T.A.E.C.
Ç E K M E C E NU C L E A R RESEARCH A N D TRAINING CENTER Is t a n b u l - t u r k e y
ÇNAEM-R-134
COMPARISON OF 65 Zn LOSS-RATE OF MYTILUS GALLOPROVINCIALIS DETERMINED IN THE FIELD AND LABORATORY CONDITIONS
By M. Y. Ünlü
P. K. 1, Hava Alani, Istanbul, Turkey
Comparison, of ^'Zn loss—rate of M y tilus galloprovincialis determined in the field and laboratory conditions
ÜNLÜ, M.Yaçar
" Cette communication ne peut, être citée sans autorisation préalable de l'auteur "
5C Abstract. We have carried out experiments on the loss-rate of "'Zn
by Mytilua galloprovincialis in the laboratory and in the field. We came to the conclusion that the results were obtained in the field and laboratory can be comparable if the physical and chemical condi tions in the field are not changed very frequently.
Résumé. Avec des Mytilus galloprovincialis à différentes sortes
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d'accumulation de Zn on a fait des expériences en campagne et en laboratoire. I)'après les résultats si les conditions physiques et chimiques en campagne ne varient pas rapidement, les valeurs de perte obtenues en laboratoire et en campagne peuvent être comparées; si
non ne peuvent l'être.
The various experimental conditions applied in laboratories on the hypothesis that the results of uptake and loss studies in the field and laboratory are not different. Heyraud and Fowler.have shown
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that no significant differences could be detected in Zn loss rate by the molluscs Tapes decussatus , the polychaete Hermione hystrix and the crustacean Pachygrapsus marmoratus in the laboratory flowing sea water system. (TSW) arid open sea water collected some distance from offshore (OSW)» They have carried out simultaneous experiments This work was supported by the IAEA contract No. 960/R2/EB.
-2-in the laboratory and -2-in the field. The result that they have obta-2-ined were similar to their first experiments. On the contrary Kane et al. have reported that tne "Zn loss rate by the crab Pachygrapsus was
effected by holding the animals in either (LSW) and (OSW) system. Conversion of laboratory uptake studies to the field loss data using theoretical calculations in ^ C o loss rate by Mya arenaria. Harrison have demonstrated that the calculated values from laboratory and from
109 field are not in consistant. Fowler and Benayoun reported that, 'Cd loss rate by Mytilas galloprovincialls in the field was significantly
slower than those maintained in the laboratory. To draw some light on this question, we planned simultaneous experiments in the labora - tory and in the field ( Küçükçekmece lagoon, brackish water ) using Mytilus gallonrovincialis as a te3t animal.
Similar sized animals were selected for the experiment and they were kept for 10 days in the laboratory for adaptation. The activity of the basin ( 6^uGi ^ Z n / l ) was kept constant. For the loss expe - riment, animals were divided into two groups, one group held below the surface of the Küçükçekmece lagoon or Marmara Sea in plastic baskets, the other group maintain in the laboratory. Water for labo ratory experiments was collected from the stations in every 5 days.
Two stations were chosen in the Küçükçekmece lagoon ( A and B station ) and cne in Marmara Sea., In the station B salinity was higher than
the station A. The experimental basins were prepared in the laboratory. The flow rate of water in laboratory was 1 lt/hour. Animals were
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periodically monitored for "Zn content and returned to containers for further loss. We used the 0.05 level as a criterion of signifi - cance. The experiments were made in two series. First series : The uptake period lasted for twenty three days. For the loss
experiments the animals were divided into 4 groups, each groups with 10 experimental animals and they v/ere monitored for 49 days. First
plankton culture twice a week during the loss period. The salinity in the Marmara Sea was between 21.14-25.04 ppt, and the temperature 5.9-8.7°C and in the lagoon salinity 7.7-9.7 ppt and temperature 4.3-8.4°C. In the laboratory the temperature were kept constant 8.0 1.0°G. Second series ; The temperature of water in the experi mental basins in the laboratory was regulated during fifteen days period according to the water temperature of the lagoon and Sea 18-23°0). The accumulation of ^“'Zn in mussels was 21.92 %o S in Sea water and 7.68 %o S in lagoon. During the uptake period the mussels were fed with phytoplankton. The loss experiment was lasted foi* fifty
eight days. As a result of seasonal variation, the temperature in the lagoon water was changed from 23.7 to 15«2°C and salinity 8.2 to 9.3 ppt in the station A and 9»1 to 10.68 ppt in the station B. The temperature of the water in the laboratory was regulated according to the variation in the stations. During the loss experiment animals were not fed.
The result showed that in the first series of experiments no 65
significant differences could be observed in Zn loss rate, although the curve of ( fig.l and 2 ) the loss rate for the animals held in the field were slightly faster than the laboratory loss rate. In the second series of experiment, the ^Zn loss rate in the station A (fig. 3 and 4 ) , was similar in the field and laboratory for at least
23 days. After that, the difference became larger. In station B
( fig. 5 &nd 6 ) the loss rate curves are quite deviated for the field and laboratory, because of changing the conditions in the field very frequently. In view of our experimental result we came to the conclu
-4-may or not be in accordance with each other, due to the fact that the conditions in the field cannot be applied exactly in the
laboratory for some experiment.
References.
KANE (J), et al., 1969.- Rapp.Comm.Int.Mer.Médit.20.
HARRISON (P.L.),1972.- IAEA/SM-SM/28. Seattle.Washington.
FOWLER (S.W.) and BENAYOUN (G),1973.- In: Comparative studies of food and environmental contamination. Proceeding of a symposium,Otaniemi. 27-31, 1973. p. 159-178.
k epi in Marmara Sea and at the laboratory. Vertical bars represent standar
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Pig,2. Biological loss of Zn by Mytilus galloprovincialis kept in Küçükçekmece lagoon and at the laboratory. Vertical bars represent standard errors.
-i . . & R
- ig* 3» Biological .l o s s oi Zn by Mybilus galloprovincialis kept in Küçükçekmece lagoon at the station A and laboratory. Mussels accumulated •'Zn from sea water. Vertical bars represent standard errors.
6 ^
Fig.4. Biological less of 'Zn by Mytilus galloprovincialis kept in Küçükçekmece lagoon at the station A and laboratory.
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Mussels accumulated ''Zn from lagoon water. Vertical bars represent standard errors.
standard errors.
Fig.6. Biological loss of 'Zn by Mytilus galloprovincialis kept in Küçük çekmece lagoon at the station B and laboratory.
Mussels accumulated Zn from lagoon water. Vertical bars represent standard errors.
