Anthropogenically induced environmental changes in the northeastern Adriatic Sea in the last 500 years (Panzano Bay, Gulf of Trieste)

Jelena Vidović,Adam Tomašových,Rafał Nawrot,Martin Zuschin,Michael Stachowitsch,Vlasta Ćosović,Alexandra Haselmair,Ivo Gallmetzer

doi:10.5194/bg-13-5965-2016

Jelena Vidović, Adam Tomašových + Show 6 more

Open Access

https://doi.org/10.5194/bg-13-5965-2016

Copy DOI

Abstract

Abstract. Shallow and sheltered marine embayments in urbanized areas are prone to the accumulation of pollutants, but little is known about the historical baselines of such marine ecosystems. Here we study foraminiferal assemblages, geochemical proxies and sedimentological data from 1.6 m long sediment cores to uncover ∼ 500 years of anthropogenic pressure from mining, port and industrial activities in the Gulf of Trieste, Italy. From 1600 to 1900 AD, normalized element concentrations and foraminiferal assemblages point to negligible effects of agricultural activities. The only significant anthropogenic activity during this period was mercury mining in the hinterlands of the gulf, releasing high amounts of mercury into the bay and significantly exceeding the standards on the effects of trace elements on benthic organisms. Nonetheless, the fluctuations in the concentrations of mercury do not correlate with changes in the composition and diversity of foraminiferal assemblages due to its non-bioavailability. Intensified agricultural and maricultural activities in the first half of the 20th century caused slight nutrient enrichment and a minor increase in foraminiferal diversity. Intensified port and industrial activities in the second half of 20th century increased the normalized trace element concentrations and persistent organic pollutants (PAH, PCB) in the topmost part of the core. This increase caused only minor changes in the foraminiferal community because foraminifera in Panzano Bay have a long history of adaptation to elevated trace element concentrations. Our study underlines the importance of using an integrated, multidisciplinary approach in reconstructing the history of environmental and anthropogenic changes in marine systems. Given the prolonged human impacts in coastal areas like the Gulf of Trieste, such long-term baseline data are crucial for interpreting the present state of marine ecosystems.

Highlights

The northern Adriatic Sea is densely urbanized and polluted (Lotze et al, 2006; Cozzi and Giani, 2011), and the areas around the Po River, the Venice Lagoon and in the Gulf of Trieste bear the highest pressure (Solis-Weiss et al, 2007; Raccanelli et al, 2009)
We evaluate the pollution in the bay using geochemical proxies and quantify the composition and diversity of foraminiferal assemblages
Mercury is a major pollutant in the area, whose concentrations during the last 500 years have significantly exceeded Italian sediment qualwww.biogeosciences.net/13/5965/2016/

Summary

Introduction

The northern Adriatic Sea is densely urbanized and polluted (Lotze et al, 2006; Cozzi and Giani, 2011), and the areas around the Po River, the Venice Lagoon and in the Gulf of Trieste bear the highest pressure (Solis-Weiss et al, 2007; Raccanelli et al, 2009). Panzano Bay, located in the northeastern part of the Gulf of Trieste, is a shallow and sheltered embayment prone to the accumulation of pollutants, with recent anthropogenic pressure coming from agricultural, maricultural, mining and industrial activities (Horvat et al, 1999). J. Vidovicet al.: Anthropogenically induced environmental changes in the northeastern Adriatic Sea has continued until present times with increasing port and industrial activities (thermoelectric plant) of the city of Monfalcone (Notar et al, 2001; Pozo et al, 2009). Vidovicet al.: Anthropogenically induced environmental changes in the northeastern Adriatic Sea has continued until present times with increasing port and industrial activities (thermoelectric plant) of the city of Monfalcone (Notar et al, 2001; Pozo et al, 2009) Such intensive anthropogenic pressures have prompted a growing scientific effort to estimate the effects of pollution on ecosystem composition here. There is a growing tendency towards integrated assessments of its present state (Cibic et al, 2007; Melis and Covelli, 2013; Franzo et al, 2015), but until today there have been no multidisciplinary studies assessing the long-term history of the environmental changes in the northeastern Adriatic and capturing its preindustrial, undisturbed state

Methods

Results

Discussion

Conclusion