Sellulêre biomerkerresponse as maatstaf van gevoeligheid van klipmossels (Mollusca) vir kadmiumbesoedeling
Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie/South African Journal of Science and Technology
| Field | Value | |
| Title | Sellulêre biomerkerresponse as maatstaf van gevoeligheid van klipmossels (Mollusca) vir kadmiumbesoedeling Cellular biomarker responses of limpets (Mollusca) as measure of sensitivity to cadmiumcontamination | |
| Creator | Reinecke, Koot Schoeman, Werner Reinecke, Sophié | |
| Description | Die bioakkumulasie van kadmium in tussengetyspesies kan stres veroorsaak wat op sellulêre vlakmeetbaar is. Verskeie klipmosselspesies kom volop op rotse aan die Suid-Afrikaanse kuslyn vooren kan moontlik vir ekotokiskologiese monitering gebruik word. Die oogmerk van die studie wasom sensitiwiteitsdata te verkry wat kan bydrae tot die kies van ’n geskikte spesie vir monitering endie uiteindelike daarstelling van ’n model vir spesie sensitiwiteitsverspreiding (SSV) wat ’nbiomerkerrespons as eindpunt gebruik. Die klipmossels Cymbula oculus, Scutellastra longicosta,Cymbula granatina en Scutellastra granularis en watermonsters is in Valsbaai versamel. Analisesvan kadmium in water en biologiese monsters is met behulp van atoomabsorpsiespektrofotometrieuitgevoer. Blootstellings van organismes aan subletale vlakke van kadmium is uitgevoer in statiesevloeitenks oor ’n periode van drie dae. Daar was ’n matige toename in liggaamskonsentrasies vankadmium oor tyd. Resultate wat by drie blootstellingskonsentrasies gekry is, het geen betekenisvolleverskille in metaalkonsentrasies tussen die verskillende C. oculus monsters uitgewys nie.Betekenisvolle verskille tussen die kontrole en die blootstellingsgroepe vir elke individueleblootstellingstyd is vir die spesie verkry behalwe tussen die kontrole en die 1mg/L CdCl2blootstellingsgroep na 24 en 72 uur van blootstelling. Cd liggaamskonsentrasies (sagteweefsel)het tussen 4.56 en 21.41µg/g (nat massa) gevarieer.Gemiddelde Cd konsentrasies in sagteweefsel van S. longicosta was aansienlik laer (variërendtussen 1.18 en 19.58 µg/g Cd ) as in weefsel van C. oculus. Die kontrolegroep van hierdie spesiehet betekenisvol verskil van die 0.8 en 1 mg/L CdCl2 blootstellings na 48 en 72 uur.Gemiddelde Cd liggaamskonsentrasies in S. granularis was die hoogste van al die blootgesteldespesies en het ’n vlak van 148 µg/g Cd by die hoogste blootstellingskonsentrasie bereik en hetbetekenisvol verskil van die ander monsters se gemiddeldes met die uitsondering van die 0.8 mg/L CdCl2 blootstellingsgroep by 72 uur en die 1 mg/L CdCl2 groep by 24 uur. Betekenisvolle verskilleis ook verkry vir die liggaamskonsentrasies van Cd van C. granatina tussen die drie verskillendeblootstellingskonsentrasies en drie blootstellingstye.Integriteit van lisosoommembrane is bepaal met behulp van die neutraalrooi retensiemetode.Drie van die vier spesies het ’n betekenisvolle afname in retentsietye getoon met ’n toename in Cdkonsentrasie. Tussenspesieverskille in gevoelighede vir omgewingsrelevante kadmium-konsentrasies is deur die biomerkerresponse uitgewys. Gebaseer op die verlaging in NRR tye, isdie volgorde van relatiewe gevoeligheid vir kadmium as volg: S. granularis C. oculus S.longicosta. C. granatina. Due to the availability and chemical nature of some heavy metals, sub-lethal toxicant levels may persist in the ocean waters and may cause physiological problems and toxicity in invertebrates and other marine organisms. Although studies of metal concentrations in False Bay showed relatively low mean concentrations of Cd, invertebrates such as molluscs, crustaceans and many other groups are able to accumulate high levels of heavy metals in their tissues and still survive in the heaviest polluted areas. They can accumulate numerous pollutants from natural waters in quantities that are many orders of magnitude higher than background levels. Bioaccumulation ofcadmium in intertidal species could cause stress which may be measurable at the cellular level. A variety of limpet species that may serve as suitable ecotoxicological monitoring species occur in abundance on rocky shores along the South African coastline. The aim of this study was to obtain sensitivity data which could contribute to the selection of a suitable monitoring species and the eventual establishment of a species sensitivity distribution model (SSD) with a biomarker responseas endpoint. The limpets Cymbula oculus, Scutellastra longicosta, Cymbula granatina and Scutellastragranularis as well as water samples were collected at two localities in False Bay, South Africa. Analysis of water and biological samples were done by atomic absorption spectrometry. Exposures were done to three different sublethal concentrations of cadmium in the laboratory in static flow tanks over three days. There was a moderate increase in cadmium body concentrations over time. Results obtained at three exposure concentrations showed no significant differences in metal concentrations between the different C. oculus samples. Significant differences were obtained between the control and the exposure groups for each exposure time except between the control and the 1mg/L CdCl2 exposure group after 24 and 72 hours of exposure. Cd body concentrations(soft tissue) varied between 4.56 and 21.41µg/g (wet mass).Mean Cd concentrations in soft tissue of S. longicosta was considerably lower (varying between 1.18 and 19.58 µg/g Cd ) than in the tissues of C. oculus. The control group differed significantly from the 0.8 and 1 mg/L CdCl2 exposures after 48 and 72 hours. Mean Cd body concentrations in S. granular is were the highest of all exposed species, reaching a level of 148 µg/g Cd at the highest exposure concentration and differed significantly from the means of the other samples of the 0.8 mg/L CdCl2 exposure group after 72 hours and from the 1 mg/L CdCl2 group after 24 hours. Significant differences were also obtained between theCd body concentrations of C. granatina for the three exposure concentrations and three exposure times. Lysosomal membrane integrity was determined for both exposed and control animals, using the neutral red retention assay. Three of the four species showed a significant decrease in retention times with an increase in Cd concentration. Inter-species differences in sensitivity to environmentally relevant cadmium concentrations were reflected in the biomarker responses. Based on reduction of NRR times, the order of relative sensitivity to cadmium was S. granularis C. oculus S. longicosta. C.granatina. | |
| Publisher | AOSIS | |
| Date | 2008-09-16 | |
| Identifier | 10.4102/satnt.v27i2.86 | |
| Source | Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie; Vol 27, No 2 (2008); 123-142 Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie; Vol 27, No 2 (2008); 123-142 2222-4173 0254-3486 | |
| Language | eng | |
| Relation |
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:
https://journals.satnt.aosis.co.za/index.php/satnt/article/view/86/72
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