Freshwater ecology

  • Article
    | Open Access

    Defoliating insects disrupt nutrient cycling of boreal catchments by redistributing carbon and nitrogen from forests to lakes. The resulting shift in lake biogeochemistry exceeds broader between-year trends observed across the boreal and north temperate region.

    • Samuel G. Woodman
    • , Sacha Khoury
    •  & Andrew J. Tanentzap
  • Article
    | Open Access

    Harmful algal and bacterial blooms are increasingly frequent in lakes and rivers. From the Sydney Basin, Australia, this study uses fossil, sedimentary and geochemical data to reveal bloom events following forest ecosystem collapse during the end-Permian event and that blooms have consistently followed warming-related extinction events, inhibiting the recovery of freshwater ecosystems for millennia.

    • Chris Mays
    • , Stephen McLoughlin
    •  & Vivi Vajda
  • Article
    | Open Access

    It is unclear whether stream detritivore diversity enhances decomposition across climates. Here the authors manipulate litter diversity and examine detritivore assemblages in a globally distributed stream litterbag experiment, finding a positive diversity-decomposition relationship stronger in tropical streams, where detritivore diversity is lower.

    • Luz Boyero
    • , Naiara López-Rojo
    •  & Catherine M. Yule
  • Article
    | Open Access

    Understanding the past is necessary to comprehend Earth’s response to present climate change, but past climate reconstruction is hampered by a lack of temperature proxies. Here the authors develop the HDI26, a proxy using cyanobacterial glycolipids to reconstruct water temperatures of lakes worldwide.

    • Thorsten Bauersachs
    • , James M. Russell
    •  & Lorenz Schwark
  • Article
    | Open Access

    Anthropogenic changes, such as eutrophication from lake pollution, can lead to rapid evolution. Comparing Daphnia resurrected from generations adapted to historical pollution to contemporary, post-cleanup populations finds that Daphnia rapidly reversed their evolved resistance to harmful cyanobacteria.

    • Jana Isanta-Navarro
    • , Nelson G. Hairston Jr
    •  & Dominik Martin-Creuzburg
  • Article
    | Open Access

    Climate change is a threat to global biodiversity, but the potential effects on freshwater fishes have not been well studied. Here the authors model future flow and water temperature extremes and predict that increases in water temperature in particular will pose serious threats to freshwater fishes

    • Valerio Barbarossa
    • , Joyce Bosmans
    •  & Aafke M. Schipper
  • Article
    | Open Access

    Leaf economics spectrum theory has greatly advanced understanding of plant functional ecology, but it is unclear whether its predictions hold in wetland communities. Here, Pan and colleagues analyse leaf economics traits in wetland plants, showing that their trait relationships deviate from fully terrestrial plants, particularly by clustering towards acquisitive plant strategies.

    • Yingji Pan
    • , Ellen Cieraad
    •  & Peter M. van Bodegom
  • Article
    | Open Access

    Sedimentary DNA can be used to infer how organisms responded to changing environmental conditions over millennia. Here, the authors use sedimentary DNA of micro-eukaryotes in low-elevation (human-impacted) and high-elevation (more pristine) lakes to show how human influences have altered lake community composition in the Anthropocene.

    • François Keck
    • , Laurent Millet
    •  & Isabelle Domaizon
  • Article
    | Open Access

    Biomonitoring via environmental DNA (eDNA) is an important conservation tool for freshwater ecosystems, but this is complicated by eDNA movement downstream. Here, Carraro et al. develop and test an approach to reconstruct high-resolution spatial biodiversity patterns from freshwater eDNA.

    • Luca Carraro
    • , Elvira Mächler
    •  & Florian Altermatt
  • Article
    | Open Access

    The authors of this study compile data on spatial and temporal dynamics of surface water bodies across China, covering a time span from 1989 – 2016. The study describes hot-spot areas with strongly decreasing trends in surface water area and terrestrial water storage in North China and discusses implications of water resources and security in China.

    • Xinxin Wang
    • , Xiangming Xiao
    •  & Bo Li
  • Article
    | Open Access

    Lake fisheries are vulnerable to environmental changes. Here, Kao et al. develop a Bayesian networks model to analyze time-series data from 31 major fisheries lake across five continents, showing that fish catches can respond either positively or negatively to climate and land-use changes.

    • Yu-Chun Kao
    • , Mark W. Rogers
    •  & Joelle D. Young
  • Article
    | Open Access

    Biogeographic patterns of genetic diversity are poorly documented, especially for fish species. Here the authors show that (mitochondrial) genetic diversity has global spatial organization patterns with different environmental drivers for marine and freshwater fishes, where genetic diversity is only partly congruent with species richness.

    • Stéphanie Manel
    • , Pierre-Edouard Guerin
    •  & Loïc Pellissier
  • Article
    | Open Access

    An important question in ecology is how much species at higher trophic levels affect lower levels through top-down cascades. Here the authors show through analyses of pelagic size spectra that such cascades are strong in freshwater systems and can also arise in nutrient rich marine systems.

    • Axel G. Rossberg
    • , Ursula Gaedke
    •  & Pavel Kratina
  • Article
    | Open Access

    Pharmaceuticals are widespread contaminants in surface waters. Here, Richmond and colleagues show that dozens of pharmaceuticals accumulate in  food chains of streams, including in predators in adjacent terrestrial ecosystems.

    • Erinn K. Richmond
    • , Emma J. Rosi
    •  & Michael R. Grace
  • Article
    | Open Access

    Macrobioerosion, the boring of rock and other hard substrates by living organisms, is used as a marker of marine paleo-environments. Here, Bolotov et al. describe a rock-boring mussel and its associated community from freshwater in Myanmar, demonstrating that macrobioerosion is a wider phenomenon.

    • Ivan N. Bolotov
    • , Olga V. Aksenova
    •  & Oleg S. Pokrovsky
  • Article
    | Open Access

    Species richness patterns are driven by biotic and abiotic factors, the relative strengths of which are unclear. Here, the authors test how species interactions or environmental traits influence fish richness across over 700 Canadian lakes, showing a surprisingly small role of negative interactions.

    • Andrew S. MacDougall
    • , Eric Harvey
    •  & Kevin S. McCann
  • Article
    | Open Access

    The morphology and abundance of streams control the rates of hydraulic and biogeochemical exchange between streams, groundwater and the atmosphere. Here, the authors show that stream hydromorphology is predictable within headwater catchments with implications for stream-atmosphere gas exchange estimates.

    • George H. Allen
    • , Tamlin M. Pavelsky
    •  & Colin J. Gleason
  • Article
    | Open Access

    Human and environmental water needs can come into conflict in dam-regulated river systems. Here, Chen and Olden investigate the potential for the use of fish–flow modeling to make recommendations for the management of native and nonnative fish species whilst providing water for society.

    • William Chen
    •  & Julian D. Olden
  • Article
    | Open Access

    The impacts of climate change on natural methane (CH4) emissions via ebullition are unclear. Here, using published and experimental multi-seasonal CH4 ebullition data, the authors find a strong relationship between CH4 ebullition and temperature across a wide range of freshwater ecosystems globally.

    • Ralf C. H. Aben
    • , Nathan Barros
    •  & Sarian Kosten
  • Article
    | Open Access

    Virophages are recently-identified small viruses that infect larger viruses, yet their diversity and ecological roles are poorly understood. Here, Roux and colleagues present time series metagenomics data revealing new virophage genera and their putative ecological interactions in two freshwater lakes.

    • Simon Roux
    • , Leong-Keat Chan
    •  & Matthew B. Sullivan
  • Article
    | Open Access

    The role of dissolved organic carbon (DOC) photo-alteration in the microbial respiration of DOC to CO2 is unclear. Here, the authors show that the impact of this mechanism depends on whether photo-alteration of DOC produces or removes molecules used by native microbial communities prior to light exposure.

    • Collin P. Ward
    • , Sarah G. Nalven
    •  & Rose M. Cory
  • Article
    | Open Access

    Global warming and hydropower regulations are major threats to future fresh-water availability and biodiversity. Here, the authors show that their impact on flow regime over a large landmass result in similar changes, but hydropower is more critical locally and may have potential for climate adaptation in floodplains.

    • B. Arheimer
    • , C. Donnelly
    •  & G. Lindström
  • Article
    | Open Access

    Rivers provide a major pathway for ocean plastic waste, but effective mitigation is dependent on a quantification of active sources. Here, the authors present a global model of riverine plastic inputs, and estimate annual plastic waste of almost 2.5 million tonnes, with 86% sourced from Asia.

    • Laurent C. M. Lebreton
    • , Joost van der Zwet
    •  & Julia Reisser
  • Article
    | Open Access

    Alluvial aquifers of river floodplains support abundant large-bodied consumers despite an absence of light and scarcity of organic carbon. DelVecchia et al. reveal that much of the biomass carbon in these freshwater consumers is ancient and derived from methane.

    • Amanda G. DelVecchia
    • , Jack A. Stanford
    •  & Xiaomei Xu
  • Article
    | Open Access

    Hypoxia has diverse effects on aquatic life. Wang et al.show that reproductive defects resulting from hypoxia are epigenetically heritable in Japanese rice fish, and that this intergenerational inheritance is accompanied by differential methylation and gene expression in sperm.

    • Simon Yuan Wang
    • , Karen Lau
    •  & Rudolf Shiu-Sun Wu
  • Article
    | Open Access

    Glacier retreat due to climate change can affect the biodiversity and ecosystem function. Here, Cauvy-Fraunié and colleagues manipulated the flow of tropical glacier-fed stream in the Ecuadorian Andes, and show that benthic fauna community composition requires several months before it can recover to the pre-blockade conditions.

    • Sophie Cauvy-Fraunié
    • , Patricio Andino
    •  & Olivier Dangles
  • Article
    | Open Access

    The rate at which carbon burial has changed in lakes in response to human-induced global change is poorly understood. Here, the authors show that carbon burial has increased significantly in remote northern lakes along with increased nitrogen deposition and warming over the last century.

    • Adam J. Heathcote
    • , N. John Anderson
    •  & Paul A. del Giorgio
  • Article
    | Open Access

    How aquatic communities influence biogeochemical cycling is not well understood. Here, Devlin et al.manipulate the abundance of fish in a whole-lake experiment and show that methane efflux is reduced by the presence of top predators, via a trophic cascade from zooplankton to methanotrophic bacteria.

    • Shawn P. Devlin
    • , Jatta Saarenheimo
    •  & Roger I. Jones
  • Article
    | Open Access

    How mechanisms underlying food-web stability may influence ecosystem regime shifts is not well understood. Combining food-web and ecosystem modelling, Kuiperet al. show that destabilizing reorganization of a small number of key trophic interactions precede catastrophic changes in shallow lake ecosystems.

    • Jan J. Kuiper
    • , Cassandra van Altena
    •  & Wolf M. Mooij
  • Article |

    Species responses to climatic change are likely to be complex, acting across multiple trophic levels and life stages. Here the authors show that Arctic charr are negatively impacted by trophic mismatches affecting both juveniles and fry, which may be responsible for recent poor catches of this fish.

    • Tomas Jonsson
    •  & Malin Setzer
  • Article
    | Open Access

    Vegetation close to streams and lakes provides organic matter to aquatic ecosystems. Here, the authors show that the dense forest cover around lakes feeds the near-shore lake food web through organic matter subsidies, leading to faster growth in planktivorous fish.

    • Andrew J. Tanentzap
    • , Erik J. Szkokan-Emilson
    •  & John M. Gunn
  • Article |

    The analysis of food web properties under different environmental conditions informs us how the ecosystem functions. Here, Tunneyet al. use post-glacial lakes as model ecosystems to show how macroscopic patterns of food webs vary with changes in habitat and resource accessibility.

    • Tyler D. Tunney
    • , Kevin S. McCann
    •  & Brian J. Shuter
  • Article |

    The habitat where early humans, hominins, lived provides information about the early part of human evolution. In this study, sedimentological and stable carbon and oxygen isotope data suggest homininArdipithecus ramiduslived in a river-margin forest in a wooded grassland landscape at Aramis, Ethiopia.

    • M. Royhan Gani
    •  & Nahid D. Gani
  • Article
    | Open Access

    Little is known about the reproductive ecology of freshwater eels. In this article, the authors describe the capture of two species of eels together with eggs and newly hatched larvae, and suggest that spawning takes place during the new moon at shallower depths than previously thought.

    • Katsumi Tsukamoto
    • , Seinen Chow
    •  & Hideki Tanaka