Estimation of freshwater influx along the eastern Adriatic coast as a possible source of stress for marine organisms

Autor: Hamer, Bojan, Medaković, Davorin, Hamer-Pavičić, Dijana, Jakšić, Željko, Štifanić, Mauro, Nerlović, Vedrana, Travizi, Ana, Precali, Robert, Kunduč, Tjaša
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: Acta Adriatica
Volume 51
Issue 2
ISSN: 1846-0453
0001-5113
Popis: Seawater salinity changes and thermal stress have been considered to be among the most important determinants of rocky intertidal zone organism distribution. The aim of present study was to determine the freshwater influx and evaluate the mussel Mytilus galloprovincialis shells as indicators of natural environmental conditions by comparing δ13C of shell carbonate layers with seawater salinity and tem- perature values measured over the 1998-2007 period. Our results show that the salinity was relatively constant in the open sea, with typical values of the northern and southern Adriatic being 37.65 ± 0.40 and 38.37 ± 0.19 respectively. It varied in intertidal zones, estuaries, locations close to under-sea freshwa- ter springs and during rainy days in closed lagoons on different locations along eastern Adriatic coast. Sa- linity and temperature variations at investigated sites showed freshwater influx which was also reflected in lower δ13C values of mussel M. galloprovincialis shell carbonates. Based on the measured parameters, three groups of locations in the investigated area (25 locations) can be defined: locations with strong to medium freshwater influence (9), with minor freshwater influence (6) and marine environment locations (10). Our results confirm that mussel M. galloprovincialis responds sensitively to subtle changes in the environmental conditions. Results of the isotopic analyses presented in this study support the hypothesis that the δ13C in mussel’s shell might be used as an indicator of environmental salinity conditions and hypo-osmotic stress. Therefore such investigations might represent an additional tool for waste water management and environmental protection.
Promjena saliniteta i temperature morske vode u stjenovitom obalnom području ograničava i utječe na raspodjela morskih organizama. U području otvorenog mora salinitet je relativno stalan, a u istraživanom razdoblju (1998.-2007.) se kretao od 37,65 ± 0,40 za sjeverni i do 38,37 ± 0,19 za južni Jadran. Salinitet značajno koleba u zoni plime i oseke, na području ušća rijeka i podmorskim izvorima slatke vode te tijekom kišnih dana u zatvorenim lagunama. Zbog dotoka slatke vode temperatura mora na istraživanim postajama pokazuje unutar sezonske razlike, uz jaka sezonska kolebanja. Kolebanje vrijednosti saliniteta i temperature morske vode na području od Limskog kanala do Dubrovnika (sjeverni - južni Jadran) pod utjecajem dotoka slatke vode izravno su se odrazili i na vrijednosti δ13C u ljušturama dagnje Mytilus galloprovincialis. Vrijednosti δ13C iz 1998. godine su rangirane i korelirane s prosječnim vrijednostima temperature i saliniteta morske vode tijekom devetogodišnjeg istraživanog razdoblja (1998.-2007.). Na temelju sadržaja d13C u ljušturama, temperature i saliniteta morske vode istraživano područje (25 postaja) je grupirano u tri skupine: srednje do jak utjecaj slatke vode (9), manji utjecaj slatke vode (6) i lokacije morskog okoliša (10). Utvrđeno je da su ljušture školjkaša, odnosno vrijednosti δ13C, dobri pokazatelji kolebanja prirodnih čimbenika, naročito saliniteta, posredstvom dotoka slatkih voda. Dagnja M. galloprovincialis se može koristiti kao indikator kolebanja ekoloških čimbenika i možebitnih onečišćenja. Stoga navedena istraživanja predstavljaju dodatni koristan alat u biomonitoring programima, primjerice ispitivanju kvalitete okoliša, upravljanju otpadnim vodama i zaštiti okoliša.
Databáze: OpenAIRE
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