ArticlePDF Available

Abstract and Figures

Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable resources that provide humanity with many ecosystem services. They are also sentinels of global and local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence of their collective degradation in terms of depletion of resources (water and food), rapid warming and loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity provides a framework to assess the dangers now threatening the world’s large lake ecosystems and to evaluate pathways of sustainable development that are more respectful of their ongoing provision of services. Here we review current and emerging threats to the large lakes of the world, including iconic examples of lake management failures and successes, from which we identify priorities and approaches for future conservation efforts. The review underscores the extent of lake resource degradation, which is a result of cumulative perturbation through time by long-term human impacts combined with other emerging stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and management and a legacy of ecological and economic costs for future generations. Large lakes will require more intense conservation efforts in a warmer, increasingly populated world to achieve sustainable, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a long-term lake observatory network to monitor and report on environmental changes in large lake ecosystems.
Content may be subject to copyright.
Scientists’ Warning to Humanity: Rapid degradation
of the world’s large lakes
Jean-Philippe Jenny
, Orlane Anneville
, Fabien Arnaud
, Yoann Baulaz
, Damien Bouffard
Isabelle Domaizon
, Serghei A. Bocaniov
, Nathalie Chèvre
, Maria Dittrich
, Jean-Marcel Dorioz
Erin S. Dunlop
, Gaël Dur
, Jean Guillard
, Thibault Guinaldo
, Stéphan Jacquet
, Aurélien Jamoneau
Zobia Jawed
, Erik Jeppesen
, Gail Krantzberg
, John Lenters
, Barbara Leoni
, Michel Meybeck
Veronica Nava
, Tiina Nõges
, Peeter Nõges
, Martina Patelli
, Victoria Pebbles
, Marie-Elodie Perga
Serena Rasconi
, Carl R. Ruetz III
, Lars Rudstam
, Nico Salmaso
, Sharma Sapna
, Dietmar Straile
Olga Tammeorg
, Michael R. Twiss
, Donald G. Uzarski
, Anne-Mari Ventelä
, Warwick F. Vincent
Steven W. Wilhelm
, Sten-Åke Wängberg
, Gesa A. Weyhenmeyer
Université Savoie Mont Blanc, INRAE, CARRTEL, 74200 Thonon-les-Bains, France
Université Savoie Mont Blanc, CNRS, EDYTEM, 73100 Chambéry, France
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Surface Waters – Research and Management, Kastanienbaum 6047, Switzerland
Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L3G1, Canada
IDYST, Faculty of Geosciences and Environment, University of Lausanne, 1015 Lausanne, Switzerland
University of Toronto Scarborough, Physical and Environmental Sciences, Toronto, ON, Canada
Aquatic Research and Monitoring Section, Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario K0L2G0, Canada
Creative Science Course (Geosciences), Faculty of Science, Shizuoka University, Japan
CNRM, Université de Toulouse, Météo-France, CNRS, 42, avenue Gaspard Coriolis, Toulouse, France
INRAE, UR EABX, 50 avenue de Verdun, Cestas, France
McMaster University, W. Booth School of Engineering Practice and Technology, Hamilton, ON, Canada
Department of Bioscience and Arctic Research Centre, Aarhus University, Silkeborg, Denmark
Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey
Great Lakes Research Center, Michigan Technological University, 1400 Townsend Drive, Houghton, MI USA
Center for Limnology, University of Wisconsin-Madison, 3110 Trout Lake Station Drive, Boulder Junction, WI USA
University of Milano-Bicocca, Department of Earth and Environmental Sciences, Piazza della Scienza 1, Milan, Italy
METIS (UPMC/CNRS/EPHE), UMR 7619, Sorbonne-universitée, 4, place de Jussieu, Paris Cedex, France
Centre for Limnology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 510006 Tartu, Estonia
Great Lakes Commission, 1300 Victors Way, Suite 1350, Ann Arbor, MI 48108, USA
Grand Valley State University, Annis Water Resources Institute, 740 W. Shoreline Drive, Muskegon, MI, USA
Cornell Biological Field Station, Department of Natural Resources, Cornell University, Ithaca, NY, 14850, USA
Department of Sustainable Agro-ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all’Adige, Italy
Department of Biology, York University, Toronto, Ontario, Canada
Limnological Institute, University of Konstanz, Mainaustr. 252, 78464 Konstanz, Germany
Ecosystems and Environmental Research Programme, University of Helsinki, Viikinkaari 1, 00014 Helsinki, Finland
Department of Biology, Clarkson University, Potsdam, NY 13699, USA
Central Michigan University, Institute for GreatLakes Research and CMU Biological Station, Mt. Pleasant, USA
Department of Aquatic Environment, Pyhäjärvi Institute, Eura, Finland
Département de Biologie, Takuvik & Centre for Northern Studies (CEN), Université Laval, Québec, QC, Canada
Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
University of Gothenburg, Marine Sciences, Carl Skottsbergs gata 22, Gothenburg, Sweden
Department of Ecology and Genetics/Limnology, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
article info
Article history:
Received 27 May 2019
Accepted 12 May 2020
Available online xxxx
Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable
resources that provide humanity with many ecosystem services. They are also sentinels of global and
local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence
of their collective degradation in terms of depletion of resources (water and food), rapid warming and
0380-1330/Ó2020 Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.
Corresponding author.
E-mail address: (J.-P. Jenny).
Journal of Great Lakes Research xxx (xxxx) xxx
Contents lists available at ScienceDirect
Journal of Great Lakes Research
journal homepage:
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
Communicated by Brigitte Vinçon-Leite
Second Warning to Humanity
Large lakes
Global change
Biodiversity loss
Ecosystem services
loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes
are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity pro-
vides a framework to assess the dangers now threatening the world’s large lake ecosystems and to eval-
uate pathways of sustainable development that are more respectful of their ongoing provision of services.
Here we review current and emerging threats to the large lakes of the world, including iconic examples of
lake management failures and successes, from which we identify priorities and approaches for future
conservation efforts. The review underscores the extent of lake resource degradation, which is a result
of cumulative perturbation through time by long-term human impacts combined with other emerging
stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and
management and a legacy of ecological and economic costs for future generations. Large lakes will
require more intense conservation efforts in a warmer, increasingly populated world to achieve sustain-
able, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a
long-term lake observatory network to monitor and report on environmental changes in large lake
Ó2020 Published by Elsevier B.V. on behalf of International Association for Great Lakes Research.
Fresh waters are the most valuable natural resource on Earth.
Lakes provide ecosystem services across four main categories, not
only to the human populations directly surrounding them, but also
at broader regional and global scales: provisioning, regulating, sup-
porting, and cultural services (Table 1). Large lakes are especially
valuable resources in all four categories. They provide drinking
water to millions of people, a crucial matter considering that the
drinking water insecurity faced by many populations may be exac-
erbated by increases in drought due to climate change. Food har-
vested from large lakes is also of cultural and economic
importance, and includes fish, invertebrates such as crayfish, and
aquatic plants. Fish harvested commercially from large lakes not
only provide regional benefits to markets but are also exported
around the world. Approximately 1.35 million tons of fish are har-
vested each year from the 25 largest lakes in the world by commer-
cial or artisanal fisheries, with approximately 95% of this harvest
coming from the African large lakes (Sterner et al., 2020). In devel-
oping countries and indigenous communities especially, the food
provided by large lakes can represent key components of the diet.
Aquaculture, a growing industry within the waters of several large
lakes (e.g., Jia et al., 2015), also provides a source of protein to a
growing human population, along with employment opportunities
and economic benefits. Large lakes can offer supplemental
resources to human populations, or in some regions the necessary
resources to sustain populations (Carpenter et al., 2007). Large
lakes also provide important shipping corridors for trade, as is
the case with the Laurentian Great Lakes. Regulating services —
benefits obtained by regulating ecosystem processes — provided
by large lakes include safe harbors (protection from storms), ero-
sion and sedimentation regulation, water storage, hydroelectric
power generation potential, water quality regulation, and waste
assimilation. In terms of non-material benefits or cultural services,
large lakes offer remarkable aesthetic experiences (viewscapes),
recreational (boating, fishing, beach use) and tourist opportunities,
and places of spiritual respite that humans value immeasurably. As
with other ecosystems, the variability in ecosystem services pro-
vided by large lakes depends on their underlying ecology and the
current state of their environment that is closely connected to
the surrounding watershed (Soranno et al., 2010).
Environmental degradation often results in a loss of ecosystem
services that support human societies (Chanda, 1996). Degradation
of lake ecosystems is evident worldwide, threatening the function-
ing of these ecosystems and the necessary services they provide at
a global scale (Fig. 1,Keeler et al., 2012). Future threats to large
lakes include the overexploitation of resources (water and food),
inputs of excess nutrients and harmful algal blooms, changing cli-
mate, overfishing, species invasions, infectious diseases, expanding
hydropower, acidification, contaminants, emerging organic pollu-
tants, engineered nanomaterials, microplastic pollution, artificial
light and noise, freshwater salinization, and the cumulative effects
of multiple stressors. Lake sediment archives keep track of the
extent to which lakes have departed from their so-called pre-
Anthropocene status (Keeler et al., 2012), following a dynamics
of change synchronized to the ‘‘Great Acceleration” phase of
human pressures on the Earth since around 1950 (Steffen et al.,
Past alteration of large lakes is also reducing their capability to
resist new threats, and degradation of water quality will continue
because of the cumulative impact of ongoing local pressures, syn-
ergies between stressors, and the imposition of global stressors
(climate, volatile compounds, and invasive species). Even in
regions that successfully combatted environmental degradation
such as eutrophication, new threats are emerging, with conse-
quences for large lakes and their ecosystem services that are diffi-
cult to fully predict. These impacts are altering large lake
ecosystems and services in unprecedented ways, causing wide-
spread concern among freshwater scientists.
We believe there is an urgent need to alert world nations about
the current state and trajectory of the world’s large lakes. In less
than a century, the effects of rapid population growth and lack of
adequate attention to environmental protection have resulted in
striking perturbations to freshwater ecosystems across the planet,
including the world’s large lakes. More broadly, the initiative fol-
lows the joint European Large Lakes Symposium (ELLS)-
Table 1
List of services provided by large lakes, and specific examples of services. Most of
these services are provided by lakes of all sizes and are not restricted to large lakes.
However, large lakes represent 90% of the total global lake surface area and hence
contribute the major portion of these services. Modified from de Groot et al., (2012).
1 Provisioning
Food, drinking water, industrial water and
hydroelectricity, water for navigation, genetic resources,
medicinal resources
2 Regulating
Water flow regulation, local climate regulation, water
quality regulation, regulation of natural risks, transfers
or sequestration of elements ...
3 Supporting
Habitats for nursery and reproduction (plant and
animal), maintenance of aquatic fauna and flora from
micro-organisms to macro-organisms, support of
migratory species and wildlife, hot spots of biodiversity
4 Cultural
Aesthetics, recreation, inspiration for culture and art,
spiritual experience, cognitive and scientific
2J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
International Association for Great Lakes Research (IAGLR) 2018
conference ‘‘Big Lakes - Small World”, held in Evian (France) in
September 2018, which brought together scientists working on
large lakes around the world. Here, the participating authors make
use of their broad expertise and knowledge of these global
resources and present an updated assessment of the threats, both
long-term and emerging, that confront large lakes of the world
today. We begin by summarizing the ecosystem services of large
lakes and the long-term and new threats that they are experienc-
ing. We then examine some of the successes, but also failures, in
the management of large lakes. We end this article with a set of
recommendations on conservation policies and approaches to pro-
tect and sustain the world’s large lakes.
General characteristics of large lakes
Choice of a quantified definition for ‘‘large lakes
The International Association for Great Lakes Research (IAGLR; uses a definition of large lakes based on
the analysis by Herdendorf (1982), defining Great Lakes to be
inland waters greater than 500 km
in area, which encompasses
the Laurentian Great Lakes and many other large lakes of the
world. Herdendorf did leave open the need for additional input
to refine this definition. For the present paper, our aim was to iden-
tify a subset of larger waterbodies as a sentinel network to track
and assess global change in the past and present. Specifically, we
analyzed the global distribution of lakes to identify a size class that
would cover gradients of hydrological (Electronic Supplementary
Material (ESM) Appendix S1, Fig. S1, S2), geochemical, and climatic
conditions (ESM Fig. S3). Based on these criteria, the size class
of 100 km
was selected, and is adopted here as a definition of
‘‘large lakes”. The lakes of this size class encompass a wide range
of human and environmental conditions, including a diverse range
of biomes, geological origins and salinities, and they are well
spread out across the world (Fig. 2 and ESM Fig. S3). As a result
of their large size, they share some limnological properties, to vary-
ing extents (see next section), and collectively they have enormous
economic (ESM Table S1) as well as ecological value. Here we
believe that our summary of the issues for large lakes would still
apply even if a different size-based definition were used.
Global large-lake characteristics
In total, 1,709 inland waters meet our 100 km
criterion for
large lakes, and their global distribution is shown in Fig. 2.Ifwe
consider lakes of all ages and origins, including tectonic, volcanic,
alluvial, glacial, moraine, karstic, and human-made waterbodies
such as dams and reservoirs, then large lakes represent only 0.2%
of the total number of lakes in the world greater than 0.1 km
However, they account for nearly 90% of the total surface area
(1,773,306 km
) and volume (178,772 km
) of the world’s lakes.
These large lakes vary greatly in many of their limnological attri-
butes, but as an overall class of waterbodies, they differ from smal-
ler lakes in terms of the following characteristics, in descending
order (ESM Fig. S4): 1) larger water volumes; 2) larger watersheds;
3) greater shoreline length; 4) greater water inflows; 5) greater
depth; 6) greater shore development; and 7) greater influence of
wind due to a much larger fetch and wave action (ESM Fig. S4,
Table S2). These properties have direct and indirect consequences
on the exposure to stressors, the intensity of the impacts, the effec-
tiveness of environmental management actions, and the duration
of recovery. For instance, the most rapid climate-induced warming
for many large, deep, dimictic lakes can be found at the surface of
the deepest, offshore waters (e.g., Lakes Superior, Michigan, Huron
(Woolway and Merchant, 2018). This is due to the high sensitivity
of the date of stratification to climate warming (Austin and
Colman, 2007; Zhong et al., 2016) which is a result of the lakes’ sig-
nificant depth. Shallower lakes such as Lake Erie do not show such
high sensitivity (Zhong et al., 2016).
A coastal catchment zone extending 10 km inland was selected
(Allan et al., 2017) to estimate the spatial extent of services pro-
vided around large lakes, and we calculated that this size class of
lake ecosystems could directly provide services to 131 million peo-
ple in their coastal zones (Fig. 3, ESM Fig.S1). Additional support for
this 10-km boundary is found in the analysis that shows that 10%
of the world’s population lives further than 10 km from a surface
freshwater body (Kummu et al., 2011). This estimate is likely to
be conservative given that many large lakes provide services to
populations that reside at distances well beyond 10 km from the
lake. For example, Lake Biwa provides drinking water via aque-
ducts for 15 million people in the Kansai region of Japan, the Lau-
rentian Great Lakes provide drinking water to 48 million people,
and Lake Chad provides water to over 30 million people at the edge
Fig. 1. Trends over time for some environmental issues identified in the 1992 Scientists’ Warning to Humanity and extent of dead zones in lakes (left axis) and large lakes
(right axis) of the world (Jenny et al., 2016a, 2016b). The number of dead zones were inventoried in lake sediment archives (a). In panel (b), global air temperature change, and
in panel (c) (in Ripple et al., 2017).
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 3
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
of the Sahara. Large lakes are present in 105 of the world’s 195
countries (Fig. 3), and at least 10 such lakes occur in each of the
hydrologic zones defined by Meybeck et al. (2013), indicating that
this global network of waters spans a wide gradient of conditions
(Fig. S2).
In spite of monitoring issues related to their size, many large
lakes are well-monitored ecosystems. Resulting datasets of envi-
ronmental parameters are shared among networks such as the
Great Lakes Observing System (GLOS) and the Global Lake Ecolog-
ical Observatory Network (GLEON), the latter of which references
almost half of their sites as large lakes. This 100 km
size class
of lakes provides an exceptional network of sentinels of environ-
mental change, and the ensemble of these long-term datasets pro-
vides a valuable resource to better understand their functioning
and vulnerability to global and local threats.
Long-term ecosystem services of large lakes: Their role for humanity
On geological timescales, the rise of human civilization during
the Neolithic around 12,000 years ago is concomitant to the
proliferation of lakes, a ‘‘Lake Age” following a glacial period
when most lakes in the Northern Hemisphere were covered by
ice or did not yet exist. The contribution of lakes to human
resources and to the regulation of biogeochemical cycles is there-
fore particularly important at the human scale. Over the last few
centuries, societal awareness and the value of provisioning, regu-
lating, or cultural ecosystem services (Table 1) provided by large
lakes have shifted, often in response to a growing human popula-
tion and previous ecosystem degradation. Large lakes provide
critically important benefits to all humanity (Table 2), and they
need increasing care and attention to meet the growing demands
Fig. 2. Stressors in large lake ecosystems of the world are represented by examples of point and diffuse nutrient pollution, and climate forcing. Note the different intensity
and the accumulation of climate and warming forcing for different regional contexts. Contrasted situations are presented (for Eastern China, Europe and North America, and
for Southern Hemisphere). World distribution of large lakes larger than 100 km
(blue dots), lakes larger than 500 km
(blue open circles) and human population density
(background map, Center for International Earth Science Information Network-CIESIN-Columbia University, 2015). (For interpretation of the references to colour in this figure
legend, the reader is referred to the web version of this article.)
Fig. 3. Effect of different size classes on the spatial distribution and abundance of large lakes in the world. a. Number of lakes by lake size class, b. number of countries and
GLEON’s lakes by size class (Sharma et al., 2015), and c. sum of shore length and number of human population by size class of lakes. Note the exponential increase in the
number of countries and humans affected by lake services as we include lakes of smaller size.
4J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
for their ecosystem services at a time of increasing threats of
ecosystem degradation.
From water samples and sediment records, lakes can provide a
detailed record of land, hydrologic, or atmospheric degradation
(e.g., Davis, 2015; Jenny et al., 2019; Williamson et al., 2009),
thereby yielding insights into human interactions with the envi-
ronment at multiple spatial and temporal scales. Given their inte-
grative behavior, including as the lowest points in the landscape,
the world’s lakes may be thought of as a vast, spatially distributed
network of sentinels of environmental change (Williamson et al.,
2009), a concept we build upon here by proposing a sentinel net-
work of large lakes. Certain lakes are especially sensitive indicators
of environmental change, for example polar and alpine lakes that
are strongly influenced by climate warming effects on the cryo-
sphere, and that lie at remote locations where the arrival of long
range contaminants can be detected (Bourgeois et al., 2018;
Vincent, 2018). Lakes are also sentinels of local human pressure,
pollution, and ecological impacts, particularly large lakes, which
integrate the impacts of human activities on land use, mass fluxes,
pollutant transfers, and management interventions, all extending
over large areas. Large lakes therefore provide evidence of socio-
ecological resilience and are an integrative measure of humanity’s
willingness to protect and sustain their environment.
About half of the world’s largest lakes are ancient waterbodies
that existed before the last glaciation, and sometimes for millions
of years (Hampton et al., 2018). These lakes not only record long
histories of environmental variation and human activity in their
sediments, but also contain very high levels of biodiversity and
endemism (Hampton et al., 2018; Vincent, 2018). These ancient
ecosystems and other large lakes are natural laboratories for wider
understanding, including as model systems to study evolutionary
Surveillance, warning and programs
There is a long history of limnological research on the degrada-
tion of large lakes and the causal mechanisms of change. This work
has given rise to public alerts and has stimulated restoration activ-
ities and monitoring programs to track the effects of restoration
and to detect new and ongoing threats. A wide variety of policy
frameworks exist to manage large lakes across the globe, with dif-
ferent levels of maturity and effectiveness. These frameworks are
essential to ensure that scientific results are communicated to pol-
icymakers and drive management actions that can protect and
restore these valuable freshwater ecosystems. Many large lakes
are transboundary, necessitating international policy frameworks.
Several examples are described in Table 3.
Major disturbances and threats
Due to intense human activities and lake uses, large lakes are
exposed to a wide variety of stressors. These stressors can be
chemical (heavy metals, nutrients, organic contaminants), physical
(temperature, radiation, water budget, habitat alteration), biologi-
cal (invasive species), or from direct human extraction of resources
(harvesting, mining). Stressors are agents that cause disturbance,
defined as pronounced changes in the function or structure of an
ecosystem, leading to decreased inherent qualities such as losses
in biodiversity or a reduced capacity to sustain ecosystem services.
Stressors can directly impact individual performances and life
history traits with cascading consequences at species, population,
and community levels. Specifically, stressors can change physical
and chemical conditions in a lake to promote or decrease photo-
synthesis and associated plant and animal growth, modify the pro-
duction of hormones, operate as lethal components by increasing
mortality, or change the behavior and seasonal timing of plant
and animal development. In addition to the direct effects, stressors
can operate indirectly through prey, predation, competition and
non-trophic interactions. Those indirect effects may propagate
through the network of species interactions and have profound
impacts on lake functioning, water quality, and ecosystem services
(Fig. 4). The most widespread stressors with strong impacts on
human society and a description of the main impacts are summa-
rized below.
Increased nutrient loading as a result of human activities has
been found to trigger ‘‘cultural eutrophication.” Cultural eutrophi-
cation is historically associated with an oversupply of phosphorus
(P) (Carpenter, 2008; Carpenter et al., 2018; Schindler, 2012, 1977).
Most common symptoms of cultural eutrophication also include
changes in species composition, decrease in water transparency,
increased incidence of anoxia, and biodiversity loss (Carpenter,
2005). Potential outcomes include the development of cyanobacte-
rial harmful algal blooms (CHAB) and an increased release of
greenhouse gases such as methane (Wurtsbaugh et al., 2019). Con-
sequently, eutrophication impairs ecosystem services such as fish-
ing, water supply, and recreation. The introduction by the public
authorities of regulations to limit eutrophication still is a source
of tension and debate on the activities identified as contributing
or having contributed decisively to these phenomena (Le Moal
et al., 2019).
Internal P loading (i.e., recycling of sedimentary P back to the
water column) is often the major reason for a delayed response
in improved lake water quality following reduced external nutrient
loading (Jeppesen et al., 2005; Schindler, 2012). The mobilization of
sedimentary P is usually associated with oxygen depletion that
Table 2
List of services provided by large lakes, related lake properties in each service class, and specific examples of services.
Services related
to Observation
and warning
Related characteristics Examples
1 Earth System
Lake area, volume, depth lakeshore length; Lake:watershed; position
within fluvial systems, and Earth system, sensitivity to climate
Climate and atmospheric regulation (local and regional), mitigation
(buffer) of water volumes and quality and hydric-pollution transfer to
the sea: storage of particulate matter, biogeochemical reactors
(erosion, carbon circulation, water-storage), Mostly equivalent to
‘regulating services’
2 Natural
Depth, age, origin, morphology, basin/ lake ratio; water renewal time,
salinity, chemistry, microbiology, endemism, species colonization
Lake system functioning, basic processes (water chemistry interface,
chemotrophic microbiota, speciation, paleo-limnology, ecological
responses to natural or anthropogenic perturbations etc).
3 Sentinels of
global and local
Length of hydrological, thermal, chemical and ecological records;
position within biomes; paleo-limnological records
Surveillance of climate and human impacts on biota, habitat, physics
and geochemical cycles.
4 Natural archives
of human history
Riparian population, drinking water supply, other irreplaceable
economic resources; documented historical records; evidence of past
/present spiritual value, land cover and uses
Anthropocene, witness of human history, Interaction of human with
nature, changes in how human value lakes, but also land ecosystems
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 5
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
triggers reduction of ferric iron to ferrous iron and the subsequent
release of associated P. However, P release has also been observed
under oxic conditions, and the mechanism behind P release may be
much more complex (Hupfer and Lewandowski, 2008; Tammeorg
et al., 2017).
The morphology of large lakes strongly affects their biogeo-
chemical cycles and the mechanisms that control these cycles.
Large and shallow lakes, such as Lake Peipsi (Estonia/Russia), Lake
Okeechobee (USA), and Lake Taihu (China) are particularly influ-
enced by sediment resuspension due to the high dynamic ratio
(square root of lake area to mean depth, Håkanson, 1982). In Lake
Erie, by contrast, external loading of nutrients has become a more
significant threat, particularly due to increased delivery of soluble
reactive phosphorus delivery from nonpoint sources via tributaries
(i.e., labile P fractions at the soil surface and transmission of sol-
uble P via subsurface drainage) (Jarvie et al., 2017).
Climate change has been identified as one of the most impor-
tant problems facing humanity today (Feulner, 2017; IPCC, 2018).
The responses of lakes to climate change are well documented
(Woolway et al., 2020), including increases in surface water tem-
perature (O’Reilly et al., 2015; Schneider and Hook, 2010), loss of
ice cover (Magnuson et al., 1990; Sharma et al., 2019), changes in
stratification and mixing regimes (Woolway and Merchant,
2019), and increased lake evaporation (Wang et al., 2018). Deep
lakes, which also tend to be ‘‘large” in surface area, are more likely
to experience winters without ice cover in a warming climate than
shallow lakes at similar latitudes (Sharma et al., 2019). Similarly,
the epilimnetic waters of large, deep lakes have often been found
to be warming at fast rates, as high as 1.0 °C per decade (O’Reilly
et al., 2015; Schneider and Hook, 2010), due in part to the afore-
mentioned high sensitivity of the date of stratification onset to
warming air temperatures (Austin and Colman, 2007; Zhong
et al., 2016). The rates of warming, however, are generally quite
variable among lakes (O’Reilly et al., 2015) and even spatially vari-
able across large lakes (Woolway and Merchant 2018). Interactions
with additional stressors can also lead to ecological surprises
(Christensen et al., 2006). For example, changes in precipitation,
evaporation, runoff, and consumptive water use have contributed
to some lakes experiencing shifts in seasonal water levels
(Lenters, 2001), while others have seen historically low / high lake
levels (Rodell et al., 2018; Wurtsbaugh et al., 2017), contributing to
alterations in water quantity and water quality (Vörösmarty et al.,
2000). Feedbacks from large lakes to the atmosphere have also
been identified, such as the warming of regional air temperature
(Le Moigne et al., 2016).
Changes in lake thermal structure will affect the ecosystem by,
for instance, altering the distribution of freshwater fishes, and/or
decreasing deep-water oxygen concentrations (Cohen et al.,
2016). In addition to modified vertical structure from climate
change, some large lakes have also shown changes in horizontal
temperature structure, such as more rapid warming of offshore
surface waters as compared to shallower, nearshore waters
(Woolway and Merchant 2018). Such characteristics are important
to consider for lake organisms, given that temperatures warmer
than a specific threshold can be lethal to some species. This is rel-
evant for coldwater species in a warming climate, for example, if
they cannot escape to cooler, deeper waters or groundwater inflow
regions (Kangur et al., 2013). The warming-related collapse of cold-
water fish populations has already been documented in many lakes
in Northern Europe (Jeppesen et al., 2012). Climate change is also
Table 3
Examples of some international and national frameworks to manage large lakes.
Programs Year Countries Description
Boundary Waters Treaty 1909 Canada (Great Britain),
Treaty for comprehensive sharing of waters between these two nations,
including the Great Lakes.
Laurentian Great Lakes Coastal Wetland
Monitoring Program
1996 US, Canada Assess coastal wetlands (Cooper et al, 2018; Uzarski et al., 2017, 2019)
EU Water Framework Directive (WFD) 2000 European Union countries Legislative framework for assessing and protecting ecological status of
all aquatic ecosystems (Directive 2000/60/EC; WFD, 2019)
The Great Lakes Water Quality Agreement
Protocol (GLWQA)
1972, 1978,
1987, 2012
US and Canada Commitment to restore and maintain the integrity of the Laurentian GL
Commission Internationale pour la Protection
des Eaux du Léman (CIPEL)
1963 Switzerland and France Commission responsible for monitoring the quality of the water in Lake
Geneva, in the Rhône and in their tributaries
International Commission for the Protection of
Lake Constance (IGKB)
1959 Germany, Austria,
Switzerland and
Observation, recommendation for coordinated preventive measures,
and discussion of planned utilization of the lake.
The Great Lakes Basin Compact (GLC) 1955 Eight US states and
Ontario and Quebec,
Enable transboundary cooperation on lake management
Canada Ontario Agreement (COA) 1994 Canada Restore, protect, conserve Laurentian Great Lakes water quality and
ecosystem health
Great Lakes Restoration Initiative (GLRI) 2010 USA Restore, protect, conserve Laurentian Great Lakes water quality and
ecosystem health
Water Pollution Prevention and Control (WPPC)
1984 China Water management to ensure emergency and back-up water resources
are available in cities
Single large lake policies
Programs Year Lakes Description
Aral Sea Program 1995 Aral Sea Restoring the Aral Sea to its former level
Convention on the Legal Status of the Caspian
2018 Caspian Sea How to divide up the potentially huge oil and gas resources
Framework Convention for the Protection of the
Marine Environment of the Caspian Sea
2006 Caspian Sea Protection of the Caspian environment from all sources of pollution
Lake Victoria Environmental Management
Program (LVEMP)
2011 Lake Victoria, Africa Tackle environmental challenges of lake basin over the long-term and
improve welfare of inhabitants that depend on its resources
Canada-Ontario Lake Erie Action Plan, under the
Great Lakes Protection Act (2015)
2018 Lake Erie Reducing P loads to the western and central basins of Lake Erie by 40%
by 2025
Convention on the sustainable management of
Lake Tanganyika
2003 Lake Tanganyika Objective to ensure the protection and conservation of the biological
diversity and the sustainable use of the natural resources
6J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
expected to amplify the impacts of eutrophication in the future
(Moss et al., 2011), in part through changes in stratification.
Changes in the length of the growing season within lakes can also
have profound impacts on the seasonal timing of population devel-
opment for organisms within lakes (Winder and Schindler, 2004).
The extent to which species phenology is affected by climate
change differs among species, which might result in a mismatch
between prey and consumers, with consequences in terms of
growth rates and survival (Adrian et al., 2006; Thackeray et al.,
2008), especially when warming is seasonally heterogeneous
(Straile et al., 2015).
Acidification has many negative biogeochemical consequences
for species diversity as well as ecosystem health and functioning
(Beamish and Harvey, 1972; Malley, 1980; Vinogradov et al.,
1987), and it is driven by inputs of acid anions, such as sulfates
and nitrates, and/or dissolution of atmospheric CO
. It implies a
decrease in water pH, carbonate ion concentration, and the satura-
tion level of biologically important calcium carbonate minerals. In
the 1960s and 1970s, acidification of natural waters was a pressing
issue of regional concern because of acid rain and local atmo-
spheric deposition, and it is not clear how pCO
in lakes will
change in the future (Hasler et al., 2016) as the global atmospheric
levels of carbon dioxide (CO
) continue to rise, reaching unprece-
dented levels of 400 ppm in the 2010s (Monastersky, 2013). Large
lakes typically have a low ratio of watershed area to lake area,
which is one of the factors that influences a lake’s susceptibility
to potential atmospheric driven acidification (Eilers et al., 1983).
However, decreasing CO
solubility and elevated algal productivity
due to increasing temperature may counterbalance the effects of
increasing atmospheric CO
(Phillips et al., 2015), but future acid-
ification trends are not well understood currently and more
research will be needed.
Fig. 4. Overview of services provided by large lakes, of most known stressors, and of the impacts of these stressors on lakes. White arrows highlight direct or indirect impacts
on the lake food web.
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 7
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
Harvesting of fisheries resources is common in large lakes and
includes commercial, recreational, and subsistence fishing. Large
lakes tend to experience more commercial fishing pressure than
smaller lakes (75% of the freshwater ports inventoried in the World
Food Program logistics global ports database are located in lakes
greater than 19,347 km
). As a result, they could be vulnerable to
over-exploitation without management intervention. Overfishing
has led to population collapses and species extirpations in some
large lakes. For example, blue pike (Sander vitreus glaucus), a locally
endemic subspecies of Walleye, was one of the most heavily har-
vested commercial species in Lake Erie until their collapse in the
1960s (Brenden et al., 2013). Overfishing continues to be a threat
today. In Lake Malawi (Africa’s 3rd largest lake), 9% of the 458 spe-
cies of fish are at high risk of extinction, with 3 out of 4 of the spe-
cies of chambo – oreochromine cichlids, the lake’s most vulnerable
fishes – being deemed as ‘‘critically endangered” due to unsustain-
able fishing (IUCN 2018). This overharvest of large-lake fishes
threatens food security and livelihoods in some of the most food-
deprived countries in East Africa. A newly emerging impact from
harvest is the rapid evolution of key yield-determining traits in fish
populations, slowing recovery and impacting resilience (Dunlop
et al., 2018). Furthermore, the impacts of harvest can spread
beyond the target fish species, as critical predator–prey relation-
ships are altered within impacted food webs (Nõges et al., 2018).
Littoral shoreline modification has obviously increased in large
lakes with the development of human society. Human settlement on
the coast, inputs of nutrients and pollutants, and creation of harbors
and beaches strongly influence local shoreline habitats, which con-
stitute hotspots of lake biodiversity (Schmieder, 2004;
Vadeboncoeur et al., 2011). In addition to previously described stres-
sors, stressors near the coast include physical alterations that induce
changes in the functioning of the whole coastal ecosystem. For
instance, shoreline transformations modify the physical influence
of waves and littoral slopes and have created sheltered areas with
higher nutrient accumulation, enhancing the development of phyto-
benthos and phytoplankton at the expense of macrophyte communi-
ties (Sand-Jensen and Borum, 1991; Weisner et al., 1997). This affects
habitats for fishes and macroinvertebrates and can disrupt the
trophic relationships of the whole ecosystem. However, the available
literature is not yet sufficient to evaluate the effects of human-made
structures on fish recruitment (Macura et al., 2019).
Invasive species have drastically altered large-lake ecosystems,
causing significant economic losses to human society. For example,
dreissenid mussels have changed nutrient pathways in the Laurentian
Great Lakes (Hecky et al., 2004), altering benthic invertebrate and
plankton communities (Madenjian et al., 2015) and leading to life his-
tory and population changes in commercially harvested fishes (Fera
et al., 2017, 2015). Water hyacinth, the world’s most invasive aquatic
weed, has invaded numerous systems, including the African large
lakes (Ogutu-Ohwayo et al., 1997). Water hyacinth forms dense mats
in shallow waters that alter fish breeding habitat, impair boat traffic
and water intake, and provide breeding opportunities for mosquitos
acting as disease vectors (Ogutu-Ohwayo et al., 1997). The threat from
invasive species will remain into thefutureasclimatechangepushes
species boundaries to new areas and as globalized trade expands. Fur-
thermore, large lakes connected to transoceanic shipping networks
(such as the Laurentian Great Lakes; Holeck et al., 2004), combined
with ship ballast introductions, can be gateways for invasive species
to expand into other surrounding inland lakes and waterways.
Complexity of interacting stressors: Insights from successes and
failures in restoring the ecological state of large lakes
In large lakes, one stressor usually does not act alone. Instead,
multiple stressors interact in additive or synergistic ways, and
their combined impacts generate complex responses. The exam-
ples below highlight this complexity in the response of large lakes
and the challenge that such complexity poses to lake management.
Hence, the ‘‘cocktail” of stressors are generally specific to each lake,
making it difficult to generalize environmental diagnostics; but
elements of categorization can still be provided at the stressor
level. For instance, the development of wastewater treatment
and associated reduction of point pollution varies greatly across
the globe. Some countries would therefore still have to conduct
policies in this direction, while others need to better manage the
diffuse pollution of their intensive agriculture, with great dispari-
ties in geographical situations, such as those related to heritage
of past uses, soils, drainage, land use, or lake tributary relations
(Kayal et al., 2019).
Successful management of eutrophication, but arrival of new problems
due to species invasions and warming
Lake Constance recovered from eutrophication due to success-
ful lake management (Güde et al., 1998), with total phosphorus
(TP) concentrations dropping by an order of magnitude to current
levels (6–8 mg/L) that were typical for the years (early 1950s) prior
to massive eutrophication (Jochimsen et al., 2013). Up through
recent years, phytoplankton and zooplankton populations
responded as predicted, and many food web changes due to
eutrophication were reversed. For example, extirpated species
(i.e., species with abundances below detection level for a long per-
iod) reappeared, including several diatom species (Kümmerlin,
1998) and the cladoceran Diaphanosoma brachyurum (Stich,
2004). On the other hand, species that had increased with eutroph-
ication fell into decline (Straile, 2015), and relative contributions of
green algae and cyanobacteria also decreased (Jochimsen et al.,
2013). Even evolutionary responses to oligotrophication (the
return to more oligotrophic conditions) were evident, such as the
re-emergence of functional diversity lost during eutrophication
(Jacobs et al., 2019). However, overall productivity decreased,
which presumably contributed to reduced catches of important
fish species such as whitefish (Thomas and Eckmann, 2007). In
recent years, Lake Constance has experienced massive changes
affecting various trophic levels of the pelagic food chain. Most
notably, sticklebacks, a littoral fish present in Lake Constance since
the 1950s, underwent a habitat change and is now the numerically
dominant fish species in the pelagic zone (Eckmann and Engesser,
2019; Rösch et al., 2018). This habitat shift seemed to have further
decreased whitefish growth and also (possibly due to stickleback
predation on larval fish) whitefish recruitment (Rösch et al.,
2018). Overall increased predation pressure in the pelagic zone
seems to have changed the zooplankton community. Furthermore,
the cyanobacterium Planktothrix rubescens recently increased in
abundance despite TP concentrations below 10 mg/L. Presently, it
is unclear to what extent climate warming and/or food web alter-
ations due to stickleback invasion of the pelagic zone are causing
these new developments. Nevertheless, Lake Constance demon-
strates that despite lake managers successfully combatting the
eutrophication problem in this lake, the arrival of new species in
the pelagic zone possibly in combination with climate change
may create new food webs, which could change the ecosystem ser-
vices that large lakes provide.
Failed management of eutrophication
Since the 1950s, excess nutrient concentrations of nitrogen and
phosphorus have been changing the trophic state of Lake Erie’s
ecosystem, leading to reduced water quality and shifting environ-
mental structures and functions within the lake ecosystem (Steffen
et al., 2014; International Joint Commission, 2014). Eutrophication,
8J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
climate change, and hydrologic dynamics have likely driven natu-
rally occurring genera of cyanobacteria, including dominance by
Microcystis spp., to multiply at a rapid rate, resulting in harmful
algal blooms (HABs). In the mid-1990s, the western basin of Lake
Erie, following years of improvement after point source P loading
reduction (International Joint Commission, 2014), was confronted
by a shift in planktonic communities from nitrogen-fixing to
non-nitrogen-fixing cyanobacteria, especially Microcystis species
that can produce toxins (Brittain et al., 2000; Chaffin and
Bridgeman, 2014; Rinta-Kanto et al., 2005). Although phosphorus
has been considered the primary driver of the biological productiv-
ity of freshwater ecosystems, including harmful algae (Schindler,
2012, 1977, 1974) such as in Lake Erie (International Joint
Commission, 2014), the precise nutrient regime that favors toxi-
genic, non-nitrogen fixing cyanobacteria is complicated and is
becoming better understood (Carey et al., 2012). Indeed, it has
been suggested in several studies that nitrogen chemistry may
shape the biological diversity of the system (e.g., Wilhelm et al.,
2003). Yet the vast majority of current nutrient management is
focused on the reduction of phosphorus loads into the watersheds
of Lake Erie (International Joint Commission, 2014), not on nitro-
gen loads (United States Environmental Protection Agency, 2017,
2015), which have also increased in the past two decades (Paerl
et al., 2016). As such, management measures may be inadequate
in mitigating the recent events of detrimental cyanobacterial
blooms of Microcystis (Gobler et al., 2016; Harke et al., 2016). How-
ever, more agencies now promote a dual strategy to reduce both N
and P (Paerl et al., 2018) even though this imputes higher societal
costs for wastewater treatment.
Success against invasive species via the use of chemical treatments,
while actively seeking alternative control options
The story of sea lamprey (Petromyzon marinus) in the Laurentian
Great Lakes is the world’s only example of the successful,
ecosystem-scale control of an invasive aquatic vertebrate. The
sea lamprey, native to the Atlantic Ocean, was first recorded in
Lake Ontario in 1835 and, after improvements to the Welland
Canal, spread throughout the remaining Laurentian Great Lakes
by the 1920s-30s (Christie and Goddard, 2003). This species inva-
sion was catastrophic both ecologically and economically, deci-
mating lake trout stocks and other native species and
contributing to the collapse of commercial fisheries (Siefkes
et al., 2013). Sea lamprey adults are parasitic, attaching to a fish
host with their suction-cup mouth, using a rasping tongue to
pierce the host’s flesh, and feeding on blood and other body fluids.
A breakthrough was made in the 1950s, when it was discovered
that a compound, 3-trifluoromethyl-4
-nitrophenol (TFM), could
selectively kill sea lamprey larvae (Applegate et al., 1957). Sea lam-
prey larvae burrow into the soft sediments of tributaries, where
they remain vulnerable to pesticide application for up to 7 years
before they transform and out-migrate to the open lake to feed.
The treatment of the Great Lakes’ tributaries with TFM is the
cornerstone of an extensive binational, science-based control pro-
gram administered by the Great Lakes Fishery Commission. Sea
lamprey populations have been suppressed by as much as approx-
imately 90% compared to pre-control levels (Heinrich et al., 2003;
Smith and Tibbles, 1980), resulting in the recovery of key fish pop-
ulations and the restoration of the 7-billion-dollar fishery (Siefkes
et al., 2013). Barriers blocking the upstream migration of spawning
sea lamprey have also contributed to control, but there is increas-
ing pressure to remove some barriers to increase connectivity for
native species (McLaughlin et al., 2013). There remains a need for
vigilance and the continued search for alternative or supplemental
control options in order to reduce reliance on TFM and avoid sea
lamprey evolving pesticide resistance (Dunlop et al., 2017, p.
2017). Also, there is a considerable economic cost to treating
streams with TFM, and although many exposed aquatic species
appear to be unharmed by TFM, there are potential negative effects
on some valued species (e.g., lake sturgeon). However, if managers
stopped these treatments, then sea lamprey populations would
likely rebound. The sea lamprey example highlights the success
of a science-based invasive species control program, but it is also
a cautionary tale for the importance of preventing exotic species
introductions in the first place to avoid costly control programs
to mitigate negative effects.
Failed conservation of lake fauna
In eight southern alpine lakes (including large lakes) non-native
species contributed between 4.0% and 71.5% to standardized fish
catches by number (Volta et al., 2018). Eutrophication is recog-
nized as the main driver of the decline of coregonid diversity
(Vonlanthen et al., 2012). Nevertheless, inappropriate fish manage-
ment practices can also have strong contribution in diversity loss
(Anneville et al. 2015). For instance, fishery management practices
such as stocking have also contributed to coregonid diversity loss
by different mechanisms (Cucherousset and Olden, 2011), such
as competition, predation, habitat modification, or genetic extinc-
tion through introgressive hybridization (Winkler et al., 2011). In
Africa, the introduction of the Nile perch (Lates niloticus) is a major
issue in Lake Victoria (Njiru et al., 2018). Introduced in the 1950s to
improve the fishery, this big carnivorous fish is famous for its flesh
quality. Native fish stocks, however, including several hundred
endemic species belonging to the Cichlidae family (Seehausen,
2006), have become depleted as the Nile perch stock increased
during the same period. The loss of species diversity is due to sev-
eral factors, including: 1) eutrophication leading to extension of
anoxic layers, increased turbidity, and changes in lake functioning,
which contribute to degraded spawning habitat of some endemic
species and shifts in food web such as increased shrimp and pelagic
fish; 2) new fishing gear and intensive exploitation without regu-
lation, causing decreased fish stocks; and 3) competition for space
and resources between Nile perch and endemic fish species
(Getabu et al., 2003). The combined effects of these different fac-
tors have led to the disappearance of endemic fish species over a
relatively short period of time. Management interventions such
as pollution regulations and invasive species prevention and con-
trol must be investigated as options to preserve fish species diver-
sity in lakes.
An example of how management actions have so far failed to
recover an iconic fish stock is the lake sturgeon in the Laurentian
Great Lakes, where historical overfishing contributed to the col-
lapse of this previously abundant species (Haxton et al., 2014). In
Lake Erie, lake sturgeon is now rare, but the lake had an estimated
historic carrying capacity of 23,000 metric tons (Sweka et al.,
2018). The collapse of this benthivore from the littoral zone likely
had profound effects on the aquatic community (Haxton et al.,
2014) and impacted the many indigenous communities around
the Laurentian Great Lakes for which the species holds great cul-
tural significance. The government listing of lake sturgeon as a
species-at-risk and the protection of stocks from fishing has unfor-
tunately failed to recover the species. This is likely because of the
many other factors affecting populations, such as barriers in tribu-
taries blocking spawning migrations, anthropogenic degradation of
spawning and nursery habitat, and invasive species that increase
the mortality of various life stages, currently limiting the recovery
of lake sturgeon (Sweka et al., 2018). However, stocking of young
sturgeon has increased sturgeon populations in the Lake Ontario
watershed (Jackson et al., 2002), and spawning habitat rehabilita-
tion in the connecting channels shows promise as spawning stur-
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 9
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
geon are attracted to these habitats (Detroit, Niagara and St Lawr-
ence Rivers).
Failed hydrologic management in the Aral Sea
The endorheic Aral Sea, the fourth largest lake in the world, has
significantly declined in volume and surface area since the 1960s
due to water withdrawal from the Amu Darya and Syr Darya rivers
for irrigation (Micklin, 2010; Micklin et al., 2014). The resulting
strong imbalance between inflow and evaporation led to the sepa-
ration of the sea into the ‘‘Small” and ‘‘Large” Aral Seas in 1986–87,
with the latter splitting further into three parts (Cretaux et al.,
2019, 2013). Salinity increased from 10 g/l during the initial period
to 30 g/l in the Small Aral during later years and greater than 100 g/
l in the Large Aral, eliminating most of the freshwater species,
while many endemic saline species have also been lost due to com-
petition with introduced marine species (Aladin and Potts, 1992).
Due to the collapse of commercial fisheries (Ermakhanov et al.,
2012), thousands of fishermen lost their livelihoods (Glantz,
1999). The desiccation of the Aral Sea has also created a large
desert, the Aralkum (Breckle et al., 2012), exposing unfertile salt
and sand contaminated with pesticides (Whish-Wilson, 2002),
heavy metals (Ge et al., 2016), and residue from weapons testing
(Bennett, 2016). Toxic dust emissions have negatively affected
female reproduction and fertility (Gulmira et al., 2018) and infant
mortality rates (>100 per thousand, caused mostly by acute respi-
ratory and diarrheal diseases), and high levels of salts in drinking
water have increased incidences of kidney and liver disease
(Whish-Wilson, 2002). Long-distance transport of salt and dust
(Xi and Sokolik, 2016) has caused soil salinization and acceleration
of the melting rate of glaciers and snow, changing the water bal-
ance of rivers in downwind areas (Abuduwaili, 2010). Loss of the
climate-moderating role of this previously large water body has
increased both diurnal (Roget and Khan, 2018) and seasonal tem-
perature ranges (Sharma et al., 2015). A dike was built in 1992 to
allow the water level to be raised in the Small Aral, maintain its
salinity below 20 g/L, and restore fishing activities (Aladin et al.,
2008), but conflicting interests between the countries sharing the
basin have so far prevented efficient efforts toward rational water
management (Bennett, 2016).
Unexpected consequences of lake restoration
Europe’s sixth largest lake – Lake Vättern – is another example
of a lake where efficient phosphorus reduction in the 1970s
through improved treatment of wastewater in the catchment area
resulted in a rapid decline of algal biomass in the lake (Willén,
2001). The outcome of the reduction was, however, different in this
large lake compared to other, smaller lakes. Because of a very long
water retention time (58 years), the successful phosphorus reduc-
tion continued over decades, and in conjunction with a natural
phosphorus concentration decline that was observed across Swe-
den in nutrient-poor reference lakes (Weyhenmeyer and Broberg,
2014), phosphorus concentrations in this large lake are now excep-
tionally low, averaging only 4.6 ± 0.3 mgL
in 1992–2010
(Sandström et al., 2014). Together with overharvesting, climate
change, and introduced species, the reduced nutrient loading was
suggested as the reason behind a collapse of the Arctic char in
the lake. Thus, the final outcome of a successful restoration pro-
gram might have contributed to a mismatch in the food web, caus-
ing the collapse of a piscivorous fish (Jonsson and Setzer, 2015).
New challenges and future threats to large lakes
Ecosystem health and ecosystem services provided by large
lakes are vulnerable to emerging threats such as microplastics,
micropollutants, and the cumulative effects of threats including
climate change, eutrophication, over-harvesting, and invasive spe-
cies. An evaluation of 50 potential stressors in the Laurentian Great
Lakes suggested that invasive species and climate change had the
greatest potential impacts on large lakes, in contrast to the long-
standing emphasis on eutrophication and bioaccumulation of con-
taminants (Smith et al., 2015). Nonetheless, eutrophication
remains a major concern in specific areas of the Laurentian Great
Lakes (e.g., western Lake Erie. Green Bay, Saginaw Bay) as well as
in many other places in the world. Here, we highlight key emerging
threats and the challenges associated with cumulative effects of
multiple stressors in the world’s large lakes.
Eutrophication in a changing climate
Phosphorus loadings to largest lakes of the world increased in
50 out of 100 lakes between 1990 and 1994 and 2005–2010
(Fink et al., 2018). Furthermore, multiple stressors, under the lens
of climate change, are an emerging challenge to freshwaters world-
wide (Smith et al., 2019). Climate change may act synergistically
with nutrients to amplify eutrophication and further degrade
ecosystem health and related ecosystem services provided by large
lakes, including provisioning of clean drinking water and recre-
ational opportunities (Moss et al., 2011; Paerl and Huisman,
2008). With a changing climate, future nutrient loading will likely
need to be reduced to lower levels than needed in the past if we are
to maintain water quality in lakes.
Climate change will have substantial effects on lake ecosystems
irrespective of their size. Higher temperatures will: 1) advance the
onset and enhance the strength and duration of stratification, cre-
ating a higher risk of oxygen depletion in bottom waters and sub-
sequent release of nutrients stimulating eutrophication, 2)
enhance the risk of temporary or permanent stratification in
polymictic lakes (even in large lakes such as Lake Taihu), and shift
some lakes from dimictic to monomictic (Woolway and Merchant,
2019), creating risk for temporary or longer-term oxygen depletion
and nutrient release, and 3) shift species composition, with a pro-
jected enhancement of dominance by potentially toxic cyanobacte-
ria or dinoflagellates, and 4) promote expanding ranges of invasive
species, resulting in new species introductions and enhanced
impacts to aquatic food webs.
In more arid climate zones, eutrophication might be further
exacerbated through reduced water levels, and in wet areas by
increasing external loading of nutrients. In temperate zones, cli-
mate change–induced precipitation changes will substantially
increase riverine total nitrogen loading by the end of the century,
such as within the continental United States (Sinha et al., 2017,
p. 201). The interactions between climate and nutrients might
induce major changes in the trophic structure by shifting domi-
nance to small omnivorous fish, leading to higher predation on
zooplankton and benthic animals and subsequently less chances
of controlling nuisance algae (Moss et al., 2011). Furthermore, in
large lakes with extensive shipping, climate change may enhance
the risk of species invasion and more importantly dominance of
these invasive species.
Shoreline modification and wetland loss in the catchment
Wetland loss in catchments and shoreline modifications are
likely to be an emerging threat in large lakes, particularly in areas
experiencing human population growth. Although the loss of
coastal wetlands in the Laurentian Great Lakes was first docu-
mented in 1982 (Whillans, 1982), there are few studies that quan-
tify wetland loss, due to the difficulty in quantifying dynamic
baseline conditions in the presence of naturally fluctuating water
levels. Whillans (1982) estimated that 57% of coastal wetlands
10 J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
were lost along the Canadian shoreline of Lake Ontario, and losses
approached 100% in heavily settled areas.
Coastal wetlands of large lakes support essential ecosystem ser-
vices, including wildlife habitat, fisheries, and water quality
improvement, which can all be substantially degraded as a result
of wetland loss (Sierszen et al., 2012, 2019; Trebitz and Hoffman,
2015; Uzarski et al., 2017). Coastal wetlands are essential to inte-
grating the pelagic habitats of large lakes with the surrounding
landscape, and in the process provide areas of high biodiversity
and nutrient cycling (Uzarski, 2009). For instance, coastal wetlands
of large lakes support a diverse assemblage of fishes, including
both permanent residents and migratory species (Cooper et al.,
2018; Jude and Pappas, 1992; Trebitz and Hoffman, 2015).
Coastal wetland loss and shoreline modification are expected to
interact with other environmental stressors in the Laurentian
Great Lakes (Kovalenko et al., 2018; Smith et al., 2019). Few studies
assess interactions among multiple stressors, highlighting an
important research area. For example, wetland loss is expected to
exacerbate nutrient loading due to reduced trapping and removal
of nutrients (Smith et al., 2019). Changes in water levels as a result
of climate change could exacerbate or alleviate shoreline modifica-
tion because higher water levels often will result in the hardening
of shorelines (i.e., wetlands loss), whereas lower water levels may
allow wetlands to recover and develop between the water and
hardened shoreline (Smith et al., 2019).
Since the start of plastics mass production in the 1940s,
microplastic contamination of aquatic environments has been a
growing problem, especially over the last decade. Microplastics
can be ingested by organisms, accumulate in specific tissues, and
be transported along the food chains. Moreover, they may act as
a medium to concentrate and transfer chemicals and persistent,
bioaccumulative, and toxic substances to organisms (Eerkes-
Medrano et al., 2015). As these polymers are highly resistant to
degradation, quantities of microplastics in aquatic environments
will most likely continue to increase over time; and, consequently,
microplastics represent a problem that future generations will
have to face (Galloway and Lewis, 2016).
The presence of microplastics in aquatic environments is widely
recognized, and various ecological consequences have been
reported (Eerkes-Medrano et al., 2015; Mani et al., 2015). Rivers
and effluents have been identified as major pathways for
microplastics of terrestrial origin (Fischer et al., 2016; Mani et al.,
2015). Recent research now shows large lakes also contain
microplastic pollution, with the highest concentrations in heavily
urbanized regions, such as Toronto (Canada) and Detroit (USA)
(Eriksen et al., 2013). For example, Castañeda et al., (2014) found
that a liter of sediment from the St. Lawrence River contained up
to 1,000 spherical microplastics – on par with the world’s most
polluted marine sediments. Volunteer beach cleanups show that
typically more than 80% of anthropogenic litter along the shoreli-
nes of large lakes is comprised of plastics (Driedger et al., 2015).
Plans to combat and curtail plastic debris pollution (i.e., by reduc-
ing debris input, but also tracking and removal efforts) in large
lakes will come at a significant economic cost, likely in excess of
$400 million annually (Driedger et al., 2015).
In the past decade, micropollutants, i.e., chemicals that occur in
the environment at trace levels mostly from anthropogenic
sources, including heavy metals, pesticides, pharmaceuticals, and
cosmetics have become recognized as key threats for aquatic
ecosystems (Blair et al., 2013; Chèvre and Gregorio, 2013;
Codling et al., 2018; Metcalfe et al., 2019; Schwarzenbach et al.,
2006). For example, certain synthetic and natural compounds, col-
lectively known as endocrine-disrupting compounds, could mimic
natural hormones in the endocrine systems of animals and human-
beings. Pharmaceuticals and personal care products (PPCPs) con-
sumed by humans are discharged into surface waters, as they are
not degraded by wastewater treatment plants (Kümmerer, 2008).
These products have been collectively grouped under the term
‘‘Chemicals of Emerging Concern” and are receiving attention
owing to their potential adverse effects on animals and humans
at trace concentrations in large lakes (Huerta Buitrago et al.,
2016; Rahman et al., 2009; Snyder et al., 2003). There are some
natural sources for these compounds (e.g., Rogers et al., 2011).
While we do not have a way to clearly distinguish anthropogenic
from natural sources at this juncture, it is clear that some popula-
tions favored by eutrophication and climate change (e.g., Microcys-
tis spp.) produce some of these chemicals.
Micropollutants can have wide-ranging impacts on freshwater
organisms, in particular because some compounds bioaccumulate
along the trophic chain (Mazzoni et al., 2018; McGoldrick and
Murphy, 2016; Rajeshkumar and Li, 2018; Visha et al., 2018).
Micropollutants can affect the survival and behavior of aquatic
species (Amiard-Triquet et al., 2015; Chèvre and Gregorio, 2013),
alter the reproductive system of aquatic organisms, and promote
the development of resistant bacterial strains, representing a
health risk to humans (McGowan et al., 2007; Uslu, 2012). The
occurrence of a combination of micropollutants is particularly con-
cerning, even if the concentrations of the micropollutants alone are
below the national or international threshold for freshwater sys-
tems; the mixture of micropollutants may synergize effects, engen-
dering the ‘‘something from nothing” effect (Chèvre and Gregorio,
Conclusions and perspectives
The demands of a growing global population with rapidly
changing consumption patterns for food, mobility, and energy are
exerting ever-increasing pressure on the Earth’s ecosystems and
their life-supporting services (GMT 8, 2015). In combination with
climate change, these changes raise concerns about the current
ecological status of large lakes and the services they can provide.
These changes require limnologists and paleolimnologists to eval-
uate and warn about the current state of ecosystems and their abil-
ity to provide ecosystem services that support humanity during its
societal, technological, and demographic transitions.
Lessons learned from past management practices
Some large lakes are ecosystems that humans have employed
enormous efforts over the last decades to sustain critical services
such as drinking water. Some generalizations of lessons can be
drawn from our synthesis on lake management, but the following
conclusions are far from exhaustive:
Restoration efforts have often achieved success: Catastrophic
degradation of lakes occurred in the past, such as acidification or
eutrophication, but humans have achieved restoration of many of
these impacted large lakes. Success in mitigating eutrophication
in European large lakes or the Laurentian Great Lakes include
strong examples for other countries facing a current increase in
nutrient loading of their waterbodies. International treaties have
been signed for many large lakes with shorelines that belong to
multiple countries (see examples in Table 3).
Complete restoration to historic or pristine conditions is hard to
achieve and sometimes even fails, but our examples show that the
worst can be avoided. The questions are still open in terms of what
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 11
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
can be a balanced target? And how do we help recover self-
functioning for freshwater ecosystems through restoration? And
who decides? While lakes can be restored to reinvigorate degraded
ecosystem services, past lake degradation always has lingering
implications; ecologically the systems are weakened, with
increased vulnerability to new threats, and economically, these
restoration and resiliency-enhancing programs require increased
human capital and financial investments. Establishing systems
for efficient management is expensive and is generally the privi-
lege of wealthier countries with more stable governance institu-
tions and greater access to capital. But the future cost of inaction
is too high, perhaps especially for developing countries, and action
has to be taken.
Current efforts are challenging because of the continuous arri-
val of new threats; Future developments may hold many ecological
surprises (Filbee-Dexter et al., 2017) because of climate change,
legacy of past perturbations, and combined stressors. Thus, large
lakes will require more intense conservation efforts in a warmer
and more anthropic world to achieve acceptable water quality.
Major challenges remain to reduce pollution (diffuse nutrient
inputs, but also micro-pollutants and micro-plastics). Moreover,
the lack of knowledge can also limit the diagnosis of causes and
therefore lead to misapplied management. It is time for humanity
to pay close attention to the signals from lakes, to correctly diag-
nose problems, and to design actions to preserve and/or recover
lake systems. Thus, the programs to restore large lakes should be
maintained and strengthened.
Plans to combat and curtail emerging threats, such as plastic
debris pollution in large lakes, will come at significant economic
cost (Driedger et al., 2015). The large costs associated with conser-
vation efforts are legitimate concerns by the citizens who bear
those costs, and who need to understand the pertinence and sus-
tainability of such programs. Furthermore, decisions about long-
term strategies will have to be supported by future generations.
As such, lake managers need to consider if these strategies can
be supported in the future and at what cost, and they should be
able to demonstrate the value of such costs as well as the social,
cultural, economic, and ecological implications from temporary
or permanent interruptions in ecosystem services due to inade-
quate investment in policies and programs for large lake monitor-
ing, restoration, and protection.
Each lake has its own history of anthropogenically-induced
change, requiring strategies that are tailored to its particular cir-
cumstances. For instance, point sources of nutrients were a leading
cause lake degradation in more industrialized nations, causing for
instance a historical degradation of oxygen conditions in Europe
(Jenny et al. 2016b). Treatment plans have been reducing these
nutrient supplies in many cases over the last decades, but point
sources are now progressively increasing to affect the quality of
the environment for various systems in developing nations, where
population is growing (e.g. Fig. 2). On the opposite, industrialized
nations are facing today high and still growing diffuse supplies of
nutrient principally due to agricultural fertilisation, whereas fertil-
isation is still low (but growing) in developing nations.
Another example concerns lake degradation in emerging econo-
mies which is occurring in a warmer climate than similar earlier
degradation in Europe and North America where management pro-
grams started decades ago; a case in point is the recent alarm
about eutrophication in China, while it was already 60 years ago
that eutrophication became a severe concern in Europe
(Vollenweider, 1968).
Conservation policies for the world’s large lakes
Large lakes are an important category of ecosystems that need
to be more explicitly integrated into international as well as local
policy instruments. Their global conservation in the face of ongoing
change, as well as recovery of the services provided by these valu-
able ecosystems, requires attention to policy actions in four main
categories: mitigation of multiple stressors, adaptation to change,
conservation measures to protect and restore environmental val-
ues, and knowledge production and dissemination.
Mitigation policies include ongoing work to restrict the produc-
tion and release of long-range contaminants such as persistent
organic pollutants and increased global attention to limiting the
discharge of microplastics, nanoparticles, pharmaceutical prod-
ucts, nutrients and other emerging pollutants into natural
Adaptation policies for sustained environmental stewardship of
large lakes must consider the multiple stresses that are imposed on
these ecosystems, including the arrival of new species and the
overarching effects of rapid climate warming. Many regions are
changing so rapidly that local policy decisions are urgently needed
to address the present and near-future challenges posed by climate
warming (Vincent, 2020).
Conservation areas play a key role in protecting species and
ecosystems from some of the additional stresses that are superim-
posed on the rapidly warming climate, and policies that support
their maintenance and expansion are now more important than
ever (Vincent, 2018). For large lakes, such areas include regional,
municipal, and national parks, ecological reserves, protected
watersheds, wetland refuges, and managed riparian zones that
act as buffers between human activities on land and the associated
Finally, the long-term stewardship of large lakes requires poli-
cies that enable knowledge acquisition and transfer, including
the promotion of education, outreach, and research programs, as
well as the dissemination of observations to the public, environ-
mental managers, policy makers, and others with influence such
as local conservation groups.
Contribution list
Conceived and designed the experiments: JG, OA, JPJ, JMD, MM,
VP, WFV. Performed the experiments: JPJ, TN. Analyzed the data:
JPJ. Coordinated the writing of the sections: OA, SJ, SS, WFV, JPJ,
MM, JG, ID, IG-E, MEP, VP, CR, DU, AJ, GAW. Wrote the paper:
ically revised, improved, and approved the final manuscript: All
Authors. The authors declare that no competing interests exist.
Appendix A. Supplementary data
Supplementary data to this article can be found online at
Abuduwaili, J., 2010. Saline dust storms and their ecological impacts in arid regions.
J. Arid Land 2, 144–150.
Adrian, R., Wilhelm, S., Gerten, D., 2006. Life-history traits of lake plankton species
may govern their phenological response to climate warming. Glob. Change Biol.
12, 652–661.
Aladin, N., Plotnikov, I., Ballatore, T., Micklin, P., 2008. Review of technical
interventions to restore the Northern Aral Sea. In: Japan International
Cooperation Agency: Study Reports: Country and Regional Study Reports:
Central Asia and Caucasus, pp. 1–12.
Aladin, N.V., Potts, W.T.W., 1992. Changes in the Aral Sea ecosystems during the
period 1960–1990. Hydrobiologia 237, 67–79.
Allan, J.D., Manning, N.F., Smith, S.D.P., Dickinson, C.E., Joseph, C.A., Pearsall, D.R.,
2017. Ecosystem services of Lake Erie: Spatial distribution and concordance of
multiple services. J. Great Lakes Res. 43, 678–688.
12 J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
Amiard-Triquet, C., Amiard, J.C., Mouneyrac, C., 2015. Aquatic Ecotoxicology:
Advancing Tools for Dealing With Emerging Risks. Academic Press.
Anneville, O., Lasne, E., Guillard, J., Eckmann, R., Stockwell, J.D., Gillet, C., Yule, D.,
2015. Impact of fishing and stocking practices on Coregonid diversity. Food
Nutr. Sci. 6, 10451055.
Applegate, V.C., Howell, J.H., Hall, A.E., Smith, M.A., 1957. Toxicity of 4,346
Chemicals to Larval Lampreys And Fishes (Federal Government Series No.
207). Special Scientific Report - Fisheries. U.S. Fish and Wildlife Service.
Austin, J.A., Colman, S.M., 2007. Lake Superior summer water temperatures are
increasing more rapidly than regional air temperatures: A positive ice-albedo
feedback. Geophys. Res. Lett. 34.
Beamish, R.J., Harvey, H.H., 1972. Acidification of the La Cloche Mountain Lakes,
Ontario, and resulting fish mortalities. J. Fish. Res. Board Can. 29, 1131–1143.
Bennett, 2016. From Aral Sea to Aral desert.: Natural Resource Conflicts: From Blood
Diamonds to Rainforest Destruction [2 volumes]: From Blood Diamonds to
Rainforest Destruction. ABC-CLIO.
Blair, B.D., Crago, J.P., Hedman, C.J., Klaper, R.D., 2013. Pharmaceuticals and personal
care products found in the Great Lakes above concentrations of environmental
concern. Chemosphere 93, 2116–2123.
Bourgeois, I., Savarino, J., Caillon, N., Angot, H., Barbero, A., Delbart, F., Voisin, D.,
Clément, J.-C., 2018. Tracing the fate of atmospheric nitrate in a subalpine
watershed using
O. Environ. Sci. Technol.
Breckle, S.-W., Wucherer, W., Dimeyeva, L.A., Ogar, N.P. (Eds.), 2012. Aralkum - a
Man-Made Desert: The Desiccated Floor of the Aral Sea (Central Asia),
Ecological Studies. Springer-Verlag, Berlin Heidelberg.
Brenden, T.O., Brown, R.W., Ebener, M.P., Reid, K.B., Newcomb, T.J., 2013. Great
Lakes commercial fisheries: Historical overview and prognoses for the future.
In: Taylor, W.W., Lynch, A.J., Leonard, N.J. (Eds.), Great Lakes Fisheries Policy and
Management: A Binational Perspective. Michigan State University Press, East
Lansing, pp. 339–397.
Brittain, S.M., Wang, J., Babcock-Jackson, L., Carmichael, W.W., Rinehart, K.L., Culver,
D.A., 2000. Isolation and characterization of microcystins, cyclic heptapeptide
hepatotoxins from a Lake Erie strain of Microcystis aeruginosa. J. Great Lakes Res.
26, 241–249.
Carey, C.C., Ibelings, B.W., Hoffmann, E.P., Hamilton, D.P., Brookes, J.D., 2012. Eco-
physiological adaptations that favour freshwater cyanobacteria in a changing
climate. Water Res. 46, 1394–1407.
watres.2011.12.016. Cyanobacteria: Impacts of climate change on occurrence,
toxicity and water quality management.
Carpenter, S.R., 2008. Phosphorus control is critical to mitigating eutrophication.
Proc. Natl. Acad. Sci. USA 105, 11039–11040.
Carpenter, S.R., 2005. Eutrophication of aquatic ecosystems: Bistability and soil
phosphorus. Proc. Natl. Acad. Sci. USA 102, 10002–10005.
Carpenter, S.R., Benson, B.J., Biggs, R., Chipman, J.W., Foley, J.A., Golding, S.A.,
Hammer, R.B., Hanson, P.C., Johnson, P.T.J., Kamarainen, A.M., Kratz, T.K.,
Lathrop, R.C., McMahon, K.D., Provencher, B., Rusak, J.A., Solomon, C.T., Stanley,
E.H., Turner, M.G., Vander Zanden, M.J., Wu, C.-H., Yuan, H., 2007.
Understanding regional change: A comparison of two lake districts.
Bioscience 57, 323–335.
Carpenter, S.R., Booth, E.G., Kucharik, C.J., 2018. Extreme precipitation and
phosphorus loads from two agricultural watersheds. Limnol. Oceanogr. 63,
Castañeda, R.A., Avlijas, S., Simard, M.A., Ricciardi, A., 2014. Microplastic pollution in
St. Lawrence River sediments. Can. J. Fish. Aquat. Sci. 71, 1767–1771. https://
Chaffin, J.D., Bridgeman, T.B., 2014. Organic and inorganic nitrogen utilization by
nitrogen-stressed cyanobacteria during bloom conditions. J. Appl. Phycol. 26,
Chanda, R., 1996. Human perceptions of environmental degradation in a part of the
Kalahari ecosystem. GeoJ. 39, 65–71.
Chèvre, N., Gregorio, V., 2013. Mixture effects in ecotoxicology. In: Férard, Jean-
François, Blaise, Christian (Eds.), Encyclopedia of Aquatic Ecotoxicology.
Springer Netherlands, Dordrecht, pp. 729–736.
Christensen, M.R., Graham, M.D., Vinebrooke, R.D., Findlay, D.L., Paterson, M.J.,
Turner, M.A., 2006. Multiple anthropogenic stressors cause ecological surprises
in boreal lakes. Glob. Change Biol. 12, 2316–2322.
Christie, G.C., Goddard, C.I., 2003. Sea Lamprey International Symposium (SLIS II):
advances in the integrated management of sea lamprey in the great lakes. J.
Great Lakes Res Sea Lamprey Int. Symp. (SLIS II) 29, 1–14.
Codling, G., Sturchio, N.C., Rockne, K.J., Li, A., Peng, H., Tse, T.J., Jones, P.D., Giesy, J.P.,
2018. Spatial and temporal trends in poly- and per-fluorinated compounds in
the Laurentian Great Lakes Erie, Ontario and St. Clair. Environ. Pollut. Barking
Essex 1987 (237), 396–405.
Cohen, A.S., Gergurich, E.L., Kraemer, B.M., McGlue, M.M., McIntyre, P.B., Russell, J.
M., Simmons, J.D., Swarzenski, P.W., 2016. Climate warming reduces fish
production and benthic habitat in Lake Tanganyika, one of the most biodiverse
freshwater ecosystems. Proc. Natl. Acad. Sci. USA 113, 9563–9568. https://doi.
Cooper, M.J., Lamberti, G.A., Moerke, A.H., Ruetz, C.R., Wilcox, D.A., Brady, V.J.,
Brown, T.N., Ciborowski, J.J.H., Gathman, J.P., Grabas, G.P., Johnson, L.B., Uzarski,
D.G., 2018. An expanded fish-based index of biotic integrity for Great Lakes
coastal wetlands. Environ. Monit. Assess. 190, 580.
Cretaux, J.-F., Kostianoy, A., Bergé-Nguyen, M., Kouraev, A., 2019. Present-Day
Water Balance of the Aral Sea Seen from Satellite. In: Barale, V., Gade, M. (Eds.),
Remote Sensing of the Asian Seas. Springer International Publishing, Cham, pp.
Cretaux, J.F., Letolle, R., Berge-Nguyen, M., 2013. History of Aral Sea level variability
and current scientific debates. Glob. Planet. Change 110, 99–113. https://doi.
Cucherousset, J., Olden, J.D., 2011. Ecological impacts of nonnative freshwater
fishes. Fisheries 36, 215–230.
Davis, B.A.S., 2015. The age and post-glacial development of the modern European
vegetation: a plant functional approach based on pollen data. Veg. Hist.
Archaeobotany 24, 303–317.
de Groot, R., Brander, L., van der Ploeg, S., Costanza, R., Bernard, F., Braat, L., Christie,
M., Crossman, N., Ghermandi, A., Hein, L., Hussain, S., Kumar, P., McVittie, A.,
Portela, R., Rodriguez, L.C., ten Brink, P., van Beukering, P., 2012. Global
estimates of the value of ecosystems and their services in monetary units.
Ecosyst. Serv. 1, 50–61.
Center for International Earth Science Information Network-CIESIN-Columbia
University, 2015. Gridded Population of the World, Version 4 (GPWv4):
Population Density Adjusted to Match 2015 UN WPP Country Totals, Beta
Driedger, A.G.J., Dürr, H.H., Mitchell, K., Van Cappellen, P., 2015. Plastic debris in the
Laurentian Great Lakes: A review. J. Great Lakes Res. 41, 9–19.
Dunlop, E.S., Feiner, Z.S., Höök, T.O., 2018. Potential for fisheries-induced evolution
in the Laurentian Great Lakes. J. Great Lakes Res. 44, 735–747.
Dunlop, E.S., McLaughlin, R., Adams, J.V., Jones, M., Birceanu, O., Christie, M.R.,
Criger, L.A., Hinderer, J.L.M., Hollingworth, R.M., Johnson, N.S., Lantz, S.R., Li, W.,
Miller, J., Morrison, B.J., Mota-Sanchez, D., Muir, A., Sepúlveda, M.S., Steeves, T.,
Walter, L., Westman, E., Wirgin, I., Wilkie, M.P., 2017. Rapid evolution meets
invasive species control: the potential for pesticide resistance in sea
lamprey. Can. J. Fish. Aquat. Sci. 75, 152–168.
Eckmann, R., Engesser, B., 2019. Reconstructing the build-up of a pelagic stickleback
(Gasterosteus aculeatus) population using hydroacoustics. Fish. Res. 210, 189–
Eerkes-Medrano, D., Thompson, R.C., Aldridge, D.C., 2015. Microplastics in
freshwater systems: a review of the emerging threats, identification of
knowledge gaps and prioritisation of research needs. Water Res. 75, 63–82.
Eilers, J.M., Glass, G.E., Webster, K.E., Rogalla, J.A., 1983. Hydrologic control of lake
susceptibility to acidification. Can. J. Fish. Aquat. Sci. 40, 1896–1904. https://doi.
Eriksen, M., Mason, S., Wilson, S., Box, C., Zellers, A., Edwards, W., Farley, H., Amato,
S., 2013. Microplastic pollution in the surface waters of the Laurentian Great
Lakes. Mar. Pollut. Bull. 77, 177–182.
Ermakhanov, Z.K., Plotnikov, I.S., Aladin, N.V., Micklin, P., 2012. Changes in the Aral
Sea ichthyofauna and fishery during the period of ecological crisis. Lakes Reserv.
Sci. Policy Manag. Sustain. Use 17, 3–9.
Fera, S.A., Rennie, M.D., Dunlop, E.S., 2017. Broad shifts in the resource use of a
commercially harvested fish following the invasion of dreissenid mussels.
Ecology 98, 1681–1692.
Fera, S.A., Rennie, M.D., Dunlop, E.S., 2015. Cross-basin analysis of long-term trends
in the growth of lake whitefish in the Laurentian Great Lakes. J. Great Lakes Res.
41, 1138–1149.
Feulner, G., 2017. Global challenges: climate change. Glob. Chall. 1, 5–6. https://doi.
Filbee-Dexter, K., Pittman, J., Haig, H.A., Alexander, S.M., Symons, C.C., Burke, M.J.,
2017. Ecological surprise: Concept, synthesis, and social dimensions. Ecosphere
8,. e02005.
Fink, G., Alcamo, J., Flörke, M., Reder, K., 2018. Phosphorus loadings to the world’s
largest lakes: Sources and trends. Glob. Biogeochem. Cycles 32, 617–634.
Fischer, E.K., Paglialonga, L., Czech, E., Tamminga, M., 2016. Microplastic pollution in
lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake
Chiusi (central Italy). Environ. Pollut. Barking Essex 1987 (213), 648–657.
Galloway, T.S., Lewis, C.N., 2016. Marine microplastics spell big problems for future
generations. Proc. Natl. Acad. Sci. USA 113, 2331–2333.
Ge, Y., Abuduwaili, J., Ma, L., Wu, N., Liu, D., 2016. Potential transport pathways of
dust emanating from the playa of Ebinur Lake, Xinjiang, in arid northwest
China. Atmos. Res. 178–179, 196–206.
Getabu, A., Tumwebaze, R., MacLennan, D.N., 2003. Spatial distribution and
temporal changes in the fish populations of Lake Victoria. Aquat. Living
Resour. 16, 159–165.
Glantz, M., 1999. Creeping Environmental Problems and Sustainable Development
in the Aral Sea Basin. Cambridge University Press.
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 13
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
GMT 8, 2015. Growing pressures on ecosystems [WWW Document]. Eur. Environ.
Agency. URL
(accessed 5.9.19).
Gobler, C.J., Burkholder, J.M., Davis, T.W., Harke, M.J., Johengen, T., Stow, C.A., Van de
Waal, D.B., 2016. The dual role of nitrogen supply in controlling the growth and
toxicity of cyanobacterial blooms. Harmful Algae 54, 87–97.
Güde, H., Rossknecht, H., Abril, G., 1998. Anthropogenic impacts on the trophic state
of Lake Constance during the 20th century. Arch Für Hydrobiol Spec Issues
Limnol Adv, 85–108.
Gulmira, Z., Aru, B., Bianchi, S., Belli, M., Yerbol, B., Macchiarelli, G., 2018. The
toxicity of lindane in the female reproductive system: A review on the Aral Sea.
Euromed. Biomed. 13, 104–108.
Håkanson, L., 1982. Lake bottom dynamics and morphometry: The dynamic ratio.
Water Resour. Res. 18, 1444–1450.
Hampton, S.E., McGowan, S., Ozersky, T., Virdis, S.G.P., Vu, T.T., Spanbauer, T.L.,
Kraemer, B.M., Swann, G., Mackay, A.W., Powers, S.M., Meyer, M.F., Labou, S.G.,
O’Reilly, C.M., DiCarlo, M., Galloway, A.W.E., Fritz, S.C., 2018. Recent ecological
change in ancient lakes. Limnol. Oceanogr. 63, 2277–2304.
Harke, M.J., Davis, T.W., Watson, S.B., Gobler, C.J., 2016. Nutrient-Controlled Niche
Differentiation of Western Lake Erie Cyanobacterial Populations Revealed via
Metatranscriptomic Surveys. Environ. Sci. Technol. 50, 604–615.
Hasler, C.T., Butman, D., Jeffrey, J.D., Suski, C.D., 2016. Freshwater biota and rising
? Ecol. Lett. 19, 98–108.
Haxton, T., Whelan, G., Bruch, R., 2014. Historical biomass and sustainable harvest
of Great Lakes lake sturgeon (Acipenser fulvescens Rafinesque, 1817). J. Appl.
Ichthyol. 30, 1371–1378.
Hecky, R.E., Smith, R.E., Barton, D.R., Guildford, S.J., Taylor, W.D., Charlton, M.N.,
Howell, T., 2004. The nearshore phosphorus shunt: a consequence of ecosystem
engineering by dreissenids in the Laurentian Great Lakes. Can. J. Fish. Aquat. Sci.
61, 1285–1293.
Heinrich, J.W., Mullett, K.M., Hansen, M.J., Adams, J.V., Klar, G.T., Johnson, D.A.,
Christie, G.C., Young, R.J., 2003. Sea Lamprey abundance and management in
Lake Superior, 1957 to 1999. J. Great Lakes Res. Sea Lamprey International
Symposium (SLIS II) 29, 566–583.
Herdendorf, C.E., 1982. Large lakes of the world. J. Great Lakes Res. 8, 379–412.
Holeck, K.T., Mills, E.L., MacIsaac, H.J., Dochoda, M.R., Colautti, R.I., Ricciardi, A.,
2004. Bridging Troubled waters: Biological invasions, transoceanic shipping,
and the Laurentian Great Lakes. Bioscience 54, 919–929.
Huerta Buitrago, B., Rodríguez Mozaz, S., Nannou, C., Nakis, L., Ruhí i Vidal, A., Acuña
i Salazar, V., Sabater, S., Barceló i Cullerés, D., 2016. Determination of a broad
spectrum of pharmaceuticals and endocrine disruptors in biofilm from a waste
water treatment plant-impacted river. Sci. Total Environ. 540, 241–249. https://
Hupfer, M., Lewandowski, J., 2008. Oxygen controls the phosphorus release from
lake sediments – a long-lasting paradigm in limnology. Int. Rev. Hydrobiol. 93,
International Joint Commission, 2014. A Balanced Diet for Lake Erie: Reducing
Phosphorus Loadings and Harmful Algal Blooms. Report of the Lake Erie
Ecosystem Priority.
IPCC, 2018. Summary for Policymakers. In: Global Warming of 1.5°C. An IPCC
Special Report on the impacts of global warming of 1.5°C above pre-industrial
levels and related global greenhouse gas emission pathways, in the context of
strengthening the global response to the threat of climate change, sustainable
development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-
O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, Moufouma-Okia, C. Péan, R.
Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy,
Maycock, M. Tignor, and T. Waterfield (eds.)]. World Meteorological
Organization, Geneva, Switzerland.
Jackson, J.R., VanDeValk, A.J., Brooking, T.E., VanKeeken, O.A., Rudstam, L.G., 2002.
Growth and feeding dynamics of lake sturgeon, Acipenser fulvescens, in Oneida
Lake, New York: results from the first five years of a restoration program. J.
Appl. Ichthyol. 18, 439–443.
Jacobs, A., Carruthers, M., Eckmann, R., Yohannes, E., Adams, C.E., Behrmann-Godel,
J., Elmer, K.R., 2019. Rapid niche expansion by selection on functional genomic
variation after ecosystem recovery. Nat. Ecol. Evol. 3, 77.
Jarvie, H.P., Johnson, L.T., Sharpley, A.N., Smith, D.R., Baker, D.B., Bruulsema, T.W.,
Confesor, R., 2017. Increased soluble phosphorus loads to Lake Erie: Unintended
consequences of conservation practices? J. Environ. Qual. 46, 123–132. https://
Jenny, J.-P., Francus, P., Normandeau, A., Lapointe, F., Perga, M.-E., Ojala, A.,
Schimmelmann, A., Zolitschka, B., 2016a. Global spread of hypoxia in freshwater
ecosystems during the last three centuries is caused by rising local human
pressure. Glob. Change Biol. 22, 1481–1489.
Jenny, J.-P., Koirala, S., Gregory-Eaves, I., Francus, P., Niemann, C., Ahrens, B.,
Brovkin, V., Baud, A., Ojala, A.E.K., Normandeau, A., Zolitschka, B., Carvalhais, N.,
2019. Human and climate global-scale imprint on sediment transfer during the
Holocene. Proc. Natl. Acad. Sci. 201908179.
Jenny, J.-P., Normandeau, A., Francus, P., Taranu, Z.E., Gregory-Eaves, I., Lapointe, F.,
Jautzy, J., Ojala, A.E.K., Dorioz, J.-M., Schimmelmann, A., Zolitschka, B., 2016b.
Urban point sources of nutrients were the leading cause for the historical
spread of hypoxia across European lakes. Proc. Natl. Acad. Sci. 113, 12655–
Jeppesen, E., Mehner, T., Winfield, I.J., Kangur, K., Sarvala, J., Gerdeaux, D., Rask, M.,
Malmquist, H.J., Holmgren, K., Volta, P., Romo, S., Eckmann, R., Sandström, A.,
Blanco, S., Kangur, A., Ragnarsson Stabo, H., Tarvainen, M., Ventelä, A.-M.,
Søndergaard, M., Lauridsen, T.L., Meerhoff, M., 2012. Impacts of climate
warming on the long-term dynamics of key fish species in 24 European lakes.
Hydrobiologia 694, 1–39.
Jeppesen, E., Søndergaard, M., Jensen, J.P., Havens, K.E., Anneville, O., Carvalho, L.,
Coveney, M.F., Deneke, R., Dokulil, M.T., Foy, B., Gerdeaux, D., Hampton, S.E.,
Hilt, S., Kangur, K., Köhler, J., Lammens, E.H. h. r., Lauridsen, T.L., Manca, M.,
Miracle, M.R., Moss, B., Nõges, P., Persson, G., Phillips, G., Portielje, R., Romo, S.,
Schelske, C.L., Straile, D., Tatrai, I., Willén, E., Winder, M., 2005. Lake responses
to reduced nutrient loading – an analysis of contemporary long-term data from
35 case studies. Freshw. Biol. 50, 1747–1771.
Jia, B., Tang, Y., Tian, L., Franz, L., Alewell, C., Huang, J.H., 2015. Impact of Fish
Farming on Phosphorus in Reservoir Sediments. Scientific Reports 5 (16617).
Jochimsen, M.C., Kümmerlin, R., Straile, D., 2013. Compensatory dynamics and the
stability of phytoplankton biomass during four decades of eutrophication and
oligotrophication. Ecol. Lett. 16, 81–89.
Jonsson, T., Setzer, M., 2015. A freshwater predator hit twice by the effects of
warming across trophic levels. Nat. Commun. 6, 5992.
Jude, D.J., Pappas, J., 1992. Fish Utilization of Great Lakes Coastal Wetlands. J. Great
Lakes Res. 18, 651–672.
Kangur, K., Kangur, P., Ginter, K., Orru, K., Haldna, M., Möls, T., Kangur, A., 2013.
Long-term effects of extreme weather events and eutrophication on the fish
community of shallow Lake Peipsi (Estonia/Russia). J. Limnol. 72, e30–e30.
Kayal, B., Abu-Ghunmi, D., Abu-Ghunmi, L., Archenti, A., Nicolescu, M., Larkin, C.,
Corbet, S., 2019. An economic index for measuring firm’s circularity: The case of
water industry. J. Behav. Exp. Finance 21, 123–129.
Keeler, B.L., Polasky, S., Brauman, K.A., Johnson, K.A., Finlay, J.C., O’Neill, A., Kovacs,
K., Dalzell, B., 2012. Linking water quality and well-being for improved
assessment and valuation of ecosystem services. Proc. Natl. Acad. Sci. 109,
Kovalenko, K.E., Johnson, L.B., Riseng, C.M., Cooper, M.J., Johnson, K., Mason, L.A.,
McKenna, J.E., Sparks-Jackson, B.L., Uzarski, D.G., 2018. Great Lakes coastal fish
habitat classification and assessment. J. Great Lakes Res. 44, 1100–1109. https://
Kümmerer, K. (Ed.), 2008. Pharmaceuticals in the Environment: Sources, Fate,
Effects and Risks. 3rd ed. Springer-Verlag, Berlin Heidelberg.
Kümmerlin, R., 1998. Taxonomical response of the phytoplankton community of
Upper Lake Con- stance (Bodensee-Obersee) to eutrophication and re-
oligotrophication. Arch. Hydrobiol. Spec. Issues Adv. Limnol. 53, 109–117.
Kummu, M., de Moel, H., Ward, P.J., Varis, O., 2011. How close do we live to water? A
global analysis of population distance to freshwater bodies. PLoS ONE 6. https://
Le Moal, M., Gascuel-Odoux, C., Ménesguen, A., Souchon, Y., Étrillard, C., Levain, A.,
Moatar, F., Pannard, A., Souchu, P., Lefebvre, A., Pinay, G., 2019. Eutrophication:
A new wine in an old bottle?. Sci. Total Environ. 651, 1–11.
Le Moigne, P.L., Colin, J., Decharme, B., 2016. Impact of lake surface temperatures
simulated by the FLake scheme in the CNRM-CM5 climate model. Tellus Dyn.
Meteorol. Oceanogr. 68, 31274.
Lenters, J.D., 2001. Long-term trends in the seasonal cycle of Great Lakes water
levels. J. Great Lakes Res. 27, 342–353.
Macura, B., Byström, P., Airoldi, L., Eriksson, B.K., Rudstam, L., Støttrup, J.G., 2019.
Impact of structural habitat modifications in coastal temperate systems on fish
recruitment: a systematic review. Environ. Evid. 8, 14.
Madenjian, C.P., Bunnell, D.B., Warner, D.M., Pothoven, S.A., Fahnenstiel, G.L.,
Nalepa, T.F., Vanderploeg, H.A., Tsehaye, I., Claramunt, R.M., Clark, R.D., 2015.
Changes in the Lake Michigan food web following dreissenid mussel invasions:
A synthesis. J. Great Lakes Res. Complex interactions in Lake Michigan’s rapidly
changing ecosystem 41, 217–231.
Magnuson, J., Meisner, J.D., Hill, D., 1990. Potential changes in the thermal habitat of
Great Lakes fish after global climate warming. Trans. Am. Fish. Soc. 119, 254–
Malley, D.F., 1980. Decreased survival and calcium uptake by the crayfish Orconectes
virilis in low pH. Can. J. Fish. Aquat. Sci. 37, 364–372.
Mani, T., Hauk, A., Walter, U., Burkhardt-Holm, P., 2015. Microplastics profile along
the Rhine River. Sci. Rep. 5, 17988.
Mazzoni, M., Buffo, A., Cappelli, F., Pascariello, S., Polesello, S., Valsecchi, S., Volta, P.,
Bettinetti, R., 2018. Perfluoroalkyl acids in fish of Italian deep lakes:
Environmental and human risk assessment. Sci. Total Environ. 653, 351–358.
McGoldrick, D.J., Murphy, E.W., 2016. Concentration and distribution of
contaminants in lake trout and walleye from the Laurentian Great Lakes
14 J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
(2008–2012). Environ. Pollut., Persistent Organic Pollutants (POPs): Trends.
Sources and Transport Modelling 217, 85–96.
McGowan, S., Juhler, R.K., Anderson, N.J., 2007. Autotrophic response to lake age,
conductivity and temperature in two West Greenland lakes. J. Paleolimnol. 39,
McLaughlin, R.L., Smyth, E.R.B., Castro-Santos, T., Jones, M.L., Koops, M.A., Pratt, T.C.,
Vélez-Espino, L.-A., 2013. Unintended consequences and trade-offs of fish
passage. Fish Fish. 14, 580–604.
Metcalfe, C.D., Helm, P., Paterson, G., Kaltenecker, G., Murray, C., Nowierski, M.,
Sultana, T., 2019. Pesticides related to land use in watersheds of the Great Lakes
basin. Sci. Total Environ. 648, 681–692.
Meybeck, M., Kummu, M., Duerr, H.H., 2013. Global hydrobelts and hydroregions:
improved reporting scale for water-related issues?. Hydrol. Earth Syst. Sci. 17,
Micklin, P., 2010. The past, present, and future Aral Sea. Lakes Reserv. Sci. Policy
Manag. Sustain. Use 15, 193–213.
Micklin, P., Aladin, N., Plotnikov, I. (Eds.), 2014. The Aral Sea: The Devastation and
Partial Rehabilitation of a Great Lake, Springer Earth System Sciences. Springer-
Verlag, Berlin Heidelberg.
Monastersky, R., 2013. Global carbon dioxide levels near worrisome milestone. Nat.
News 497, 13.
Moss, B., Kosten, S., Meerhoff, M., Battarbee, R.W., Jeppesen, E., Mazzeo, N., Havens,
K., Lacerot, G., Liu, Z., Meester, L.D., Paerl, H., Scheffer, M., 2011. Allied attack:
climate change and eutrophication. Inland Waters 1, 101–105.
Njiru, J., van der Knaap, M., Kundu, R., Nyamweya, C., 2018. Lake Victoria fisheries:
Outlook and management. Lakes Reserv. Sci. Policy Manag. Sustain. Use 23,
Nõges, T., Anneville, O., Guillard, J., Haberman, J., Järvalt, A., Manca, M., Morabito, G.,
Rogora, M., Thackeray, S.J., Volta, P., Winfield, I.J., Nõges, P., 2018. Fisheries
impacts on lake ecosystem structure in the context of a changing climate and
trophic state. J. Limnol. 77, 46–61.
Ogutu-Ohwayo, R., Hecky, R.E., Cohen, A.S., Kaufman, L., 1997. Human impacts on
the African Great Lakes. Environ. Biol. Fishes 50, 117–131.
O’Reilly, C.M., Sharma, S., Gray, D.K., Hampton, S.E., Read, J.S., Rowley, R.J.,
Schneider, P., Lenters, J.D., McIntyre, P.B., Kraemer, B.M., Weyhenmeyer, G.A.,
Straile, D., Dong, B., Adrian, R., Allan, M.G., Anneville, O., Arvola, L., Austin, J.,
Bailey, J.L., Baron, J.S., Brookes, J.D., Eyto, E. de, Dokulil, M.T., Hamilton, D.P.,
Havens, K., Hetherington, A.L., Higgins, S.N., Hook, S., Izmest’eva, L.R., Joehnk, K.
D., Kangur, K., Kasprzak, P., Kumagai, M., Kuusisto, E., Leshkevich, G.,
Livingstone, D.M., MacIntyre, S., May, L., Melack, J.M., Mueller-Navarra, D.C.,
Naumenko, M., Noges, P., Noges, T., North, R.P., Plisnier, P.-D., Rigosi, A., Rimmer,
A., Rogora, M., Rudstam, L.G., Rusak, J.A., Salmaso, N., Samal, N.R., Schindler, D.E.,
Schladow, S.G., Schmid, M., Schmidt, S.R., Silow, E., Soylu, M.E., Teubner, K.,
Verburg, P., Voutilainen, A., Watkinson, A., Williamson, C.E., Zhang, G., 2015.
Rapid and highly variable warming of lake surface waters around the globe.
Geophys. Res. Lett. 42, 10,773-10,781.
Paerl, H.W., Huisman, J., 2008. Climate. Blooms like it hot. Science 320, 57–58.
Paerl, H.W., Otten, T.G., Kudela, R., 2018. Mitigating the expansion of harmful algal
blooms across the freshwater-to-marine continuum. Environ. Sci. Technol. 52,
Paerl, H.W., Scott, J.T., McCarthy, M.J., Newell, S.E., Gardner, W.S., Havens, K.E.,
Hoffman, D.K., Wilhelm, S.W., Wurtsbaugh, W.A., 2016. It takes two to tango:
When and where dual nutrient (N & P) reductions are needed to protect lakes
and downstream ecosystems. Environ. Sci. Technol. 50, 10805–10813. https://
Phillips, J.C., McKinley, G.A., Bennington, V., Bootsma, H.A., Pilcher, D.J., Sterner, R.
W., Urban, N.R., 2015. The potential for CO
-induced acidification in freshwater:
A Great Lakes case study. Oceanography 28, 136–145.
Rahman, M.F., Yanful, E.K., Jasim, S.Y., 2009. Endocrine disrupting compounds
(EDCs) and pharmaceuticals and personal care products (PPCPs) in the aquatic
environment: implications for the drinking water industry and global
environmental health. J. Water Health 7, 224–243.
Rajeshkumar, S., Li, X., 2018. Bioaccumulation of heavy metals in fish species from
the Meiliang Bay, Taihu Lake. China. Toxicol. Rep. 5, 288–295.
Rinta-Kanto, J.M., Ouellette, A.J.A., Boyer, G.L., Twiss, M.R., Bridgeman, T.B., Wilhelm,
S.W., 2005. Quantification of toxic Microcystis spp. during the 2003 and 2004
blooms in Western Lake Erie using Quantitative Real-Time PCR. Environ. Sci.
Technol. 39, 4198–4205.
Ripple, W.J., Wolf, C., Newsome, T.M., Galetti, M., Alamgir, M., Crist, E., Mahmoud, M.
I., Laurance, W.F., 2017. World Scientists’ warning to humanity: A second
notice. Bioscience 67, 1026–1028.
Rodell, M., Famiglietti, J.S., Wiese, D.N., Reager, J.T., Beaudoing, H.K., Landerer, F.W.,
Lo, M.-H., 2018. Emerging trends in global freshwater availability. Nature 557,
Rogers, E.D., Henry, T.B., Twiner, M.J., Gouffon, J.S., McPherson, J.T., Boyer, G.L.,
Sayler, G.S., Wilhelm, S.W., 2011. Global gene expression profiling in larval
zebrafish exposed to microcystin-LR and microcystis reveals endocrine
disrupting effects of Cyanobacteria. Environ. Sci. Technol. 45, 1962–1969.
Roget, E., Khan, V.M., 2018. Decadal differences of the diurnal temperature range in
the Aral Sea region at the turn of the century. Tellus Dyn. Meteorol. Oceanogr.
70, 1–12.
Rösch, R., Baer, J., Brinker, A., 2018. Impact of the invasive three-spined stickleback
(Gasterosteus aculeatus) on relative abundance and growth of native pelagic
whitefish (Coregonus wartmanni) in Upper Lake Constance. Hydrobiologia 824,
Sand-Jensen, K., Borum, J., 1991. Interactions among phytoplankton, periphyton,
and macrophytes in temperate freshwaters and estuaries. Aquat. Bot. Ecol.
Submersed Aqu. Macrophytes 41, 137–175.
Sandström, A., Ragnarsson-Stabo, H., Axenrot, T., Bergstrand, E., 2014. Has climate
variability driven the trends and dynamics in recruitment of pelagic fish species
in Swedish Lakes Vänern and Vättern in recent decades? Aquat. Ecosyst. Health
Manag. 17, 349–356.
Schindler, D.W., 2012. The dilemma of controlling cultural eutrophication of lakes.
Proc. Biol. Sci. 279, 4322–4333.
Schindler, D.W., 1977. Evolution of phosphorus limitation in lakes. Science 195,
Schindler, D.W., 1974. Eutrophication and recovery in experimental lakes:
Implications for lake management. Science 184, 897–899.
Schmieder, K., 2004. European lake shores in danger — concepts for a sustainable
development. Limnologica, Lake-shores — Ecology, Quality Assessment.
Sustainable Dev. 34, 3–14.
Schneider, P., Hook, S.J., 2010. Space observations of inland water bodies show rapid
surface warming since 1985. Geophys. Res. Lett. 37, L22405.
Schwarzenbach, R.P., Escher, B.I., Fenner, K., Hofstetter, T.B., Johnson, C.A., von
Gunten, U., Wehrli, B., 2006. The challenge of micropollutants in
aquatic systems. Science 313, 1072–1077.
Seehausen, O., 2006. African cichlid fish: a model system in adaptive radiation
research. Proc. R. Soc. B Biol. Sci. 273, 1987–1998.
Sharma, S., Blagrave, K., Magnuson, J.J., O’Reilly, C.M., Oliver, S., Batt, R.D., Magee, M.
R., Straile, D., Weyhenmeyer, G.A., Winslow, L., Woolway, R.I., 2019. Widespread
loss of lake ice around the Northern Hemisphere in a warming world. Nat. Clim.
Change 9, 227.
Sharma, S., Gray, D.K., Read, J.S., O’Reilly, C.M., Schneider, P., Qudrat, A., Gries, C.,
Stefanoff, S., Hampton, S.E., Hook, S., Lenters, J.D., Livingstone, D.M., McIntyre, P.
B., Adrian, R., Allan, M.G., Anneville, O., Arvola, L., Austin, J., Bailey, J., Baron, J.S.,
Brookes, J., Chen, Y., Daly, R., Dokulil, M., Dong, B., Ewing, K., de Eyto, E.,
Hamilton, D., Havens, K., Haydon, S., Hetzenauer, H., Heneberry, J.,
Hetherington, A.L., Higgins, S.N., Hixson, E., Izmest’eva, L.R., Jones, B.M.,
Kangur, K., Kasprzak, P., Köster, O., Kraemer, B.M., Kumagai, M., Kuusisto, E.,
Leshkevich, G., May, L., MacIntyre, S., Müller-Navarra, D., Naumenko, M., Noges,
P., Noges, T., Niederhauser, P., North, R.P., Paterson, A.M., Plisnier, P.-D., Rigosi,
A., Rimmer, A., Rogora, M., Rudstam, L., Rusak, J.A., Salmaso, N., Samal, N.R.,
Schindler, D.E., Schladow, G., Schmidt, S.R., Schultz, T., Silow, E.A., Straile, D.,
Teubner, K., Verburg, P., Voutilainen, A., Watkinson, A., Weyhenmeyer, G.A.,
Williamson, C.E., Woo, K.H., 2015. A global database of lake surface
temperatures collected by in situ and satellite methods from 1985–2009. Sci.
Data 2, 150008.
Siefkes, M., Steeves, T., Sullivan, W., Twohey, M., Li, W. (Eds.), 2013. Sea Lamprey
control: past, present, and future. Great Lakes Fish. Policy Manag. Eds Taylor
WW Lynch AJ Leonard NJ Mich. Second. State Univ. Press East Lansing MI, pp.
Sierszen, M.E., Morrice, J.A., Trebitz, A.S., Hoffman, J.C., 2012. A review of selected
ecosystem services provided by coastal wetlands of the Laurentian Great Lakes.
Aquat. Ecosyst. Health Manag. 15, 92–106.
Sierszen, M.E., Schoen, L.S., Kosiara, J.M., Hoffman, J.C., Cooper, M.J., Uzarski, D.G.,
2019. Relative contributions of nearshore and wetland habitats to coastal food
webs in the Great Lakes. J. Great Lakes Res. 45, 129–137.
Sinha, E., Michalak, A.M., Balaji, V., 2017. Eutrophication will increase during the
21st century as a result of precipitation changes. Science 357, 405–408. https://
Smith, B.R., Tibbles, J.J., 1980. Sea Lamprey (Petromyzon marinus) in Lakes Huron,
Michigan, and Superior: History of Invasion and Control, 1936–78. Can. J. Fish.
Aquat. Sci. 37, 1780–1801.
Smith, S.D.P., Bunnell, D.B., Burton Jr., G.A., Ciborowski, J.J.H., Davidson, A.D.,
Dickinson, C.E., Eaton, L.A., Esselman, P.C., Evans, M.A., Kashian, D.R., Manning,
N.F., McIntyre, P.B., Nalepa, T.F., Perez-Fuentetaja, A., Steinman, A.D., Uzarski, D.
G., Allan, J.D., 2019. Evidence for interactions among environmental stressors in
the Laurentian Great Lakes. Ecol. Ind. 101,.
ecolind.2019.01.010 203211.
Smith, S.D.P., Mcintyre, P.B., Halpern, B.S., Cooke, R.M., Marino, A.L., Boyer, G.L.,
Buchsbaum, A., Burton, G.A., Campbell, L.M., Ciborowski, J.J.H., Doran, P.J.,
Infante, D.M., Johnson, L.B., Read, J.G., Rose, J.B., Rutherford, E.S., Steinman, A.D.,
Allan, J.D., 2015. Rating impacts in a multi-stressor world: a quantitative
assessment of 50 stressors affecting the Great Lakes. Ecol. Appl. Publ. Ecol. Soc.
Am. 25, 717–728.
J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx 15
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
Snyder, S.A., Westerhoff, P., Yoon, Y., Sedlak, D.L., 2003. Pharmaceuticals, personal
care products, and endocrine disruptors in water: Implications for the water
industry. Environ. Eng. Sci. 20, 449–469.
Soranno, P.A., Cheruvelil, K.S., Webster, K.E., Bremigan, M.T., Wagner, T., Stow, C.A.,
2010. Using landscape limnology to classify freshwater ecosystems for multi-
ecosystem management and conservation. Bioscience 60, 440–454. https://doi.
Steffen, M.M., Belisle, B.S., Watson, S.B., Boyer, G.L., Wilhelm, S.W., 2014. Status,
causes and controls of cyanobacterial blooms in Lake Erie. J. Great Lakes Res. 40,
Steffen, W., Crutzen, P.J., McNeill, J.R., 2007. The Anthropocene: Are humans now
overwhelming the great forces of Nature?. Ambio 36, 614–621.
Sterner, R.W., Keeler, B., Polasky, S., Poudel, R., Rhude, K., Rogers, M., 2020.
Ecosystem services of Earth’s largest freshwater lakes. Ecosyst. Serv. 41,. https:// 101046.
Stich, H.B., 2004. Back again: The reappearance of Diaphanosoma brachyurum in
Lake Constance. Arch. Für Hydrobiol. 423–431.
Straile, D., 2015. Zooplankton biomass dynamics in oligotrophic versus eutrophic
conditions: a test of the PEG model. Freshw. Biol. 60, 174–183.
Straile, D., Kerimoglu, O., Peeters, F., 2015. Trophic mismatch requires seasonal
heterogeneity of warming. Ecology 96, 2794–2805.
Sweka, J.A., Neuenhoff, R., Withers, J., Davis, L., 2018. Application of a depletion-
based stock reduction analysis (DB-SRA) to lake sturgeon in Lake Erie. J. Great
Lakes Res. 44, 311–318.
Tammeorg, O., Möls, T., Niemistö, J., Holmroos, H., Horppila, J., 2017. The actual role
of oxygen deficit in the linkage of the water quality and benthic phosphorus
release: Potential implications for lake restoration. Sci. Total Environ. 599–600,
Thackeray, S.J., Jones, I.D., Maberly, S.C., 2008. Long-term change in the phenology of
spring phytoplankton: species-specific responses to nutrient enrichment and
climatic change. J. Ecol. 96, 523–535.
Thomas, G., Eckmann, R., 2007. The influence of eutrophication and population
biomass on common whitefish (Coregonus lavaretus) growth — the Lake
Constance example revisited. Can. J. Fish. Aquat. Sci. 64, 402–410. https://doi.
Trebitz, A.S., Hoffman, J.C., 2015. Coastal Wetland Support of Great Lakes Fisheries:
Progress from Concept to Quantification. Trans. Am. Fish. Soc. 144, 352–372.
Uslu, M.O., 2012. Chemicals of Emerging Concern in the Great Lakes Region.
International Joint Commission.
Uzarski, D.G., 2009. Wetlands of Large Lakes. In: Likens, G.E. (Ed.), Encyclopedia of
Inland Waters. Academic Press, Oxford, pp. 599–606.
Uzarski, D.G., Brady, V.J., Cooper, M.J., Wilcox, D.A., Albert, D.A., Axler, R.P., Bostwick,
P., Brown, T.N., Ciborowski, J.J.H., Danz, N.P., Gathman, J.P., Gehring, T.M.,
Grabas, G.P., Garwood, A., Howe, R.W., Johnson, L.B., Lamberti, G.A., Moerke, A.
H., Murry, B.A., Niemi, G.J., Norment, C.J., Ruetz, C.R., Steinman, A.D., Tozer, D.C.,
Wheeler, R., O’Donnell, T.K., Schneider, J.P., 2017. Standardized Measures of
Coastal Wetland Condition: Implementation at a Laurentian Great Lakes Basin-
Wide Scale. Wetlands 37, 15–32.
Vadeboncoeur, Y., McIntyre, P.B., Vander Zanden, M.J., 2011. Borders of Biodiversity:
Life at the Edge of the World’s Large Lakes. Bioscience 61, 526–537. https://doi.
Vincent, W.F., 2018. Lakes: A Very Short Introduction. Oxford University Press.
Vincent, W.F., 2020. Arctic Climate Change: Local Impacts, Global Consequences,
and Policy Implications. In: Coates, K.S., Holroyd, C. (Eds.), The Palgrave
Handbook of Arctic Policy and Politics. Springer International Publishing, Cham,
pp. 507–526.
Vinogradov, G.A., Klerman, A.K., Komov., V.T., 1987. Peculiarities of ion exchange in
the freshwater molluscs at high hydrogen ion concentrations and low salt
content in the water. Ekologiya 3, 81–84.
Visha, A., Gandhi, N., Bhavsar, S.P., Arhonditsis, G.B., 2018. A Bayesian assessment of
polychlorinated biphenyl contamination of fish communities in the Laurentian
Great Lakes. Chemosphere 210, 1193–1206.
Vollenweider, 1968. Water management research. Scientific fundamentals of the
eutrophication of lakes and flowing waters with particular reference to nitrogen
and phosphorus as factors in eutrophication. Organization for Economic Co-
operation and Development. Directorate for Scientific Affairs. Paris. Current
status of research on eutrophication in Europe, the United States and Canada, 20
p. Limnol. Oceanogr. 15, 169–170.
Volta, P., Jeppesen, E., Sala, P., Galafassi, S., Foglini, C., Puzzi, C., Winfield, I.J., 2018.
Fish assemblages in deep Italian subalpine lakes: history and present status
with an emphasis on non-native species. Hydrobiologia 824, 255–270. https://
Vonlanthen, P., Bittner, D., Hudson, A.G., Young, K.A., Müller, R., Lundsgaard-Hansen,
B., Roy, D., Di Piazza, S., Largiader, C.R., Seehausen, O., 2012. Eutrophication
causes speciation reversal in whitefish adaptive radiations. Nature 482, 357–
Vörösmarty, C.J., Green, P., Salisbury, J., Lammers, R.B., 2000. Global water
resources: Vulnerability from climate change and population growth. Science
289, 284–288.
Wang, W., Lee, X., Xiao, W., Liu, S., Schultz, N., Wang, Y., Zhang, M., Zhao, L., 2018.
Global lake evaporation accelerated by changes in surface energy allocation in a
warmer climate. Nat. Geosci. 11, 410–414.
Weisner, S.E.B., Strand, J.A., Sandsten, H., 1997. Mechanisms regulating abundance
of submerged vegetation in shallow eutrophic lakes. Oecologia 109, 592–599.
Weyhenmeyer, G.A., Broberg, N., 2014. Increasing algal biomass in Lake Vänern
despite decreasing phosphorus concentrations: A lake-specific phenomenon?
Aquat. Ecosyst, Health Manag.
Whillans, T.H., 1982. Changes in marsh area along the Canadian Shore of Lake
Ontario. J. Great Lakes Res. 8, 570–577.
Whish-Wilson, P., 2002. The Aral Sea environmental health crisis. Journal of Rural
and Remote Environmental Health 1, 29–34.
Wilhelm, S.W., DeBruyn, J.M., Gillor, O., Twiss, M.R., Livingston, K., Bourbonniere, R.
A., Pickell, L.D., Trick, C.G., Dean, A.L., McKay, R.M., 2003. Effect of phosphorus
amendments on present day plankton communities in pelagic Lake Erie. Aquat.
Microb. Ecol. 32, 275–285.
Willén, E., 2001. Phytoplankton and water quality characterization: experiences
from the Swedish large lakes Mälaren, Hjälmaren, Vättern and Vänern. Ambio
30, 529–537.
Williamson, C.E., Saros, J.E., Vincent, W.F., Smol, J.P., 2009. Lakes and reservoirs as
sentinels, integrators, and regulators of climate change. Limnol. Oceanogr. 54,
Winder, M., Schindler, D.E., 2004. Climatic effects on the phenology of lake
processes. Glob. Change Biol. 10, 1844–1856.
Winkler, K.A., Pamminger-Lahnsteiner, B., Wanzenböck, J., Weiss, S., 2011.
Hybridization and restricted gene flow between native and introduced stocks
of Alpine whitefish (Coregonus sp.) across multiple environments. Mol. Ecol. 20,
Woolway, R.I., Kraemer, B.M., Lenters, J.D., Merchant, C.J., O’Reilly, C.M., Sharma, S.,
2020. Global lake responses to climate change. Nat Rev Earth Env In press.
Woolway, R.I., Merchant, C.J., 2019. Worldwide alteration of lake mixing regimes in
response to climate change. Nat. Geosci. 12, 271–276.
Woolway, R.I., Merchant, C.J., 2018. Intralake heterogeneity of thermal responses to
climate change: A sudy of large Northern Hemisphere lakes. J. Geophys. Res.
Atmospheres 123, 3087–3098.
Wurtsbaugh, W.A., Miller, C., Null, S.E., DeRose, R.J., Wilcock, P., Hahnenberger, M.,
Howe, F., Moore, J., 2017. Decline of the world’s saline lakes. Nat. Geosci. Doi
Wurtsbaugh, W.A., Paerl, H.W., Dodds, W.K., 2019. Nutrients, eutrophication and
harmful algal blooms along the freshwater to marine continuum. WIREs Water
6,. e1373.
Xi, X., Sokolik, I.N., 2016. Quantifying the anthropogenic dust emission from
agricultural land use and desiccation of the Aral Sea in Central Asia. J. Geophys.
Res. Atmospheres 121, 12270–12281.
Zhong, Y., Notaro, M., Vavrus, S.J., Foster, M.J., 2016. Recent accelerated warming of
the Laurentian Great Lakes: Physical drivers. Limnol. Oceanogr. 61, 1762–1786.
16 J.-P. Jenny et al. / Journal of Great Lakes Research xxx (xxxx) xxx
Please cite this article as: J.-P. Jenny, O. Anneville, F. Arnaud et al., Scientists’ Warning to Humanity: Rapid degradation of the world’s large lakes, Journal of
Great Lakes Research,
... The nearshore regions of the Great Lakes host inordinate amounts of biodiversity (Vadeboncoeur et al., 2011), but the proximity of the species' habitats to terrestrial environments results in a greater susceptibility to anthropogenic stressors (Allan et al., 2013;Riseng et al., 2018). Maintaining these ecosystems is not a simple task as lakes, and in particular, the Great Lakes, are complex ecosystems with varying interacting internal and catchment-scale influences from invasive species to local climate, geology, and land cover (e.g., Allan et al., 2013;Goforth and Carman, 2005;Riseng et al., 2018;Jenny et al., 2020). ...
... Moreover, the Great Lakes coastal regions are sensitive to the influences of climatic change, including warming air temperatures, storm events, watershed inflows, and seasonal and annual water level fluctuations (Blagrave et al., 2022;Jenny et al. 2020;Trumpickas et al., 2015). For example, in response to warming air temperatures, summer surface water temperatures in the Great Lakes are warming faster than the global average (O'Reilly et al., 2015). ...
We provide the first comprehensive analysis of spatial heterogeneity in water quality across the Canadian nearshore regions of the Laurentian Great Lakes (LGL) with periodic sampling in the ice-free seasons from 2000 to 2019 for 24 water quality variables from 52 nearshore sites. We asked: (1) What is the extent, range, and magnitude of spatial heterogeneity in water quality conditions across the nearshore of the Canadian Great Lakes? and (2) How do features of anthropogenic development, sub-basin characteristics, anticipated coastal circulation, and weather influence water quality conditions in the nearshore of the Canadian Great Lakes? Principal Components Analysis explained 42% of the variation in water quality across the Canadian Great Lakes, with high spatial heterogeneity both within and among lakes, ranging from oligotrophic conditions in Lake Superior to eutrophic conditions in Lake Erie. Lakes Erie and Ontario generally had higher concentrations of chloride, chlorophyll a, and nutrients while higher silicate concentrations were observed in Lake Superior. Consistent patterns of degraded water quality were observed in Areas of Concern, such as Hamilton Harbour, Bay of Quinte, Nipigon Bay, and near Thunder Bay. Across the nearshore of the Canadian Great Lakes, regions with warmer air temperatures, in addition to urbanized and agricultural landscapes, were associated with deteriorated water quality. Our study highlights the importance of improving management practices across urban and agricultural landscapes, particularly in consideration of climatic change cumulatively degrading water quality conditions in the highly biologically, culturally, and socioeconomically important nearshore regions of the LGL.
... Deep lakes are particularly exposed to the double threat posed by climate change through increased temperature and its effect on nutrient cycling (Jenny et al., 2020). However, the complex implication of these two factors on lake water quality and ecosystem functioning remains largely unresolved. ...