within the WATERS project

Development of diatom

indicators for assessing

inland waters

Hafok AB

Coordinated by: Funded by:

Partners:

Maria Kahlert

Dept. of Aquatic Sciences and Assessment

Swedish University of Agricultural Sciences - SLU

Development of diatom

indicators for assessing inland

waters

Maria Kahlert

Leader for WP 4.3 Benthic diatoms, streams and lakes

Maria Kahlert Dept. of Aquatic Sciences and Assessment

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

Diatom method in Sweden

Main indices Additional indices

IPS

Eutrophication

& Organic

pollution

TDI Eutrophication

%PT Organic pollution

ACID Acidity

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)

Used for assessment of acidity

(not acidification)

Used for classification of

ecological status

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

ACHD

ACHD

AMPH

AMPH

AULA

AULA

BRAC BRAC

ENCP ENCP

EUNO EUNO

FRAG

FRAG

GOMP

GOMP

NAVI

NAVI

NITZ

NITZ

STRS

STRS

TABE TABE

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Streams Lakes

Rela

tive a

bundance (

%)

Eunotia

Frustulia

Tabellaria

Brachysira

Eolimnia

Cocconeis Planothidium

Amphora

Axis

2

Axis

2

Axis 1

Axis 1

A

B Δ Lakes

○ Streams

pH

AC

ID

4 5 6 7 8 90

2

4

6

8

10

LakesStreams

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

The Swedish diatom indices respond significantly and similarly

log10 (TP) (µg/l)

IPS

0,0 0,5 1,0 1,5 2,0 2,56

8

10

12

14

16

18

20

LakesStreams

The Swedish diatom indices respond significantly and similarly

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

Regression plots of assemblage composition (NMDS axis scores) vs.

phosphorus levels (log total phosphorus in µg L-1) and pH.

phytoplankton

macroinvertebrates

benthic diatoms

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

Axis 1

Axis

2

SOM

123456789101113141516171819202122232425

xmas

vatmarkakerang

skogvelocity

turbid

pHmean

Tot-PTot-N_ps

cond

Axis 1

Axis

2

CA CCA

pH

TP

höjd

Reference communities

Axis 1

Axis

2

SOM25

14578101314151618192021222425

TP

pH

• -

Saxån

(5, 16) Höjeå

(3, 21, 23a)

Nybroån

(10, 11, 12, 18, 20)

Rönneå

(25, 49, 57)

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

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

Maria Kahlert and Brendan G. McKie Dept. of Aquatic Sciences and Assessment

Result algal groups

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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!