conservation of margaritifera margaritifera (linnaeus
TRANSCRIPT
The LIFE+ programme is co-financed by the European Commission and by :
Study area in Brittany and Lower-Normandy. The breeding station is located in Brasparts.
Freshwater pearl mussel distribution and populations in Europe (from Geist, 2005).
The red ellipse indicate the area of the LIFE project.
Conservation of Margaritifera margaritifera (Linnaeus, 1758) in the Armorican Massif (Brittany and Lower-Normandy, France)Programme LIFE+ NAT FR 000583 / 1st September 2010 - 31st August 2016
Maintain and support existing populations1.
1. Harvesting glochidias
Fig. 1. Developmental course of glochidia of 3 freshwater pearl mussel
populations (Bonne Chère, Elez and Loc'h) in 2011. Dots: occurrence of
respective larval stage. Solid line: average water temperature in the
respective year (adapted from Scheder et al. 2011).
4. Breeding station
The breeding station was built in 2011-2012 in order to rear the main 6 populations of freshwater
pearl mussels of west of France. Water in the station comes from the river Rivoal and 3 different
sources and is filtered at 36 µm.
The current breeding system is shown on Fig. 2. Substrate was added 3 months after excystment
to allow higher survival rates (Thielen F., comm. pers.). Mussels are fed every day (except
sunday), with microalgae at 30 000 cells/mL (Mair et al., 2009). Shellfish diet 1800 and
Nannochloropsis sp. are currently used. A microalgae culture room will permit the nutrition with
fresh microalgae very soon.
2. Meeting fish and glochidias
River
Bonne Chère
Elez
Loc'h
Nb of mussel
5
8
2
Date of collect
22-29/08
16-21/09
15/09-17/10
Nb of fish
2 200
2 100
400
Hooked glochidia estimation
1-2 millions
2 millions
80 000
Tabl 1. Encystment at the breeding station using 0+ brown trout from 10 to 40 g (in 2011)
River
Bonne Chère
Nb of mussel
2
Date of collect
29/08
Nb of fish
31
Hooked glochidia estimation
31 000
Tabl 3. In-situ infestation with local brown trout from 20 to 30 cm immediatly released (in 2011)
River
Elez
Nb of fish
700
Hooked glochidia estimation
1 750 000
Tabl 2. Release of reared local brown trout infested at the breeding station
(in automn 2011 and spring 2012)
After harvesting glochidias in the field, they were
brought to the breeding station for infestation with
brown trouts (Tabl.1). The brown trout stock used
was reared by the Fédération de pêche du
Finistère from wild fish from the Elez river. The
major "black point" for freshwater pearl mussel
functionnality on the Elez river is the lack of fish
hosts. In order to support this fish population and
support mussel population, infected brown trout
were released in automn 2011 and spring 2012
(Tabl. 2).
Initially planed on all rivers of the project, the
local brown trout infestation immediatly released
could be done only on Bonne Chère river in 2011
(Tabl. 3).
3. Excystment
First ex-cysted young mussels were observed the 29/05/12
and during 3 weeks (until 22/06/12). Millions of young
mussels were collected and some of them were kept in the
breeding station : 3 000 for the Bonne Chère, 10-15 000 for
the Elez and 6 000 for the Loc'h river. The rest of them
(millions for the Elez and 2 000 for the Loc'h) were released
directly on adequate river substrates.
Young mussels kept at breeding station were neatly sorted
(one by one) by the LIFE team and by 25 volunteers (280 h
of voluntary work in 3 weeks).
Fig. 2. Actual breeding system : a buffer tank contains 36 µm filtered water with microalgae
(30 000 cells by mL). Aquariums contain about 1 000 mussels by 20 L of water. 80 % of water is
changed every week and microalgae are added every day. The buffer tank food mussel aquariums
in continue.
www.life-moule-perliere.org
Bibliography
Barnhart M.C. 2006. Buckets of muckets: A compact system for rearing juvenile freshwater mussels. Aquaculture, 254: 227-233.
Geist J. 2005. Conservation Genetics and Ecology of European Freshwater Pearl Mussels (Margaritifera margaritifera L.). Dissertation PhD, Technischen Universität Münich, Germany. 121 p.
Geist J. & Auerswald K. 2007. Physicochemical stream bed characteristics and recruitment of the freshwater pearl mussel (Margaritifera margaritifera). Freshwater Biology, 52: 2299-2316.
Mair R. A., Gatenby C. M. & Neves R. J. 2009. A Suitable Feed Concentration, Diet, And Culture System For Rearing Endangered Northern Riffleshell, Epioblasma torulosa rangiana. International Seminar of Projet LIFE Nature « Restauration des populations de moules perlières en Ardennes »‐ LIFE05NAT/L/000116. 25th-28th November, 2009. Clervaux, Luxembourg
Scheder C., Gumpinger C. & Csar D. 2011. Application of a five-stage field key for the larval development of the freshwater pearl mussel (Margaritifera margaritifera Linné, 1758) under different temperature conditions – A tool for the approximation of the optimum time for host fish infection in captive breeding. Ferrantia
5. Experiment
Malo Desrues (intern) has carried on an experiment on young mussel diet (young mussels from the
Elez river). Growth and survival were monitoring during 6 weeks since the mussel excystment. 5
bucket systems were made (inspired from Barnhart, 2006) with closed water system changed every
day. Each bucket contained 8 mesh boxes of 150 µm (2 Artemia sieves fitted together). Each box
contained initially 100 young mussels of ~ 400 µm long. Results are presented below.
a. Feeding with Shellfish Diet 1800
b. Feeding with Nanno 3600
c. Feeding with Shellfish Diet 1800
& Nanno 3600
d. Feeding with river water filtered at 36 µm
e. Feeding with "detritus" from wetland
Fig. 3. Survival percentage (left) and growth in µm (right) of 5 different feeding systems (vertical bars
shows the standard deviation)
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Loch river
date
deve
lopm
enta
lsta
ge
wate
rte
mpera
ture
(°C
)
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Elez river
date
deve
lop
menta
lsta
ge
wate
rte
mpera
ture
(°C
)
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7
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Bonne Chere river
date
deve
lopm
enta
lsta
ge
wate
rte
mpera
ture
(°C
)
janv
.2011
févr
.2011
mars
2011
avr
.2011
mai2011
juin
2011
juil.
2011
août2011
sep
t.2011
oct
.2011
nov.
2011
déc.2011
janv
.2012
févr
.2012
mars
2012
avr
.2012
mai2012
juin
2012
juil.
2012
5
5,5
6
6,5
7
7,5
8
8,5
9
Bonne Chère
Elez
Loc’h
Airou
Rouvre
Sarthon
pH
0 cm -5 cm -10 cm150
200
250
300
350
Airou river
substrate depth
Re
d-o
xp
ote
ntia
l(m
V)
Bre
tagn
e V
iva
nte
Environment
Biological quality is measured twice during the project, in 2011 and 2014, using 2
indicators : the "Normalized Global Biologic Index" (IBGN in French) and the "Biogenic
Aptitude Ratio" (Cb2 in French). Both of these indicators use the invertebrate population
composition to assess the environment quality.
Host-fish population
Electrofishing is done each 2 years (2011, 2013 and 2015) to monitor host-fish populations
(Salmo trutta fario) on freshwater mussel populations.
He
rvé
Ro
nné
Recover a favourable environment for
freshwater pearl mussels
S ix rivers located in the north-west of France
are known to still shelter the main population
of Freshwater pearl mussel (Margaritifera
margaritifera). All these six populations are
still reproducing but are only potentially
functional and will, without assistance,
disappear in the near future.
Therefore within a LIFE+ Nature project
established by the European Commission
and government agencies, a rearing station
was built in order to save these populations.
To achieve this goal, actions are undertaken
to unite and educate river stakeholders and
environmental restoration managers, to
improve our knowledge of the species and
finally, to be able to ensure the continuity of
the actions performed during the project.
Assess and monitor the environment3.
IN PARTNERSHIP WITH
Capoulade M. , Dury P. , Pasco P.-Y. & Ribeiro M.
(1) Bretagne Vivante - SEPNB – 186 rue Anatole France, BP 63121,
29231 Brest Cedex 3, France.
(2) Fédération de pêche du Finistère – 4 allée Loeïz Herrieu, Zone
de Kéradennec, 29000 Quimper, France.
(3) CPIE Collines normandes – Maison de la Rivière et du Paysage, Le
moulin, 61100 Ségrie-Fontaine, France.
International Meeting on Biology and
Conservation of Freshwater Bivalves
Bragança, Portugal, 4th-7th September 2012
AN ACTION COORDINATED BY
(1) (2) (1) (3)
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0.457
0.483
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0.510
0.528
0.560
Days
Length
(m
m)
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0.456
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0.4990.506
0.541
Days
Len
gth
(m
m)
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0.535
Days
Length
(m
m)
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Days
Length
(m
m)
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0.540
Days
Length
(m
m)
janv.
2011
févr
.2011
mars
2011
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.2011
mai201
1
juin
2011
juil.
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1
août201
1
sept.
201
1
oct.
2011
nov.
201
1
déc.201
1
janv.
2012
févr
.2012
mars
2012
avr
.2012
mai201
2
juin
2012
juil.
201
2
0
1
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6
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10
Bonne Chère
Elez
Loc’h
Airou
Rouvre
SarthonN-N
O3
(mg
/L)
Fig. b. Evolution of Nitrate N-NO3 in mg/L (from january 2011 to july 2012) in the different rivers
Shellfish diet 1800
2 milliards cells/mL (5-20 µm)
Isochrysis 40%
Pavlova 15%
Tetraselmis 25%
Thalassiosira weissflogii (TW) 20%
Nannochloropsis sp.
750 millions cells/mL (1-2 µm)
Concentration of ~ 30 000 cells/mL (Mair et al., 2009)
Shellfish diet : 2 drops / 20 L
Nanno : 175 µL / 20 L
Composition of microalgae solutions:
River Undertaken actions
Tabl b. Restoration actions to recover a favourable habitat for freshwater pearl mussel populations
Restoration contract leaded by the Syndicate of the Blavet river valley
Restoration actions leaded by the Syndicate of the Rouvre river ; Syndicate of communes of Athis ; Syndicate of drinking water of the Houlme ; Natura 2000 contracts (CPIE des Collines normandes) ; Fishing Federation of Orne actions
Restoration contract leaded by the Normandie-Maine National Nature Reserve ; Natura 2000 contracts (Normandie-Maine National Nature Reserve)
Restoration contract leaded by the SIAES ; Natura 2000 contracts (SIAES)
Natura 2000 contracts (CCCA/CCKB) ; Restoration actions leaded by the Syndicate of Kerné-Uhel ; Fishing Federation of Côte-d'Armor actions
Natura 2000 contracts (Armorique National Nature Reserve) ; Fishing Federation of Finistère actions ; Council of Finistère department
Bonne Chère
Elez
Loc'h
Airou
Rouvre
Sarthon
River Catchment size (ha)Catchment size (ha)
in Natura 2000 area
River linear with
tributaries (km)
River linear with tributaries (km)
in Natura 2000 area
Tabl a. Some geographical caracteristics of LIFE rivers linked to Natura 2000 areas
Bonne Chère
Elez
Loc'h
Airou
Rouvre
Sarthon
1 737.3
2 769.6
1 864.5
11 530.9
32 435.5
12 033.4
18.5
971.3
99.9
708.2
428.9
16.5
26.7
29.7
28.9
138.6
360.9
127.6
2.0
21.2
9.2
64.7
12.4
127.6
Quality of freshwater pearl mussel habitats
is improved by encouraging river managers
to help with the implementation of
measures on short-term (set up fences,
riverbank stabilization, control of farms,
etc.), but also on medium-term (e.g. land
acquisition). Increased public awareness
with habitat issues is also very important :
river's managers, fishermen and farmers
from watershed, as well as general public.
The context of the six rivers is very different
(Tabl. a.) and threats for freshwater pearl
mussel populations are not the same on
each catchment. Then, the means to
recover a favourable environment for the
mussels are also different (Tabl. b).
The physico-chemical quality of the water, quality of the habitat, substrate, the status of host-
fish are monitored. All these parameters are contributing 1) to caracterise mussel
environment and 2) to look for reinforcement area of young reared mussels.
Water parameters
Manual measures are done every month in water near freshwater mussel populations. The
multiparameter Hanna HI 9828 (Hanna instrument) records 3 different parameters (among
others) : pH (Fig. a.), conductivity and dissolved oxygen. A sensor, HOBO0167, records
temperature each hour. Nitrate N-NO3 (Fig. b.) and Orthophosphate P-PO4 samples are
analysed by a laboratory. In 2011 and 2015, 20 pesticides molecules are searched by a
laboratory (sample after more than 10 mm of rain in 24 h).
Substrate parameters (Geist & Auerswald, 2007)
A multiparameter WTW 3110 with a Pt probe and an Ag/Cl reference probe is used to
measure the red-ox potential (Eh) at different depth (0, 5, 10 cm) in order to record the
substrate oxygenation (Fig. c.). A pocket penetrometer (0-500 kN/m²) is also used with
adapted discs to measure substrate resistance.