Thursday, 16 January 2014

A look at ladybirds, drugs and floods - CEH paperblog 9

For our first paperblog of 2014 we take a look at ladybirds, drugs and floods.

We start with three new papers highlighting different aspects of ladybird research (although the invasive Harlequin ladybird (Harmonia axyridis) figures prominently in each!).

In a paper in Biological Invasions, Richard Comont and colleagues from CEH and Rothamsted Research explore the relative importance of life-history and resource-use traits, as well as climate, habitat and the impact of the Harlequin ladybird, in driving local extinction and colonisation dynamics across 25 ladybird species. They found that the only factor that both increased the local extinction likelihood and reduced colonisation likelihood was urban land cover, while ecological overlap with the Harlequin ladybird greatly increased extinction rates.

Richard was also lead author of the paper "Escape from parasitism by the invasive alien ladybird, Harmonia axyridis", published in Insect Conservation and Diversity. The astonishing success of the Harlequin ladybird in Britain has given researchers a unique opportunity to investigate a key ecological theory, the Enemy Release Hypothesis. You can find out more in our news story, Harlequin ladybirds escape enemies while native species succumb.

Both studies above featured Dr Helen Roy (@UKLadybirds) as a co-author. Helen also features on the final ladybirds paper we highlight, in PLOS ONE, in which scientists used radar data to reveal the astonishing heights (up to ~1100 metres) and speeds (up to ~60 km per hour) of ladybird flight paths. Average flight time was estimated to be 36.5 minutes, although flights of up to two hours were observed. The results have important implications for predicting long-distance dispersal of these important aphid predators (the paper is open access).

We move from ladybirds to the aquatic environment, in particular the presence of pharmaceuticals in the wider aquatic environment, an area of growing concern and research. "The apparently very variable potency of the anti-depressant fluoextine" (you may have heard of one of its trade names, Prozac) is examined in an open access paper in Aquatic Toxicology. Professor Andrew Johnson of CEH is a co-author. The researchers admit that not very much can be concluded at the moment, as the apparent variability in sensitivity of different aquatic species prevents a consensus being reached. It will take years and a lot more reproducible research to answer the question of whether it presents an environmental risk.

Anticancer drugs are the focus of another paper, again featuring Prof Johnson as well as CEH colleagues Neville Llewellyn and Richard Williams. In "Prioritising anticancer drugs for environmental monitoring and risk assessment purposes", published in Science of the Total Environment, scientists establish a shortlist of drugs that can 'breakthrough' to receiving waters, being sufficiently persistent to warrant inclusion in environmental screening programmes.

We finish with a new floods research paper published in Natural Hazards and Earth System Sciences which attempts to reassess flood frequency for the Sussex Ouse by including historical information. Systematic flood level readings from 1960 and accounts detailing past flood events within the catchment are compiled back to c.1750. This extended flood record provides an opportunity to reassess estimates of flood frequency over a timescale not normally possible within flood frequency analysis. The researchers say their findings support calls for greater use of historical flood information in flood frequency analysis, as a means by which uncertainty can be reduced in high magnitude flood estimation. The paper is still in the discussion stage and is open for comments until 13 February.

Paulette Burns, Media Coordinator

Additional information

If you'd like a fuller picture of new papers from CEH, just follow the CEH Paper Alerts Twitter feed, which lists CEH peer-reviewed papers newly published online. Full details of Centre for Ecology & Hydrology science publications, including those published in peer-reviewed science journals, are eventually catalogued on the NERC Open Research Archive (NORA).

Those of you who follow the scientific literature will know some journal websites require registration and some are subscription-only. CEH, as part of NERC, is working with publishers and funders to make more of our output open access, and we have indicated above where this is the case.

We also publish lots of our other outputs including biological records atlases and project reports. More details can be found in the publications section of the CEH website.

Tuesday, 14 January 2014

CEH research shows ammonia emissions affect sensitive habitats upwind of a poultry farm

CEH recently led a study that found that ammonia emissions from an intensive poultry unit were detected nearly three kilometres upwind, deep within a Natura 2000 site, Newborough Warren, an important sand dune system in Wales. The research was highlighted by the European news alert service Science for Environment Policy, as well as industry website The Poultry Site.

The paper by Dr Laurence Jones describes the findings, which have major implications for the way we consider the control of emissions from intensive animal production units.

Laurence continues:

“While the majority of ammonia is transported downwind, this study suggests that ammonia emissions could be a significant source of nitrogen pollution to sensitive sites even upwind from the source.

Mobile sand dunes, a highly biodiverse habitat

Ammonia caused exceedance of UNECE nitrogen thresholds within the nearby Natura site and experiments showed that dune plant species were being affected by the nitrogen. The paper has already convinced the Environment Agency to consider effects of local wind direction and more recent meteorological data in casework.

Ammonia emissions were monitored around the farm and up to 2.8 km upwind of the prevailing wind direction for a year.

At the furthest sampling point upwind, levels of ammonia concentrations rose and fell in cycles coinciding with emissions from the farm in all months, although were much lower (averaging 0.9 μg/m3, compared with 60.1 μg/m,3 at the farm itself).

The Natura site, Newborough Warren, is one of Wales’ largest sand dune systems and is designated for a wide range of Biodiversity Action Plan priority habitats and rare species. Within parts of the site, ammonia from the farm caused exceedance of the critical level for ammonia of 1 μg/m3, and exceedance of the critical load of 8 – 15 kg N/ha/yr for sand dune grasslands. The farm contributed an additional 50% to the background levels of nitrogen deposition in parts of the site.

Common Centaury, Centaurium erythraea, a low growing biennial
often found on sand dunes

Experiments in the study showed that plants take up the ammonia as a nutrient source, and nitrogen-loving grasses and other species grew better when exposed to the ammonia than other dune species.

The study was funded by Countryside Council for Wales (now Natural Resources Wales). It confirms other CEH studies which highlight that sand dune habitats are sensitive to excess nitrogen pollution from atmospheric deposition and in groundwater.”

Laurence Jones

Additional information

Paper reference: Jones, L., Nizam, M.S., Reynolds, B. et al. (2013). Upwind impacts of ammonia from an intensive poultry unit. Environmental Pollution. 180: 221-228. DOI: 10.1016/j.envpol.2013.05.012

Related CEH links

Staff page of Dr Laurence Jones 

Monday, 6 January 2014

An interim update on the UK's hydrological situation

Terry Marsh, the leader of the National Hydrological Monitoring Programme* at CEH, has just sent us an interim update on the UK's hydrological situation. The information below adds to the detail in our most recent Hydrological Summary for the UK (for November 2013). The next monthly summary will be published on or before 15 January 2014.

Please note that the text is necessarily provisional because we are awaiting the latest flow figures before confirming the rarity of the current flooding episode. For the latest information on flooding in your area, please visit the Environment Agency website.

UK hydrological summary - 6 January 2014

A vigorous Jet Stream has brought a succession of moisture-laden Atlantic low pressure systems across the UK. Their impact has been exacerbated by high tides and strong winds. Tidal ‘blocking’ of river outflows has been a significant factor in coastal flooding.

Saturated catchment conditions over the last six weeks have meant that even moderate rainfall has increased flood risk, particularly recently when most rivers have been flowing close to bankfull.

Flood levels at Wallingford bridge on 9 January 2014
when they were approaching the 2003 marker.
Photo: Heather Lowther / Centre for Ecology & Hydrology

Examples of all flood categories: fluvial, pluvial (flash), tidal and groundwater have been reported in late 2013/early 2014.

Fluvial flooding has occurred in most river basins across the country and outflow (total river flows) from England & Wales has been exceptionally high - we are awaiting figures but recent daily totals are likely to be the highest since the late 2000 floods (and possibly amongst the highest since 1947).

However, whilst floodplain inundations have been extensive and sustained, extreme flow events in individual rivers have been relatively uncommon (the relatively even distribution of the rainfall and the speed of passage of the low pressure systems are key factors in this spatial distribution).

Flood defences have generally performed well. Most flooding of property, to date, has been on sites constructed on floodplains or low-lying coastal locations. The most damaging flooding is normally local or regional in extent (the summer floods of 2007 in Yorkshire and South/Central England and the July/Sept floods of 1968) being examples of regional flooding. Recent weeks are most notable for the wide areal extent of notably high flows rather than record runoff in individual rivers.

Floodplain inundations have been extensive.
Photo: Paulette Burns / Centre for Ecology & Hydrology

None of the flooding in the last 50 years matches that experienced in March 1947 when a warm front brought moderate rainfall and a rapid increase in temperature which melted snow accumulations of >30cm across much of England & Wales. At that time, flood defences were rudimentary. Such floods are less likely to occur in a warming world and, although the frequency of high flows has increased in the last 50 years, there is no compelling long-term trend in annual maximum flows for UK rivers.

However, with sea levels rising (exacerbated by isostatic re-adjustment in some regions), the type of fluvial/tidal flooding recently experienced may be expected more frequently in the future.  

With regard to the UK’s Water resources (which supply water for household and industrial use) the rainfall in December and early January has ensured that reservoir stocks are above average across almost all of the UK and groundwater levels have generally risen rapidly over the last six weeks. The water resources outlook for 2014 is therefore very healthy.

Terry Marsh, Centre for Ecology & Hydrology, 6 January 2014

Additional information

Key floods publications from CEH

Report - The 2010-12 drought and subsequent extensive flooding [PDF]
The section from pages 44-47 covers recent decades in the context of long-term trends for rainfall, runoff (river flows) and groundwater levels.

Report - The Summer 2007 floods in England and Wales [PDF]

Report - The 2000/2001 floods

Briefing Note - Understanding Floods [PDF]

Related links

CEH Blog: Rainfall, UK floods and the potential impacts of climate change?

Flickr: Photos of January 2014 flooding in Wallingford, Oxfordshire

*The National Hydrological Monitoring Programme (NHMP) aims to provide an authoritative voice on hydrological conditions throughout the UK, to place them in a historical context and, over time, identify and interpret any emerging hydrological trends. Such information is essential for improved water management strategies and its dissemination helps to increase public understanding of hydrological and water resources issues.

This is accomplished through regular monthly and annual bulletins, occasional reports on floods and droughts, and engagement with the media. Hydrological analysis and interpretation within the programme is based on the data holdings of the National River Flow Archive and National Groundwater Level Archive, including rainfall, river flows, borehole levels, and reservoir stocks.

The NHMP is run with the cooperation of the principal Measuring Authorities of the Environment Agency (England), Natural Resources Wales, the Scottish Environmental Protection Agency, and the Rivers Agency (Northern Ireland).

Amongst the NHMP outputs are:

NB: This post was edited on 9 January 2014 to include a new photograph of the flood level mark at Wallingford Bridge. All photos indicating the rising flood levels are available on our Flickr set.

Rainfall, UK floods and the potential impacts of climate change?

Water is again much in the news this week with widespread flooding across the UK following several weeks of very stormy weather. It's been a difficult time for many homeowners, particularly those by the coast, and the emphasis is now shifting to those living adjacent to several of our major river systems.

Yesterday (Sunday 5 January 2014), the Environment Agency published a news story naming the Thames, Dorset Stour and Frome, Somerset Levels, 'rivers' in the South East and the Severn as rivers where the flood threat remains into next week as larger rivers start to reach their peak.

Flooding on the river Thames at Wallingford, Oxfordshire January 2014

CEH has already had calls from a number of journalists asking if the current weather and flooding patterns are anything out of the ordinary. CEH science and the data archives we host play a key role in informing the UK's operational agencies during this type of event. Within CEH we have teams of scientists working on furthering our understanding of hydrological processes, water resources, water information management, hydrological status and reporting, the climate system, hydrological modelling and risk, and hydrological modelling and forecasting.

A few examples include:

The Centre for Ecology &  Hydrology jointly operates the National Hydrological Monitoring Programme (for the UK) in conjunction with the British Geological Survey. NHMP scientists produce the UK Monthly Hydrological Summary which assesses rainfall, river flows, groundwater and reservoir levels. They also operate the UK's National River Flow Archive. The NHMP also has a remit to analyse major flood and drought events in the UK and analyse long-term trends in UK hydrological data. The team publish a series of occasional reports on major hydrological events, including reports on the UK's major flood events in 2000/2001, 2007 and 2012.

The UK's Monthly Hydrological Summary is published on, or before, the tenth working day of the following month. A Hydrological Outlook for the UK is also available.

CEH's Grid-to-Grid (G2G)*, which is now used as the main hydrological model underpinning flood warning and forecasting by both the Environment Agency / Met Office Flood Forecasting Centre for England & Wales and the SEPA / Met Office Scottish Flood Forecasting Service for Scotland.

In 2012 CEH staff concluded a major project looking at "Future Flows and Groundwater Levels: British projections for the 21st century". The research looked at the impact of climate change on river flows and groundwater levels across England, Wales and Scotland and produced two unique datasets, which are now available via the CEH website, through the CEH Information Gateway and downloadable from the National River Flow Archive and National Groundwater Archive.

And finally on Friday 3 January, CEH climate scientist Chris Huntingford wrote this piece for the Guardian: "We desperately need to predict what climate change is doing to UK rainfall".

Additional information

* The Grid-to-Grid hydrological model is a tool developed by the Centre for Ecology & Hydrology (CEH) for translating rainfall into river flows to predict potential river flooding. Intensive work on the Grid-to-Grid project began in 2002 at CEH and continues today in collaboration with the Environment Agency. Total NERC investment in the project (via CEH) is estimated at £1.2 million with additional funding provided by other organisations.

Further links

Jamie Hannaford from the Centre for Ecology & Hydrology contributed a chapter to the Living with Environmental Change climate change report card for water entitled, "Observed long-term changes in UK river flow patterns: a review"

More photos of the flooding at Wallingford, Oxfordshire (January 2014) on our Flickr photostream