River doctors: Learning from medicine to improve
, Roger G. Young
Faculty of Science and Technology, University of the Basque Country (UPV/EHU), PO Box 644, 48080 Bilbao, Spain
Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, 16775 Stechlin, Germany
Department of Ecology, Berlin Institute of Technology (TU Berlin), Ernst-Reuter-Platz 1, 10587 Berlin, Germany
Cawthron Institute, Private Bag 2, Nelson, New Zealand
Received 9 J anuary 2017
Received in revised form 19 March 2017
Accepted 20 March 2017
Available online xxxx
Editor: D. Barcelo
Effective ecosystem management requires a robust methodology to analyse, remedy and avoid ecosystem dam-
age. Here we propose that the overallconceptualframework and approaches developed over millennia in med-
ical scienceand practice to diagnose, cure and prevent disease can provide anexcellent template. Key principles
to adopt include combiningwell-establishedassessment methods with new analyticaltechniques and restricting
both diagnosis and treatment to qualiﬁed personnel at various levels of specialization, in addition to striving for a
better mechanistic understanding of ecosystem structure and functioning, as well as identifying the proximate
and ultimate causes of ecosystem impairment. In addition to applying these principles, ecosystem management
would much beneﬁt from systematically embracing how medical doctors approach and interview patients, diag-
nose health condition, select treatments, take follow-up measures, and prevent illness. Here we translate the
overall conceptual framework from medicineinto environmental terms and illustrate with examples from rivers
how the systematic adoption of the individual steps proven and tested in medical practice can improve ecosys-
© 2017 Elsevier B.V. All rights reserved.
Human activities are now shaping the earth surface (Vitousek et al.,
1997; Foley et al., 2005) to an extent that many contend a new geological
epoch has begun, the Anthropocene (Zalasiewicz et al., 2010; Ruddiman
et al., 2015). The accelerated transformation of earth is beginning, in
turn, to threaten human society itself (Gleick and Palaniappan, 2010;
Steffen et al., 2015), prompting calls for adopting sustainability principles
and ecosystem stewardship (Chapin et al., 2010). These goals require an
effective methodology to manage ecosystems to maintain biodiversity
and ensure the continued provision of ecosystem services valued by soci-
ety (Zhenga et al., 2013; Costanza et al., 2014).
Rapport (1995) pointed out that the similarities between ecosystem
integrity and human health and its assessment go beyond an analogy,
although this recognition has not gained strong traction. Indeed, apart
from controversial discussions about whether ecosystem health is a
valid scientiﬁcconcept(Jax, 2010), there have been few attempts to
scrutinize the degree to which principles and practices from medicine
can be useful in ecosystem management. The central tenet of this
paper is that much can be learned from how patients are diagnosed,
treated and subsequent illness prevented, to improve the ways in
which ecosystems are assessed and restored, and undesirable condi-
tions avoided in the ﬁrst place, since the fundamental methodological
issues are strikingly similar. Therefore, the conceptual framework of
medical health protocols holds tremendous potential to beneﬁtecosys-
tem management by appropriately translating concepts and practices
(e.g. Barton et al., 2015). This tenet is independent of whether one sub-
scribes or objects to the concept of ecosystem health (Rapport et al.,
1998; Simberloff, 1998; Karr, 1999; Boulton, 1999; Meyer et al., 2005;
Jax, 2005). An important advantage of adopting the medical analogy is
that it provides common intuitive ground of concepts and terms,
which facilitates interactions among different people and disciplines
participating in ecosystem management (scientists, policy makers,
stakeholders etc.). Although is clear that one cannot ignore the funda-
mental difference between humans and ecosystems, which, for in-
stance, neither reproduce nor die, this recognition does not invalidate
the usefulness of the parallel.
Conventional medicine is the result of knowledge accumulated at
least since the Greek physician Hippocrates over 2500 years ago. Never-
theless, it has only been during the last 150 years that great leaps for-
ward have been made, with medical innovation and improvements
Science of the Total Environment 595 (2017) 294–302
☆Authorship —all authors conceived and wrote the paper.
E-mail addresses:email@example.com (A. Elosegi), firstname.lastname@example.org
(M.O. Gessner), email@example.com (R.G. Young).
0048-9697/© 2017 Elsevier B.V. All rights reserved.
Contents lists available at ScienceDirect
Science of the Total Environment
journal homepage: www.elsevier.com/locate/scitotenv
rapidly accelerating at present. The success of conventional medicine
lies in its systematic approach, its capacity to adopt scientiﬁc and tech-
nological innovations, its use of controlled trials and detailed case-stud-
ies as sources of evidence, and also its adherence to a suite of basic
principles, along with substantial resourcing for research and patient-
centered care. As we illustrate below, these points can be adapted to
ecosystem management. Many have already been applied in various
contexts, but we argue that substantial further beneﬁts can be gained
from systematically embracing the principles of medical practice as a
Here we ﬁrst identify a series of key medical principles to highlight
their potential for ecosystem management. Then we illustrate how spe-
ciﬁc steps of the medical methodology (i.e. how physicians approach
and interview patients, diagnose their condition, select treatments,
take follow-up measures, and prevent illness) can be translated into
ecosystem management. Finally, we highlight a set of treatment rules
that have proven powerful in medical practice. The speciﬁc examples
relating to ecosystem management that we provide are drawn from riv-
ers to ensure a tangible and coherent account (Table 1), but we expect
that the general lessons we derive are similarly applicable to other
types of ecosystems.
2. Embracing medical principles
Despite the diversity of medical ﬁelds, all physicians follow a series
of core principles. Six among these appear to be especially relevant for
2.1. Understanding structure and function
The ﬁrst principle is to base practice on a detailed understanding of
the anatomy, physiology and functioning of the healthy human body.
Similarly, ecosystem management is best based on mechanistic insights
into the structure of ecosystems unaffected by anthropogenic pressures
(i.e. their constituent elements, including organisms and abiotic factors,
their spatial conﬁguration and temporal dynamics) and into the pro-
cesses that connect the individual elements. The functional dimension
of ecosystems has long been ignored in river assessments, although an
emerging awareness of its importance (Bunn et al., 1999; Gessner and
Chauvet, 2002) increasingly leads to including functional indicators in
assessment protocols (Young et al., 2008; Yates et al., 2014). The
consequence of adopting these principles is that continuous investment
is required to improve understanding of the structure and functioning
of unaffected ecosystems that serve as benchmarks toevaluate impacts.
2.2. Identifying causes and mechanisms
A second medical principle rests on the premise that the causes and
mechanisms of an illness should be understood before prescribing a
cure, so the odds are high that the treatment is effective and does no
harm. During much of human history, disorder and disease were erro-
neously interpreted as a result of agents such as evil spirits and disequi-
librium in vital force (Maher, 1999; Ismail et al., 2005). Finding an
effective cure on this basis was a matter of luck combined with past ex-
perience, and medical advances were slow. Today, the causes of a vast
number of illnesses have been identiﬁed, including external agents
such as infectious diseases or poisons, internal physiological or genetic
disorders, dietary deﬁciencies, or disorders with mixed causes. The un-
derlying mechanisms are often well understood at levels ranging from
biochemical reactions to global epidemic outbreaks.
Similarly, changes in ecosystems can be caused by external agents
(e.g. pollutants, invasive species), internal factors (e.g. natural changes
in species distribution or population genetic structure) or, commonly,
mixed causes (multiple stressors). Changes caused by internal factors
may not be perceived as impairment, thus limiting the analogy between
human bodies and ecosystems. However, since natural processes can
lead to undesirable states of ecosystems, for example from a conserva-
tion or productivity point of view, the fundamental problems posed to
ecosystem management and physicians in practice still remain very
similar.Irrespective of thenature of ecosystemchange, it is critically im-
portant for taking effective management measures to identify the prox-
imate (e.g. excessive nutrient supply) and ultimate (e.g. climate or land-
use change) factors causing a particular symptom (e.g. lack of ﬁsh or ex-
cessive algal growth).
2.3. Deﬁning goals depending on context
Individual medical ﬁelds differ in their focus and speciﬁcgoals.Rou-
tine checks involve basic techniques to detect incipient health problems
and assess the general health status of a broad population. Sports med-
icine, in contrast, seeks to maximize physical performance in an elite
group of athletes. Plastic surgery focuses on aesthetics, which may or
A selection of parallels between medicine and river ecosystem management.
Focus General purpose Medicine River management
Diagnosis Routine examination Body temperature, heart rate, physical examination, weight,
breathing (asthma, silicosis, pneumonia…)
Water temperature, ﬂow, river habitat survey, conductivity, oxygen
deﬁcit (ground water, organic matter…)
Speciﬁc test Blood examination, electrocardiogram Detailed water chemistry, oxygen dynamics, hydrology
Microbiological analysis of pathogens Microbiological analysis of pathogens
Structural integrity Radiology, physical examination Community composition of biotic elements
Poisoning Toxicology Ecotoxicology
Risk assessment DNA analyses for tumor screening and tumor susceptibility Molecular community analyses to detect invasive species
Treatment Structure restoration Regenerative surgery Channel restoration
Tumor removal Dam, levee or pipe removal
Aesthetics Plastic surgery Landscaping
Diet restriction Nutrient control
Insulin injection Liming
Palliative treatment Dialysis Flushing ﬂow releases
Prevention Guidelines Healthy life-style Best management practices, sound resource management planning
Regulation Health and safety regulation Environmental regulations
Protection Condom, sunscreen Bio-security measures to prevent spread of invasives, waste water
Enhance resilience Wound-healing drugs Enhance river connectivity
Enhance resistance Vaccination Maintenance of genetic diversity
Education Health education Environmental education
295A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
may not be related to physical or psychological health issues. Regenera-
tive medicine focuses on restoring essential body functioning in patients
suffering severe damage. Finally, palliative medicine seeks to alleviate
the suffering of patients with terminal illness, not to recover their
health. Thus, to deal with different goals, medicinehas developed differ-
ent approaches and methods, all subject to equally stringent training
and monitoring programs.
Ecosystem management faces strikingly parallel situations (Table 1).
For instance, agencies in many parts of the world routinely monitor riv-
ers by measuring basic chemical variables (e.g. pH, oxygen, nutrients)
and determining biological community composition. Speciﬁcally
adapted protocols are used in some rivers vulnerable to a particular
type of chemical pollution (e.g. pesticide analyses) or receiving special
protection to conserve biodiversity (e.g. assessment of pearl mussel re-
cruitment). Similarly, restoration works reintroducing large wood and
boulders in river channels with heavy machinery (Nilsson et al., 2005)
are analogous to regenerative medicine, while channel reconﬁguration
to enhance visual appeal has parallels with aesthetic surgery. Despite
these different goals, ecosystem managers tend to apply standard sets
of tools, borrowed from one domain for another. For example, metrics
developed for the EU Water Framework Directive (WFD), whose objec-
tive is to achieve “good ecological status”in all water bodies, are applied
to rivers protected under the EU Natura 2000 network, whose goal is to
preserve biodiversity in a subset of ecosystems. Clearly, maladapted
methods are generally unsuccessful, suggesting that much can be
gained by developing and critically evaluating speciﬁc approaches for
contrasting management goals.
2.4. Developing and applying the best possible technology
A fourth principle of conventional medicine is to constantly enhance
established methodology with new technology. Medical laboratories in-
vest large amounts of money to develop and improve techniques, some
of many recentexamples being positron emission tomography, metabo-
lomics or robotic surgery. Ecosystem management has also beneﬁted
from technological advances. Notable examples are large-scale analyses
by remote sensing (Stumpf et al., 2012) or water quality monitoring
with permanently deployed sensors, which enables ﬁne-scale analysis
of temporal trends in water quality and whole-ecosystem metabolism
(e.g., Clapcott et al., 2016; Val et al., 2016).
Such technological progress notwithstanding, the tools routinely
used in ecosystem management are still crude by comparison. This is
partly due to incomparably smaller budgets that society is willing to in-
vest in environmental counterparts of human health. However, the
much more limited funds mobilized for environmental issues, do notin-
validate the principle that constantly seeking improvement is essential
to progress in the long run. Further, budgets and opportunities are likely
to grow as environmental technologies improve (e.g. through radically
new approaches to species surveys such as eDNA analyses; Rees et al.,
2014, Goldberg et al., 2016) and environmental awareness grows, not
least in the context of the burgeoning One Health approach
(Uchtmann et al., 2015) that recognizes the impact of environmental
conditions on human health.
2.5. Employing reliable designs
Related to the principle of developing and applying the best possible
technology are the constant efforts in medicine to improve study de-
signs. Of particular concern is the fact that medical assessments are eas-
ily misled by false positives, so that success tends to be overestimated
(Dresselhaus et al., 2002). Historically, this is exempliﬁed by the prepos-
terous practice of blood-letting, which, although ineffective, if not detri-
mental, used to be extremely popular (Wootton, 2006). Approaches
such as double-blind tests have been devised to preclude bias in judge-
ment, and allowed establishment of what is known as evidence-based
medicine (Sackett et al., 1997; Grol and Grimshaw, 2003).
Ecosystem management would beneﬁt from similarly stringent pro-
cedures to evaluate remediative action (Sutherland et al., 2004, 2015),
particularly by fully embracing the weight-of-evidence approach also
used in risk assessment (Weed, 2005; Chapman, 2007). Regrettably, it
is still not uncommon in present practice that agencies continue to in-
vest money into ecosystem management measures that lack a sound
theoretical basis or empirical supportive evidence. This needs to change.
For instance, as argued by Ollero (2011), the so-called “river parks”cre-
ated for conservation purposes in Spain have resulted in more environ-
mental harm than beneﬁt,which prompted him to callfor a moratorium
on action until the basics of river restoration are well understood by the
authorities. A ﬁrst step towards adopting the stringent medical proce-
dures to assessments of restoration effectiveness would beto require in-
dependent accredited experts to conduct these assessments.
2.6. Relying on speciﬁcally trained personnel
A sixth principle is that medicine is practiced exclusively by speciﬁ-
cally trained and qualiﬁed staff. Even apparently simple procedures,
such as taking blood samples, are restricted to trained personnel, either
medical doctors or nurses. Furthermore, there is a clear-cut distinction
among the tasks that each person is allowed to perform, from the
nurse to the general practitioner and specialist, and from the anesthesi-
ologist to the surgeon. Additionally, most modern health systems have
established procedures to ensure speciﬁc professional education, recog-
nizing that continued learning is mandatory to keep up with medical
advances (Schrock and Cydulka, 2006). Importantly, training must be
sufﬁcient to enable recognition not only of common but also of rare
health problems. This is the reason why it is compulsory to have exten-
sive clinical training in hospitals, where a much larger range of disorders
is encountered than in a general practitioner's ofﬁce.
The lesson for ecosystem management is that procedures need to be
devised, implemented and enforced to train and certify professionals, as
human error jeopardizes reliable assessments and treatment success
(Haase et al., 2010). This includes clear deﬁnition of the functions and
aptitudes of particular categories of staff, ranging from sampling and
sorting to identifying organisms, and from straightforward chemical or
hydrological analyses to sophisticated chemical analytics or the design
of large-scale restoration projects. Deﬁning the learning trajectory in
the education of practitioners is equally important, preferably at an in-
ternational level. First steps have been taken by learned societies (e.g.
Ecological Society of America, Society for Freshwater Science) to estab-
lish accreditation systems based on training and certiﬁcation of special-
ized ecologists. However, the systems in place (e.g. the Society for
Freshwater Science Taxonomic Certiﬁcation Program; http://www.
sfstcp.com) are neither comprehensive nor legally binding. Reﬁnement,
wide application and legal establishment are needed to ensure that spe-
cialized staff perform specialized tasks. Similar to clinical training in
hospitals, training would be particularly effective if it included extensive
visits of case studies where speciﬁc stressors play a role and have been
3. A medicine-inspired approach to ecosystem management
Medical doctors follow a stepwise procedure to diagnose impair-
ment, prescribe treatments and follow up the evolution of patients.
This strict sequence of action can serve as a rule for ecosystem manage-
The ﬁrst step in curing a disease is an accurate and precise diagnosis.
Medical diagnosis starts with anamnesis, where physicians examine the
medical history of patients and inquire about personal matters such as
general constitution, profession and life-style before asking questions
about the particular health problem. Anamnesis is a key step, as a
296 A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
patient's medical history can be critical to understand current symp-
toms, assess health risks or prevent particular therapeutic approaches
(Coulehan and Block, 2005). Likewise, historical information on im-
paired ecosystems, such as past toxic spills, chronic pollution, species in-
troductions, or geomorphological modiﬁcations, should be gathered to
identify legacies not immediately evident. Notably, legacies can include
incidences remote from the siteof enquiry, because of long-distance at-
mospheric or river transport, thus necessitating expansion of anamnesis
to whole drainage basins or potentially even larger areas. Historical en-
vironmental data tend to be limited and unreliable, which puts ecosys-
tem managers in a position akin to that of medical doctors working in
situations where a functioning medical system is lacking (e.g. in some
rural areas of developing countries or regions affected by conﬂict). It
is, nonetheless, important to gather all available information, and to
be able to discern the parts that can be most relevant and reliable.
Medical interviews follow prescribed protocols with questions that
go beyond the stated problems (Stoeckle and Billings, 1987). Informa-
tion such as age, job and habits (smoking, alcohol consumption, partic-
ipation in high-risk sports) is routinely considered to evaluate the
diagnostic ﬁndings in context and to pinpoint the most likely issues. Im-
portantly, physicians are aware that patients often provide incomplete
or incorrect information, and exaggerate or play down symptoms
(Nardone et al., 1992). Therefore, seemingly irrelevant questions are de-
vised to gain contextual information, including delicate issues such as
family abuse, without the patient suspecting the intention. When eco-
system managers interview stakeholders to gather information on the
history and state of impaired ecosystems, the same precautions apply
but are rarely recognized: stakeholders can give incomplete, partial,
narrow, exaggerated, or plainly inaccurate information (Box 1). There-
fore, questions must be carefully designed and responses cautiously an-
alyzed to serve ecosystem management as well as anamnesis helps
physicians in diagnosis.
3.2. Differential diagnosis
Anamnesis is followed by medical examination combining the
collection of both general and speciﬁc evidence to identify likely
health problems (Stoeckle and Billings, 1987). Since most symptoms
can have multiple causes, the goal is to narrow down the possible or-
igins of a problem by applying a set of criteria to distinguish between
alternative diseases. This is the purpose and approach of differential
diagnosis. Examinations routinely start by monitoring general vari-
ables such as body weight, heart rate and blood pressure before
applying speciﬁc diagnostics. Sometimes general practitioners di-
rectly make measurements, sometimessamples(blood,urine,etc.)
or the patients are sent for analyses or examinations requiring spe-
ciﬁc expertise or equipment (e.g., analytical laboratory, radiologist,
cardiologist). Physicians can employ a huge diagnostic toolbox, and
selecting the most meaningful tests can be challenging. Although ex-
perience and intuition play a role, accurate diagnosis is primarily a
result of logical reasoning. This includes identifying the most rele-
vant indicators, taking into account the prevalence of diseases in dif-
ferent sectors of society (Fig. 1A–D).
Diagnosis and treatment of an impaired river ecosystem: Hypothetical
Stream is a mountain stream with an abnormally low abundance of
Step 1. Anamnesis
Gather information about the stream, including geology and
catchment land use, and question water managers and local resi-
dents. The local angling association reports huge fish catches in
the past. The Wildlife Service states that trout densities in thepast
were not extraordinarily high. Rangers assert that trout abundance
has declined, but cannotsay whether the declinehad been gradual
or sudden. Similar declines are not evident in other streams in the
region. A dairy farm present in the catchment for over 100 years
changed farming practices about 15 years ago. Other potential
stressors include extensive landfills originating from mines aban-
doned decades ago, which have not changed over the last
20 years. There is also no evidence of a region-wide stressor,such
as acid rain or pesticide use.
Step 2. Differential diagnosis
Start gathering existing information and measuring general indica-
tor variables. Instream habitat is appropriate for trout. Local water
authorities providedata on water quality and invertebrate commu-
nities, which do not indicate a problem. No change has been de-
tected in flow regime. The riparian vegetation is intact. Based on
this information, initial hypotheses are formulated about causes
of the trout decline.
Analyze specific indicators with special attention given to effects
of the farm (growth of filamentous algae, anoxia, etc.) and mine
waste (pH, metal concentrations). Litter decomposition is slower
than in similar streams nearby. Diatom communities suggest inci-
dences of acidification and metal pollution, supporting the initial
hypothesis of mining impact. The trout population is dominated
by old fish. Other indicators, such as growth of benthic algae
protected from grazing, are within a normal range.
Obtain information on acidification. Bioassays confirm that adult
trout survive in the stream for at least 20 days. However, trout
and stream sediments show elevated metal concentrations. Mon-
itoring during rainfall events revealsepisodes of low pH (b4.5) and
high metal concentrations, suggesting leachate of mine waste
from the landfills into the stream.
Broaden the spatial scope. Incorporate tools for differential diag-
nosis. The catchment upstream appears to have experienced little
influence from human activity. Few changes have occurred in the
last decades, except for the dairy farm. A low dam effective as a
fish barrier was built 13 km downstream 16 years ago.
A diagnosis is finally reached. The periodic leaching of acidic mine
waste during occasional heavy rainfall affects the trout popula-
tion, although it does not cause adult fish mortality. The problem
has probably been chronic for a long time, but fish re-colonizing
from downstream disguised the lack of recruitment. The dam con-
struction prevented re-colonization, and thus,the population grad-
Step 3. Treatment
Address both factors supposed to have caused the trout decline.
First, divert rainwater to prevent seepage of mine waste from
the landfill. Secondly, re-establish longitudinal connectivity by
installing a fish ladder in the dam, ensuring that juvenile trout
can pass but invasive black bass in the lower reaches cannot.
Step 4. Monitoring
Monitor trout density and age structure on an annual basis for five
years following the remediation measures. Establish a stream-wa-
ter monitoring programme to determine whether heavy rainfall
leads to acid pulses. Monitor the stream reach upstream of the
dam by bimonthly environmental DNA analyses and annual elec-
trofishing to track whether black bass have invaded. Stock the up-
stream reach with young-of-the-year trout caught downstream,
and set aside funds to address any upstream incursions of black
Step 5. Dissemination
The diagnosis, treatment and results of the monitoring are shared
worldwide ina scientific journal article and on a dedicated website
(e.g. Sutherland et al., 2004).
297A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
Differential diagnosis is equally applicable to ecosystems (Fig. 2),
where it could be deﬁned as a systematic approach to distinguish,
based on unique sets of characteristics, between two or more potential
causes of ecosystem impairment that share symptoms. Differential di-
agnosis starts with broad indicators and progresses using increasingly
speciﬁc criteria to screen out potential causes of a problem (Box 1). A
wide range of indicators has been developed.Examples for river ecosys-
tems (Bonada et al., 2006; Woolsey et al., 2007; Friberg et al., 2011)in-
clude some with speciﬁc targets, such as diatom indices to reveal
impacts of acidiﬁcation (Van Dam,1988). However, a general diagnostic
framework for selecting indicators to differentiate among multiple
causes of ecosystem impairment is lacking. Many indicators (e.g.
macroinvertebrate community structure) have been developed to
provide an integrated assessment of general ecological state, and
therefore offer little diagnostic power. First steps have recently
been made towards establishing a differential diagnosis approach
to river assessment (Elosegi and Sabater, 2013), but clearly more de-
velopment is required in theory and practice. This includes integra-
tion of both the structural and functional dimensions of ecosystem
condition (Bunn and Davies, 2000; Gessner and Chauvet, 2002)ina
Although most patients suffer from one of a relatively short list of
diseases, such as ﬂu or intestinal disorders, physicians are aware of the
possible incidence of other and sometimes rare afﬂictions. Similarly, en-
vironmental stressors such as excessive nutrient loading, toxic pollution
or channel modiﬁcation are frequent in rivers, and hence the target of
most management efforts. However, a solid understanding of a much
broader range of stressors (e.g. pharmaceuticals, endocrine disruptors,
various factors relating to climate change), including their prevalence
and effects, is needed for accurate diagnosis in rare or complex cases.
Patients and ecosystems alike often show multiple symptoms at the
same time, as reﬂected by the term syndrome to describe a suite of eco-
system responses to particular stressors (e.g., the urban stream syn-
drome; Paul and Meyer, 2001; Walsh et al., 2005). It is important to
recognize these, as well as multiple-stressor situations (Townsend et
al., 2008;Ormerodet al., 2010), where one stressor mightreduce the ef-
fect of a remedial action to reduce damage caused by another stressor,
or preclude the use of particular treatments. For instance, increasing
longitudinal connectivity might be the measure of choice to alleviate
the common problem of fragmented populations in river networks;
however, the associated high risk of invasion by exotic species might
preclude implementation of this measure. An important precaution in
this context is to consider that impacts can be due to indirect effects
Fig. 1. Four contrasting people subject to varying medical risk factors, illustrating the
parallels between prospective medical patients and potenti ally impaired river
ecosystems. Medical doctors use the same general approach, but different sets of
indicators in the diagnosis of each patient. For example, a pregnancy test wo uld be
relevant only for individual A. Similarly, although all four people could have lung cancer,
the probability is much higher for individual D. All four individuals could be subject to a
physical performance test, but expectations on healthy performance and future health
goals would differ widely. The medical goals would also differ: top physicalperformance
(A), relatively autonomous and painless life (B), early detection of emerging problems
(C), and changing risky habits (D).
Fig. 2. Four rivers affe cted by different s tressors. Ecosystem managers can adopt the
approaches established in medicine to diagnose and tr eat disease, based on a set of
general and speciﬁc indicators while recognizing that objectives vary among rivers. A
key goal for a pristine forest stream (A) may be biodiversity conservation involving
expensive measures to protect a single critically endan gered species. A ma nagement
priority for a river affected by deforestation and livesto ck grazing (B) would be to
restore riparian vegetation. Wate r temperature, the presence of leaf-shredding
invertebrates and litter decomposition rate could serve as indicators to assess success.
Identifying the sources of gross river pol lution indicated by a thick foam cover (C) is
straightforwa rd, but any remediative measures need to be followed by mo nitoring
water chemistr y and benthic inve rtebrate communities. In strongly modiﬁed urban
rivers (D) options for improvement are severely restricted, and may be limited to
simply meeting minimumwater quality standards.
298 A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
caused by altered species interactions, which can lead to counterintui-
tive outcomes (Gessner and Tlili, 2016).
3.3. Treatment approaches
After reaching an accurate diagnosis, medical doctors must select
among alternative treatment approaches. Some types of treatment are
curative in the sense that they solve a given problem, others are pallia-
tive, meaning that damage or symptoms are only alleviated. This dis-
tinction also has evident parallels with actions taken in ecosystem
management. For example, a heavily modiﬁed ecosystem could receive
a treatment equivalent to palliative care (e.g. the construction of artiﬁ-
cial pool-rifﬂe sequences to improve habitat diversity in rivers), without
restoring the ecosystem, whereas remediation of an ecosystem affected
by toxic contaminants could aim for full recovery. Some treatments
need to be applied just once to be effective, others are prescribed forev-
er. Dam removal from rivers is a one-time operation, whereas stocking
of juvenile ﬁsh may have to be perpetual, if conditions cannot be sufﬁ-
ciently improved to establish self-sustaining populations. Ecosystem
management involves recognition that restoration to meet one environ-
mental goal may limit the ability of other social, economic or environ-
mental objectives to be met. Therefore, trade-offs between different
goals and values are an inherent consideration when deciding on
Treatments can follow one of two general strategies: the causative
agent such as a pathogen or environmental stressor is removed to en-
able recovery. This is passive restoration. Examples from rivers are the
removal of livestock to let riparian forests regenerate or sewage treat-
ment before discharge into a receiving stream. By virtue of their intrin-
sically dynamic and resilient nature, rivers often recover rapidly from
anthropogenic impacts, and may thus serve as models to implement
this approach, whereas the response of other ecosystems can be much
slower. Alternatively, recovery of impacted ecosystems can be actively
promoted. Examples for rivers include ﬁsh stocking, channel widening,
wood and boulder additions, dam demolition to re-establish longitudi-
nal connectivity or artiﬁcial ﬂoods to partially restore natural ﬂow re-
gimes (e.g. Bernhardt et al., 2005; Marks et al., 2010; Poff et al., 2010;
Cross et al., 2011; Olden et al., 2014).
One important rule to select treatment approaches is to minimize
unwanted side-effects. This rule encapsulates the 2500-year old Hippo-
cratic oath as a foundation of western conventional medicine (Palmer et
al., 2005). It is equally relevant in the context of ecosystem manage-
ment. One example of undesirable side-effects is the detrimental com-
paction and disturbance of riparian soil by using heavy machinery to
improve habitat structure and diversity of river ﬂoodplains. Similarly,
attempts to restore longitudinal connectivity of river channels also re-
move barriers for invasive species, which can have detrimental effects
on upstream populations of indigenous species.
Minimizing intrusion is another important point to consider when
selecting treatments, and has led to great progress in medicine. Open sur-
gery is increasingly replaced by endoscopy, broad-spectrum antibiotics
by speciﬁc ones, and advances in chemotherapy have improved speciﬁc
targeting of carcinogenic cells. Similarly, ecosystem management should
favour methods that minimize intervention. For instance, although river
bends can be dug with heavy machinery to revitalize straightened chan-
nels of formerly meandering or braided rivers, an attractive alternative is
to trigger natural lateral movement of riverbeds by breaching levees, re-
moving rip-rap and introducing large wood to initiate bank erosion
(Tockner et al., 1998; Kail et al., 2007). The second, minimally intrusive
option reﬂects natural dynamics and thus is clearly preferable in most cir-
cumstances. In addition, it is less expensive, which enables application at
Treatment selection must also consider risks and uncertainties. An
incorrect diagnosis leads to an incorrect prescription and can cause
harm. Therefore, medical doctors carefully weigh the risks and beneﬁts
of taking action. Even simple medical interventions like blood
withdrawal involve risks. This is similarly true for most actions taken
in ecosystems. For example, re-connecting river channels to their ﬂood-
plain could entail property damage and even deaths during ﬂoods, or
mobilize toxic chemicals stored in the ﬂoodplain. Therefore, it is essen-
tial to identify all signiﬁcant risks with potential to damage humans or
the environment. The ubiquity of risks has led to warnings against the
overreliance on medicine to address the public health challenges of
modern western society (Gigerenzer, 2013). This point clearly has par-
allels in ecosystem management, where large investments are some-
times made in traditional hard engineering when passive measures
would be cheaper, more effective and less risky (Feld et al., 2011).
How doctors weigh risk is strongly dependent on context. When the
potential beneﬁts are large and alternatives are lacking, even measures
involving high risk may be acceptable. Physicians are legally obliged to
inform their patients about both the beneﬁts and risks of a proposed
treatmentand any alternatives. Similarly, in the case of ecosystems, res-
idents, agencies, industries and others possibly affected by management
actions should be informed about the beneﬁts and risks associated with
a proposed intervention. This requires suitable participatory processes
to ensure that the stakeholders can play a role in decisions to be taken.
Choices about medical therapy can involve triage, a contentious
issue referring to the diversion of scarce resources away from patients
with low recovery prospects to others with a better chance of recovery.
Though ethically lessdelicate, deﬁningpriorities for ecosystem manage-
ment efforts is often similarly controversial. Clearly, however, it can be
appropriate to avoid devoting resources to situations where positive
ecological outcomes will be limited (Statzner and Sperling, 1993;
Statzner et al., 1997). This insight has gained recognition in several en-
vironmental policies. For example, the EU WFD deﬁnes so-called heavi-
ly modiﬁed water bodies, for which lower standards are accepted if
some speciﬁed uses such as elementary human needs and drinking
water supply are compromised by measures to improve ecosystem
One important factor that causes risks is uncertainty, which
hence needs to be carefully considered as well. This situation is par-
ticularly familiar to hospital emergency departments, where, to pre-
vent serious damage, immediate action may be needed before all
relevant information can be gathered. Similarly, ecosystem manage-
ment measures must sometimes be taken with incomplete informa-
tion at hand because action cannot be delayed (Cullen, 1990; Singh,
2002). Toxic spills in rivers are an analogue of accident patients in
emergency hospital departments, requiring prompt decisions. Im-
portantly, however, uncertainties are by no means restricted to
emergency situations but are commonly due to ambiguous diagnos-
tic outcomes or even failure to diagnose any particular problem. To
minimize risks, it is crucial in all of these situations involving uncer-
tainties that sound protocols are established to guide decisions –as
much for impacted ecosystems (Schindler and Hilborn, 2015)asfor
3.4. Monitor response to therapy and adapt treatment accordingly
Medical advances only started speeding up when the scientiﬁc
method was fully embraced. This includes patient surveillance fol-
lowing treatment. One alarmingly weak feature of ecosystem man-
agement practices in general, and river restoration in particular, is
the lack of adequate monitoring (Jähnig et al., 2011; Bernhardt et
al., 2005; Palmer et al., 2005). Clearly, monitoring is an indispensable
component of ecosystem management, particularly after restoration
measures have been taken, and investing the necessary funds to
implement a monitoring scheme is thus imperative. Given that
ﬁnancial resources are nearly always limiting, this may involve
accepting a reduction in the desired scope of a particular restoration
serving contingency funds for adaptive measures if unanticipated
negative consequences arise.
299A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
Adaptiveecosystem management has arisen as an approach to make
decisions in the face of uncertainty and recognizes the need for robust
monitoring to determine the success of alternativemanagement actions
and support future decision making (Holling, 1978). While showing
much promise, attempts to implement adaptive management often suf-
fer, however, from problems with the associated monitoring programs,
as well as from a lack of connection with stakeholders (Greig et al.,
3.5. Widely publicize treatment outcomes
Clinical research has achieved a high level of internationalization.
Large-scale studies are conducted in multiple nations to boost sam-
pressure and incentives to disseminate results to the broad medical
community. This includes reporting both positive and negative out-
comes to limit publication bias. Importantly, the international di-
mension of major clinical trials often goes beyond communicating
results in the technical literature and also includes targeted dissem-
ination of information to practitioners.
Given limited communication, most ecosystem restoration projects
go unnoticed beyond a small geographic range. This prevents knowl-
edge transfer and thus obliges othersto learn from their own experience
and mistakes. Consequently, embracing the duty to inform others about
the outcomes of management measures as a principle is likely to propel
progress in ecosystem management. A critical point is to avoid bias to-
wards successful projects (Jähnig et al., 2011). Failures are often equally
instructive, as they can point to important misconceptions (Bernhardt
and Palmer, 2011). Although an effective communication system
could be put in place in various ways, a system that involves both incen-
tives and pressure is likely to be needed to promote wide commitment
of the community.
3.6. Further prevention
With the causes and mechanisms of action identiﬁed for many dis-
eases, methods have been devised to prevent the risk of suffering
from speciﬁc diseases. The same is true for ecosystems, as knowledge
grows about the causes of stressors and poor ecosystem conditions.
The importance of preventing excessive nutrient supply and the spread
of invasive species is widely recognized in ecosystem management.
Nevertheless, policy makers and ecosystem managers often repeat mis-
takes in different places and contexts, as a consequence of a lack of ei-
ther knowledge or political will. For instance, the introduction of
exotic species for various reasons, such as landscape restoration or
sport angling, has caused not only ecological harm but also huge eco-
nomic loss (Pimentel et al., 2005).
Despite the value of the precautionary principle, complete risk
prevention is not only impossible, but sometimes unwise. Opportu-
nity costs must be taken into account to avoid spending resources
in situations where marginal beneﬁts are the best possible outcome
(Statzner et al., 1997). Preventive measures are often taken by the
medical community at a very broad spatial scale, such as when a
risk of pandemics has triggered measures to limit the movement of
goods or people (Stein, 2015). Clearly, prevention does not necessar-
ily work at the individual level alone. This lesson can be transferred
to ecosystem management where preventive measures should con-
sider the broader landscape. For rivers, this includes the ﬂoodplain,
river network, catchment and even larger geographical units, includ-
ing earth as a whole.
Information alone cannot prevent all issues. People aware of the
habits and attitudes that promote health (e.g. healthy food, exercise,
no smoking) may ignore them for many reasons. Similarly, people
aware of environmentally friendly habits and attitudes often ignore
or struggle to apply them, although well-informed individuals tend
to adopt healthier and more environmentally friendly behaviours
(Silles, 2009; Coertjens et al., 2010). This suggests that, apart from
legal measures, education can be effective at overcoming tendencies
to ignore disease and environmental risks and thus enhance both
public health and ecosystem stewardship. Examples of this include
the steady decline in cigarette smoking and the more widespread
adoption of safe driving behaviour by road users over the last de-
cades. Striking examples for river ecosystems are the growing
awareness and political drive to remove dams (Marks et al., 2010),
re-establish natural ﬂow regimes (Poff et al., 2010; Olden et al.,
2014)andrestoreﬂoodplain connectivity instead of relying on
hard channel engineering for ﬂood protection (Tockner et al.,
1998). Similarly, environmental education campaigns have been
effective in helping constrain the spread of invasive species (e.g.
Didymosphenia geminata;Root and O'Reilly, 2012). Clearly, however,
there is still much to improve in terms of risk prevention in ecosys-
4. Limitations of the medical template
As we have illustratedby numerous examples, there is a wide range
of parallels between medicine and ecosystem management and there
are many medical principles and practices that could beneﬁt ecosystem
management. However, like any analogy, the similarities can only be
taken so far. In particular, the challenge of ecosystem management is
often described as a so-called ‘wicked problem’(Brown et al., 2010)re-
quiring collective action from different sectors of the community to de-
ﬁne the problem and seek solutions that are often case-speciﬁc.
Appropriate therapies are easily identiﬁed in some cases, but social, eco-
nomic or ﬁnancial constraints complicate the implementation, especial-
ly when action is required at large scale. Different sectors of the
community often have differing values and their goals are often com-
peting and may change over time. Therefore, it is often not a simple
matter of treating one issue in the absence of any consideration about
other requirements of the system. This contrasts with medical practice
where maintenance and improvement of human health is a common
goal that is widely held, although it can also be constrained by ﬁnances,
competing views among different medical specialty areas, or complica-
tions caused by changing levels of health care expectations.
To conclude, the immense successes of medical practiceindicate that
a sound mechanistic understanding of ecosystem structure, function,
and the consequences of human stressors is important for effective eco-
system management. This understanding must be combined with a sys-
tematic application of a comprehensive toolbox for environmental
assessment, including anamnesis and tools for differential diagnosis to
remediate environmental problems effectively. As this toolbox becomes
more complex, a broad array of speciﬁc professional skills is necessary
to maximize success and prevent unwanted side effects. Effective train-
ing and information exchange amongpractitioners andstakeholders are
hence important ingredients of success when applying principles of
medical practices to ecosystem management. While our illustrations
of parallels between medicine and ecosystem management is focused
on rivers, we expect that the conclusions drawn are applicable to eco-
system management in general. It is time that maintaining and improv-
ing ecosystem conditions is accepted as a moral goal for humanity, as
well as a necessity for achieving a sustainable future. Consequently, it
must be undertaken with similareffort and diligence as efforts to main-
tain and improve human health, notwithstanding the greater difﬁculty
to raise the required funds for environmental purposes. Indeed,
thoughtful ecosystem stewardship can have ramiﬁcations well beyond
the conservation and restoration of ecosystems, including positive feed-
backs to the health and well-being of present and future generations
(Messer et al., 2014; Uchtmann et al., 2015).
300 A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
This paper beneﬁted from funding by the EU Commission (pro-
jects GLOBAQUA, grant agreement no. 603629-ENV-2013-6.2-1,
and MARS, grant agreement no. 603378-ENV-2013.6.2-1) and the
New Zealand government (MBIE Rehabilitation of Aquatic Ecosys-
tems programme C01X1002). We are grateful to Emily S. Bernhardt
(Nicholas School of the Environment, Duke University, USA), Pedro
R. Grandes (Faculty of Medicine, University of the Basque Country,
Spain), Linda Reinemer (Department of General Psychiatry, Clinic
Königshof, Germany), Laszlo Matéﬁ(Swiss Accident Insurance, SU-
VA, Switzerland), Sergi Sabater (Catalan Institute of Water Research,
ICRA, Spain) and Klement Tockner (IGB Berlin, Germany) for discus-
sion or comments on a previous draft.
Barton, P.S., Pierson, J.C., Westgate, M.J., Lane, P.W., Lindenmayer, D.B., 2015. Learning from
clinical medicine to improve the use of surrogates in ecology. Oikos 124, 391–398.
Bernhardt, E.S., Palmer, M.A., 2011. River restoration: the fuzzy logic of repairing reaches
to reverse catchment scale degradation. Ecol. Appl. 21, 1926–1931.
Bernhardt, E.S. , Palmer, M.A., Allan, J.D., Alexander, G., Barnas, K., Brooks, S., Carr, J.,
Clayton, S., Dahm, C.N., Follstad-Shah, J., Galat, D., Gloss, S., Goodwin, P., Hart, D.,
Hassett, B., Jenkinson, R., Katz, S., Kondolf, G.M., Lake, P.S., Lave, R., Meyer, J.L.,
O'Donnell, T.K., Pagano, L., Powell, B., Sudduth, E., 2005. Synthesizing U.S. river resto-
ration efforts. Science 308, 636–637.
Bonada, N.,Prat, N., Resh, V.H., Statzner, B., 2006.Developments in aquatic insect biomon-
itoring: a comparative analysis of recent approaches. Annu. Rev. Entomol. 51 ,
Boulton, A.J., 1999. An overview of river health assessment: philosophies, practice, prob-
lems and prognosis. Freshw. Biol. 41, 469–479.
Brown, V.A., Harris, J.A., Russell, J.Y. (Eds.), 2010. Tackling Wicked Problems Through the
Transdisciplinary Imagination. Earthscan Publishers, Oxon, UK.
Bunn, S.E., Davies, P.M., 2000. Biological processes in running waters and their implica-
tions for the assessment of ecological integrity. Hydrobiologia 422, 61–70.
Bunn, S.E., Davies, P.M., Mosisch, T.D., 1999. Ecosystem measures of river health and their
response to riparian and catchment degradation. Freshw. Biol. 41, 333–345.
Chapin III, F.S., Carpenter, S.R., Koﬁnas, G.P., Folke, C., Abel, N., Clark, W.C., Olsson, P.,
Stafford Smith, D.M., Walker, B., Young, O.R., Berkes, F., Biggs, R., Grove, J.M., Naylor,
R.L., Pinkerton, E., Steffen, W., Swanson, F.J., 2010. Ecosystem stewardship: sustain-
ability strategies for a rapidly changing planet. Trends Ecol. Evol. 25, 241–249.
Chapman, P.M., 2007. Determining when contamination is pollution —weight of evi-
dence determinations for sediments and efﬂuents. Environ. Int. 33, 492–501.
Clapcott, J.E., Young, R.G., Neale, M.W., Doehring, K., Barmuta, L.A., 2016. Land use affects
temporal variation in stream metabolism. Freshw. Sci. 35, 1164–1175.
Coertjens, L., Boeve-De Pauw, J., De Maeyer, S., Van Petegem, P., 2010. Do schools make a
difference in their students' environmental attitudes and awareness? Evidence from
PISA 2006. Int. J. Sci . Math. Educ. 8, 497–522.
Costanza, R., de Groot,R., Sutton, P., van der Ploeg, S., Anderson, S.,Kubiszewski, I., Farber,
S., Turner, R.K., 2014. Changes in the global value of ecosystem services. Glob. Envi-
ron. Chang. 26, 152–158.
Coulehan, J.L., Block, M.R., 2005. The Medical Interview: MasteringSkills for Clinical Prac-
tice. ﬁfth ed. F. A., Davis, CA, USA.
Cross, W.F.,Baxter, C.V., Donner, K.C., Rosi-Marshall, E.J., Kennedy, T.A., Hall, R.O., Wellard
Kelly, H.A., Rogers, R.S., 2011. Ecosystem ecology meets adaptive management: food
web response to a controlledﬂood on the Colorado River, GlenCanyon. Ecol. Appl. 21,
Cullen, P., 1990. The turbulent boundary between water science and water management.
Freshw. Biol. 24, 201–209.
Dresselhaus, T.R., Luck, J., Peabody, J.W., 2002. The ethical problem of false positives: a
prospective evaluation of physician reporting in the medical record. J. Med. Ethics
Elosegi, A., Sabater, S., 2013. Effects of hydromorphological impacts on river ecosystem
functioning: a review and suggestions for assessing ecological impacts. Hydrobiologia
Feld, C.K., Birk, S., Bradley, D.C., Hering, D., Kail, J., Marzin, A., Melcher, A., Nemitz, D.,
Pedersen, M.L., Pletterbauer, F., Pont, D., Verdonschot, P.M., Friberg, N., 2011. From
natural to degraded and back again: a test of restoration ecology theory and practice.
Adv. Ecol. Res. 44, 119–209.
Foley, J.A., DeFries, R., Asner, G.P., Barford, C., Bonan, G., Carpenter, S.R., Chapin, F.S., Coe,
M.T., Daily, G.C., Gibbs, H.K., Helkowski, J.H., Holloway, T., Howard, E.A., Kucharik,
C.J., Monfreda, C., Patz, J.A., Prentice, I.C., Ramankutty, N., Snyder, P.K., 2005. Global
consequences of land use. Science 309, 570–574.
A.G., Lamouroux, N., Trimmer, M., Woodward, G., 2011. Biomonitoring of human im-
pacts in freshwater ecosystems: the good, the bad and the ugly. Adv. Ecol. Res. 44, 1–68.
Gessner, M.O., Chauvet, E., 2002. A case for using litter breakdown to assess functional
stream integrity. Ecol. Appl. 12, 498–510.
Gessner, M.O., Tlili, A., 2016. Fostering integration of freshwater ecology with ecotoxicol-
ogy. Freshw. Biol. 61, 1991–2001.
Gigerenzer, G., 2013. Risk Savvy: How to Make Good Decisions. Penguin, New York, NY, USA.
Gleick, P.H., Palaniappan, M., 2010. Peak water: conceptual and practical limits to fresh-
water withdrawal and use. Proc. Natl. Acad. Sci. U. S. A. 107, 11155–11162.
McKee, A., Oyler-McCance, S.J., Cornman, R.S., Laramie, M.B., Mahon, A.R., Lance, R.F.,
P., 2016. Critical considerations for the application of environmental DNA methods to
detect aquatic species. Methods Ecol. Evol. 7, 1299–1307.
Greig, L.A., Marmorek, D.R., Murray, C., Robinson, D.C.E., 2013. Insight into enabling adap-
tive management. Ecol. Soc. 18 (3), 24.
Grol, R., Grimshaw, J., 2003.From best evidence to best practice: effective implementation
of change in patients' care. Lancet 362, 1225–1230.
Haase, P., Pauls, S.U., Schindehütte, K., Sundermann, A., 2010. First audit of macroinverte-
brate samples from an EU Water Framework Directive monitoring program: human
error greatly lowers precision of assessment results. J. N. Am. Be nthol. Soc. 29,
Holling, C.S., 1978. Adaptive Environmental Assessment and Management. John Wiley &
Ismail, H., Wright, J., Rhodes, P., Small, N., 2005. Religiousbeliefsaboutcausesandtreat-
ment of epilepsy. Br. J. Gen. Pract. 55, 26–31.
Jähnig, S.C., Lorenz, A.W., Hering, D., Antons, C., Sundermann, A., Jedicke, E., Haase, P.,
2011. River restoration success: a question of perception. Ecol. Appl. 21, 2007–2015.
Jax, K., 2005. Function and “functioning”in ecology: what doe s it mean? Oikos 11 1,
Jax, K., 2010. Ecosystem Functioning. Cambridge University Press, Cambridge, UK.
Kail, J., Hering, D., Muhar, S., Gerhard, M., Preis, S., 2007. The use of large wood in stream
restoration: experiences from 50 projects in Germany and Austria. J. Appl. Ecol. 44,
Karr, J.R., 1999. Deﬁning and measuring river health. Freshw. Biol. 41, 221–234.
Maher, P., 1999. Areviewof‘traditional’aboriginal health beliefs. Aust. J. Rural Health 7,
Marks, J.C., Haden, G.A., O'Neill, M., Pace, C., 2010. Effects of ﬂow restoration and exotic
species removal on recovery of native ﬁsh: lessons from a dam decommissioning.
Restor. Ecol. 18, 934–943.
Messer, L.C., Jagai, S.C., Rapazzo, K.M., Lobdell, D.T., 2014. Construction of an environmen-
tal quality index for public health research. Environ. Health 13, 39.
Meyer, J.L., Paul, M.J., Taulbee, W.K., 2005. Stream ecosystem function in urbanizing land-
scapes. J. N. Am. Benthol. Soc. 24, 602–612.
Nardone, D.A., Johnson, G.K., Faryna, A., Coulehan, J.L., Parrino, T.A., 1992. A model for the
diagnostic medical interview: nonverbal, verbaland cognitive assessments. J. Gen. In-
tern. Med. 7, 437–442.
Nilsson, C., Lepori, F., Malmqvist, B., Tornlund, E., Hjerdt, N., Helﬁeld, J.M., Pa lm, D.,
Ostergren, J., Jansson, R., Brannas, E., Lundqvist, H., 2005. Forecasting environmental
responses to restoration of rivers used as log ﬂoatways: an interdisciplinary chal-
lenge. Ecosystems 8, 779–800.
Olden, J.D., Konrad, C.P., Melis, T.S., Kennard, M.J., Freeman, M.C., Mims, M.C., Bray,
E.N., Gido, K.B., Hemphill, N.P., Lytle, D.A., McMullen, L.E., Pyron, M., Robinson,
C.T., Schmidt, J.C., Williams, J.G., 2014. Are large-scale ﬂow experiments
informing the science and management of freshwater ecosystems? Front. Ecol.
Environ. 12, 176–185.
Ollero, A., 2011. Sobre el objeto y la viabilidad de la restauración ambiental.
Geographicalia 59-60, 267–279.
Ormerod,S.J., Dobson, M., Hildrew, A.G.,Townsend, C.R., 2010. Multiplestressors in fresh-
water ecosystems. Freshw. Biol. 55, 1–4.
R., Kondolf, G.M., Lave, R., Meyer, J.L., O'Donnell, T.K., Pagano, L., Sudduth, E., 2005. Stan-
dards for ecologically successful river restoration. J. Appl. Ecol. 42, 208–217.
Paul, M.J., Meyer, J.L., 2001. Streams in the urban landscape. Annu. Rev. Ecol. Syst. 32,
Pimentel, D., Zuniga, R., Morrison, D., 2005. Update on the environmental and economic
costs associate d with alien-invasive species in the United States. Ecol. Econ. 52,
Poff, N.L., Richter, B.D., Arthington, A.H., Bunn, S.E., Naiman, R.J., Kendy, E., Acreman, M.,
Apse, C., Bledsoe, B.P., Freeman, M.C., He nriksen, J., Jacob son, R.B., Kennen, J.G.,
Merritt, D.M., O'Keeffe, J.H., Olden, J.D., Rogers, K., Tharme, R.E., Warner, A., 2010.
The ecological limits of hydrologic alteration (ELOHA): a new framework for devel-
oping regional envir onmental ﬂow standards. Freshw. Biol. 55, 147–170.
Rapport, D.J., 1995. Ecosystem health —more than a metaphor. E nviron. Values 4,
Rapport, D.J., Costanza, R., McMichael, A.J., 1998. Assessing ecosystem health. Trends Ecol.
Evol. 13, 397–402.
Rees, H.C.,Maddison, B.C., Middleditch, D.J., Patmore, J.R.M., Gough, K.C., 2014. The detec-
tion of aquatic animal species using environmental DNA—areviewofeDNAasasur-
vey tool in ecology. J. Appl. Ecol. 51, 1450–1459.
Root, S., O'Reilly, C.M., 2012. Didymo control: increasing the effectiveness of decontami-
nation strategies and reducing spread. Fisheries 37, 440–448.
Ruddiman,W.F., Ellis, E.C., Kaplan, J.O., Fuller, D.Q., 2015. Deﬁning the epoch we live in: is
a formally designated “Anthropocene”a good idea? Science 348, 38–39.
Sackett, D.L., Rosenberg, W.M.C., Gray, J.A.M., Haynes, R.B., Richardson, W.S., 1997. Evi-
dence based medicine: what it is and what it isn't —it's about integrating individual
clinical expertise and the best external evidence. Brit. Med. J. 312, 71–72.
Schindler, D.E., Hilborn, R., 2015. Prediction, precaution, and policy under global change.
Science 347, 953–954.
Schrock, J.W., Cydulka, R.K., 2006. Lifelong learning. Em. Med. Clin. N. Am. 24, 785–795.
Silles, M.A., 2009. The causal effect of education on health: evidence from the United
Kingdom. Econ. Educ. Rev. 28, 122–128.
301A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302
Simberloff, D., 1998. Flagships, umbrellas, and keystones —is single-species management
passed in the landscape era? Biol. Conserv. 83, 247–257.
Singh, J.S., 2002. The biodiversity crisis: a multifaceted review. Curr. Sci. 82, 638–647.
Statzner, B., Sperling, F., 1993. Potential contribution of system-speciﬁc knowledge (SSK)
to stream-management decisions —ecological and economic-aspects. Freshw. Biol.
Statzner, B., Capra, H., Higler, L.W.G., Roux, A.L., 1997. Focusing environmental manage-
ment budgets on nonlinear systemresponses: potential for signiﬁcant improvements
to freshwater ecosystems. Freshw. Biol. 37, 463–472.
Steffen, W., Richardson, K., Rockström, J., Cornell, S.E., Fetzer, I., Bennett, E.M., Biggs, R.,
Carpenter, S.R., de Vries, W., de Wit, C.A., Folke, C., Gerten, D., Heinke, J., Mace, G.M.,
Persson, L.M., Ramanathan, V., Reyers, B., Sörlin, S., 2015. Planetary boundaries: guid-
ing human development on a changing planet. Science 347, 736.
Stein, R.A., 2015. Political will and international collaborative frameworks in infectious
diseases. Int. J. Clin. Pract. 69, 41–48.
Stoeckle, J.D., Billings, J.A., 19 87. A history of history-taking —the medical interview.
J. Gen. Intern. Med. 2, 119–127.
Stumpf, R.P., Wynne, T.T., Baker, D.B., Fahnenstiel, G.L., 2012. Interannual variability of
cyanbacterial blooms in Lake Erie. PLoS One 7 (8), e42444.
Sutherland, W.J., Pullin, A.S., Dolman, P.M., Knight, T.M., 2004. The need for evidence-
based conservation. Trends Ecol. Evol. 19, 305–308.
Sutherland, W.J., Dicks, L.V., Ockendon, N., Smith,R.K., 2015. What works in conservation?
Open Books, Cambridge, U.K.
Tockner, K., Schiemer, F., Ward, J.V., 1998. Conservation by restoration: the management
concept for a river ﬂoodplain system on the Danube River in Austria. Aquat. Conserv.
Mar. Freshwat. Ecosyst. 8, 71–86.
Townsend, C.R., Uhlmann, S.S., Matthaei, C.D., 2008. Individual and combined responses
of stream ecosystems to multiple stressors. J. Appl. Ecol. 45, 1810–1819.
Uchtmann, N., Herrmann, J.A., Hahn, Edwin III,C., Beasley, V.R., 2015. Barriersto, efforts in,
and optimization of integrated One Health surveillance: a review and synthesis.
EcoHealth 12, 368–384.
Val, J., Chinarro, D., Pino, M.R., Navarro, E., 2016. Global change impacts on river ecosys-
tems: a high-resolution watershed study of Ebro river metabolism. Sci. Total Environ.
Van Dam, H., 1988. Acidiﬁcation of three moorland pools in the Netherlands by acid pre-
cipitation and ext reme drought periods over seven decades. Freshw. Biol. 20,
Vitousek, P.M., Aber, J.D., Howarth, R.W., Likens, G.E., Matson, P.A., Schindler, D.W. ,
Schlesinger, W.H., Tilman, D., 1997. Human alteration of the global nitrogen cycle:
sources and consequences. Ecol. Appl. 7, 737–750.
Walsh, C.J., Roy, A.H.,Feminella, J.W.,Cottingham, P.D.,Groffman, P.M., Morgan, R.P.,2005.
The urban stream syndrome: current knowledge and the search for a cure. J. N. Am.
Benthol. Soc. 24, 706–723.
Weed, D.L., 2005. Weight of evidence: a review of concepts and methods. Risk Anal. 25,
Woolsey, S., Capelli, F., Gonser, T., Hoehn, E., Hostmann, M., Junker, B., Paetzold, A.,
Roulier, C., Schweizer, S., Tiegs, S.D., Tockner, K., Weber, C., Peter, A., 2007. A strategy
to assess river restoration success. Freshw. Biol. 52, 752–769.
Wootton, D., 2006. Bad Medicine. Doctors Doing Harm Since Hippocrates. OxfordUniver-
sity Press, Oxford, UK.
Yates, A.G., Brua, R.B.,Culp, J.M., Chambers, P.A., Wassenaar, L.I.,2014. Sensitivity of struc-
tural and functional indicators depends on type and resolution of anthropogenic ac-
tivities. Ecol. Indic. 45, 274–284.
Young, R.G., Matthaei, C.D., Townsend,C.R., 2008. Organic matter breakdown and ecosys-
tem metabolism: functional indicators for assessing river ecosystem health. J. N. Am.
Benthol. Soc. 27, 605–625.
Zalasiewicz, J., Williams, M., Steffen, W., Crutzen, P., 2010. The new world of the
Anthropocene. Environ. Sci. Technol. 44, 2228–2231.
Zhenga, H., Robinson, B.E., Liang, Y.-C., Polasky, S., Mae, D.-C., Wange, F.-C., Ruckelshaus,
M., Ouyanga, Z.-Y., Daily, G.C., 2013. Beneﬁts, costs, and livelihood implications of a
regional payment for ecosystem service program. Proc. Natl. Acad. Sci. U. S. A. 110,
302 A. Elosegi et al. / Science of the Total Environment 595 (2017) 294–302