Freshwater biodiversity
Status, trends, pressures and challenges
Joachim Maes
Joint Research Centre – Institute of Environment and Sustainability
Rural Water and Ecosystem Resources Unit
Action Biodiversity, Water and Ecosystem Services (BIOMES)
Global distribution of freshwater ecosystems
Freshwater ecosystem host a disproportionally
rich species diversity
Vertebrates
Number
Share in
freshwater
30.000
(41+1) %
Amphibians
5.700
>70 %
Reptiles
8.200
5%
10.000
9%
5.400
6%
Fishes
Birds
Mamals
• 1/3 of all vertebrates are ecologically
dependent on fresh water
• 6 % of all described species
• There is a lack of global information
for invertebrates and micro-organisms
inhabiting fresh water
"Pinocchio" Frog, recently discovered in New Zealand, National Geographic
High levels of endemism explain in part
this rich freshwater biodiversity
Total number of amphibian species per country per km2
Source: World Resources Institute
The species flock of Cichlid
fishes in the African great
rift lakes:
A group of 500 closely
related fish species that
underwent rapid adaptive
radiation during the last
100.000 years
Verheyen et al. Science 300.
Red: endemic fish species
Freshwater biodiversity in crisis
The LPI measures
trends in vertebrate
population
abundance over time.
Sources: Burtchart et al.
(2010) Science; Global
population dynamics
database, Imperial College
London
Source: EEA-ETC, Article 17 reports, 2009
Source: EEA-ETC, Article 17 reports, 2009
Amphibian
population trends
from 1950 to 1997
using 936 populations.
Source: Houlahan et al. Nature 404
Geographical pattern of the dominant
causes of rapid decline
Source: Stuart et al. Science 306.
Alien species in European fresh water
Eriocheir sinensis, Chinese mitten crab
11.000 aliens
Sources: Burtchart et al. (2010) Science; Global population dynamics database,
Imperial College London
FRESHWATER
7%
TERRESTRIAL
90%
100 worst
TERRESTRIAL
52%
MARINE
7%
Source: DAISIE European Invasive Alien Species Gateway (http://www.europe-aliens.org/)
FRESHWATER
28%
MARINE
35%
Habitat fragmentation is a major driver
of biodiversity loss in freshwater ecosytems
Flow regulation structures in France
The river continuum and flood pulse concepts describe the
longitudinal and transversal interactions in river systems. These
interactions are essential to maintain biodiversity
Poor water quality
blocks fish migration.
Source: Maes et al. 2008
ECSA
1.0
0.9
0.8
Capture probability
Too much nutrients
and organic pollution
creates hypoxic zones
in the river which
cannot be passed by
fishes moving
upstream or
downstream
Logistic reponse of diadromous fish to DO
eel anguille
0.7
smelt
éperlan
0.6
0.5
3-spined
stickleback
épinoche
flounder flet
0.4
0.3
twaite shad
alose feinte
0.2
0.1
0.0
0
1
2
3
4
5
6
7
8
9
Dissolved oxygen (mg O2 L-1)
10
11
TURBID
In shallow pond and lakes, increasing nutrient
loading shifts the ecosystem from a stable clear
state dominated by macrophytes to a stable but
turbid state dominated by small phytoplankton
species.
loa
din
g
CLEAR
TURBID
TURBID
CLEAR
ien
t
Chlorophyl concentration
Nu
tr
CLEAR
Pictures taken from STOWA, Van helder naar troebel en weer
terug.
Scheffer et al. TREE 8
Nutrient loading
<0.5 mg L-1
0.5 – 1.5 mg L-1
>1.5 mg L-1
Map of potential risk for eutrophication
for surface freshwater based on
estimated total nitrogen concentrations
Source: Grizzetti et al. In press. Nitrogen as a threat to
European water quality. In "The European Nitrogen
Assessment"
Ecological status of European lakes
according to the harmonized
methodology of the Water Framework
Directive Intercalibration Group.
Recovery of freshwater biodiversity
Recovery of freshwater biodiversity
Improving water quality is an effective
method for rehabilitating fish
populations in streams where natural
colonization is possible.
Source: Data from INBO, Belgium
Recovery of freshwater biodiversity
“Recovery of the Hudson River
population of Shortnose sturgeon
suggests the combination of species
and habitat protection with patience
can yield successful species recovery,
even near one of the world’s largest
human population centers”.
Source: Bain et al. (2007) Plos ONE.
Freshwater biodiversity supports the provision
of key ecosystem services by aquatic ecosystems
Provisioning services
Regulating services
Cultural services
Availability of fresh water
(% inland waters)
Purifying water
(nutrient retention capacity)
Source: CLC2000
Source: Grizzetti et al. GREEN model, JRC
Recreation
(number of compliant bathing
waters Source: EEA)
Low
High
Summary and conclusions
•
•
•
•
Freshwater ecosystems support 6% of all described species and 1/3 of all vertebrates.
Freshwater ecosystems provide key ecosystem services to sustain human livelihoods.
Fresh waters experience greater than average declines in biodiversity. The high level of
endemism makes freshwater ecosystems particularly vulnerable.
Biodiversity assessments remain difficult; the present knowlegde base is insufficient.
–
–
•
•
BIOFRESH project: to improve capacity to protect and manage freshwater biodiversity in the face of ongoing
changes to global climate and socioeconomics. www.freshwaterbiodiversity.eu
Coordinator is Prof. Dr. Klement Tockner (Leibniz-Institute of Freshwater Ecology and Inland Fisheries)
The most important threats are flow modification/habitat destruction, pollution and
invasion by exotic species.
Recovery, sometimes rapid (decade), is possible but requires a combination of policy,
persisted efforts and, importantly, patience.
Acknowledgements
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•
•
•
•
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Bruna Grizzetti, JRC
Faycal Bouraoui , JRC
Ana-Cristina Cardoso , JRC
Jochen Vandekerkhove , JRC
Alberto Aloe , JRC
Jan Breine, INBO, Belgium