Informe El medio ambiente en Europa: Estado y perspectivas 2020

PART 2
and storage, and flood protection, in
addition to providing habitats for many
protected species. Hence, achieving good
status of Europe’s surface waters not
only serves the objective of providing
clean water but also supports the
objective of providing better conditions
for some of Europe’s most endangered
ecosystems, habitats and species, as listed
under the Habitats and Birds Directives.
Unfortunately, however, both surface
water ecosystems and wetlands are under
considerable pressure.
Trends in the ecological status
of water
The quality of surface water ecosystems
is assessed as ecological status under
the Water Framework Directive.
The ecological status assessment is
performed for 111 000 water bodies in
Europe and it is based on assessments
of individual biological quality elements
and supporting physico-chemical and
hydromorphological quality elements
(definitions can be found in EEA, 2018b
and Section 4.3.2). A recent compilation
of national assessments, done as part of
the second river basin management plans
required under the Water Framework
Directive (EEA, 2018b; EC, 2019), shows
that 40 % of Europe’s surface water
bodies achieve good ecological status ( 1 ).
This is the same share of water bodies
achieving good status as reported in
the first river basin management plans.
Lakes and coastal waters tend to achieve
better ecological status than rivers and
transitional waters, and natural water
bodies are generally found to have better
ecological status than the ecological
potential found for heavily modified or
artificial ones. Across Europe, there is a
difference between river basin districts in
densely populated central Europe, where
a high proportion of water bodies do not
achieve good ecological status, and those
in northern Scandinavia, Scotland and
some eastern European and southern
river basin districts, where more tend to
achieve good ecological status (Map 4.1).
The ecological status assessment is based
on the ‘one out, all out principle’, i.e. if
one assessed element of quality fails to
achieve good status, the overall result is
less than good status. Thus, the status
of individual quality elements may be
better than the overall status. Overall,
for rivers, 50-70 % of classified water
bodies have high or good status for
several quality elements, whereas only
40 % of rivers achieve good ecological
status or better. Since the first river basin
management plans, many more individual
quality elements have been monitored,
improving the confidence of assessments,
even if the variability of methods used
by Member States remains so large
that comparisons have to be made with
caution (Table 4.2).
Trends in wetlands
40 %
of the surface water bodies
in Europe have a good
ecological status.
Across Europe, wetlands are being
lost. Between the years 2000 and 2018
the already small area of wetlands
decreased further by approximately 1 %
(Chapter 5). Many wetlands are found
in undisturbed floodplains, the areas
next to the river covered by water during
floods. Scientific estimates suggest that
70-90 % of floodplains are degraded
(Tockner and Stanford, 2002; EEA, 2016).
As a consequence, the capacity of
floodplains to deliver important and
valuable ecosystem services linked to
flood protection and healthy functioning
of river ecosystems has been reduced,
ultimately reducing their capacity to
support achieving good ecological and
conservation status. The conservation
status of many freshwater habitats and
species listed in the Habitats and Birds
Directives is not changing, and it remains
predominantly unfavourable or bad
(Table 4.2). The habitat group ‘Bogs, mires
and fens’ (different wetland types) has
the highest proportion of unfavourable
assessments — almost 75 % (Chapter 3).
The group ‘Freshwater habitats’ is also
predominantly unfavourable, as are
assessments of amphibians (Chapter 3).
Pressures and driving forces
The main reasons for not achieving
good ecological status are linked to
hydromorphological pressures (40 %),
diffuse pollution (38 %) and water
abstraction (Section 4.4). The
understanding of the links between
status and pressures has improved
with the development of river basin
management plans, and it is expected
that the implementation of the Water
Framework Directive will increasingly
lead to a reduction in the most critical
pressures and thus to improved
ecological status of surface water bodies
(Table 4.2). Freshwater habitats are
subject to many of the same pressures
as surface water bodies, and they are
often very sensitive to overabstraction
of water. In reporting under the
Habitats Directive for freshwater
habitats, changes in hydrology are
most frequently reported as being
important, as is ‘pollution to surface
waters’ Chapter 3). In parts of Europe
where groundwater abstraction
is high, the pressure on wetlands
( 1 ) The WISE WFD database that underlies the WFD visualisation tool is subject to updates. This may lead to values in the visualisation tool differing
from those presented in this chapter. The numbers in the text refer to values available on 1 January 2019. Recently, the database has been
updated by Norway and Ireland, and these updates are captured in Map 4.1 and Map 4.2 but not in the values provided in the text.
98 SOER 2020/Freshwater