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Microplastics found in fifty percent of insects in South Wales rivers

October 10, 2018
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The River Usk in South Wales. Half of the aquatic insects sampled in the river were found to contain microplastics. Image: Photo Monkey | Flickr Creative Commons

Microplastic pollution is a rapidly growing issue in aquatic ecosystems across the world. Microplastics are tiny pieces of plastic debris less than 5mm in size. They enter aquatic environments in two main ways. First, diffusely: through the erosion of larger plastic items such as drinks bottles, fishing nets and plastic bags. Second, directly: through the run-off of abraded road paints, textiles, and vehicle tyres, and in sewage containing plastic textile fibres from washing machines.

Plastics can take thousands of years to degrade and break down. As a result, understanding the impact of increasing microplastic pollution into aquatic ecosystems is an important emerging topic for environmental science and policy.

In marine environments, microplastics have been found in invertebrateszooplankton, shellfish, fish, and birds, and washed up on shorelines across the world. Whilst microplastics are present at all tropic levels in marine food webs, research is ongoing in understanding how this accumulation affects the feeding, growth, reproduction, and survival of aquatic communities. By comparison, our understanding of the extent and impacts of microplastic pollution in freshwater environments is relatively sparse (read our blog on the topic from 2015 here).

Microplastics widespread in South Wales rivers

A new open-access study by researchers from Cardiff University found that half of aquatic insects (or macroinvertebrates) sampled from three rivers in South Wales had ingested microplastics.

A research team led by Fred Windsor, a PhD researcher at Cardiff University School of Biosciences, sampled three different kinds of mayfly and caddis larvae at five sites on the Usk, Taff and Wye catchments. Each sampling site was located close to a waste water treatment plant, allowing macroinvertebrates to be sampled both above and below water outflows from each plant.

The researchers found microplastics at each of their five river sampling sites. These were found in individual insects across each of the three sampled macroinvertebrate species, regardless of their feeding methods, habitat preferences and ecological niche.

The research team found that, on average, microplastic levels were similar in river stretches both above and below waste water treatment plants. However, the researchers did observe that microplastic levels increased where waste water treatment plant outflows comprised a significant proportion of downstream river flows. This suggests that microplastic pollution originates from multiple sources – most likely transport networks and urban areas – across the wider landscape, rather than from discharge from waste water treatment plants alone.

Lead author of the study Fred Windsor says, “Every year, between eight and twelve million tonnes of plastics are thought to be entering the World’s oceans, but around four million tonnes of it passes along rivers. In some cases, there can be over half a million plastic fragments per square metre of river bed, so that ingestion by insects is very likely.”

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Microscopic images of the microplastics (A and B) and plastic fibres (C) found by the researchers in the three rivers. Image: Study Authors

The emerging environmental risks of microplastic pollution

Co-author Professor Steve Ormerod, Co-Director of Cardiff University’s Water Research Institute continues, “Urban rivers in the UK have been recovering from decades of gross pollution, but growing information illustrates that plastics are a new risk for river organisms not just in towns and cities, but even in some rural areas.

Problems could arise from the physical effects of microplastics, from their direct toxicity or from pollutants that they transport. Plastics in insects mean that animals using them as prey could also be affected. At present, however, our understanding of the risks to wildlife and people is absolutely rudimentary. We need to improve this situation urgently to know how best to manage the problems.”

The research team conclude that more research is urgently required to understand the sources and transport of microplastics in freshwater environments, and how microplastics are ingested and transferred across different organisms in freshwater food webs. Such research could allow scientists and water managers to develop more complete biological risk assessment approaches for mitigating the potential impacts of microplastics on freshwater life.

Microplastic pollution: a key topic for environmental science and policy

Professor Isabelle Durance, Director of the Water Research Institute at Cardiff University, adds, “Although people are more and more aware of the damage caused to ocean wildlife from ingesting plastics, the potential problem of plastics in river ecosystems has been seriously overlooked.

“The water industry, environmental regulators, the plastics and packaging industries, and ordinary people concerned about the environment see this as an increasing priority, and this study provides yet more evidence that we need a fuller assessment of the sources, movements and effects of microplastics as they are transported between the land and sea along rivers.”

The interconnection of freshwater and marine environments highlighted by Prof Durance – in which microplastics are transported through river catchments out to estuaries and the open sea – is a key aspect of this emerging environmental issue. For example, another recently published paper by Alexandra McGoran and colleagues found microplastics in a third of fish sampled in the Thames and Clyde estuaries in the UK.

As a result, the management of microplastic pollution in coming years is likely to require close co-operation between scientists, policy-makers and water managers across both freshwater and marine realms, both to understand the extent of the microplastic problem, and what can be done to mitigate its effects on aquatic life.

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Windsor, F. et al. (2018), Microplastic ingestion by riverine macroinvertebrates, Science of the Total Environment, Volume 646, 68-74 (open-access)

Lake type affects how climate change causes algal blooms in European lakes

September 28, 2018
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Algal bloom on Loch Leven in Scotland. Image: Laurence Carvalho

Blooms of blue-green algae – otherwise known as cyanobacteria – are likely to increase in European lakes as a result of climate change, according to a new study. However, this trend is likely to vary depending on the individual characteristics of different lakes.

Writing in Global Change Biology, Dr. Jessica Richardson from the Centre for Ecology and Hydrology and colleagues used data from lakes across Europe to explore the sensitivities of different types of lakes to multiple environmental stressors associated with climate change and human activities.

The research team – funded by the EU MARS project – wanted to find out how climate change effects, coupled with nutrient pollution, influences cyanobacteria growth. Characteristic ‘blue-green’ cyanobacteria blooms can be a common sight across Europe during the summer months, particularly in shallow lakes in agricultural or urban landscapes.

Whilst cyanobacteria communities are a natural – and valuable – part of almost all aquatic ecosystems, their rapid growth and spread – often following nutrient pollution during hot weather – can have adverse effects for the wider environment. Cyanobacteria blooms can cause hypoxic conditions with low dissolved oxygen levels, block light from entering the water column, and cause toxic health risks to humans and animals.

These effects can cause serious environmental and economic problems. As a result, understanding how and why cyanobacteria blooms occur in response to multiple stressors from human activities is important.

Gathering data from lakes across Europe

The research team used data on 494 natural European lakes to examine how eutrophication, temperature and prolonged periods of drought interact to influence cyanobacteria levels. The lake data was taken from the WISER database, and was based on scientific sampling of the individual lakes between 2000 and 2009.

The lakes were categorised into eight different types based on their alkalinity, the presence of humic substances (and consequently, the colour of the water), and the characteristics of water mixing in the water column. This categorisation was based on the common European lake typology scheme used in the Water Framework Directive. Lake data was paired with corresponding catchment and climate data from the same period, taken from the MARS geodatabase and JRC Agri4Cast Data Portal, respectively.

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Clyndrospermum sp. – microphotograph of a species of cyanobacteria. Image: Matthew Parker | Wikipedia Creative Commons

Modelling the interactions and impacts of multiple stressors

Three key stressors were chosen for analysis in this study: total phosphorus, water temperature and water retention time. Phosphorus is a nutrient pollutant commonly found in aquatic environments – often originating from agricultural fertilisers, run-off from urban areas, or waste-water treatment plants – which at high concentrations can prompt rapid cyanobacteria blooms.

Water temperature increases are widely predicted in lakes globally as a result of ongoing climate change. Previous studies have examined the impacts of temperature increases on lake water quality and biodiversity, particularly in how warming might exacerbate the environmental impacts of nutrient pollution.

Water retention time is a measure of how long water is ‘resident’ in a lake. Retention time is higher during times of drought (when there are low water flows), and lower during periods of heavy rainfall (when there are high water flows). Cyanobacteria blooms can occur when water retention times are high, as a result of increased concentrations of nutrients (which are not ‘flushed out’ of the system) and stable physical conditions. Lakes in regions where lower rainfall and drought is predicted under future climatic changes are likely to exhibit increased water retention time.

The sensitivity of European lakes to climate change is influenced by lake type

Around a quarter of the lakes analysed in the new study had average cyanobacteria levels which exceeded the World Health Organisation ‘low risk’ threshold. The majority of these lakes were located in central Europe. Lakes with lowest cyanobacteria levels were found in the most northerly regions of Europe, following a pattern of decreasing temperature and phosphorus levels with increasing latitude.

Overall, cyanobacteria levels increased with temperature and water retention time in five of the eight lake types. The effects of temperature were greatest in lake types at high latitudes, which suggests that lakes in these regions will become increasingly at risk from climate warming in the future.

However, the sensitivity of cyanobacteria to phosphorus levels, water temperature and retention time varied with lake type. For example, cyanobacteria levels in shallow, humic lakes with medium-high alkalinity were explained by water retention time, and a synergistic relationship between phosphorus levels and temperature. However, in lakes with similar characteristics – but this time with clear (non-humic) water – only water retention time was identified as an explanatory variable for cyanobacteria levels.

In short, the sensitivity and response of European lakes to climate change is shown – in terms of impacts on cyanobacteria levels – to be strongly influenced by lake type. The researchers state that in most lake types, management will become increasingly necessary as the effects of climate change – higher temperatures and retention times –  impact lakes in the future. They suggest that as climate effects cannot be locally controlled, there is a need for effective management of nutrient pollution in order to minimise harmful algal blooms.

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Algal bloom on the Spree River in Berlin. Image: Lars Plougmann | Flickr Creative Commons

European lakes under climate change: a ‘perfect storm’ for cyanobacteria blooms?

Lead author Dr. Jessica Richardson from the Centre for Ecology & Hydrology says, “Lakes are getting warmer and also experiencing longer periods of water retention because of prolonged droughts. In human impacted, nutrient rich lakes we think that these conditions could be the ‘perfect storm’ for promoting blooms of cyanobacteria.”

In our study of almost 500 European lakes, we found that higher temperatures, longer retention times and higher nutrients do increase the amount of cyanobacteria but not to the same degree in all lakes. This is not very surprising as there are many different types of lakes which are sensitive to these stresses in different ways.”

This site-specific variation in the impact of multiple stressors on European lakes has important implications for environmental policy and management, as Richardson explains,

“While climate change and eutrophication are important risk factors in the development of cyanobacterial blooms, other factors which also affect the growth and competition of cyanobacteria with other algae, like the depth of the lake, the colour of the lake, or the location of the lake may be equally as important.”

This means that when it comes to risk management, and predicting future risks of cyanobacterial blooms, a ‘one-size fits all’ approach can’t be applied. Instead, we need to consider that management of different types of lakes may need to be tailored according to their sensitivities.”

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Richardson, J. et al (2018), Effects of multiple stressors on cyanobacteria abundance vary with lake type, Global Change Biology, https://doi.org/10.1111/gcb.14396

MARS Project website

 

RiBaTox: a new online portal for chemical pollution policy and management

September 10, 2018
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Image: RiBaTox

RiBaTox (Guide to Tools and Services for River Basin Toxicants) is a new, open-access online portal designed to support the policy and management of aquatic chemical pollution in Europe. Designed and built by the EU SOLUTIONS project, RiBaTox provides guidance on the science and management of toxic pollutants for policy makers, water managers, scientists and the interested public.

RiBaTox is designed to guide users through the methods developed and used in the SOLUTIONS project, illustrating the online tools or services which can support user needs in managing river basin toxicants, from the local to the national scale.

RiBaTox hosts descriptions of its tools and services as downloadable pdf factsheets. RiBaTox is designed as a guidance system, and its factsheets contain references to scientific publications and contact information for the developer(s) or supplier(s) of each tool or service.

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RiBaTox contains factsheets on four key areas related to chemical pollution. Image: RiBaTox website.

RiBaTox provides three options to help users find the specific tool or service to meet their needs:

(1) a user guide based on a decision tree;
(2) an overview of all factsheets, subdivided into useful categories, and;
(3) a search function, scanning all texts contained on the site.

More detail about these options can be found in the RiBaTox manual (pdf), and the full set of factsheets can also be downloaded as a reference document (pdf).

RiBaTox contains several additional applications. An abatement module provides an overview of current technical and non-technical abatement options. A diagnostic toolbox supports the assessment of ecological effects of pollutant mixtures using a decision matrix. Links to the SOLUTIONS Integrated Data Portal (IDPS) help users to identify links between toxicant exposure and epidemiological data, and to explore the potential biological effects of chemical pollution.

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RiBaTox guides users to three online tools which support chemical pollution policy and management. Image: RiBaTox website

Frank Sleeuwaert – developer of RiBaTox – says, “The focus of RiBaTox is problem-solution oriented, not research oriented. However, scientists who would like to be introduced to specific and new findings from the SOLUTONS project may find RiBaTox, with its factsheets and references sections, useful. In order to reach a broad user community the interface of RiBaTox was developed following consultation with end-users to require minimal learning time, with only a few steps necessary to get recommendations and factsheets.”

Kees Kramer – editor of the factsheets – adds, “All the factsheets were edited to allow maximum consistency in the use of texts that can be understood by the reader. The factsheet concept was further improved by offering guidance to methods of approach rather than a set of scientific results. The end-user will find their way in identifying what we call a ‘SOLUTIONS Tool or Service’, used by project partners to tackle certain scientific questions related to management of river basin toxicants. In this way the end-user can anticipate whether a given method could be a useful approach to solve their own challenges, whether being a researcher, policy maker or implementer of the Water Framework Directive.”

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Find out more:

RiBaTox: a Guide to Tools and Services for River Basin Toxicants

SOLUTIONS Project Website

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The EU SOLUTIONS project provides new and improved models, tools, guidelines and databases to support decisions on current and emerging pollutants and their mixtures in European surface waters. SOLUTIONS is an FP7 research project funded by the European Commission and carried out by a consortium of thirty-nine organizations including research institutes, companies and universities.

‘Blue spaces’ help improve public health

September 7, 2018
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Spending time near water has even greater health benefits than visiting a forest or park, according to researchers. Image: Frederica Diamanta / Unsplash

A post from our partners at Horizon: the EU Research & Innovation Magazine.

Living close to bodies of water such as a river or even a fountain can help improve public health, whilst also reducing medical costs for governments, according to researchers.

There is growing evidence that spending time in the natural environment can foster important mental and physical health benefits, and help prevent illness and reduce medical bills. One study found that people in England made 1.23 billion active trips to parks and woodlands, which was estimated to be worth £2.18 billion in terms of annual health benefits.

Now research by the same team suggests that so-called ‘blue spaces‘ – areas with water features like a river, ocean, spring, or even a fountain in a city centre – could be particularly beneficial.

‘What we find time and time again is that being exposed to blue environments often has even greater (health benefits) than visiting a green space (like a park or forest),’ said Dr Mathew White, an environmental psychologist at the University of Exeter, in the UK, who helped conduct the research.

One reason is that people who take trips to bodies of water are more likely to also go for longer walks or cycles – as well as swimming – which can help lower their risk of developing chronic disease like diabetes, heart disease and cancer. But water can have other benefits too.

‘Blue spaces can directly reduce psychological stress and improve mood,’ said Dr White, who is also a lead researcher in BlueHealth, an EU project examining the relationship between this type of blue infrastructure and people’s health and wellbeing.

The reasons why water is mentally therapeutic may be connected to the open vistas, reflected light and associated soundscapes, according to the researchers. Depression has also been linked to detachment from the natural environment so blue spaces are useful for ‘reducing the negative and improving the positive,’ said Dr White.

The mental and physical benefits of blue spaces may seem obvious to the 200 million people in Europe who live close to the coast. However, to help the general public embrace the full health benefits, it requires specifically designed ways of safely accessing and appreciating blue spaces.

‘One thing we are interested in is how to quantify blue spaces so we can put an economic value on them to justify infrastructure investment,’ said Dr White.

BlueHealth is aiming to gather data to help convince policymakers to invest in blue spaces, particularly in urban areas. They recently conducted an international survey asking 18,000 people about the kinds of activities they do in blue spaces across Europe, in an attempt to determine the implications this has for public health. The results are expected later this year.

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A new coastal amphitheatre in Plymouth, UK, will allow school children to spend more time by the water. Image: BlueHealth

‘Urban acupuncture’ to connect communities to water

BlueHealth is also working on innovative ways to increase public access to blue spaces, from using virtual reality for those physically unable to make the journey to the ocean,  to improving access through local community interventions termed ‘urban acupuncture’.

Urban acupuncture is an urban planning concept that involves working with local communities to make small adjustments to bodies of water to connect the potential physical and mental health benefits to the public. This can include a viewing platform along a lake or a pathway to a river.

Improving access to water, however, does increase risks such as public exposure to flooding, or potential drownings if a blue space is left unsupervised. However, according to Professor Lora Fleming from the University of Exeter and the principal investigator of BlueHealth, ‘natural environments have both risks and benefits’, but you can still improve access to blue spaces with these in mind.

In one of several case studies across Europe, BlueHealth researchers worked with Plymouth City Council on England’s south coast to help regenerate an area along the seafront in an attempt to boost local health and wellbeing. By engaging with local residents and stakeholders, they helped build a small coastal facing amphitheatre and safe playing area for children, which will host special family events and school sessions run by, among others, the local aquarium and wildlife trust.

The researchers also considered the potential impacts of rising sea levels due to climate change and coastal erosion, building the theatre in such a way as to protect it for decades to come.

Projects designed like this can help to connect children with the natural environment for generations and improve their health and wellbeing over their lives, but in order to be successful, local communities need to be involved. ‘Otherwise they won’t use it,’ said Prof. Fleming.

Working with local people when developing blue space access can also bring environmental advantages, according to Professor Sheila Heymans, the executive director of the European Marine Board (EMB), a research think-tank specialising in marine science policy.

She believes that once people begin to appreciate blue spaces more they will want to protect them from pollution, overfishing and poor urban planning. But to design ways of providing safe access to blue spaces that incorporates all these factors will require significant investment, from researching the local needs to choosing a site and then the actual construction.

Supporting human and environmental health through ‘blue thinking’

‘There isn’t a single place where blue spaces are actually coordinated from,’ Prof. Heymans said. ‘Incorporating blue spaces very much depends on one or two people in the local authority.’

Prof. Heymans believes that government policies need to be moulded so that they complement each other and support more ‘blue thinking’ across sectors such as health, environment, tourism, and transportation.

‘Some of the policies and directives in Europe are counterproductive, the habitat and bird directives expect you to save seabirds, but the reduction in discards from the reform of the common fisheries policy will reduce food for seabirds that are dependent on these discards, so different policies can sometimes work at cross purposes,’ said Prof. Heymans.

Policymakers therefore need specific information that can help convince local authorities about the combined potential environmental, economic, social, and health benefits.

The EMB are now working with the Exeter BlueHealth team to coordinate a new project called SOPHIE, which is examining how the marine environment and human health are inextricably linked.

‘There is a link to the health of humans to the health of the oceans,’ said Prof. Heymans. ‘You need to fund interdisciplinary research to make that clear.’

 

More information:

BlueHealth

SOPHIE

The Alliance for Freshwater Life is launched

August 31, 2018
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The Vjosa river and floodplain in Albania: one of the last intact large river systems in Europe, currently threatened by proposed dam construction projects. Image: Lukas Thuile Bistarelli

A new global network aiming to halt and reverse the ongoing freshwater biodiversity loss crisis launched last Sunday at the World Water Week conference in Stockholm. The Alliance for Freshwater Life is an interdisciplinary network of scientists, conservation professionals, educators, policy experts, creative practitioners, and citizens working to improve the conservation and sustainable use of freshwater ecosystems and biodiversity.

Freshwaters are some of the most biodiverse ecosystems in the world, many supporting populations of rare and endemic species. However, freshwaters are also impacted by multiple pressures, many of which stem from human activities. Freshwater ecosystems are a fundamental resource for human life, providing water, food, energy and natural materials. However, growing pressures such as the pollution, over-abstraction, fragmentation and alteration of water bodies, and the spread of invasive species, habitat loss and alteration – all shadowed by the emerging effects of global climate change – are placing enormous stress on freshwater life.

As a result, freshwater vertebrate populations have declined by more than 80% over the past 50 yearsa rate of decline twice that recorded for either marine or terrestrial systems – according to a 2016 World Wide Fund for Nature report. Approximately one-third of the 28,000 freshwater species assessed for the IUCN Red List is threatened with extinction. An estimated threequarters of the world’s inland natural wetlands were lost during the 20th century, according to a 2014 study by Nick Davidson. Staggeringly, a 2017 World Economic Forum report ranks freshwater supply as third in a list of the top10 global risks, behind weapons of mass destruction and extreme weather events. It is such symptoms of a global freshwater biodiversity crisis that the Alliance for Freshwater Life has been formed to address.

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Delegates at World Water Week 2018 in Stockholm. Image: Thomas Henriksson / SIWI

Reflecting on the Stockholm launch, Alliance co-chair William Darwall says, “The showcase to launch our new initiative was well attended despite our 9am Sunday morning time-slot, receiving extensive endorsement and interest from a wide range of organisations present. We received many excellent ideas during the discussions session to help guide our next steps in taking the initiative forwards. We thank all those who attended and for their ideas and support.”

Darwall – Head of the Freshwater Biodiversity Unit at the IUCN Global Species Programme – continues, “The importance of this new initiative was confirmed through much of the dialogue during the week where the need for better representation of freshwater life in water policy and conservation action were abundantly clear. The event was supported by the publication of our paper in Aquatic Conservation: Marine and Freshwater Ecosystems in the previous week, which has already received tremendous interest through social media.”

 

The newly published paper – available here – is a manifesto for positive action for freshwater biodiversity conservation and policy. It outlines the Alliance’s vision of a global collaboration between national and international organisations and individuals which brings together expertise on education, outreach, research, conservation, and policy-making for the sustainable management of freshwater biodiversity.

The authors identify two key drivers of the ongoing crisis of freshwater biodiversity loss. First, they highlight the significant growth in global demand for water resources over the last century, leading to widespread freshwater habitat loss and degradation, water pollution and over-abstraction, and considerable alterations to the flow and course of many rivers and streams. The authors cite studies suggesting that global demands for drinking water, hydropower and agriculture will increase significantly in coming decades.

Second, the authors argue that existing environmental policies do not adequately protect freshwater biodiversity and ecosystems. They state that the human valuation and usefulness of freshwaters is often foregrounded in environmental policy, at the detriment of non-human life. This, they suggest, often leads to “the unnecessary and often inadvertent sacrifice of freshwater life as collateral damage in global development, which can lead to the destruction of the very ecosystems required to support these same objectives.” In short, the paper argues that whilst human pressures on freshwaters continue to increase and interact, existing environmental policies don’t adequately address their impacts.

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Pacific salmon migrating upstream. Salmon populations are threatened by dam construction, mining, over-fishing and climate change. Image: Jason Ching / World Fish Migration Day

In response, the paper outlines five key areas of work to be undertaken by the Alliance to raise the public and political profile of freshwater issues. More research is needed to understand the distribution and status of freshwater biodiversity and ecosystems globally, in order to design effective conservation and restoration initiatives. Freshwater biodiversity data should be better synthesised and made accessible to conservation practitioners.

The core focus of the Alliance is to develop a global network and community of practice for freshwater biodiversity conservation, which fosters collaborations to design and implement largescale conservation actions. There is relatively low public awareness of the threats to freshwater ecosystems, and resulting biodiversity loss (a trend which has underpinned the work of this blog over the last eight years), and the Alliance plan to host a range of education and outreach activities to address this shortfall. Finally, the Alliance is designed to provide a voice for freshwater life in global policy making, and its members plan to engage with policy makers both on the implementation of existing policies, and the development of new ones. The aim here is to place freshwater species and their ecosystems on the global agenda as key targets for conservation action.

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Wetlands in the Kemeri National Park, Latvia. Around threequarters of the world’s inland natural wetlands were lost during the 20th century, according to a recent study. Image: Dmitrijs Kuzmins, CC BY 3.0

Darwall outlines the way forward for the Alliance, “The next steps are to fully develop and formalise the strategic plan and to obtain setup funding for the next two-year period during which time we will expand our membership to be globally representative, develop new partnerships, and start work to raise public awareness of the crisis facing our freshwater life.”

Darwall continues, “This exciting new initiative creates an opportunity to step up actions to ensure this growing coalition of organisations and individuals provides the critical mass required for the effective representation of freshwater biodiversity at policy meetings; to develop solutions balancing the needs of development and conservation; and better convey the important role freshwater ecosystems play in human well‐being. Through this united effort we hope to reverse this tide of loss and decline in freshwater biodiversity.

“In the context of the current call for a Paris-style agreement to save life on Earth, calling for a massive increase in our efforts save life on Earth which is in crisis, we have formed the Alliance for Freshwater Life as an endeavour specifically focused on saving freshwater biodiversity, which remains the least poorly appreciated, least funded, and most heavily threatened and declining of all biodiversity, and risks being largely absent from future global agreements – despite contributing a disproportionate amount to the global needs of humans.”

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The World Water Week Showcase was convened by Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), IHE Delft, International Union for Conservation of Nature (IUCN), World Wide Fund for Nature (WWF), Conservation International (CI), Alliance for Global Water Adaptation (AGWA), National Great Rivers Research and Education Center (NGRREC). The Showcase was sponsored by Leibniz IGB. Outreach and social media development was funded by NGRREC.

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Read more:

Alliance for Freshwater Life website

Darwall, W et al (2018) “The Alliance for Freshwater Life: A global call to unite efforts for freshwater biodiversity science and conservation”, Aquatic Conservation: Marine and Freshwater Ecosystems, https://doi.org/10.1002/aqc.2958 (open-access)

More Postcards from Heatwave Europe

August 17, 2018
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Low water levels on Thirlmere in the English Lake District in late July 2018. Image: Stephan Brzozowski

We recently published the first in a series of ‘Postcards from Heatwave Europe‘, in which aquatic scientists from across Europe offered their observations on how this summer’s extreme weather was affecting rivers and lakes in their local landscapes.

Today we have two more contributions to the series, from Sweden and the English Lake District. In Britain, at least, the weeks of hot, dry weather experienced this summer have recently been replaced by more unsettled conditions and regular thunderstorms. However, water levels in many lakes and rivers have yet to return to typical summer levels as a result of the prolonged dry spell.

You can read the first set of ‘postcards’ here.

Sweden

In the Swedish county of Uppland, we have been racing to complete fieldwork for the BiodivERsA-facilitated CROSSLINK project before our streams dried out or went into extreme low flows. Fortunately, there was good snowfall over winter which meant the streams all started with high base-flows in spring. However, it is not difficult to imagine a scenario where a poor snow year coincides with another extremely dry summer, which could place catastrophic strains on systems already under pressure from human activities.

Notably, the spring transition this year was extraordinarily rapid, leading to record warm temperatures in May. This warming seemingly bolstered seasonal emergence of stream insects, leading to a noticeable pulse of riparian insect activity around our study sites early in the season. We hope to quantify the effects of this spatial subsidy on receiving terrestrial consumers using biomarker analyses.

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A stream study-site near Uppsala in early May 2018. Image: Francis J. Burdon

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Extreme low flows in the same stream in late June 2018 after a long period of hot, dry weather. Image: Francis J. Burdon

Another aspect of the CROSSLINK project is assessing the benefits of woody riparian buffers to stream ecosystems. In this year’s heatwave, our buffered sites in Sweden have been on average 0.5°C cooler than the un-buffered sites upstream. This observation adds further credence to calls for riparian plantings as a climate adaptation tool in catchments facing multiple pressures. However, we have noticed that our forested headwater reference sites all face hydrological challenges during the summer months. Whilst this natural feature of our systems has likely been exacerbated by drainage practices, there may also be a perverse tradeoff between the benefits of shading and the transpiration exerted by trees.

The severity of the drought in Sweden has caused an unprecedented number of wildfires throughout the country. Our study sites have not been affected, and with temperatures starting to cool and some much-needed rain, the situation seems to be stabilising. Similar to reports from Wales, we have experienced torrential thunderstorms in the past two weeks, leading to surface flooding in urban areas of Uppsala. However, like the situation in the UK, these rain events have only marginally improved the low-flow conditions in our streams. It is safe to say we wait with bated breath to see what more the weather will deliver in 2018.

Dr. Francis J. Burdon, Swedish University of Agricultural Sciences

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Dry lake bed at Thirlmere in the English Lake District. Image: Stephan Brzozowski

England

The height of the ‘heatwave’ broke here in mid-July, and a threatened hose-pipe ban has been postponed thanks to some rain, cooler temperatures and a drop in water demand. However the hot, dry conditions through May, June and early July – with average air temperatures 2 – 2.5°C above the 1981 – 2010 average and rainfall being only between a third and just under three-quarters of the average for this time of year – have meant water levels in our lakes and rivers have declined.

By the end of July, river levels in a number of the rivers in the northwest of England were at historically low levels and reservoir stocks were much lower this year, particularly in Cumbria and the Lake District where levels were 10 – 30% lower than on average. So what are the impacts of these hydrological and meteorological conditions on some of the lakes in the Lake District?

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Figure 1: Surface temperature data from Windermere, north basin. The blue line represents the 1981–2010 average, and the dotted lines one standard deviation from this average. The yellow line represents the 2018 data. All data are from the CEH Cumbrian lakes long-term monitoring programme.

At CEH we have been monitoring lakes in the Lake District since the 1940s, so we’re in a good position to see how this year fits into the longer-term pattern. We can see by looking at our long-term record of surface water temperatures, that average temperatures during May, June and July 2018 were between 2.4 and 4°C higher than the 1981–2010 average.  (See the example from Lake Windermere’s north basin in Figure 1).

The additional heating of the surface waters also means that the seasonal water column temperature stratification is particularly strong this year, meaning the difference in temperature between the surface and deep water of Windermere is around 16°C, which also has implications for aquatic life in the lakes.

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Figure 2: A measure of total algal biomass, chlorophyll a, for Blelham Tarn and Windermere, north basin. The blue line represents the 1981 – 2010 average and dotted lines are 1 standard deviation from the average. The yellow line represents the data from 2018. All data are part of the CEH Cumbrian lakes long-term monitoring programme.

Interestingly, the warmer water has not – during this early part of summer at least – increased the overall amount of algae in the lakes. One measure of algae levels – total chlorophyll a – is not generally above the long-term average (See Figure 2).

At first this may seem at odds with the incidences of cyanobacteria blooms that have been reported for a number of Lake District lakes. However, these species of algae – or more strictly speaking, photosynthetic bacteria – are particularly well adapted to the warm, stable water column conditions that we have been experiencing, because they have the ability to float to the surface and out-compete other species for light. Their buoyancy also means that they can be readily moved by water currents into shoreline areas where they accumulate and become a problem for humans and other animals.

cyanobacteria

Examples of some of the cyanobacterial genera present in the Cumbrian lakes Windermere and Esthwaite Water this summer. From top left clockwise: Microcystis, Anabaena (straight form), Anabaena and Woronichinia, Anabaena (coiled form) and Aphanizomenon. Image: CEH

Our algal community data suggest that this group are particularly dominant this year, with cyanobacterial genera Anabaena, Aphanizomenon, Woronichinia and Microcystis being present in the community. The lower amount of algae that we have seen this year compared to the long-term average, is likely to be a response to the nutrients available, which enable the algae to grow.

The depletion in the surface water concentrations of these nutrients has been particularly rapid this year, which may be limiting the overall amount of algae that is being supported. The more recent rainstorms at the middle to end of July may have altered this availability by bringing in nutrients from the lake catchments, which could promote more algal growth over the remainder of the summer.

Dr. Ellie Mackay, UK Centre for Ecology & Hydrology, Lancaster, UK.

Read Part One of ‘Postcards from Heatwave Europe’

Postcards from Heatwave Europe

August 3, 2018
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Low water levels on Lake Nisser in Norway. Image: Anne Lyche Solheim

Across the world, this summer’s weather has been characterised by extremes. The USA has experienced severe droughts and wildfires in the West, and flash flooding in the East, whilst an ‘unprecedented’ heatwave in Japan has been attributed as the cause of over 65 deaths.

Most of Europe has experienced an extended period of high temperatures and minimal rainfall, causing wildfires to spread in both the Arctic Circle and Greece. Meteorologists predict that the European temperature record of 48C (118.4F) set in Athens in July 1977 could be broken this weekend in Spain and Portugal.

In Europe, the heatwave has been caused by the stalling of the northern hemisphere jet stream, which generally brings cooler Atlantic weather over the continent. As a result, a huge ‘pocket’ of hot, dry air has been present over Europe (particularly northern regions) in recent months.

Analysis of the heatwave in northern Europe between May-July of this year by the World Weather Attribution group suggests that this extreme weather has been made at least twice as likely by ongoing climatic changes.  Similarly, speaking recently to The Guardian about this year’s global weather extremes, climate scientist Prof. Michael Mann, at Penn State University said, “This is the face of climate change. We literally would not have seen these extremes in the absence of climate change.”

The high air and water temperatures, low rainfall and flashy storms and flooding experienced across Europe are all key pressures on the health and status of freshwater ecosystems. To gain a picture of how this summer’s weather is affecting European waters, we put a call out to our network of aquatic scientists across the continent, asking them to send in brief ‘postcards’ of their observations.

The first responses are collected here, and more will be published in the coming weeks. If you would like to submit your own observational ‘postcard’, please email info@freshwaterblog.eu

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Water levels in tributaries of Lake Nisser in Norway are extremely low, and in some cases completely dry. Image: Anne Lyche Solheim

Norway

I am currently on holidays close to Norway’s 10th largest lake (Nisser in Telemark) where the water level is extremely low, and most of the tributaries have dried out completely, or have become reduced to minor streams. Yesterday, a farmer in the local neighbourhood came with his tractor and a big water tank to get water from the lake for his cattle, who are suffering in a grazing area in the hills, where all the streams have tried out. This has never happened before.

The well we use for water supply to our summer house here have lost two-thirds of its water, so we don’t know how long we can stay here before the well runs dry. There is absolutely zero re-charge over the past weeks and months now. 12th of June was the last time we had any substantial rain in South-Eastern Norway.

The air temperature during daytime varies from 28 to 31C, and it’s been like that since mid-May. There are almost no insects, except a few bumble bees. The grass is mostly yellow and the grain crops are likely to be < 1/3 of normal. There is a crisis for cattle farmers, as they do not have enough fodder for them, so a lot has been slaughtered.

The surface water in the lake is now 25C, which is highly exceptional (although perfect for swimming). The littoral zone is completely dried out.

Dr. Anne Lyche Solheim, Niva

Turkey

The weather has been completely weird this year! We had no winter: no snow, no rain, and very dry and warm weather. Between May and mid-June we had extreme rains with flash floods all around the country. Lakes and rivers across Turkey suffered from dissolved organic carbon problems, which are normally unheard of.

Now since mid-June, every day is record breakingly hot. In this heatwave, many small ponds are drying out, and lake levels are going down more than 1 cm/day. Evaporation is very high, which leads to an increase in salinity and conductivity in the water column. Of course, we’re seeing widespread algal and cyanobacteria blooms as water temperatures rise and nutrient concentrations increase.

Prof. Meryem Beklioğlu, Middle East Technical University

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Huge blooms of blue-green algae in brackish coastal waters in the Gulf of Finland and Archipelago Sea. Image: ESA Copernicus Sentinel Data, 16 July 2018, processing by SYKE

Finland

With wildfires blazing in Greece and Sweden, the heatwave across Europe has not left Finland cold either. Temperatures were record-breaking both in May and July, with average temperatures 2–5 degrees above long-term mean values. This has not come without responses in Finnish freshwaters.

In Lake Enäjärvi in Southern Finland, mass deaths of lake mussels occurred, likely due to oxygen depletion in the exceptionally warm water. Also fish kills were observed in some lakes across Southern Finland, and extensive blooming of cyanobacteria occurred in many lakes. The hot weather also boosted a massive blue-green algae bloom in July in the Gulf of Finland and parts of the Archipelago Sea.

In inland fish farm ponds, salmonids have been suffering the prolonged heat. Across fishing sites in streams, there were pleas to temporarily cease salmonid fishing as catch-and-release might cause additional fatal stress to the fish already stressed by warm water.

Dr. Jukka Aroviita, Finnish Environment Institute (SYKE)

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Flash flooding in Cardiff, Wales, after weeks of hot, dry weather. Image: Steve Ormerod

Wales

In Wales — as in much of the UK — we’ve been heading for what has looked like the driest summer since modern records began in 1961. River discharge levels have been very close to record lows throughout July, while air temperatures at or near 30C in mid and south Wales have meant the region’s rivers have been at 24C or higher. Parallels have drawn increasingly with the major drought of 1976, surpassing the extremes of more recent events in the early 1990s or 2003.

All of these past drought years brought significant ecological effects. In 1976, low water levels, high temperatures and attendant low oxygen concentrations in the River Wye (now a Natura 2000 river) were exacerbated by the dieback and decomposition of mats of Ranunculus fluitans causing extensive salmonid mortality. Here, at the south-west edge of the Atlantic Salmon’s European range, recruitment falls substantially following hot, dry summers like 2018, so we expect echoes of current conditions next year and beyond.

It’s very likely that the full effects of the 2018 drought will only be known retrospectively. As an example, droughts during several summers in the early 1990s were subsequently shown to have led to the widespread extinction across Wales of the cool-water flatworm, Crenobia alpina — and it hangs on now only where thermally damped subterranean discharge keeps water temperatures below 12-13C.

The current hot, dry conditions over Wales came to an abrupt end over the weekend of July 28th/29th, when 40-60 mm of rain fell over different parts of the nation. Although there was localised urban flooding, effects on river levels have been small or transient.

Hydrographs Wye tributaries

Hydrographs of tributaries of the River Wye, Wales, showing low water flows, even after heavy rain in late July 2018. Image:

These two 30 day hydrographs from the Ithon and Irfon – respectively left and right bank tributaries of the Wye – illustrate modest effects on discharge that also reflect local geological damping and slightly lower catchment altitude of the Ithon.

With a return to drier conditions forecast for much of July and August, the 2018 summer may yet break more records.

Prof. Steve Ormerod, Cardiff University

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