Threatening processes and conservation management
of endemic freshwater fish in the Mediterranean basin:
a review
Virgilio HermosoA,B,E and Miguel ClaveroC,D
A
Australian Rivers Institute, Griffith University, Nathan, Qld 4111, Australia.
The Ecology Centre, School of Biological Sciences, University of Queensland,
St Lucia, Qld 4072, Australia.
C
Grup d’ecologia del Paisatge, À rea de Biodiversitat, Centre Tecnològic Forestal de Catalunya,
Solsona, Catalonia, Spain.
D
Departament de Ciències Ambientals, Universitat de Girona, Girona, Catalonia, Spain.
E
Corresponding author. Email: virgilio.hermoso@gmail.com
B
Abstract. Mediterranean endemic freshwater fish are among the most threatened biota in the world. The Mediterranean
basin has experienced substantial reductions in precipitation and water availability, which will worsen with climate
change. Current water policy is directed to increase water-supply demands, especially for agriculture, and not to improve
water-use efficiency and implement integrated and sustainable water management. Illegal extractions are common,
exacerbating problems for important protected areas. Management is needed to mitigate the conflicts between
environmental water and human demand, and ensure availability of water to maintain ecological processes and
Mediterranean freshwater biodiversity. Water availability is not the only threat, although it is exacerbated by pollution
and invasive species. The uneven spatial distribution of threats across the Mediterranean basin requires different strategies
to conserve freshwater biodiversity. Implementation of multi-national laws (e.g. Water Framework Directive in the
European Union) will help future management of freshwater ecosystems. Management actions must be planned at wholecatchment scales, with collaboration among different countries and water-management authorities. The current reserve
area is small compared with other areas in the world and driven by terrestrial interests, and should be evaluated for its
effectiveness to protect the Mediterranean freshwater biodiversity.
Additional keywords: climate change, drought, environmental flows, invasive species, pollution, climate change
Introduction
Biodiversity is rapidly declining (Olson et al. 2002), with
extinction rates 100–1000 times higher than those in pre-human
times across many different taxonomic groups and a wide range
of environments (Pimm et al. 1995). Freshwater ecosystems
hold some of the most diverse and threatened biological communities on earth (Allan and Flecker 1993; Revenga and Mock
2000; Malmqvist and Rundle 2002). These systems are subject
to higher pressures and threats than are adjacent terrestrial
ecosystems (Nel et al. 2007) because of their importance to
human welfare and development. Climate change is accelerating degradation of freshwater environments in many areas
because of a reduction in water availability and the consequent
increase in water-allocation conflicts (Thomas 2008).
In spite of this, some aspects of freshwater ecosystems such
as longitudinal connectivity (Vannote et al. 1980) are overlooked when designing conservation strategies (Saunders et al.
2002; Dudgeon et al. 2006; Nel et al. 2007). Presence of dams
and deterioration of water quality as a result of wastewater
disposals in a basin are just two examples of how freshwater
communities apparently protected within reserves can be seriously threatened by processes operating far away. Therefore,
effective protection of freshwater biodiversity requires management of whole river basins, a scale that imposes more challenges
than in terrestrial conservation planning (Likens et al. 2009;
Grantham et al. 2010). Additional constraints are imposed
by the strong social and political resistance to restrict water
allocations to existing demands (Phillips et al. 2010), limiting
the amount of water available for conservation (Grantham et al.
2010).
Freshwater fish, 425% of all vertebrate species on Earth,
are some of the world’s most threatened taxa (Duncan and
Lockwood 2001; Darwall et al. 2008). The freshwater fish fauna
of the Mediterranean basin is particularly threatened, because
of a high level of endemism (Myers et al. 2000; Olson and
Dinerstein 2002; Abell et al. 2008). Over 70% of the 228 species
Table 1. Conservation status of Mediterranean endemic freshwater-fish species, by family, in the Mediterranean, compared with other global
Mediterranean-climate areas and taxa groups in the Mediterranean basin
EX, Extinct; EW, Extinct in the Wild; CR, Critically Endangered; EN, Endangered; VU, Vulnerable; NT, Nearly Threatened; LC, Low Concern; DD, Data
Deficient
Taxon
No. of genera
No. of species
No. of species
EX
EW
CR
EN
VU
6
1
NT
LC
DD
1
1
1
4
A
Mediterranean endemic fish
Accipenseridae
Balitoridae
Blenniidae
Cichlidae
Clupeidae
Cobitidae
Cottidae
Cyprinidae
Cyprinodontidae
Gasterosteidae
Gobiidae
Percidae
Petromyzontidae
Salmonidae
Siluridae
Valenciidae
Total
%
Other freshwater fishB
Eastern Africa
Southern Africa
Madagascar
Other taxonomic groupsC
Mediterranean dragonflies
Mediterranean amphibians
Mediterranean reptiles
Mediterranean mammals
World amphibians
World birds
World mammals
1
3
1
3
1
1
1
26
1
1
3
1
2
3
1
1
50
1
15
2
6
2
21
1
164
8
1
12
2
2
13
1
2
253
1
3
1
1
1
3
2
4
1
1
24
2
1
3
1
1
2
1
1
1
9
1
36
9
39
1
24
3
2
2
1
3
1
1
2
1
6
27
2
7
2.8
1
0.4
2
45
17.9
46
18.5
51
20.2
901
356
98
0.2
0
3.1
0
0
1.0
4.2
3.4
12.2
4.1
5.4
13.3
19.4
2.5
28.6
164
106
355
297
6260
9998
5487
2.4*
0.9
0.3
2.7*
0.6
1.3
1.4
0
0
0
0
0.02
0.04
0.04
3.0
0.9
3.7
3.0
7.8
1.9
3.4
7.9
12.3
6.2
5.1
12.6
3.6
8.2
7.9
12.3
3.1
8.4
11.4
6.7
9.2
4
1
1
10
4
6
1
52
20.6
41
16.3
1.3
2.5
2.0
62.6
66.2
12.2
8.1
20.3
27.6
16.5
16.0
10.1
7.7
6.1
8.4
5.9
58.5
57.5
71.3
60.6
37.0
77.4
56.7
3.7
0
5.4
12.5
24.5
0.7
15.2
A
Smith and Darwall (2006).
Darwall et al. (2008).
C
IUCN (2008).
B
of endemic fish for which adequate data are available (Smith
and Darwall 2006) are threatened with extinction (i.e. they are
Critically Endangered, Endangered or Vulnerable) or are
already extinct (Table 1). These estimates are more than three
times higher than for other animal groups in the Mediterranean
basin (Table 1), such as dragonflies (22%), amphibians (26%),
reptiles (14%) and mammals (21%). Moreover, the proportion
of threatened species among endemic Mediterranean freshwater
fish is among the highest recorded in IUCN regional assessment
of the conservation status of freshwater fish (Darwall et al.
2008) (Table 1), being similar to that of Madagascar (58.2%).
We review the distribution of the main threats affecting
highly imperilled endemic Mediterranean freshwater-fish species (e.g. compiling information for each species from the IUCN
Red List (IUCN 2008)). We also discuss effectiveness of current
management strategies in dealing with threats, given future
challenges of climate change.
Geographic and climate variability in the
Mediterranean basin
The Mediterranean basin is the cradle of some of the world’s
more ancient cultures and civilisations and has been transformed
by humans for millennia. Today’s landscapes result from the
dynamic interactions between environmental characteristics
and human activities (Blondel and Aronson 1999). The basin
encompasses more than 25 countries, a population of 250
million and different cultures, languages and socioeconomic
contexts (Kark et al. 2009). With a mean population density
of 134.7 inhabitants km—2, the region holds some of the most
densely populated areas in the world (420 000 inhabitants km—2),
but also complete desert areas with low population densities.
The Mediterranean climate has high intra-annual variability
in precipitation, with a rainy season mainly in autumn and spring
(Bolle 2003; Alvarez Cobelas et al. 2005) and severe dry periods
in summer (Gasith and Resh 1999). There is strong inter-annual
Precipitation (mm)
<364.0
364.1–536.0
536.1–541.8
541.9–755.0
>755
Precipitation
seasonality
<36.9
37.0–53.6
53.7–72.0
72.1–91.6
>91.7
Temperature (°C)
<6.0
6.1–13.4
13.5–16.2
16.2–18.4
>18.5
N
0
1000
2000
Kilometres
Fig. 1. Climate variability in the Mediterranean basin; mean air temperature (8C), annual precipitation (mm year—1) and precipitation seasonality (coefficient
of variation of monthly precipitation). Data source: WORLDCLIM, Version 1.4 (see Hijmans et al. 2005).
variation in precipitation (Gasith and Resh 1999; Merenlender
et al. 2008). Water balance is often negative, with the range
of annual precipitation : potential evapotranspiration ratio of
0.1–1.0 (Alvarez Cobelas et al. 2005). As a result, many
watercourses, especially the low-order ones, dry up during
summer, being reduced to a succession of isolated pools. This
variation of flows and water availability is an important factor
shaping Mediterranean freshwater communities (Bonada et al.
2006, 2007; Magalhães et al. 2007; McGarvey and Hughes
2008).
There is a general north–south gradient in temperature and
precipitation (increasing mean air temperature and decreasing
precipitation), and an east–west gradient in precipitation seasonality, measured as the coefficient of variation of mean
monthly precipitation (Fig. 1). Mean annual precipitation in
the Mediterranean basin is 571 mm year—1, with high spatial
variability. In northern areas, it can exceed 2000 mm year—1 in
wet years, whereas some southern areas receiveo200 mm year—1
in dry years (Hijmans et al. 2005). Mean annual air temperature
is 14.78C, with high spatial variability, ranging from 1.28C to
23.28C. The natural renewable freshwater resource in the Mediterranean basin is low (1.2 x 1012 ML; Benoit et al. 2005),
although spatially highly variable, even within countries (Blinda
et al. 2007), reflecting rainfall patterns. The region holds 3% of
global freshwater resources and 50% of the world’s water-poor
population (Benoit et al. 2005).
Endemic freshwater fish
Mediterranean freshwater-fish communities have a medium–
low diversity (o20 species per basin) and a high endemicity
(470% of species in some basins; Reyjol et al. 2007; Abell
et al. 2008). The similar taxonomic structure of freshwater-fish
communities across the Mediterranean basin is explained by
ancient land connections that allowed dispersal of freshwater
fish through the Mediterranean basin (Banarescu 1989; Bianco
1990; Doadrio 1990). These contacts ceased in the Pliocene
(2–5 million years ago) and subsequent mountain ranges isolated Mediterranean freshwater-fish communities from the
species-rich communities of northern Europe (Reyjol et al.
2007; Lévêque et al. 2008). There is no clear spatial pattern in
endemic-species richness across the Mediterranean basin, with
peak values (414 endemic native species) distributed in distant
river basins (Smith and Darwall 2006), including Orontes River
(eastern Mediterranean), Po River (northern Italy) and Guadiana
River (south-western Iberian Peninsula). Turkey and Greece
have 73 and 62 endemic species, respectively, whereas Algeria,
Lebanon, Libya and Egypt have fewer than 25 endemic species
(Fig. 2).
Endemic Mediterranean freshwater-fish species are distributed among 16 families and 50 genera (Smith and Darwall
2006). Cyprinidae is the most diverse family, with two-thirds
of the species (n ¼ 164) and half of the genera (n ¼ 52). The
remaining families hold 1–3 genera and 1–21 species. In all, 9 of
the 16 families have more than 25% of their species assessed as
Critically Endangered, and only Cottidae and Siluridae have no
Critically Endangered species (Table 1). Turkey stands out with
27% of its endemic species being assessed as Critically Endangered and 32% as Endangered (Fig. 2), followed by Israel, Syria
and Lebanon, with 420% of their endemic species Endangered
(28, 38 and 32%, respectively) according to the last regional
assessment (Smith and Darwall 2006). In Spain, Portugal and
Morocco, 420% of the endemic species are considered Vulnerable (Fig. 2). Despite these assessments, there are important
gaps in the knowledge on freshwater-fish communities in the
Mediterranean basin. For example, the total number of species is
not known, with new endemic fish species being continually
described (e.g. Doadrio and Carmona 2006; Doadrio and Elvira
2007; Kottelat and Freyhof 2007). The lack of knowledge is
especially problematic in the African part of the basin, where
freshwater ecosystems and their fish are not well studied
(Alvarez Cobelas et al. 2005; Smith and Darwall 2006). This
makes estimates of the threatened status of North African
endemic-fish communities and the relative importance of the
threats particularly uncertain.
Non-climate threats
We compiled data on threats affecting 228 endemic Mediterranean freshwater-fish species (with information unavailable
for 25 species) from the IUCN Red List (IUCN 2008) across
the Mediterranean basin. We simplified this information into
the following six basic threats: pollution, water extraction,
agriculture, reservoirs (also including channelisation), invasive
species and overfishing (Clavero et al. 2010), on the basis of the
IUCN classification of major threats (version 2.1, available at
http://intranet.iucn.org/webfiles/doc/SSC/RedList/AuthorityF/
threats.rtf, accessed March 2009). We excluded species’
intrinsic factors such as small distributions or limited dispersal
capacity and, initially, the potential impacts of climate change.
To explore the spatial pattern of threats across the Mediterranean basin, we combined the spatial distribution of each species
(downloaded from www.uicnmed.org/web2007, accessed
March 2009, and projected into a 10 x 10-km grid) and their
threats. At each 10 x 10-km cell, we recorded the number of
species affected by each of the six threats and calculated
their percentages in relation to species richness, excluding datadeficient species (Clavero et al. 2010).
Fish species were affected on average by 3.2 (±1.1, s.d.) of
the six threats. Water pollution and water extraction were the
most commonly cited threats, affecting 85.5% and 82.0%,
respectively, of the species. Invasive species were the next most
frequent threat (57.0%), followed by reservoirs (44.3%), agriculture (35.1%) and overfishing (14.5%). The spatial distribution of threats was not even across the basin (Fig. 3). For
example, agriculture was more prominent in the southern areas
and reservoirs in the northern areas, whereas invasive species
affected a large proportion of species in the western part of the
region.
Pollution is ubiquitous along the Mediterranean basin, affecting most species (Clavero et al. 2010), although it is less of a
threat in the Iberian Peninsula and northern Africa (Fig. 3). The
high water demand in the Mediterranean areas, sometimes
exceeding the availability of the resource, greatly reduces the
dilution of effluents from cities, industries or agricultural areas
(Prat and Munné 2000). This dilution potential is also highly
variable seasonally (minimum in summer) and among years
(Prenda et al. 2006). Although the establishment of waste-water
treatment plants has reduced the pollution load, there are many
non-treated Mediterranean rivers and streams. For example,
26% of coastal cities with 4100 000 inhabitants, and 32% with
10 000–100 000 inhabitants, did not have waste-water treatment
plants in 2000 (UNEP/MAP/WHO 2004). Although unknown,
the numbers could be similar in non-coastal cities and small
towns. Increasing population, industrial pressure and agricultural intensification (non-point-source pollution) also increase
pollution levels.
Richness
<15
16–30
31–45
46–60
>60
Proportion vulnerable
<5
6–10
11–15
16–20
>20
Proportion endangered
<5
6–10
11–15
16–20
>20
Proportion critically
endangered
<5
6–10
11–15
16–20
>20
N
0
1000
2000
Kilometres
Fig. 2. Endemic-species richness and the proportion of threatened endemic species in the Mediterranean countries. The spatial distribution of species was
downloaded from the IUCN Mediterranean Centre for Cooperation (www.uicnmed.org, accessed 1 March 2009).
Water extraction is one of the main threats to freshwater
ecosystems worldwide (e.g. Xenopoulos et al. 2005), particularly in arid and semiarid regions, such as the Mediterranean.
Most water withdrawn from the Mediterranean rivers is for
agriculture (Grantham et al. 2010), averaging 65%, compared
with 23% for industrial and 12% for urban (WWF 2006) use.
The area of irrigated land has nearly doubled in 40 years, from
11 million hectares in 1961 to 20.5 million hectares in 2000,
especially in Turkey and Spain. Overexploitation of surface and
groundwater freshwater resources affects a higher proportion of
fish species in the Mediterranean basin than in any other region
where fish conservation status has been assessed (Darwall et al.
Pollution
Water extraction
Invasive species
Reservoirs
Agriculture
Overfishing
% Threatened species
0
1–25
26–50
51–75
>76
N
0
1000
2000
Kilometres
Fig. 3. Spatial distribution of six main threats in the Mediterranean basin. Threats were measured
as the proportion of endemic species threatened by each factor, according to the last IUCN review
of the conservation status of endemic Mediterranean freshwater fish (IUCN 2008, available at
www.iucnredlist.org, accessed 11 March 2009).
2008). Water extraction threatens endemic fish fauna in most of
the Mediterranean basin, except in central and southern Italy and
northern Africa (Fig. 3). Natural flow regimes in the Mediterranean watercourses are considerably altered by water extraction,
extending summer dry periods and drying out perennial watercourses (e.g. Benejam et al. 2010). In many areas of the
Mediterranean basin, groundwater hydrology is as important
as surface hydrology for the persistence and functioning of
aquatic ecosystems (Alvarez Cobelas et al. 2005). Decreasing
watertables as a result of water extraction intensify dry periods
and often threaten remaining pools in rivers and streams, the
critical summer refuges for freshwater biota (Magalhães et al.
2002; Sheldon et al. 2010). For example, the Tablas de Daimiel,
an inland Spanish wetland, was completely dried up as a result
of the overexploitation of groundwater resources in the upper
catchment of the Guadiana River basin, even though it was
protected as a National Park and listed as a RAMSAR site and
UNESCO’s Biosphere Reserve (Bromley et al. 2001; Castañ oCastañ o et al. 2008). Water extraction is difficult to control and
manage, especially because some of it is illegal. There are an
estimated 4510 000 illegal wells in Spain, extracting more than
3.6 x 105 ML per year, which is ,45% of the total annual
groundwater abstraction (WWF 2006).
Invasive species are a common threat to the conservation
of freshwater fish around the world (Darwall et al. 2008),
particularly in the Mediterranean areas (Light and Marchetti
2007; Darwall et al. 2008; Hermoso et al. 2010a). The rivers and
streams in the five Mediterranean-climate areas are among the
most invaded systems around the world (Leprieur et al. 2008;
Marr et al. 2010). On average, the main river basins in the
Iberian Peninsula have more invasive than native species
(Clavero and Garcı́a-Berthou 2006), as in other Mediterranean
countries, such as Italy (Bianco and Ketmaier 2001) and Israel
(Roll et al. 2007). Widespread invasive fish species have
displaced imperilled endemic fish species, leading to local
extinction in lotic (e.g. Blanco-Garrido et al. 2009) and lentic
(e.g. Leonardos et al. 2008) systems. At a large scale, the impact
of invasive species matches the level of imperilment of endemic
freshwater-fish communities across the Mediterranean basin
(Clavero et al. 2010). In the Guadiana River basin, which is
especially rich in Mediterranean endemics, the abundance of
invasive species was the strongest factor determining the distribution of most native species (Hermoso et al. 2009a) and
some invasive species have become more common than native
species (Hermoso et al. 2008). Invasive fish species were often
introduced by public fisheries or nature-conservation organisations during the 20th century, with recent illegal introductions
and inter-basin transfers of already introduced species (Clavero
and Garcı́a-Berthou 2006). This makes control and prevention
of further introductions difficult.
+
+
For example, sport-fishing drives introductions of exotic fish
species in the Mediterranean (e.g. Clavero and Garcı́a-Berthou
2006).
+
Agriculture
Channelisation
Pollution
+
Reservoirs
Native fish
+
+
+
+
—
Invasive species
—
Water extraction
Climate change
+
—?
Fig. 4. Conceptual diagram of threats and freshwater biodiversity interactions. Overfishing is not shown in the figure, because of its low incidence
in the Mediterranean basin.
The asynchronous seasonality of water demand and availability (peak demand coincides with dry summer months)
and the unpredictable inter-annual variation of water availability have led Mediterranean rivers to be highly regulated
(Kondolf and Batalla 2005). There are more than 4000 large
reservoirs (41000-ML capacity) across the Mediterranean basin
– the highest number of dams per person in the world. Spain has
,1300 large reservoirs, with a storage capacity of ,5.6 x
107 ML (Magdaleno and Fernandez 2010). Reservoirs drastically change diverse heterotrophic lotic systems to autotrophic,
structurally simple limnetic systems. Dams are also impassable
for fish, limiting their movements along watercourses and
fragmenting populations of riverine fish species. They provide
reduced habitat for available catadromous species (e.g. the
Critically Endangered eel, Anguilla anguilla) and extirpated
anadromous species from whole river basins (e.g. the Critically
Endangered Atlantic sturgeon, Acipenser sturio) (Prenda et al.
2006). Reservoirs also disrupt Mediterranean flow regimes,
attenuating rainy-season floods and summer droughts
(Grantham et al. 2010). Introduced fish thrive in the stable
environments provided by reservoirs (Clavero et al. 2004), allowing them to then invade natural systems (Johnson et al. 2008).
Agriculture threatens the conservation of endemic Mediterranean freshwater fish, especially in northern African and
eastern Mediterranean countries and in southern Italy (Fig. 3).
Although agriculture is directly related to other threats (e.g.
overexploitation of water resources, pollution; Fig. 4), it also
often poses additional threats such as the destruction and
channelisation of floodplains (e.g. Urrea and Sabater 2009;
Magdaleno and Fernandez 2010). Moreover, established agricultural areas on floodplains must be protected from periodic
flooding surrounding banks.
Overfishing is not a major threat in the Mediterranean basin
(Darwall et al. 2008), compared with other areas of the world
where freshwater fish are an important source of protein.
However, sport-fishing increases the severity of other threats.
Future threats to endemic Mediterranean fish
Southern Europe and the entire Mediterranean basin are
expected to suffer severe impacts under future climate change,
because of increasing temperature and reduced precipitation
(Blinda et al. 2007). In the past century, mean precipitation
decreased up to 20% and will continue to decrease by 20–40%
on average and up to 60% in areas of the Iberian Peninsula. With
an increase of 4–5.58C in the mean temperature, mean runoff
in the Mediterranean basin is estimated to decline by 20–40%,
relative to 1980–1999. Such a reduction is among the most
severe predicted in the world (Bates et al. 2008). Current conflicts between conservation and development will be aggravated, and environmental water could be considerably reduced,
as many Mediterranean countries become water scarce by 2025
(UNECA 1999). This will exacerbate the effects of threats not
currently related to climate (e.g. invasive species and pollution;
Fig. 4). According to the last review on the conservation status of
endemic Mediterranean fish species (Smith and Darwall 2006),
drought and water extraction are the factors with the highest
increase in the number of species that they directly threaten
(from 41 and 115 to 112 and 160 species, respectively) and these
rates are likely to increase in decades to come. Pollution, water
extraction and drought are expected to be the most important
future threats, with 197, 183 and 180 species, respectively,
directly threatened (Smith and Darwall 2006). The number of
endemic species threatened by invasive species, currently 89,
will increase substantially, to 111 species.
Current conservation
The European Water Framework Directive (European Commission 2000) is one of the most important attempts to conserve
and rehabilitate freshwater systems and their biodiversity in the
Mediterranean basin, although the directive is restricted to the
European Union countries. This directive aims to protect and
improve the quality of all freshwater ecosystems in the European Union countries, and to promote sustainable water use.
To fulfill the environmental objectives of the directive, each
country should enhance and restore the ecological condition of
aquatic ecosystems and prevent future deterioration. Water and
habitat quality must be enhanced in European rivers, streams,
lakes and wetlands to restore biotic communities to the expected
reference conditions. Also, costs of water services, including
environmental and resource costs need to be recovered. This
should help contain the increasing demand for water supply.
Inadequate pricing systems, lack of compliance with water
legislation, and economic subsidies have traditionally stimulated water demand. For example, large areas of traditional rainfed crops have shifted to irrigated cultivation in the past few
decades (Blinda et al. 2007). New water prices should help
overcome this situation by promoting an increase in water-use
efficiency and by reducing demand.
About 1% of the Mediterranean basin is currently protected
(IUCN Categories I–IV), and with Category V, the total rises
to 4.3% (Underwood et al. 2009). This is the lowest protection
level among Mediterranean bioregions of the world and constitutes o12% of the total land area currently in the world’s
protected-area network (Hoekstra et al. 2005). Such poor
representation reflects the low priority for conservation areas
in the southern rim of the Mediterranean basin, particularly in
northern African countries. The proportion of the Mediterranean
bioregion currently reserved in Morocco, Tunisia, Algeria and
Libya is 0.8, 0.3, 1.8 and 0%, respectively, of their land masses
within the Mediterranean bioregion (World Database on
Protected Areas, UNEP_WCMC 2009). Only Egypt (5.8%)
protects a proportion of its Mediterranean-bioregion area similar
to that in other European countries (e.g. 5.8% in Portugal and
5.3% in Spain). Most existing protected areas were designed for
terrestrial conservation, making protection of freshwater biodiversity uncertain (Dudgeon et al. 2006). Regional evaluation
of how adequately existing reserves represent and protect the
Mediterranean basin’s freshwater biodiversity is required, complementing local-scale assessment (Filipe et al. 2004; Abellán
et al. 2005; Hermoso et al. 2009b, 2010b).
The current reserve system in the Mediterranean also lacks
efficacy in protecting freshwater biodiversity (e.g. degradation
of the Tablas de Daimiel National Park). Furthermore, climate
change threatens the future of ,30% of the protected areas
(Klausmeyer and Shaw 2009), as well as probably amplifying
other threats. Some species currently within a reserve will be
forced to move outside their boundaries (Araujo et al. 2004).
To improve the effectiveness of the current protected areas in
protecting their freshwater biodiversity, planners must consider
resilience to climate change for new priority areas (Baron et al.
2009). Adaptation to climate change, rather than resistance, is
the best option for protecting valued ecosystems and their
species.
The proposed Natura 2000 Network may improve the protection of freshwater biodiversity in the European portion of the
Mediterranean basin. This approach focuses on enhancing the
protection of European endangered species and habitats, previously listed in the annexes of the ‘Conservation of Natural
Habitats and of Wild Fauna and Flora’ directive (European
Commission 1992). It requires the identification of special areas
for conservation (SAC), where the protection of the listed
species and habitats is feasible. Already 2928 SAC have been
identified, being almost 20% of the total land area of the
European Union. This proposed network is designed to protect
70 freshwater fish species (46 species endemic to the Mediterranean basin). However, it is clearly not sufficient, given that
only half of the Critically Endangered endemic Mediterranean
species (11 of 22) and one-third of the Endangered species (7 of
21) inhabiting the European countries are adequately covered.
Further studies are necessary to evaluate the capacity of this
network of protected areas to maintain the Mediterranean freshwater biodiversity and ascertain how to cover the species that are
not adequately represented.
Given the intense river regulation in the Mediterranean basin,
adequate environmental flows are necessary to maintain healthy
aquatic ecosystems (Arthington et al. 2006), even within protected areas. Only a few countries in the Mediterranean basin
have explicitly established legislation for environmental flows.
Italy first developed environmental-flow legislation (Fisheries
Protection Act 1978), followed by France (Fisheries Act 1984).
The number of studies addressing the success of environmental
flows has increased in recent years across the basin (IUCN 2004)
in countries such as Spain (Alcácer Santos 2004), Turkey
(Özesmi and Gürer 2004), Lebanon (Storey 2004) and Tunisia
(Smart 2004). However, most of these studies remain as research
outcomes without implementation. Moreover, the environmental flows are often estimated as minimum flows, a fact that is
especially problematic for rivers that dry up seasonally (Garcı́a
de Jaló n 2003). For environmental flows to maintain ecological
functionality, flows need to imitate natural flow variation,
with summer minima and a series of irregular floods during
the rainy season (Arthington et al. 2006). Before granting waterextraction licenses, there should be an assessment of environmental flow requirements (e.g. Slovenian Environmental
Protection Act 2004).
Future management
The Mediterranean basin is one of the world’s most threatened
biomes, with future climate changes exacerbating this status.
Management is needed to mitigate the conflict between environmental water and human demand, ensure water availability
for maintaining ecological processes, and reduce current widespread (e.g. pollution) and emerging threats (e.g. invasive species). Water planning needs to satisfy environmental objectives
and incorporate assessment of environmental flows. Rules of
thumb for minimum flows should be replaced with accurate
models that ensure that environmental flows imitate natural
hydrological regimes. To fulfill these objectives, water-use
efficiency and integrated and sustainable water management
need to be addressed. The Water Framework Directive lays the
foundations for new water-management strategies; however,
further legislation is needed for the remaining Mediterranean
countries not included in the European Union.
Increasing water supply is not an option in this water-scarce
area, so funding policies should be focussed on renewing old
and inefficient water-supply infrastructures and promoting
better and more efficient water-use practices. Given the importance that agriculture has as the main water demand, this should
be a priority intervention. Also, additional effort must be
devoted to mitigate pollution, channelisation, siltation and the
introduction and spread of exotic freshwater species. The control of exotic species deserves special attention because of their
impact on native-fish communities (Clavero et al. 2010; Hermoso et al. 2010a). Effective legislation and public awareness
programs are needed to reduce introduction rates as well
improving eradication or long-term control. Finally, the adequacy of the current network of reserves to represent and protect
Mediterranean freshwater biodiversity must be evaluated as
well as improving the information base for data-poor areas
(e.g. northern African basins).
Conclusion
The decline of endemic freshwater fish in the Mediterranean
basin calls for urgent action. The uneven distribution of threats
across the Mediterranean basin requires different strategies
to ensure protection of freshwater biodiversity. This also
highlights the need to evaluate the relative importance of each
threat at a fine scale. However, planning must be at the
whole-catchment scale for maximum effectiveness. For
example, Tablas de Daimiel National Park will not recover if
groundwater exploitation outside the protected area is not well
regulated. Effective whole-catchment management will often
require collaboration among different countries, and overcoming legal and institutional barriers (cf. Sommerwerk et al.
2010). Finally, the implementation of multi-national laws, such
as the Water Framework Directive in the European Union,
can help achieve common and minimum commitments for the
management of freshwater ecosystems in the European Union
countries and serve as an example for the rest of the Mediterranean basin.
Acknowledgements
We acknowledge the Salit Kark and the IUCN Centre for Mediterranean
Cooperation for providing the data on the distribution of endemic Mediterranean freshwater fish species. M.C. benefitted from a Juan de la Cierva
contract funded by the Spanish Ministry of Science and Education.
The authors also thank Richard Kingsford, Andrew Boulton, Stephanie
Janwchouski and two anonymous reviewers for their comments on the
previous versions of the manuscript.
References
Abell, R., Thieme, M. I., Revenga, C., Bryer, M., Kottelat, M., et al. (2008).
Freshwater ecoregions of the world: a new map of biogeographic
units for freshwater biodiversity conservation. Bioscience 58,
403–414. doi:10.1641/B580507
Abellán, P., Sánchez-Fernández, D., Velasco, J., and Millán, A. (2005).
Conservation of freshwater biodiversity: a comparison of different
area selection methods. Biodiversity and Conservation 14, 3457–3474.
doi:10.1007/S10531-004-0550-1
Alcácer-Santos, C. (2004). Environment flow assessment for the Ebro delta
in Spain. Improving links between wetland and catchment management.
In ‘Assessment and Provision of Environmental Flows in Mediterranean
Watercourses. Mediterranean Case Study’. Available at www.iucn.org/
themes/wani/flow/cases/Spain.pdf [accessed 1 November 2009].
Allan, J. D., and Flecker, A. S. (1993). Biodiversity conservation in running
waters. BioScience 43, 32–43. doi:10.2307/1312104
Alvarez Cobelas, M., Rojo, C., and Angeler, D. G. (2005). Mediterranean
limnology: current status, gaps and the future. Journal of Limnology 64,
13–29.
Araujo, M. B., Cabeza, M., Thuiller, W., Hannah, L., and Williams, P. H.
(2004). Would climate change drive species out of reserves? An
assessment of existing reserve-selection methods. Global Change
Biology 10, 1618–1626. doi:10.1111/J.1365-2486.2004.00828.X
Arthington, A. H., Bunn, S. E., Poff, N. L., and Naiman, R. J. (2006).
The challenge of providing environmental flow rules to sustain river
ecosystems. Ecological Applications 16, 1311–1318. doi:10.1890/10510761(2006)016[1311:TCOPEF]2.0.CO;2
Banarescu, P. (1989). Zoogeography and history of the freshwater fish
fauna of Europe. In ‘The Freshwater Fishes of Europe’. (Ed. J. Holcik.)
pp. 89–107. (Aula-Verlag: Wiesbaden, Germany.)
Baron, J. S., Gunderson, L., Allen, C. D., Fleishman, E., McKenzie, D., et al.
(2009). Options for national parks and reserves for adapting to climate
change. Environmental Management 44, 1033–1042. doi:10.1007/
S00267-009-9296-6
Bates, B. C., Kundzewicz, Z. W., Wu, S., and Palutikof, J. P. (Eds) (2008).
‘Climate Change and Water. Technical Paper of the Intergovernmental
Panel on Climate Change.’ (IPCC Secretariat: Geneva.)
Benejam, L., Angermeier, P. L., Munné, A., and Garcı́a-Berthou, E.
(2010). Assessing effects of water abstraction on fish assemblages in
Mediterranean streams. Freshwater Biology 55, 628–642. doi:10.1111/
J.1365-2427.2009.02299.X
Benoit, G., Comeau, A., and Chabason, L. (Eds) (2005). ‘A Sustainable
Future for the Mediterranean: The Blue Plan’s Environment and Development Outlook.’ (Earthscan: London.)
Bianco, P. G. (1990). Potential role of the paleohistory of the Mediterranean
and Paratethys basins on the early dispersal of Euro-Mediterranean
freshwater fishes. Ichthyological Exploration of Freshwaters 1,
167–184.
Bianco, P. G., and Ketmaier, V. (2001). Anthropogenic changes in the
freshwater fish fauna of Italy, with reference to the central region and
Barbus graellsii, a newly established alien species of Iberian origin.
Journal of Fish Biology 59, 190–208. doi:10.1111/J.1095-8649.2001.
TB01386.X
Blanco-Garrido, F., Clavero, M., and Prenda, J. (2009). Jarabugo (Anaecypris hispanica) and freshwater blenny (Salaria fluviatilis): habitat
preferences and relationship with exotic fish species in the middle
Guadiana basin. Limnetica 28, 139–148.
Blinda, M., Boufarouna, M., Carmi, N., Davy, T., Detoc, S., et al. (2007).
Technical report on water scarcity and drought management in the
Mediterranean and the Water Framework Directive. Available at
www.emwis.net/topics/WaterScarcity [accessed 1 November 2009].
Blondel, J., and Aronson, J. (Eds) (1999). ‘Biology and Wildlife of the
Mediterranean Region.’ (Oxford University Press: Oxford, UK.)
Bolle, H. J. (Ed.) (2003). ‘Mediterranean Climate. Variability and Trends.’
(Springer Verlag: Berlin.)
Bonada, N., Rieradevall, M., Prat, N., and Resh, V. H. (2006). Benthic
macroinvertebrate assemblages and macrohabitat connectivity in
Mediterranean-climate streams of northern California. Journal of the
North American Benthological Society 25, 32–43. doi:10.1899/08873593(2006)25[32:BMAAMC]2.0.CO;2
Bonada, N., Rieradevall, M., and Prat, N. (2007). Macroinvertebrate community structure and biological traits related to flow permanence in a
Mediterranean river network. Hydrobiologia 589, 91–106. doi:10.1007/
S10750-007-0723-5
Bromley, J., Cruces, J., Acreman, M. C., Martinez-Cortina, L., and Llamas,
M. R. (2001). Problems of sustainable groundwater management in
an area of over-exploitation: the Upper Guadiana catchment, central
Spain. Water Resources Development 17, 379–396. doi:10.1080/
07900620120065156
Castañ o-Castaño, S., Martinez-Santos, P., and Martinez-Alfaro, P. E.
(2008). Evaluating infiltration losses in a Mediterranean wetland: Las
Tablas de Daimiel National Park, Spain. Hydrological Processes 22,
5048–5053. doi:10.1002/HYP.7124
Clavero, M., and Garcı́a-Berthou, E. (2006). Homogenization dynamics and
introduction routes of invasive freshwater fish in the Iberian Peninsula.
Ecological Applications 16, 2313–2324. doi:10.1890/1051-0761(2006)
016[2313:HDAIRO]2.0.CO;2
Clavero, M., Blanco-Garrido, F., and Prenda, J. (2004). Fish fauna in Iberian
Mediterranean basins: biodiversity, introduced species and damming
impacts. Aquatic Conservation: Marine and Freshwater Ecosystems 14,
575–585. doi:10.1002/AQC.636
Clavero,M.,Hermoso,V.,Levin,N.,andKark,S.(2010). Geographical linkages
between threats and imperilment in freshwater fish in the Mediterranean basin. Diversity & Distributions 16, 744–754. doi:10.1111/
J.1472-4642.2010.00680.X
Darwall, W., Smith, K., Allen, D., Seddon, M., McGregor Reid, G., et al.
(2008). Freshwater biodiversity – a hidden resource under threat. In
‘Wildlife in a Changing World – An Analysis of the 2008 IUCN Red List
of Threatened Species’. (Eds J. C. Vié, C. Hilton-Taylor and S. N.
Stuart.) pp. 43–53. (IUCN: Gland, Switzerland.)
Doadrio, I. (1990). Phylogenetic relationships and classification of west
Palearctic species of the genus Barbus (Osteichthyes: Cyprinidae).
Aquatic Living Resources 3, 265–282. doi:10.1051/ALR:1990028
Doadrio, I., and Carmona, J. A. (2006). Phylogenetic overview of the genus
Squalius (Actinopterygii, Cyprinidae) in the Iberian Peninsula, with
description of two new species. Cybium 30, 199–214.
Doadrio, I., and Elvira, B. (2007). A new species of the genus Achondrostoma Robalo, Almada, Levy and Doadrio, 2007 (Aactynopterigii,
Cyprinidae) from Western Spain. Graellsia 63, 295–304. doi:10.3989/
GRAELLSIA.2007.V63.I2.96
Dudgeon, D., Arthington, A. H., Gessner, M. O., Kawabata, Z. I., Knowler,
J., et al. (2006). Freshwater biodiversity: importance, threats, status and
conservation challenges. Biological Reviews of the Cambridge Philosophical Society 81, 163–182. doi:10.1017/S1464793105006950
Duncan, J. R., and Lockwood, J. L. (2001). Extinction in a field of bullets:
a search for causes in the decline of the world’s freshwater fishes.
Biological Conservation 102, 97–105. doi:10.1016/S0006-3207(01)
00077-5
European Commission (1992). Directive 1992/43/EEC on the conservation
of natural habitats and of wild fauna and flora. Official Journal of the
European Communities, L206. Available at http://europa.eu/legislation_
summaries/environment/nature_and_biodiversity
[accessed
15
December 2009].
European Commission (2000). Directive 2000/60/EC of the European
Council and of the Council of 23 October 2000 establishing a framework
for community action in the field of water policy. Official Journal of
the European Communities, L327 1-72. Available at http://europa.eu/
legislation_summaries/agriculture/environment [accessed 15 December
2009].
Filipe, A. F., Marques, T. A., Seabra, S., Tiago, M. P., Ribeiro, F., Moreira
da Costa, L., Cowx, I. G., and Collares-Pereira, M. J. (2004). Selection of priority areas for fish conservation in Guadiana River basin,
Iberian Peninsula. Conservation Biology 18, 189–200. doi:10.1111/
J.1523-1739.2004.00620.X
Garcı́a de Jaló n, D. (2003). The Spanish experience in determining minimum flow regimes in regulated streams. Canadian Water Resources
Journal 28, 185–198. doi:10.4296/CWRJ2802185
Gasith, A., and Resh, V. H. (1999). Streams in Mediterranean climate
regions: abiotic influences and biotic responses to predictable seasonal
events. Annual Review of Ecology and Systematics 30, 51–81.
doi:10.1146/ANNUREV.ECOLSYS.30.1.51
Grantham, T. E., Merenlender, A. M., and Resh, V. H. (2010). Climatic
influences and anthropogenic stressors: an integrated framework for
streamflow management in Mediterranean-climate California, USA.
Freshwater Biology 55, 188–204. doi:10.1111/J.1365-2427.2009.
02379.X
Hermoso, V., Blanco-Garrido, F., and Prenda, J. (2008). Spatial distribution
of exotic fish species in the Guadiana river basin, with two new records.
Limnetica 27, 189–194.
Hermoso, V., Clavero, M., Blanco-Garrido, F., and Prenda, F. (2009a).
Assessing freshwater fish sensitivity to different sources of perturbation
in a Mediterranean basin. Ecology Freshwater Fish 18, 269–281.
doi:10.1111/J.1600-0633.2008.00344.X
Hermoso, V., Linke, S., and Prenda, J. (2009b). Identifying priority sites
for the conservation of freshwater fish biodiversity in a Mediterranean
basin with a high degree of endemics. Hydrobiologia 623, 127–140.
doi:10.1007/10750-008-9653-0
Hermoso, V., Clavero, M., Blanco-Garrido, F., and Prenda, F. (2010a).
Invasive species and habitat degradation in Iberian streams: an analysis
of their role and interactive effects on freshwater fish diversity loss.
Ecological Applications, in press. doi:10.1890/09-2011.1
Hermoso, V., Linke, S., Prenda, J., and Possingham, H. P. (2010b).
Addressing longitudinal connectivity in the systematic conservation
planning of the fresh waters. Freshwater Biology. doi:10.1111/J.13652427.2009.02390.X
Hijmans, R. J., Cameron, S. E., Parra, J. L., Jones, P. G., and Jarvis, A.
(2005). Very high resolution interpolated climate surfaces for global
land areas. International Journal of Climatology 25, 1965–1978.
doi:10.1002/JOC.1276
Hoekstra, J. M., Boucher, T. M., Ricketts, T. H., and Roberts, C. (2005).
Confronting a biome crisis: global disparities of habitat loss and
protection. Ecology Letters 8, 23–29. doi:10.1111/J.1461-0248.2004.
00686.X
IUCN (2004). ‘Assessment and Provision of Environmental Flows in
Mediterranean Water Courses. Concepts, Methods and Emerging Practice.’ (Centre for Mediterranean Cooperation, Malaga.) Available at
www.uicnmed.org [accessed 1 November 2009].
IUCN (2008). ‘IUCN Red List of Threatened Species. Version 2008.1.’
Available at www.iucnredlist.org [accessed 11 March 2009].
Johnson, P. T. J., Olden, J. D., and Vander Zanden, M. J. (2008). Dam
invaders: impoundments facilitate biological invasions into freshwaters.
Frontiers in Ecology and the Environment 6, 357–363. doi:10.1890/
070156
Kark, S., Levin, N., Grantham, H. S., and Possingham, H. P. (2009).
Between-country collaboration and consideration of costs increase
conservation planning efficiency in the Mediterranean basin. Proceedings of the National Academy of Sciences, USA 106, 15 368–15 373.
doi:10.1073/PNAS.0901001106
Klausmeyer, K. R., and Shaw, M. R. (2009). Climate change, habitat
loss, protected areas and the climate adaptation potential of species in
Mediterranean ecosystems worldwide. PLoS ONE 4, e6392. doi:10.1371/
JOURNAL.PONE.0006392
Kondolf, G. M., and Batalla, R. J. (2005). Hydrological effects of dams
and water diversions on rivers of Mediterranean-climate regions: examples from California. In ‘Catchment Dynamics and River Processes:
Mediterranean and Other Climate Regions’. (Eds C. Garcia and R. J.
Batalla.) pp. 197–211. (Elsevier: Amsterdam.)
Kottelat, M., and Freyhof, J. (2007). ‘Handbook of European Freshwater
Fishes.’ (Kottelat: Cornol, Switzerland.)
Leonardos, I. D., Kagalou, I., Tsoumani, M., and Economidis, P. S. (2008).
Fish fauna in a protected Greek lake: biodiversity, introduced fish
species over a 80-year period and their impacts on the ecosystem.
Ecology Freshwater Fish 17, 165–173. doi:10.1111/J.1600-0633.2007.
00268.X
Leprieur, F., Beauchard, O., Blanchet, S., Oberdorff, T., and Brosse, S.
(2008). Fish invasions in the world’s river systems: when natural
processes are blurred by human activities. PLoS Biology 6, 404–410.
Lévêque, C., Oberdorff, T., Paugy, D., Stiasnny, M. L. J., and Tedesco, P. A.
(2008). Global diversity of fish (Pisces) in freshwaters. Hydrobiologia
595, 545–567. doi:10.1007/S10750-007-9034-0
Light, T., and Marchetti, M. P. (2007). Distinguishing between invasions
and habitat changes as drivers of biodiversity loss among California’s
freshwater fishes. Conservation Biology 21, 434–446. doi:10.1111/
J.1523-1739.2006.00643.X
Likens, G. E., Walker, K. F., Davies, P. E., Brookes, J., Olley, J., Young,
W. J., Thoms, M. C., Lake, P. S., Gawne, B., Davis, J., Arthington, A. H.,
Thompson, R., and Oliver, R. L. (2009). Ecosystem science: toward a
new paradigm for managing Australia’s inland aquatic ecosystems.
Marine and Freshwater Research 60, 271–279. doi:10.1071/MF08188
Magalhães, M. F., Beja, P. R., Canas, C., and Collares-Pereira, M. J. (2002).
Functional heterogeneity of dry-season fish refugia across a Mediterranean catchment: the role of habitat and predation. Freshwater Biology
47, 1919–1934. doi:10.1046/J.1365-2427.2002.00941.X
Magalhães, M. F., Beja, P., Schlosser, I. J., and Collares-Pereira, M. J.
(2007). Effects of multi-year droughts on fish assemblages of seasonally
drying Mediterranean streams. Freshwater Biology 52, 1494–1510.
doi:10.1111/J.1365-2427.2007.01781.X
Magdaleno, F., and Fernandez, J. (2010). Hydromorphological alteration of
a large Mediterranean river: relative role of high and low flows on the
evolution of riparian forests and channel morphology. River Research
and Applications. doi:10.1002/RRA.1368
Malmqvist, B., and Rundle, S. (2002). Threats to the running water
ecosystems of the world. Environmental Conservation 29, 134–153.
doi:10.1017/S0376892902000097
Marr, S. M., Marchetti, M. P., Olden, J. D., Garcıa-Berthou, E., Morgan,
D. L., Arismendi, I., Day, J. A., Griffiths, C. L., and Skelton, P. H.
(2010). Freshwater fish introductions in mediterranean-climate regions:
are there commonalities in the conservation problem? Diversity &
Distributions 16, 606–619. doi:10.1111/J.1472-4642.2010.00669.X
McGarvey, D. J., and Hughes, R. M. (2008). Longitudinal zonation of
Pacific Northwest (USA) fish assemblages and the species-discharge
relationship. Copeia 2, 311–321. doi:10.1643/CE-07-020
Merenlender, A. M., Deitch, M. J., and Feirer, S. (2008). Decision support
tools for stream flow recovery and enhanced water security. California
Agriculture 62, 148–155. doi:10.3733/CA.V062N04P148
Myers, N., Mittermeier, R. A., Mittermeier, C. G., da Fonseca, G. A. B., and
Kent, J. (2000). Biodiversity hotspots for conservation priorities. Nature
403, 853–858. doi:10.1038/35002501
Nel, J. L., Roux, D. J., Maree, G., Kleynhans, C. J., Moolman, J., Reyes, B.,
Rouget, M., and Cowling, R. M. (2007). Rivers in peril inside and outside
protected areas: a systematic approach to conservation assessment of
river ecosystems. Diversity & Distributions 13, 341–352. doi:10.1111/
J.1472-4642.2007.00308.X
Olson, D., and Dinerstein, E. (2002). The global 200: priority ecoregions
for global conservation. Annals of the Missouri Botanical Garden 89,
199–224. doi:10.2307/3298564
Olson, D. M., Dinerstein, E., Powell, G. V. N., and Wikramanayake, E. D.
(2002). Conservation biology for the biodiversity in crisis. Conservation
Biology 16, 1–3.
Özesmi, U., and Gürer, I. (2004). Sultan Sazligi: biodiversity and natural
resources management pilot project in Turkey (GEF-II). In ‘Assessment
and Provision of Environmental Flows in Mediterranean Watercourses.
Mediterranean Case Study’. Available at www.iucn.org/themes/wani/
flow/cases/Turkey.pdf [accessed 1 November 2009].
Phillips, C., Allen, W., Fenemor, A., Bowden, B., and Young, R. (2010).
Integrated catchment management research: lessons for interdisciplinary
science from the Motueka Catchment, New Zealand. Marine and Freshwater Research 61, 749–763. doi:10.1071/MF09099
Pimm, S. L., Rusell, G. J., Gittleman, J. L., and Brooks, T. M. (1995). The
future of biodiversity. Science 269, 347–350. doi:10.1126/SCIENCE.
269.5222.347
Prat, N., and Munné, A. (2000). Water use and quality and stream flow in a
Mediterranean stream. Water Research 34, 3876–3881. doi:10.1016/
S0043-1354(00)00119-6
Prenda, J., Clavero, M., Blanco-Garrido, F., and Hermoso, V. (2006).
Threats to the conservation of biotic integrity in Iberian fluvial ecosystems. Limnetica 25, 377–388.
Revenga, C., and Mock, G. (2000). Freshwater biodiversity in crisis. Earth
Trends World Resources Institute: 1–4. Available at http//earthtrends.
wri.org [accessed 15 December 2009].
Reyjol, Y., Hugueny, B., Pont, D., Bianco, P. G., Beier, U., et al. (2007).
Patterns in species richness and endemism of European freshwater fish.
Global Ecology and Biogeography 16, 65–75. doi:10.1111/J.1466-8238.
2006.00264.X
Roll, U., Dayan, T., Simberloff, D., and Goren, M. (2007). Characteristics
of the introduced fish fauna of Israel. Biological Invasions 9, 813–824.
doi:10.1007/S10530-006-9083-8
Saunders, D. L., Meeuwing, J. J., and Vincent, C. J. (2002). Freshwater
protected areas: strategies for conservation. Conservation Biology 16,
30–41. doi:10.1046/J.1523-1739.2002.99562.X
Sheldon, F., Bunn, S. E., Hughes, J. M., Arthington, A. H., Balcombe, S. R.,
et al. (2010). Ecological roles and threats to aquatic refugia in arid
landscapes: dryland river waterholes. Marine and Freshwater Research
61, 885–895.
Slovenian Ministry of the Environment and Spatial Planning (2004).
‘Slovenian Environmental Protection Act. (ZVO-1) SOP-2004-011694.’ Available at http://www.mop.gov.si/en/legislation/environment/
the_evnironment_protection_act [accessed 15 December 2009].
Smart, M. (2004). River flow regulation and wetland conservation in a dry
country: Ichkeul, Tunisia. In ‘Assessment and Provision of Environmental Flows in Mediterranean Watercourses. Mediterranean Case
Study’. Available at www.iucn.org/themes/wani/flow/cases/Lebanon.
pdf [accessed 1 November 2009].
Smith, K. G., and Darwall, W. R. T. (Eds) (2006). ‘The Status and
Distribution of Freshwater Fish Endemic to the Mediterranean Basin.’
(IUCN: Gland, Switzerland.)
Sommerwerk, N., Bloesch, J., Paunović, M., Baumgartner, C., Venohr, M.,
Schneider-Jacoby, M., Hein, T., and Tockner, K. (2010). Managing
the world’s most international river: the Danube River Basin. Marine
and Freshwater Research 61, 736–748. doi:10.1071/MF09229
Storey, R. (2004). Assessing groundwater and surface water flows through
Aammiq Wetland. In ‘Assessment and Provision of Environmental
Flows in Mediterranean Watercourses. Mediterranean Case Study’.
Available at
www.iucn.org/themes/wani/flow/cases/Lebanon.pdf
[accessed 1 November 2009].
Thomas, R. J. (2008). Opportunities to reduce the vulnerability of dryland
farmers in central and west Asia and north Africa to climate change.
Agriculture Ecosystems & Environment 126, 36–45. doi:10.1016/
J.AGEE.2008.01.011
Underwood, E. C., Klausmeyer, K. R., Cox, R. L., Busby, S., Morrison,
S. A., et al. (2009). Expanding the global network of protected areas
to save the imperiled Mediterranean biome. Conservation Biology 23,
43–52. doi:10.1111/J.1523-1739.2008.01072.X
UNECA (1999). Freshwater stress and scarcity in Africa by 2025. United
Nations Economic Commission for Africa, Addis Ababa, Ethiopia.
UNEP/MAP/WHO (2004). Municipal wastewater treatment plants in Mediterranean coastal cities (II). MAP Technical Reports Series No. 157.
UNEP/MAP, Athens.
UNEP_WCMC (2009). ‘Data Structure of the World Database on Protected
Areas (WDPA). Annual Release 2009, New WDPA Schema, Webdownload Version – February 2009.’ Available at http://www.wdpa.org/
AnnualRelease.aspx [accessed 15 December 2009].
Urrea, G., and Sabater, S. (2009). Epilithic diatom assemblages and
their relationship to environmental characteristics in an agricultural
watershed (Guadiana River, SW Spain). Ecological Indicators 9,
693–703. doi:10.1016/J.ECOLIND.2008.09.002
Vannote, R. L., Minshall, G. W., Cummins, K. W., Sedell, J. R., and
Cushing, C. E. (1980). The river continuum concept. Canadian Journal
of Fisheries and Aquatic Sciences 37, 130–137. doi:10.1139/F80-017
WWF (2006). Drought in the Mediterranean – WWF policy proposals.
World. WWF/Adena, WWF Mediterranean Programme, WWF, Berlin.
Xenopoulos, M. A., Lodge, D. M., Alcamo, J., Marker, M., Schulze, K., et al.
(2005). Scenarios of freshwater fish extinctions from climate change and
water withdrawal. Global Change Biology 11, 1557–1564. doi:10.1111/
J.1365-2486.2005.001008.X
Manuscript received 30 November 2009, accepted 2 November 2010
http://www.publish.csiro.au/journals/mfr