Development of diatom
indicators for assessing
inland waters
within the WATERS project
Maria Kahlert
Dept. of Aquatic Sciences and Assessment
Swedish University of Agricultural Sciences - SLU
Coordinated by:
Funded by:
Partners:
Hafok AB
Maria Kahlert
Dept. of Aquatic Sciences and Assessment
Development of diatom
indicators for assessing inland
waters
Maria Kahlert
Leader for WP 4.3 Benthic diatoms, streams and lakes
Hafok AB
Current
SE diatom
method
index calculation: all diatom species
included:
relative abundance [%]
indicator value specific for each species
• sensitivity value: impact
• tolerance value:
weight
• classification
1
high
2
good
3
moderate
4
poor
5
bad
Used for classification of
ecological status
Diatom method in Sweden
Main indices
Additional indices
IPS
TDI
Eutrophication
%PT
Organic pollution
ACID
Eutrophication
& Organic
pollution
Acidity
Used for assessment of acidity
(not acidification)
IPS: Indice de Polluo-sensibilité Spécifique (Cemagref 1982)
%PT: Pollution Tolerant Valves (Kelly 1998)
TDI: Trophic Diatom Index (Kelly 2008)
ACID: ACidity Index for Diatoms (Andrén & Jarlman 2007)
WATERS WP 4.3 Benthic
diatoms, streams and lakes
• Development of lake method
• Detection of impact of toxins (malformations)
• Reference diatom assemblages, steering factors
• Fast assessment of other benthic algal groups
Lake method
• The stream diatom method can be
applied in lakes as well,
despite some differences in diatom
assemblage composition
• Benthic diatoms reflect lake water
chemistry at least equally good as
plankton
Steffi Gottschalk
100%
Relative abundance (%)
90%
80%
70%
TABE
STRS
NITZ
NAVI
EUNO
ENCP
ENCP
BRAC
AULA
AMPH
BRAC
60%
40%
30%
STRS
NITZ
NAVI
GOMP
FRAG
EUNO
GOMP
FRAG
50%
TABE
AULA
AMPH
20%
ACHD
ACHD
10%
0%
Streams
Lakes
Eunotia
Eolimnia
Frustulia
Axis 2
Cocconeis
Planothidium
Amphora
Tabellaria
Brachysira
Axis 1
Axis 2
A
Δ Lakes
○ Streams
B
Axis 1
The Swedish diatom indices respond significantly and similarly
10
ACID
8
6
4
2
0
Lakes
Streams
4
5
6
7
pH
ACID vs. pH
lake
ACID = –9.13 + 2.23pH, p = 0.000, r2 = 0.67
stream
ACID = –9.2 + 2.26pH, p = 0.000, r2 = 0.74
Fitting was restricted to pH < 8.4
8
9
The Swedish diatom indices respond significantly and similarly
20
18
IPS
16
14
12
10
8
6
0,0
Lakes
Streams
0,5
1,0
1,5
log10 (TP) (µg/l)
IPS vs. total P (TP) (as log10[TP] [µg/L])
lake
IPS = 21.18 – 3.18log10(TP) (µg/L), p = 0.000, r2 = 0.55
stream
IPS = 22.88 – 4.67log10(TP) (µg/L), p = 0.000, r2 = 0.63
2,0
2,5
benthic diatoms
phytoplankton
macroinvertebrates
Regression plots of assemblage composition (NMDS axis scores) vs.
phosphorus levels (log total phosphorus in µg L-1) and pH.
pH range: 4,8-8,0
TP range: 2-30 µg/l
Impact of toxins (malformations)
• The impact of toxins is not reflected by the indices
used today
• We found that the amount of deformed diatom
valves can be used as an indicator of the impact of
heavy metals
Ivana Rasic
Preliminär screening metod
now tested in regular
monitoring
Kahlert, M. (2012). Utveckling av en
miljögiftsindikator – kiselalger i rinnande vatten.
Länsstyrelsen Blekinge län, Karlskrona, Report
2012:12, 40 pp.
More studies
are needed to
understand the
correlation
toxins-deformations
Reference diatom assemblages
• Following method for the ‘Eastern Canadian Diatom
Index (IDEC)’ (Grenier et al. 2010):
Self-Organizing-Maps (SOM) for classification
• Regional differences in assemblage composition
were rather low
• Diatoms were mainly steered by water chemistry
Isabel Lavoie
Institut national de la recherche scientifique,
Québec, Canada
Different diatom communities in
Sweden, steered by pH, TP and
altitude
x
mas
pHmean
velocity
skog
vatmark
turbidangaker
cond
Tot-N_ps
Tot-P
TP
Axis 1
Axis 1
CA
pH
höjd
Axis 2
Axis 2
SOM
1
2
3
4
5
6
7
8
9
10
11
13
14
15
16
17
18
19
20
21
22
23
24
25
CCA
Reference communities
TP
Axis 2
SOM25
1
4
5
7
8
10
13
14
15
16
18
19
20
21
22
24
25
Axis 1
pH
Saxån
(5, 16)
Höjeå
(3, 21, 23a)
• Rönneå
(25, 49, 57)
Nybroån
(10, 11, 12, 18, 20)
Helgeå
(11B, 24F, 27)
Careful:
A method based on
community
composition does
only work if
different identifiers
have harmonized
their view on
diatom names and
identification!
Fast assessment of algal biomass?
• A new instrument for a fast assessment of
the entire benthic algal community was
tested (BenthoTorch)
• Uses pigment fluorescence
• However, only total biomass can be
assessed.
• Algal groups cannot be
separated.
Brendan McKie
Maria Kahlert and Brendan G. McKie
Dept. of Aquatic Sciences and Assessment
Comparing new and
conventional methods to
estimate benthic algal
biomass and
composition in
freshwaters
Comparison of fluorescence measurement in
situ with conventional analysis of pigments &
microscopical biovolume analysis
Latnajaure
http://pubs.rsc.org/en/content/articlelanding/2014/em/c4em00326h/unauth#!divAbstract
Result algal groups
WATERS WP 4.3 Benthic
diatoms, streams and lakes
• Next steps:
Reference diatom assemblages, steering factors
Analysis of the entire Swedish dataset
• Thanks to everyone who contributed to this work!