Top 19 posts of 2019

In these first days of 2020, we look back over 2019 to collect 19 of our most popular posts of the year.

It’s been another good year for the Freshwater Blog, with our biggest audience yet. 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.

Happy 2020!

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Community-based conservation of arapaima and giant turtles in the Amazon Basin (January)

Arapaima are one of the world’s most unique freshwater animals. A true ‘megafauna‘ species, these huge fish (which can grow to more than three metres in length) are native to the to the Amazon and Essequibo basins of South America.

Last year, Brazil’s prestigious national science prize for the best PhD thesis  was awarded to Joao Vitor Campos-Silva for his research entitled “Community-based management of Amazonian giants”. On a recent trip to Brazil, Paul Jepson – former manager of this blog with BioFresh, and now Nature Recovery Lead at Ecosulis – caught up with Joao to find out more (read more).

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Protecting and restoring Europe’s waters: the future of the Water Framework Directive (February)

A new survey of European water experts suggests that whilst the Water Framework Directive – the keystone of European Union water policy – provides a strong basis for the conservation and restoration of aquatic environments, there are three key areas for improving its future implementation. These include: monitoring and assessment, management measures, and policy integration.

Writing in the journal Science of the Total Environment, the researchers – led by Laurence Carvalho at the Centre for Ecology and Hydrology  – evaluate the strengths and weaknesses of current WFD implementation, identify where innovation offers new opportunities for monitoring and management, and address potential interactions between the WFD and other policy frameworks. In so doing, they ask, “Is the WFD fit-for purpose after 18 years and what improvements should be made in future implementation or revision?” (read more).

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Global insect declines: 33% of aquatic species threatened with extinction (February)

Global insect biodiversity is in dramatic decline according to a new review of existing scientific evidence. Aquatic insects are particularly threatened, with mayfly, dragonfly, stonefly and caddisfly species all showing significant declines over recent years.

Population declines of terrestrial and aquatic insects – in 41% of all species – are roughly twice those estimated for other vertebrates (mammals, birds and amphibians – 22% of species). The total global mass of insects is falling by an average of 2.5% each year, the study suggests, with potentially severe impacts on ecosystems and their services – such as pollination – globally (read more).

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Microplastics from the 1950s found in London lake sediments (March)

Microplastics dating back to the 1950s have been found in a sediment core taken from the lake bed of Hampstead Pond No.1 in London, UK. Plastic pollution is frequently featured in the news as a contemporary, oceanic environmental problem. However, a new open-access study by Dr. Simon Turner from University College London and colleagues provides evidence of long-term plastic accumulation in urban freshwater environments.

Hampstead Pond No.1 is one of thirty ponds on Hampstead Heath in North London, dug in the 17th and 18th centuries as reservoirs. Other ponds on the Heath are open to outdoor swimmers, anglers and model boating enthusiasts. However, despite their location in a cherished area of urban green space, the new study demonstrates that the ponds have been receiving plastic pollution for more than 60 years (read more).

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Acoustic monitoring of freshwater ecosystems: Costa Rica study reveals diverse underwater soundscapes (April)

Freshwater ecosystems across the world are disproportionately threatened by human activity, causing ongoing losses of aquatic biodiversity globally. Many freshwater conservationists highlight the need for more comprehensive ecological monitoring and assessment programmes to better understand ecosystem changes, and to strengthen conservation initiatives accordingly.

An innovative new study seeks to address this need using an unusual approach: acoustic monitoring of freshwater soundscapes. Researchers from Purdue University, USA and Nanjing University of Science and Technology, China recorded the aquatic soundscape of a Neotropical freshwater swamp in Costa Rica for 23 days in 2015. They used special underwater microphones – known as hydrophones – to delve into the acoustic world of the freshwater wetland. They wanted to better understand how soundscape recording might enhance existing freshwater ecosystem monitoring and assessment initiatives (read more).

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The IPBES Global Assessment: five things we learnt about freshwater ecosystems (May)

A landmark global report summarised earlier this week suggests that around 1 million animal and plant species are threatened with extinction. For many species, extinction could occur within decades. The global rate of species extinction is already at least tens to hundreds of times higher than the average rate over the past 10 million years and is accelerating, the report states. What does the IPBES Report tell us about the state of global freshwater environments? (read more).

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Europe’s aquatic ‘life support system’: good ecological condition correlates with ecosystem service provision (May)

European aquatic ecosystems can better provide vital services – such as water purification and flood protection – to humans when they are in good ecological condition, according to a new study. These findings highlight the need to protect and restore European waters, not only for the non-human lives they support, but also for the health and well-being of human communities.

Bruna Grizzetti and colleagues mapped European aquatic ecosystem services in relation to ecological conditions in rivers, lakes, groundwaters, coastal and transitional waters, floodplains, riparian areas and wetlands across the continent. They found that there was a strong correlation between the delivery of regulating and cultural ecosystem services and good ecological condition (read more).

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Europe’s largest dam removal project underway on the Sélune River in France (June)

Europe’s largest dam removal project so far took a significant step forward last week as the first breach was made in the 36-metre high Vezins Dam in Normandy, France. The dam, located on the Sélune River, was been scheduled for dismantling in 2017, along with another 15-metre high dam, La Roche-Qui-Boit.

The removal of the dams is designed to reconnect migration routes for fish such as the Atlantic Salmon and European Eel, and to improve water quality in the river and re-naturalise flows of sediment through the Sélune catchment. The story here is indicative of global trends: a recent study suggests that only around one-third of global rivers are free-flowing – with dam construction a key factor in fragmenting and regulating water flows (read more).

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Lakes in the long term (June)

A guest blog by Dr. Stephen Thackeray, a lake ecologist at the Centre for Ecology & Hydrology.

A cold wind bites and stiffens fingers that deftly prepare the probe for its descent. Moments later the instrument slips through the surface and glides from well-lit to ever-darker waters, where it will gather important data on the living conditions experienced by the hidden life of the lake. This is a world unseen. A world of constant change, where warmth, light, nourishment and danger vary hugely in time and space. It is also a place of super-abundant life.

This event is the latest episode in a multi-decade scientific endeavour that has tracked the changing fortunes of some of England’s most iconic lakes in Cumbria; a landscape now endowed with UNESCO World Heritage Status. Data from this ongoing year-round research, initiated by the Freshwater Biological Association in the 1940s and continued by the Centre for Ecology & Hydrology since 1989, tells a story of long-term change in the physical, chemical and biological conditions of the lakes. In Windermere, it is a story of decades of nutrient enrichment caused by sewage inputs and agricultural run-off and, increasingly, a story of climate change (read more).

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Illegal trafficking of the European eel: the ‘world’s greatest wildlife crime’ (July)

Recent evidence shows the increasing impact of illegal fishing and trafficking as a major factor in European eel declines. Whilst the export of European eels out of the European Union has been suspended since 2010, between 300 to 350 million eels – as much as 100 tonnes of fish – are illegally trafficked from Europe to Asia each year, according to EUROPOL. This figure accounts for around one-quarter of the total number of glass eels reaching the European coastline each year.

Where a glass eel might cost a euro to buy, a fully grown eel can be sold for ten times as much. This profit margin has led to an illegal trade in European eels estimated to be worth €3 billion each year. This trade has been called ‘the world’s greatest, yet least known, wildlife crime’ by the Sustainable Eel Group (read more).

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‘A beautiful underwater world awash with light’: Michel Roggo’s Freshwater Project (July)

Freshwater ecosystems are often key parts of our everyday landscapes: whether ponds, lakes, rivers, wetlands and canals that we might cross and pass by regularly. However, glimpsing the life that goes on below the surface of freshwaters can often be challenging, even to the most regular visitors.

Some creative artists have used film to shed a light on underwater lives, whilst others have used sound to ‘eavesdrop’ on their aural worlds. Since 2010, Swiss artist Michel Roggo has been using photography to explore and document global freshwater habitats through his Freshwater Project. Roggo’s work has taken him to more than 40 freshwater ecosystems across the world, each containing unique and unusual biodiversity and geology (read more).

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Toxic legacy of historical pollution hinders ecological recovery on urban rivers (August)

Toxic chemicals released in past decades could be impeding the ecological restoration and recovery of Britain’s urban rivers, according to a new study. ‘Legacy pollutants’ such as PCBs (Polychlorinated Biphenyls) and flame-retardant chemicals (PBDEs) from historical industrial discharge persist in river catchments, potentially disrupting aquatic food webs.

Fred Windsor, lead author of the new study, explained: “Despite major success in controlling sewage pollution in South Wales’ rivers over the last three decades, something appears to be holding back biological recovery.” Windsor, a doctoral student at Cardiff University, continued: “Our investigations show that persistent contaminants might be responsible as they still occur widely in invertebrates, particularly in urban river environments.” (read more).

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Check, clean, dry: how can canoers help control the spread of invasive species? (August)

A guest blog by Dr. Paul Jepson, Nature Recovery Lead at Ecosulis Ltd.

On a hot Saturday in June I rolled up at the UK’s National Water Sport Centre. The place was abuzz with cars, kayaks, club flags and paddle-carrying athletes chatting bucket starts, heats, duck tape and Nelos. Everyone was readying to race on a highly engineered stretch of freshwater. It looked and felt a world apart from my world of conservation science and policy. Yet walking along with my daughter to get her kayak weighed, I spied a Wildlife Trusts flag and two fellow conservationists raising awareness of biosecurity and invasive species.

Gemma Rose and Helen Carter-Emsell work for North Wales Wildlife Trust, and had made the 120 mile journey to Nottingham to promote good conservation practices among kayakers. Gemma explained that the River Dee, which rises in Snowdonia and flows into the sea near Chester on the Welsh / English border, is rich in native wildlife but also hugely popular with canoeists. The Trust has teamed up with British Canoeing and the GB Non-Native Species Secretariat to raise awareness among canoeists of invasive species and the damage they can do to aquatic systems (read more).

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Vivid and lively aquatic worlds: the art of Jacek Matysiak (September)

We recently came across the work of illustrator and designer Jacek Matysiak, and were so impressed that we knew we wanted to share it with you. Jacek is based in Dublin, Ireland, and his work provides a unique window onto the natural world. We caught with him recently to find out more (read more).

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Bending the curve of freshwater biodiversity decline (September)

What are the most significant and pressing freshwater biodiversity research questions that, if answered, would improve our ability to understand the state of freshwater biodiversity and improve its management and restoration, now and in the future?

This is the question asked by researchers affiliated with the Alliance for Freshwater Life as part of a new ‘horizon scanning’ research project seeking to identify the big questions in freshwater science, policy and conservation (read more).

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Global Swimways: conserving migratory fish populations (October)

A new ‘Global Swimways’ project has been launched this month, aiming to apply the insights of the ‘flyway’ concept to global migratory fish conservation. As part of this project, scientists will create the first global map of fish migration routes, identifying migration hotspots or ‘swimways’ and develop a new tool that highlights presence of migration routes near existing or planned infrastructure.

“Since the 1930s, people have developed and utilised the concept of flyways for the conservation of birds. They realised that in a world of changing habitats and building threats, you need global cooperation. It has led to successful agreements such as the Ramsar convention and international policies for conservation of ecological hotspots,” says Dr. William Darwall, project lead of the Global Swimways project, and Head of the Freshwater Biodiversity Unit of IUCNs Global Species Programme (read more).

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Europe must put environmental concerns at the heart of Common Agricultural Policy reform, scientists say (November)

Environmental scientists across Europe are campaigning for the European Parliament to take action in response to ‘catastrophic declines’ of birds, mammals, reptiles, amphibians, and insects as a result of intensive agricultural practices across the continent.

Earlier this week a letter signed by 2,500 scientists was sent to the European Parliament arguing that the intensive agricultural practices encouraged by EU’s Common Agricultural Policy (CAP) significantly threaten the continent’s biodiversity. There is now “unequivocal scientific consensus” that intensive farming is a key cause of the decline of bird and insect populations documented across the continent in recent decades, the authors state (read more).

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Catchment geology and human activity influence photosynthesis in aquatic plants (November)

Like all plants, aquatic plants rely on carbon to photosynthesise. However, unlike in the open air, carbon dioxide (CO₂) is not a reliable source of carbon underwater. CO₂ doesn’t diffuse efficiently through the water column, and is rapidly depleted as a result. So, how do aquatic plants get the carbon they need to live and grow? And how does this shape the distribution of where different plants are found?

A major new study shows that many aquatic plants have evolved the ability to use inorganic carbon, largely bicarbonate derived from the weathering of rocks and soils, in photosynthesis. Writing in Science, Lars L. Iversen and colleagues show that around half of the 131 global submerged plant species they studied showed this bicarbonate adaptation (read more).

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Water Framework Directive declared ‘fit for purpose’ (December)

European water policy continues to be ‘fit for purpose’ in protecting and restoring the continent’s rivers and lakes, according to a new review by the European Commission. Adopted in 2000, the Water Framework Directive (or WFD) is the European Union’s flagship water policy. It requires member states to guide their rivers, lakes, estuaries and groundwaters to ‘good ecological status’ through environmental policy and management, and prevent any future deterioration of status (read more).

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Thanks for reading, and a very happy 2020 to you! If you are in need of more freshwater stories, you can read our previous annual post round-ups for 2018, 2017 and 2016.