FISHERIES AND MARINE SERVICE Translation Series No. 4354

a
•
FISHERIES AND MARINE SERVICE
Translation Series No.
4354
An experimental study on the acute toxicity of salts of
cobalt, antimony, strontium and silver to several species
of crustaceans and their larvae and to several species of
teleosts
by J.C. Amiard
Original title: Etude expérimentale de la toxicité aigue de sels de cobalt
d'antimoine, de strontium et d'argent chez quelques crustacés et leurs
larves et chez quelques téléostéens
,
From:
Rev. Int. Oceanogr. Med. 43: - 79 95, 1976
-
Translated by the Translation Section
Department of the Environment
Department of the Environment
Fisheries and Marine Service
Halifax Laboratory
Halifax, N. S.
1978
21 pages typescript
-
1717 2/36 11
AN EXPERIMENTAL STUDY
ON THE ACUTE TOXICITY OF SALTS OF COBALT,
ANTIMONY, STRONTIUM AND SILVER
TO SEVERAL SPECIES OF CRUSTACEANS AND THEIR LARVAE
AND TO SEVERAL SPECIES OF TELEOSTS
by J C Amiard*
INTRODUCTION
Metallic pollution of the marine environment is a matter deserving
of concern in most parts of the world because of the growing number of
industrial plants which discharge metallic waste into the water and also
because of the considerable increase in the amount of metallic material
in contact with the aquatic environment.
The metals studied in this experiment are of some importance
industrially:
- Cobalt is used in electroplating
and as a pigment in glass,
pottery and enamel, and it has many metallurgical applications.
- Strontium is used in pyrotechnics, in phosphorescent materials,
thermionic cathodes and electron tubes. Strontium oxide is used in the
sugar industry.
- Silver is used in the form of alloys. Silver bromide and iodide
are used in the photographic industry. Silver iodide is used in cloudseeding, and silver chloride in dry cell batteries.
- Antimony is used mainly in alloys.
*
CEA, Department of environmental protection, Environmental study and
research service, Radio-ecology
section, LPE BP No 1,
13115 Saint-Paul-lez-Durance.
and Biological oceanography laboratory, Université Pierre et Marie Curie
(Paris VI), Bâtiment A, 4, Place Jussieu, 75230 PARIS Cedex 05.
80
Our knowledge of the toxicity of metals is still generally of a
qualitative and empirical nature. The purpose of this study was to collect
numerical data on the toxic range of two metals considered to be of low
toxicity (strontium and cobalt), one metal regarded as toxic (silver), and
one metalloid (antimony) for certain crustaceans and teleosts.
In a first
investigation such as this, it is useful to determine the lethal dose of
substances about whose toxicity little is known, and to make such determinations was the aim of this study.
The toxic threshold provides
information about the maximum amount of the element tolerable in the
environment.
The elements chosen for study are naturally present in sea water in
trace amounts. Their biological functions are very different.
Cobalt
is indispensable to life, while strontium is
12
chemically close to calcium, an essential mineral. On the other hand,
associated with Vitamin B
silver and antimony, whose biological action is at present unknown, are
generally considered to be of no use to living organisms.
I - MATERIALS AND METHOD
- Sea water
The sea water was taken from the northeastern coast of the Cotentin
Peninsula. Sea water contains between 0.01 and 1.4 pg/L of cobalt (Fukai
and Meinke, 1959; Goldberg, 1965; Robertson et al, 1968, 1969;
Robertson and Forster, 1969; Schutz and Turekian, 1965), between 0.04
and 0.30 pg/L of silver (Black and Mitchell, 1952; Goldberg, 1965; Preston
et al, 1972; Robertson et al, 1968, 1969; Schutz and Turekian, 1965),
between 8 and 13 mg/L of strontium (Goldberg, 1965) and about 0.165 pg/L
of antimony (Robertson and Forster, 1969; Robertson et al, 1968, 1969).
- Species studied
The species used in the tests were the following
. Adult crustaceans
Carcinus maenas
Palaemon serratus
• Larval crustaceans
C. maenas
P. serratus
Homarus vulgaris (Mysis I, II, III)
Maia squinado (Zoeo I)
. Adult teleosts
Pleuronectes platessa
Blennius
pAalL
81
There was wide variation in weight among the adults used in the test:
3 g to 100 g for C. maenas, 1.1 g to 6.7 g for P. serratus, 5 g to 120 g
for P. platessa and 4 g to 30 g for B. pholis.
- Experimental conditions
The experiments on the adult animals were conducted in ten-litre
buckets containing two litres of sea water.
Each bucket was equipped with
an aeration device. There were two adult crabs or five adult shrimp in
each bucket.
The crustacean larvae were placed in crystallizers containing one litre
of sea water as soon as they hatched.
The water was not aerated. There were
two lobster larvae, ten shrimp larvae, or thirty crab or spider crab larvae
per crystallizer.
The animals were kept in a water at a temperature of 15 ° C Li 1 ° C, except
for the lobster larvae, which were kept at 22 ° C II 1° C.
The larvae were not fed for the duration of the test, but the H. vulgaris
larvae at stages 1, 2 and 3 were fed before being used.
About fifty adults of each species, fifty lobster larvae, and a hundred
larvae of the other species of crustaceans were tested at each concentration
of each salt.
- Pollutants studied
Information on the pollutants studied is presented in Table I.
TABLE I
Pollutants studied
Legend (See photocopy of original)
1
Pollutant
2
Salt
3
Amount added (in ppm)
4
Salt
5
Element
6
Silver
7
Antimony
II
,1
uvent
Les individus adultes testés couvrent une grande gamme de tailles
qualitative
1
., es
chiffrées
es (strontium, •
!elques
3
à 100 g. pour C.maenpa, 1,1 à 6,7 g. pour P. perratuci 5 à 120 g. pour P. platenaa
et:4 à 30 g. pour B. phaia.
Crustacés
dose létale
1 cité
va en effet
ins
- Aquariologie :
Les expériences sur les animaux adultes sont réalisées dans des seaux
est prati-
le milieu.
naturellement
es sont très
le à la vie
essaire
(calcium).
actuellement
vettes adultes par seau).
Les larves de Crustacés sont. placées dès l'éclosion dans des cris t allisoirs contenant un litre d'eau de mer. Aucune aération de l'eau n'est effectuée
(il y a respectivement 2 larves de homard ou 10 larves de crevettes ou 30 larves
de crabes ou d'araignées par cristallisoir).
Les animaux sont maintenus dans une eau de température égale à
15 ° C ± 1 ° C,
à l'exception des larves de homard élevées à la température de
22 ° C •± 1 ° C.
Le's
Cotentin.
1
de cobalt
1969 ;
larves ne sont pas nourries pendant la durée du test mais les
larves d'H. vulgam:s sont nourries aux stades 1, 2 et 3 avant d'être utilisées:
• Pour chaque dilution et chaque sel une cinquantaine d'individus
adultes et de larves de homard et une centaine de larves des autres espèces
de Crustacés ont été testés.
et 0,30 ug/1
- Les'polluants étudiés :
1., 1972 ;
Les renseignements relatifs aux polluants étudiés sont rassemblés
et 13 mg/I
‘obertson
dans le tableau n ° • I.
TABLEAU n ° I
Les polluants étudiés
I
a
Polluant
Cobalt (Co)
(t, JArgent
7
(Ag)
Antimoine (Sb)
.
.
.
3 Surcharge introduite (en ppm)
4. sel ,
5 élément .
Sel
CoC1
Strontium (Sr)
Il)
!'
d'une contenance de 10 litres contenant deux litres d'eau de mer. Un dispositif
d'aération est présent dans chaque seau (il y a respectivement 2 crabes ou 5 cre-
2
0,1
•
SrC1
2
AgNO 3
0,1
SbC1
.
3
0,1
1.10
81
-3
à 2265
il.
5000
0,045
à
5000 •
à
10
0,055 à 2760
-4
6.10 à 6,4
à
1000
0,05
à 534
.
i•
82
Remarks
*
Strontium chloride reaches its solubility maximum at a concentration
of 1000 ppm.
Above this level, the strontium is largely in
suspension.
**
It is impossible to dissolve very low concentrations of antimony
trichloride in sea water, but the salt dissolves totally at very high
concentrations (Bothorel, 1958).
Two types of solutions, A and B,
were therefore made up. Solution A was a suspension of antimony
trichloride in sea water.
To prepare solution B, the antimony trichloride
was dissolved in sea water that had been acidified with hydrochloric
acid (pH 1) and then neutralized with bicarbonate at pH 8.
***
All measurements of pollutant concentrations are expressed in mg/L
(or ppm) of salt (cobalt and strontium chloride, antimony trichloride
and silver nitrate).
- pH variations
The pH of the natural sea water used was 7.8.
The addition of cobalt
chloride in proportions of 2000 and 5000 ppm gave pHs of 7.6 and 7.4
respectively.
The addition of strontium chloride in proportions of 2000
and 5000 ppm gave pHs of 7.65 and 7.3.
- Controls
Equal numbers of control and test animals were used in each experiment.
The mortality rate of adult animals placed in sea water at pH 7.3 did not
show any increase nor did that of the animals placed in sea water that had
been acidified (pH 1) and neutralized
WI
8).
- Physical chemistry of the pollutants
It was not possible to study the physical chemistry of the pollutant
salts using the stable isotopes.
However, the physicochemical properties
of the radioisotopes in sea water under identical experimental conditions
(Robertson, 1971) were determined by reference to previous experiments in
which ion-exchange resins were used (Schubert, 1948; Guegueniat, 1971).
Thus:
* Strontium 85 remains in cationic form (Amiard, 1973a).
* Cobalt 60 evolves from cationic forms toward anionic forms
(Amiard and Le Lannou, 1972).
83
* Antimony 125 remains in anionic form (Amiard, 1973b).
* Silver 110m is half in anionic form or uncharged and half in
cationic f.orm (Pouvreau and Amiard, 1974).
- Toxicity tests
The acute toxicity test performed in this experiment is one of the
most frequently used of the numerous types that have been developed (Amiard
and Amiard-Triquet, 1974):
the dose lethal to 50% of the animals after
96 hours of exposure.
The study was completed by investigation of the effects of prolonged
exposure for periods of 25 to 30 days.
II - RESULTS AND DISCUSSION
- Mortality rates among control animals
The mortality rate among the adult animals was almost always less than
10% (figures 1 to 4).
However, among C. maenas and B. pholis, it reached
20% after 10 and 15 days of exposure respectively (figures 2 and 4).
The mortality rate among the control larvae was higher, and it grew
rapidly with time, which limits the period over which the test is valid.
Thus, for the first larval stage of the lobster, mortality was 5% after 12
hours, 20% after 48 hours and 50% after 96 hours (Figure 6).
For the
•
third larval stage, which was more resistant, mortality was 5% after 96 hours
and 20% after 216 hours (Figure 5).
- Concentrations lethal to 50% of the animals after 12 to 96 hours
of exposure
Table II gives the results of this test.
Of the four salts under consideration, silver nitrate seems to be the
most toxic, 100 to 1000 times more than the chlorides of antimony, cobalt
and strontium. The relative toxicity of the three latter salts varies with
the organism studied.
The nature of the salt can affect toxicity, but as
Mathews (1904) points out, the toxic action of metals is a periodic function
of atomic weight.
At any given concentration, the toxic effects of a given
salt will be felt more strongly the longer the period of contact with the
pollutant (figures 2, 3, 4, 5, 6 and 7).
84
TABLE II
Concentrations (in ppm) of salts of cobalt, strontium, silver and antimony
lethal to 50% of test animals in 96 hours (4 days).
(The concentrations
given indicate the amounts over and above those present in natural sea
water added for the purposes of the experiment.)
Legend (See photocopy of original)
1
Species
2
Silver
3
Antimony
4 Adult
5 Zoea I
6
Green crab
7
Common prawn
8
Plaice
9
Blenny
10 Spider crab
The crab and prawn larvae were five to a thousand times times more
sensitive to the pollutants than the adults.
This is not a new finding;
the same observation has been made many times before (Fontaine, 1972).
results varied widely with the species and the pollutant.
The
The Palaemon
Serratus larvae seemed slightly more resistant to cobalt chloride than the
Carcinus maenas larvae, which in turn were more resistant than the Maia
squinado larvae.
At a temperature of 15 °C, resistance to cobalt chloride
seemed to depend on size, with bigger larvae being better able to withstand
the added cobalt. The stage I Homarus vulgaris larvae were appreciably less
resistant than the stage 2 and 3 larvae, while the stage 3 larvae were
slightly more resistant than the stage 2 animals.
TABLEAU
•N°
II
Concentrations létales 50 6 (en ppm) 4 6 Ilures (4 jours) chez plusieurs espèces
de Crustacés et leurs larvs et chez dPux espces de Téléoste:ens pour les sels
de Cobalt;, de strontium, d'argent e t d'antimoine.
(Ces concentrations correspondent aux surcharges expérimentales effectuées
indépendamment de la concentration naturelle de l'eau de mer).
COBALT
STRONTIUM
(CoC1 )
2
(SrC1 2 )
,2
3
ARGENT
(,(crabe enragé)
,
Palaemon serratus
7(crevette rose)
`f zoé I
500 à 1000
zoé I
50 à 100
(Plie).
(SbC1 )
3
1000à1500
(Blennie) '
zoé I
Maia squinado .
/C) (Araignée)
1000à1500
1000
1 à 2
10 à 100 0,01 à 0,1
10
5000
500à1000
5000
7
•
A
13
1000
500
500
re
5
10 à 100
0,2 à 5
1 à 10
1 à 10
r Il
7
Id
/11111111111
Blennius pholis
Homarus oulgaris
50
adulte
Pleuronectes platessa
g
500 à 1000
ANTIMOINE
(AgNO 3 )
!Espèce
adulte
Carcinus weenas If
too -
0,5 à 1
zoé II
10 à 20
zoé 111
10 à 50
zoé 1
0 à 10
5000
.,/ /. ,,,,,
1 à 10
1000
//,z_
712/1.
er
• 77 7 // //1,/
7./://
' ,////,
Alle
/
, Les larves de crabes et de crevettes sont de 5 à 1000 fois plus sensibles eux polluaes que 'les adultes. Ce résultat n'est pas nouveau et a été maintes
fois signalé (Fontaine, 1972). Les résultats sont très variables selon l'espèce
et le polluant : les larves de Palacmon serratus semblent légèrement plus résistantes' au chlorure de cobalt que les larves de Carcinus maenas, elles—emes étant
moins sensibles que les larves de Maïa squinado. A la température de 15 ° C, la
résistance nu Chlorure de cobalt semble it.re fonction de la taille, les larves
les plus grandes supportant mieux les surcharges en cobalt. Parmi les larves de
Homarus vulgaris, celles du stade 1 sont nettement moins résistantes que celles
des stades 2 et 3. Les larves du stade 3 semblent résister légèrement :mieux que
celles du stade 2.
84
Ane
1;k4rewl
1.441
5 07,
85
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration (mg/L)
Figure 1 - Mortality rates observed at 4 days among adults of the species
Carcinus maenas, Palaemon serratus, Pleuronectes platessa and Blennius
pholis as a function of cobalt salt concentration.
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration
Figure 2 - Mortality rates observed at 4 days and 10 days among adults of
the species Carcinus maenas, as a function of cobalt salt concentration.
P:u , enio gr
urs
r los
mo'.1
de
modulde
•
eCtnéeS •
---TIMO1NE
SbC1 )
3
Ccucinus nmenus
✓
PokernOn sestatut
A
Pleusonectes plalet10
•
Blennius pholis
• ei
o
7-
/
.5%
1
0
.
10
100
2
250
500
1000 2000
5000
loom
Concenlrhon en tel de cobalt (rngil)
/.
Fig. l. - Evolution des taux de mortalité observés en quatre jours en fonction
de la concentration en sel de cobalt chez Carcinus maenas, Palaemon serratus,
Pleuronectes platesila et Btennius phoLis adultes.
1
Pour cenloge
de
/.
)4,
modelde
100%
• diours
O 10jours
plus sensia été maintes
50%
)n l'espèce
1
plus résis-
s-emes étant
15 ° C, la
es larves
; larves de
5%
01
1.52 2.5 3 4 5
1.0
io
Ibo
que celles
. mieux que
i
2.;0
sbo lobo Woo
5doo
2, Concentration en sel de cobalt (mg/1)
Fig. 2 - Evolutien des taux de mertalité observés en quatre jours .et dix jours
en fonction de la concentration en sel de cobalt chez Carcinus maenas adulte.
85
F.
Zt-ee:ej-,eeeeu ,iorueeetxeneegeetgngee
-51ffl
86
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration (mg/L)
3
Prawn
4
Plaice
5
One day
6
Two days
Figure 3 - Mortality rates observed at 1, 2, 3 and 4 days among adults of the
species Palaemon serratus and Pleuronectes platessa, as a function of
cobalt salt concentration.
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration (mg/L)
3
One day
4
Four days
Figure 4 - Mortality rates observed at 1, 2, 4, 10 and 15 days among adults
of the species Blennius pholis, as a function of cobalt salt concentration.
f Pounemeage
Pourcentage
MI de
mortalité
modolde
loo Z -1
3 . CUVE Un
A
I iou,
2 jours
3 -
•
4 -
•
6•
so M
50%4,
5::
g,ç
te°
sz
1
' 20 go
5000
.
10Ô-00
1000
Concentratiod en sel de cobalt
2000
5000
.(mg/ I)
Fig. 3 - Evolution des taux de mortalité obs'ervés en un, deux, trois et quatre
jours en fonction de la concentration en sel de cobalt chez Palaemon serratus
et Pleuronectes platessa adultes.
Fig. 5 - Ev,
en fonction
d'Homarus v!
,
POU1Ceedoge
1„1Yri:P-
MOdOlde
MO%
Pourcentage
de
modalité
,e
3•
•
if
lem
• 1100 , 5
IIII
-
10
—
• 15 -
À
50%
7.;
4
,
lig
X;
1000
100 2000 .
1
5000
3000
•
2
100
1
25
.0
5 013 1000'
Concentration en sel de cobalt (rngil )
Fig. 4- Evolution des taux de mortalité observés en un, deux, quatre, dix et
quinze jours en fonction de la concentration en sel. de cobalt chez Btennius
pholis adulte.
5%
•
0.5
.
Fig. 6 - Evc
en fonction
d'llomarus vr
86
P77.777P7
kle'‘
87
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration (mg/L)
3
Larval stage 3
Figure 5 - Mortality rates observed at 12, 48, 96 and 216 hours in larval
stage 3 of Homarus vulgaris, as a function of cobalt salt concentration.
Legend (See photocopy of original)
1
Percentage mortality
2
Cobalt salt concentration (mg/L)
3
Larval stage 1
Figure 6 - Mortality rates observed at 12, 48, 96 and 216 hours in larval
stage 1 of Homarus vulgaris, as a function of cobalt salt concentration.
Pourcentage
100%{'
de
mariante
3
PI OE
•
OW
•
?jours
STADE LARVAIRE 3
• 12
A
h
96h
• 216
h
50 •
57.
100
50
ID
et quatre
.
8 C r1'2t UD
2 Concentration en sel de cobalt (mg/1)
Fig. 5 - Evolution des taux de mortalité observés en 12, 48, 96 et 216 heures
en fonction de la concentration en sel de cobalt chez le stade larvaire 3
d'lloinczrua Vulgario.
/Powcentae
10 0%
de
mariante
3
STADE LARVAIRE 1
•
• 12h
À 48h
.•96 h
1
250 50 0 Kke
5%
•
0.5
re, dix et
5
IO
;0
100 150200
50
•
Blennius
1000
500
Concentiation en sel de cobalt
Fig. G - Evolution des taux de mortalité observés en 12, 118, 96 et 216 heures
en fonction de la concentration en sel de cobalt chez le stade larvaire 1 .
d ' lloniaru8 vutguri.s.
87
P7A
,,i',
e' ‘eimigek,F,'
..ilke-leiire'Cift:
;froN
.
?1177e17n'"Fere4''.' ' ' '
-4eî,;14é,, i.:,'),Z,
*Wei.del`-s„meisevid:itit
t.•,,,,,tieeme
ee
xitl
eiyetil,,,tz....,,i
se,>,ogie,tive
reeel
t4.4lie-4.41eMks
t
i
e
fle
:
-.
1
/
2
e>1,
1, ,*. eirea
,
e:e5441*
"4 ,e ,41:nries
., ,Tà‘itee: ,,,,,',1i;e:T4ite..à. 2
4.,
rgYA
effl ZWX.itatil, Zel
2t l
88
The adults of the four species studied seemed to react inlmuch the same
way to the various pollutants, with a few exceptions (figures 1 and 3).
The
influence of size on resistance to pollutants could not be precisely
determined.
The scope of the experiments on the two forms of antimony, A and B,
were too limited for a valid comparison to be made, but form B seems to be
the more toxic.
- Concentrations lethal to 50% of the animals in 216 hours (9 days) and
over survival periods of more than 9 days
Except for cobalt, a limited amount of data was obtained on the toxic
effects of the salts over a period of 216 hours (Table III). Since fewer
animals (a minimum of five for each concentration) and a smaller range of
concentrations were used to establish the data than in the preceding experiment, the results obtained were also less precise.
However, the 50% lethal concentrations were found to be lower for longer
survival times in the presence of the toxic substance (figures 2, 4, 5 and 7).
With some of the metal concentrations previously mentioned, death did
not occur until about a month or more had passed.
C. maenas and B. pholis
survived for this length of time in the presence of cobalt (Figure 4), as
did B. pholis in the presence of antimony (Figure 7).
Legend (See photocopy of original)
1
Percentage mortality
2
Antimony salt concentration
(mg/L)
Figure 7 - Mortality rates observed at 10, 15 and 20 days among adults of
the species , Carcinus maenas, as a function of antimony salt concentration
(form B).
Les. adultes des quati .e espèces étudiées semblent réagir sensiblement
de la même façon aux divers polluants, è quelques exceptions près (Fig. 1 et 3).
L'influence de la taille sur la résistance aux polluants n'a pu être mise en
évidence de façon suffisante pour nous permettre d'en tirer des conclusions.
Nos expériences sur les deux formes (A et B) d'antimoine sont trop •
restreintes pour que nous puissions les comparer valablement, toutefois la
forme B semble être la plus toxique.
- Concentrations létales 50 % en 216 heures (9 jours) et pour des
temps de survie supérieurs à 9 jours :
Sauf en ce qui concerne le cobalt, nous disposons d'un nombre•limité
d'informations sur les effets toxiques des sels étudiés pour une période de
Esp
Carc
(cral
216 heures (Tableau III). Le nombre d'animaux (cinq au minimum pour chaque
concentration) et la gamme de concentrations qui nous ont permis d'établir ces
Palat
(cr(
données étant également plus restreints que dans l'expérience précédente, nous
obtenons des résultats moins précis.
Pleur
Toutefois, nous constatons que les concentrations létales 50 X sont
plus faibles pour un temps de survie'plus long en présence de toxique.(Fig. 2, 4,
Blenn
(g
5 et 7).
Certaines des.concentrations en métal réalisées précédemment n'entraî-
Homar
naient la mort qu'après des périodes atteignant ou dépassant un mois. C'est le
cas de l'action du cobalt sur C. macnas et B.. pholis (Fig. 4) ou de l'antimoine
sur C. maenas (Fig. 7).
100,
• cp,
Maia e
(Arai
• 10 jours et 15 • 20 -
vett
eat
chic
10 p
_mues
.quée
IO
30 50
100
300 500
MOO
2, Concentration en sel d'antimoine
(mg/I)
Fig. 7
Evolution des taux de mortalité observés en dix, quinze et vingt jours
en fonction de la concentration en sel d'antimoine (B) chez Carainus maenao
adulte.
88
eeefe.'i e
89
TABLE III
Concentrations (in ppm) of salts of cobalt, strontium, silver and antimony
lethal to 50% of test animals in 216 hours (9 days).
(The concentrations
given indicate the amounts over and above those present in natural sea
water added for the purposes of the experiment.)
Legend (See photocopy of original)
1
Species
2
Silver
3
Antimony
4
Adult
5 Zoea
6
Green crab
7
Common prawn
8
Plaice
9 Blenny
10 Lobster
11 Spider crab
- Non-lethal physiological consequences of the added salts
Frequent moults not followed by death were observed among the adult
prawns placed in strontium chloride (1000 ppm) or silver nitrate (1 ppm).
A change in spawning was also observed among the crabs and prawns placed
in antimony trichloride; at 10 ppm, 20% of the test crabs spawned, at
500 and 1000 ppm, 10% of them spawned, and at 500 ppm, 10% of the prawns
spawned. Would the moultings and spawnings of the crustaceans have
occurred anyway or were they provoked by the presence of the pollutant?
No conclusion can yet be drawn.
I IfflitYalil
'••
. •
,
qensiblement
Fig. i et 3).
TABLEAU N 0 III
e mise en
Concentrations létales 50 % (en ppm) 216 heures (9 Purs) chez plusieurs espèces
de .Crustacés et leurs larves et chez une espèce de Téléostéens pour les sels
de cobalt, de strontium, d'argent et d'antimoine.
(Ces concentratiems correspondent aux surcharges expérimentales effectuées
indépendamment de la concentration naturelle de l'eau de mer).
ri usions.
sont trop
fois la
'
pour des
COBALT
STRONTIUM
(CoC1 2 )
(SrC1 2 )
-1 ANTIMOINE
a ARGENT
(AgNO 3 )
(SbC1 3 )
A
B
1000
30 à 50
'Espèce
carcinus ms„as
mbre limité
.
((crabe enragé)
iode de
Ji, adulte
500 à 1000
100
jrzoé I
100
100
chaque
Palaemon serratus
/(crevette rose)
établir ces
adulte
:7
.dente, nous
Pleuronectes pléztessa
(Plie)
g
: 50 % sont
ue (Fig. 2, 4,
ient n'entraî-
Homarus vulgaris
)0 (Homard)
s. C'est le
or Ar À
.rele
•
ver
rmorm
A
500 à 1000 r
500
À
o
0,5
"
1
zoé II
1 à 10
zoé III
zoé I
0,1
Or
l i antimoine
Maia squinaab
11 (Araignée) '
9"
0,01
41111
zoé 1
5
7
500
r
Blenneus pholis
01 (Blennie)
0,01
r
FAAre•relaWAIlir
i
le
e edd
r4
À
d
(Al
I
)0
-
Observations de quelques conséquences physiologiques non létales des
surcharges en sels
Nous avons observé des mues fréquentes non suivies de la mort des crevettes ' adultes placées dans le chlorure de strontium (1000 ppm) ou dans le nitrate
d'argent (1 ppM). Nous avons également remarqué des pontes en présence de trichlorure d'antimoine pour les crabes (20 Z des animaux placés en expérience à
10 ppm et 10 Z à 50Q et 1000 ppm) et pour les crevettes (10 Z à 500 ppm). Les
mues et les pontes de Crustacés sont-elles naturelles ou bien sont-elles provoquées par la:présence dm polluant ? Nous ne pouvons pas encore conclure.
›-
(me )
t vingt jours
.Inlimoine
us macnas
89
4.
5%
'
J
' •
!
90
The blennies displayed avoidance behaviour within twenty-four hours of
being placed in the water with the additional 10 ppm silver nitrate.
They
tried to keep their heads and gills out of the polluted water.
Precipitated silver was observed on the bottoms of the buckets in
which the blennies, plaice and prawns exposed to additional silver nitrate
concentrations of 10 ppm were kept. Such deposits were not observed in the
buckets containing the crabs. After 72 hours of contact with the silver
nitrate, the gills of the prawns had taken on a whitish colouration, indicating
that these organs had become heavily coated with silver. However, all
of
these prawns survived more than 96 hours.
Despite the added cobalt, many of the lobster larvae continued to
develop and moult (normal onset of moulting); 20% of the larvae passed from
stage 1 to stage 2, 50% from stage 2 to stage 3, and 25% from stage 3 to
stage 4.
Some of the moults aborted, causing the death of the larva, but
most proceeded normally. (Moults aborted at stage 1: 5%, at stage 2: 5%,
and at stage 3: 50%).
These data indicate that the requirements for the
onset of moulting are more rigourous when the moult will take the larvae from
stage 1 to stage 2 or stage 3 to stage 4 than when it will take them from
stage 2 to stage 3.
The moult between stages 3 and 4 seems to be more
difficult to carry through successfully than the others.
This can be linked
to the fact that the behaviour and morphology of stage 4 individuals in this
case are similar to those of adults, so that the third moult could be said
to be an imaginal one.
-
General discussion
The data presented here do not conflict with those found in the literature,
which concern almost exclusively the toxicity of metallic salts to freshwater fish.
Ebeling (1928) observed that cobalt chloride was not toxic to fresh
water species at a concentration of 1 ppm, but Thomas (1915) noted adverse
effects with concentrations of 7 to 15 ppm.
Ellis (1937) observed death in
30 hours with CoC1 2 at 1000 ppm, and Iwao (1936) determined the concentration
of cobalt lethal in 24 hours to be 1840 ppm. Thomas (1915) felt that the
various cobalt chlorides would not be toxic to salt water fish at concentrations of 200 ppm.
91
According to Marsh and Robinson (1908) and Jones (1939) silver
nitrate was "toxic" to fresh water fish at concentrations of 0.004 to
0.04 ppm .
Similarly, Laroze (1955) observed that silver salts were very
toxic to Squalus cephalus. The observations of Clarke (1947), Croghan
(1958), Drzewina and Bohn (1926) and Soyer (1964) confirm that silver is
extremely toxic to crustaceans and echinoderms.
and SrNO had
3
2
"lethal" effects at "strong" concentrations. Jones (1938) and Powers
According to Powers (1917) and Iwao (1936), SrC1
was more toxic than SrC1
2'
3
Jones (1939) felt that most "heavy" metals affected fish by plugging
(1917) felt that SrNO
their gills, causing asphyxiation gradually or rapidly, depending on the
electron affinities of the ions, while the alkalis and alkaline-earth
metals were the only true internal poisons.
The literature indicates that metals are in general more toxic to
animals living in fresh or brackish water than to salt-water species
belonging to related zoological groups. There are several possible
explanations for this.
Osmoregulatory processes produce greater "regulation"
of metallic salts in salt-water species than in fresh-water ones (Fontaine,
Also, since there is generally greater dilution of isotopes in sea
1969).
water, the concentration factors are lower where marine species are involved
(Amiard, 1973a; Fontaine, 1960; Polikarpov, 1966), which means that toxicity
is less.
III - CONCLUSION
It has long been known that metals and metalloids are toxic, as
bibliographic reviews of the subject show (Doudoroff and Katz, 1953;
Bryan, 1971).
In this experiment, the order of increasing toxicity most
frequently encountered was as follows:
silver.
strontium, cobalt, antimony and
This is in agreement with the observations of Mathews (1904) and
Jones (1939) to the effect that the toxic action of metals, with a few exceptions, increases directly with atomic weight and inversely with atomic
volume.
Increases in the toxicity of metals are,,however, even more clearly
correlated with decreases in solution tension and increases in the
,
92
electron affinity (electrode potential) of the ions.
The larvae were observed to be more sensitive to metallic pollutants
than the adults, and the smallest larvae were the most sensitive. The
adults of all species seemed to react in much the same way to the pollutants
considered.
Toxicity studies are necessary if we are to understand certain physiological mechanisms and determine the maximum allowable concentrations of
the toxic element in the natural environment.
At the same time, there is a
need for studies of narrower scope on the alteration of physiological
functions by pollutants, such as those done by Rulon (1956, 1957) for
embryogenesis, Soyer (1964) for larval development and Amiard et al (1976)
for amino acid levels in Carcinus Maenas. Fontaine (1972) has reviewed
most of the effects of pollutants on the physiology of marine animals.
The
studies of specific toxicity should also be followed through by experiments
on the transfer of pollutants along food chains (Amiard-Triquet and Amiard,
1974; Amiard and Amiard-Triquet, 1974).