites on the pupae of other species of beetle, particularly those of the ground beetle Amara convexiuscula and a staphylinid beetle, Ocypus ater.

I think these gorgeous and enthralling beetles definitely warrant being surveyed for this coming Summer.

References:

Eisner, T. (2003) For Love of Insects. Harvard University Press, Cambridge Ma.
Lyneborg, L. (1976) Beetles in colour. Blandford Press, Dorset.
Bombardier beetle found near Honeybourne. Worcestershire Biological Records Centre (December 2015): http://www.wbrc.org.uk/WorcRecd/Issue11/BombBtle.htm
Isaak, M. 1997. Bombardier Beetles and the Argument of Design (December 2015):
http://www.talkorigins.org/faqs/bombardier.html
Streaked Bombardier Beetle. Buglife (December 2015) https://www.buglife.org.uk/campaigns-and-our-work/streaked-bombardier-beetle
Brachinus sclopeta UK Priority Species Data Collation. Joint Nature Conservation Committee. http://jncc.defra.gov.uk/_speciespages/2093.pdf

Deep-sea biodiversity. A taster.

I want to share an amazing experience with you and to start to think about some of the issues raised in thinking about deep-sea biodiversity.

Back in 2012 I was incredibly fortunate to join an artist, Michelle Atherton, on a 4-hour-long submarine dive off the coast of Roatán, Honduras. We travelled up to 2,000 feet (610 metres) below sea level into the mesopelagic zone. All of the images in this blogpost are stills taken from the artist’s video during this trip.

go-deeper — The submarine, *Idabel*, that would take us on our exciting adventure 2,000 feet into the ocean depths.

Marine ecosystems support approximately half of global primary productivity and a range of ecosystem services operating from local to global scales. It is widely acknowledged that deep-sea ecosystems are the most extensive on Earth, represent the largest reservoir of biomass, and host a large proportion of undiscovered biodiversity (Ramirez-Llodra et al. 2011; Snelgrove et al. 2014; Tyler, 2003).

As sampling techniques and underwater exploration have improved, so the identification of new deep-sea species has grown year-on-year (Levin and Dayton 2009; Miloslavich and Klein, 2009; Ausubel et al. 2010; Danovaro, Snelgrove and Tyler, 2014). There is, however, still a lack of data for the middle waters and deep-sea ecosystems.

Screen Shot 2015-12-03 at 17.11.14 — On a cross-section of the global oceans, the spectrum from red to blue extends from many to few or no records. The records are concentrated near the shores and in shallow waters, while the largest habitat on Earth, the vast middle waters, is largely unexplored. Ausubel et al (2010)

Deep-sea megafauna have evolved a variety of adaptations to deal with the unique circumstances associated with the depths, such as: darkness, cold, high atmospheric pressure, ocean currents and unreliable food sources. This has resulted in peculiar morphological traits such as dark or red-colouration or even translucence to avoid detection; bioluminescence to attract prey often on a ‘lure’ or as a flash to serve as a warning or create confusion. The fauna are also quite often soft-bodied, small in size and sedentary or carried by the motion of the water.

Grimpoteuthis sp.

Leptostomias sp.

Acanthacaris caeca

Bathypterois phenax

Chaunaax suttkusi

Mnemiopsis leidyi

Chaunax stigmaeus

Polyp of a solitary octocoral

Squat lobster

Featured: Chaunax stigmaeus, the redeye gaper anglerfish; Leptostomias sp. dragon fish with bioluminescent chin barbel lure; unidentified polyp of a solitary octocoral; Dumbo octopod Grimpoteuthis sp.; squat lobster surrounded by snake stars Asteroschema sp. entwined with wire coral Cirrhipathes leutkeni; Acanthacaris caeca deep-sea lobster; bioluminescent comb jelly Mnemiopsis leidyi; Suttkus Sea Toad Chaunax suttkusi; and Bathypterois phenax tripod fish resting on the ocean floor.

With the recent discovery of Jurassic deep-sea fossils of extant families in the Austrian Alps providing evidence of colonisation of shallow waters from the deep (Thuy et al. 2014), the deep sea should be considered a biodiversity refugium.

Anthropogenic impacts such as bottom trawling and deep sea gas and oil extraction do, however, pose a significant threat to this biodiversity and ecosystem functioning (Costello et al. 2010; Baker, Ramirez-Llodra and Billet 2013; Ramirez-Llodra et al. 2011). It is imperative that an international conservation framework be agreed and implemented in order to preserve this ecosystem that we are only now beginning to explore.

tumblr_nfstu2PU4C1qbsotxo4_r1_1280 — A group of stalked sea lilies, Endoxocrinus parre carolinae, and three yellow featherstars, Crinometra brevipinna on a glass sponge with anemones on either side.

References:

Ausubel, J.H., Crist, D.T., Waggoner, P.E. eds. (2010). First Census of Marine Life 2010: Highlights of a Decade of Discovery. New York, Census of Marine Life.

Baker, M., Ramirez-Llodra, E., Billett, D. (2013). Preface [in special issue: Deep-Sea Biodiversity and Life History Processes] Deep Sea Research Part II: Topical Studies in Oceanography, 92. 1-8. DOI: 10.1016/j.dsr2.2013.03.040

Costello, M., Coll, M., Danovaro, R., Halpin, P., Ojaveer, H., & Miloslavich, P. (2010). A Census of Marine Biodiversity Knowledge, Resources, and Future Challenges. PLoS ONE, 5 (8) DOI: 10.1371/journal.pone.0012110

Danovaro, R., Snelgrove, P.V., Tyler, P. (2014). Challenging the paradigms of deep-sea ecology. Trends in Ecology and Evolution. 8:465-75. DOI: 10.1016/j.tree.2014.06.002

Levin, L.A. and Dayton, P.K. (2009). Ecological theory and continental margins: where shallow meets deep. Trends in Ecology and Evolution. 24: 606-627.

Miloslavich, P. and Klein, E. (2009). The world conference on marine biodiversity: Current global trends in marine biodiversity research. Marine Biodiversity. 39(2):147-152

Ramirez-Llodra, E., Tyler, P.A., Baker, M.C., Bergstad, O.A., Clark, M.R., Escobar, E., Levin, L.A., Menot, L., Rowden, A.A., Smith, C.R., Van Dover, C.L. (2011). Man and the Last Great Wilderness: Human Impact on the Deep Sea. PLoS ONE 6(8): e22588. DOI: 10.1371/journal.pone.0022588

Thuy, B., Kiel, S. Dulai, A., Gale, A.S., Kroh, A., Lord, A.R., Numberger-Thuy, L.D., Stöhr, S., Bisshack, M. (2014). First glimpse into Lower Jurassic deep-sea biodiversity: in situ diversification and resilience against extinction. Proceedings B of The Royal Society. DOI: 10.1098/rspb.2013.2624