The Freshwater Blog

Top 17 posts of 2017

Water outflows from Fewston Reservoir, UK. Image: James Whitesmith | Flickr Creative Commons

As the end of the year approaches, we’ve looked back over 2017 to collect 17 of our most popular posts on freshwater science, policy and conservation.

It’s been the most successful year yet for the Freshwater Blog, with record numbers of visitors. Thanks, as always, for reading. You can keep up to date with our posts, and add your voice to the debate, through our Twitter, Facebook and LinkedIn pages.

The MARS project, which has investigated the interactions and impacts of multiple stressors on aquatic ecosystems since 2014 (and which supports this blog), hosts its final conference in January 2018. You can find out details here.

Happy 2018!

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Caddisfly larvae tend remarkable underwater ‘gardens’ (January)

Caddisfly (Tinodes waeneri) larva. Image: Guam Insects | Creative Commons

Caddisflies are found in freshwaters across Europe, with their larvae well-known for their remarkable ability to build cases from organic materials such as vegetation, sand and silt (which can take on beautiful creative forms). In Britain alone, there are around 200 different caddisfly species, making them one of the most diverse groups of pond animals.

New research by a team of ecologists from the UK, Germany and Malaysia has shown how caddisflies are not only resourceful ‘house builders’, but also productive ‘gardeners’ of their habitats. Writing in Freshwater Biology, the researchers, led by Nicola Ings, describe how caddisflies actively encourage food growth in their local environment, through ‘weeding’ and ‘fertilisation’. (read more)

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Small birds, big effects: the little auk transforms high Arctic ecosystems (February)

Little Auk colony on the Cape York Peninsula, Greenland. Image: T Davidson

The North Water Polynya is a large area of open sea in Baffin Bay between Greenland and Canada. The area is the largest polynya – an area of sea that remains ice-free year-round, though surrounded by sea ice – in the world, and is one of the most biologically productive marine habitats in the Arctic Ocean.

Ecosystems on the Greenland coastline of the North Water Polynya are transformed – both positively and negatively – by nutrients brought back to land from the open sea by a tiny ‘ecosystem engineer’ bird, the little auk, according to a new study. (read more)

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Life in a Drop of Water: an interview with underwater photographer Liam Marsh (February)

Mayfly larvae after moult, in a drop of water. Image: Liam Marsh

Liam Marsh is an award-winning natural history and wildlife photographer based in the Blackdown hills of south Somerset in England. His photographs of aquatic life – both above and below the waterline – are creative, unusual, and often beautiful. We spoke to Liam to find out about his approaches to revealing freshwater worlds through photography. (read more)

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The restored Lippe River in Germany. Image: Benjamin Kupilas | REFORM

A new study by researchers based in Germany and the USA examined the responses of fish communities to the restoration of the Lippe River in Germany over a 21 year period. The Lippe has been heavily modified by human activity since the early 1800s, with a largely reinforced and straightened channel and bed, highly fragmented flows as a result of numerous weirs, and the widespread destruction of its riparian and floodplain landscapes.

The research team analysed data collected for 4 years before, and 17 years after, restoration at Klostermersch, where two stretches totaling over 3km in length were restored in 1996 and 1997. Restoration involved reconnecting the river’s floodplain with the river, removing bank fixations, widening the river from 18 to 45 metres in width, building a series of small islands, introducing full trees as deadwood, and reintroducing ‘natural’ floodplain drainage systems. In essence, the Lippe River ecosystem was encouraged to become more diverse in structure and dynamic in process. (read more)

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Common ground for multiple stressor research (March)

Delegates at the Portugal meeting. Image: Vanessa Bremerich / Markus Venohr

Last week, researchers from three EU aquatic science projects – MARS, GLOBAQUA and SOLUTIONS – met in Sesimbra, Portugal to present their findings, and to discuss opportunities for collaboration. The three projects share a common interest in the effects of multiple stressors on aquatic ecosystems, and their representatives met at a workshop to develop the potential for shared outputs such as policy briefs and water management guidance. (read more)

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The rapid evolution of Europe’s newly-discovered first cave fish (March)

The newly discovered cave loach from the Danube-Aach system. Image: Jasminca Behrmann-Godel

A diver has made an unusual discovery in an inaccessible underground cave system in Southern Germany: a population of Europe’s first documented cave fish. The pale coloured loach of the genus Barbatula is thought to have diverged from surface fish around 16,000 to 20,000 years ago, following the retreat of ice age glaciers.

“The cave fish was found surprisingly far in the north in Southern Germany,” said project leader Jasminca Behrmann-Godel of the University of Konstanz in Germany, lead author on a newly-published study in Current Biology. “This is spectacular as it was believed before that the Pleistocene glaciations had prevented fish from colonizing subterranean habitats so far north.” (read more)

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What is good ecological status and why does it matter? (April)

‘Good ecological status’ is a key term in the EU Water Framework Directive – the policy framework through which European freshwaters are managed. Member states are required to conserve and restore their rivers and lakes to good ecological status by 2027. But what does ‘good ecological status’ mean, and why does it matter?

A new film by the EU MARS project gives an engaging and accessible introduction to the concept. Produced by MARS scientists Christian Feld and Sebastian Birk at the University of Duisburg-Essen, the short film ‘Good ecological status of rivers and lakes’ emphasises the value of healthy aquatic ecosystems to human and non-human life, both now and in the future. (read more)

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Multiple pressures and the ecological status of European rivers (May)

Floodplain on the River Ouse, Yorkshire. Image: alh1 | Flickr Creative Commons

The EU Water Framework Directive is the ambitious water policy designed to reduce pressures and achieve a good ecological status for all European water bodies. However, assessing the multiple pressures acting on aquatic ecosystems, and understanding their combined impact on the ecological status of rivers and lakes is challenging, particularly at large scales. Understanding these interactions and impacts is crucial to the planning of effective water policy and management.

In this context, a recently published study provides an assessment of multiple human pressures and their relationships with ecological status for all European rivers. Writing in the (open-access) Nature: Scientific Reports journal, Bruna Grizzetti from the EC Joint Research Centre and colleagues estimate that only 38% of EU rivers reach ‘good’ or ‘high’ ecological status. 20% are rated as ‘bad’ or ‘poor’, whilst 42% are ‘moderate’. (read more)

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Environmental restoration prompts widespread water quality increases in China (May)

Lake Taihu on the Yangtze Delta Plain, China: one of the water bodies assessed in the new study. Image: Balázs Andor Zalányi | Flickr Creative Commons

Restoration is a key element of contemporary environmental management, as damaged or degraded ecosystems are guided towards healthier, more resilient and diverse states. As a result, there is widespread interest and attention given to restoration in scientific, management and policy circles globally, particularly about the outcomes and effectiveness of different restoration initiatives.

New insights into restoration management are emerging from China, where many aquatic ecosystems have been highly altered and degraded in recent decades. A new study published in the journal Water Research suggests that water quality in rivers and lakes across China has improved in recent years as a result of significant investment in environmental restoration and water treatment, funded by the Chinese government. (read more)

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Protect the Eels (June)

The European eel is one of the continent’s most remarkable and wide-ranging aquatic animals. Young eels (known as elvers) are born in the Sargasso Sea in the West Atlantic Ocean, and migrate back to European watercourses. Here, they mature and grow larger over a number of years, before making the journey back to the Sargasso Sea to spawn themselves.

However, European eel populations are subject to considerable threats. Some eel populations have dropped by over 90% across the continent in recent decades, largely as the result of overfishing and habitat loss. The European eel has been designated as ‘Critically Endangered’ by the IUCN Red List of Threatened Species since 2008 as a result.

A new community-engaged animation has sought to tell the eel’s story, through the voices of children. Protect the Eels is a an animated journey into the hidden ecologies of the River Avon in south-west England, as told by the children of Victoria Park Primary School Bristol, using their drawings, ideas and voices. (read more)

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The politics of biodiversity and hydropower on ‘Europe’s last wild river’ (July)

Local residents and environmental NGOs protest against hydropower development on the Vjosa. Image: Oblak Aljaz

After 20 years of postponement, an unfinished hydropower construction on the Vjosa River in Albania was cancelled earlier this year. The Vjosa is Europe’s last ‘wild’ large river, flowing entirely unobstructed through inaccessible gorges and enormous gravel banks and islands on a course of almost 270 kilometers from the Pindus Mountains to the Adriatic Sea. However, the river system is currently the subject of a number of hydropower constructions, which potentially threaten its rich – but little researched – biodiversity. (read more)

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European public want more environmental protections according to new survey (August)

Water is a key element of EU environmental policy. Image: Symbolique 2006

Over half of the European public are in favour of more environmental protections across the continent, according to a new European Parliament survey.

53% of the 27,901 EU citizens interviewed by Kantar Public for the survey thought that existing environmental protections across Europe were ‘insufficient’. 75% of citizens thought that more policy and management interventions were necessary to protect European environments. (read more)

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Vulnerable estuary fish populations require stronger conservation management (August)

Gweek estuary, Cornwall. Image: Tony Armstrong | Flickr Creative Commons

Estuaries are transitional ecosystems where freshwater and marine waters meet, and their biodiversity overlaps. As a result of their supporting roles in trade, transport, fishing and tourism, estuaries are often also highly altered and pressurised ecosystems.

According to a new study, European estuaries are home to some of the most vulnerable and least resilient estuarine fish populations in the world. Writing in Nature Scientific Reports, Rita P. Vasconcelos and colleagues outline that European estuaries are particularly pressurised by human activities such as overfishing, habitat alteration and pollution. However, the authors of the newly published study argue that these highly-pressurised European estuaries are often lacking in sufficient protected area coverage to help conserve vulnerable fish species. (read more)

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The restoration of large woody debris rapidly increases degraded river biodiversity (September)

The River Wensum in Norfolk, England – one of the rivers used to observe the effects of large woody debris additions in this study. Image: Colinsd40 | Flickr Creative Commons

The reintroduction of large woody debris is a common tool for river restoration schemes which aim to encourage biodiversity and natural flood protection. However, environmental managers have, as yet, been hindered by a lack of scientific evidence on the ecological effects of adding trees and logs to river and stream ecosystems.

A new study by Murray Thompson from the Centre for Environment, Fisheries and Aquaculture Science and colleagues provides valuable new insights to this knowledge gap. Writing in the Journal of Applied Ecology, Thompson and colleagues report on how the presence or absence of large woody debris influences aquatic species and food webs along five rivers in England.

The research team found that populations of aquatic invertebrates and brown trout were higher in the restored and target stretches than in the control stretches. In other words, the presence of large woody debris caused rapid increases in invertebrate and brown trout abundance. (read more)

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Freshwater megafauna as conservation flagships? (October)

The arapaima, a fish native to the Amazon Basin, which can grow to over 3 metres in length. Image: Lynn Chan | Flickr Creative Commons

Freshwater megafauna such as sturgeon, river dolphins and turtles could act as valuable ‘flagships’ for freshwater conservation, according to a new open-access study published in the journal BioScience.

In the last decade or so, it has become apparent that freshwater biodiversity is both highly threatened, and is decreasing at a higher rate than its terrestrial or marine counterparts. In part, this awareness can be mapped to an influential – and highly cited – 2006 paper by David Dudgeon and colleagues.

Despite the multiple threats and pressures faced by freshwater ecosystems across the world, they tend to receive less conservation attention, research and investment than their terrestrial and marine equivalents. In their new paper, lead author Dr. Savrina F. Carrizo (IUCN) and Dr. Sonja Jähnig (Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB) together with other IGB researchers and a team of international co-authors, suggest that freshwater megafauna could provide a focus for conservation action by acting as flagships for overlooked aquatic ecosystems and biodiversity. (read more)

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Sketching another world: Stephen Thackeray’s aquatic art/science drawings (November)

Daphnia and microplastics. Image: Stephen Thackeray

At the start of last month, a succession of drawings of curious organic forms began appearing on our twitter feed. Penned by CEH and MARS freshwater scientist Stephen Thackeray as part of ‘Inktober‘, the images revealed a fascinating underwater world of often-microscopic aquatic life.

Keen to find out more about his interdisciplinary talents, we spoke to Stephen about his art/science practice. (read more)

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AQUACROSS interviews address gender equality in research (November)

Image: AQUACROSS

AQUACROSS seeks to advance the application of ecosystem-based management for aquatic ecosystems in an effort to support the EU 2020 Biodiversity Strategy and other international conservation targets.  The women featured in the AQUACROSS interview blog series will share their common passion for aquatic biodiversity and conservation, their motivations to advance scientific knowledge, and their stellar achievements on this path.

Ultimately, in outstanding research there are no genders. We as researchers share a passion for providing answers and transferring our science to others, with the pledge to leave behind a better world than the one we found. The featured interviews in this blog series will showcase the progress that these AQUACROSS researchers are carrying out towards this goal. (read more)

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Thanks for reading, and a very happy 2018 to you!