Climate Change Impact in the Ria de Aveiro Lagoon Ecosystem: A Case Study

Lopes Lopes,Dias Dias,Lopes Lopes

doi:10.3390/jmse7100352

Lopes Lopes, Dias Dias + Show 1 more

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https://doi.org/10.3390/jmse7100352

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Abstract

Climate change and global sea-level rise are major issues of the 21st century. The main goal of this study is to assess the physical and biogeochemical status of the Ria de Aveiro lagoon (Portugal) under future climate scenarios, using a coupled physical/ eutrophication model. The impact on the lagoon ecosystem status of the mean sea level rise (MSLR), the amplitude rise of the M2 tidal constituent (M2R), the changes in the river discharge, and the rising of the air temperature was investigated. Under MSLR and M2R, the results point to an overall salinity increase and water temperature decrease, revealing ocean water dominance. The main lagoon areas presented salinity values close to those of the ocean waters (~34 PSU), while a high range of salinity was presented for the river and the far end areas (20–34 PSU). The water temperature showed a decrease of approximately 0.5–1.5 °C. The responses of the biogeochemical variables reflect the increase of the oceanic inflow (transparent and nutrient-poor water) or the reduction of the river flows (nutrient-rich waters). The results evidenced, under the scenarios, an overall decreasing of the inorganic nitrogen concentration and the carbon phytoplankton concentrations. A warm climate, although increasing the water temperature, does not seem to affect the lagoon’s main status, at least in the frame of the model used in the study.

Highlights

Climate change due to global warming, resulting from past and ongoing emissions of anthropogenic carbon, is one of the major issues of the 21st century
Under the scenario SC2, corresponding to the combined effect of Mean Sea Level Rise (MSLR), M2R, and low river discharge, it was found that the salinity becomes almost constant (~34 PSU) for the lagoon, reflecting its infilling with ocean water, a situation resulting from the combined effect of increasing ocean flow and decreasing of the river’s freshwater discharge
The present work was designed to assess the impact of climate changes on the physical and biogeochemical status of the Ria de Aveiro lagoon, through the analysis of the combined effects of: the rising of the mean sea level and of the amplitude of the M2 tidal constituent, the decreasing of the river discharges and the increasing average air temperature

Summary

Introduction

Climate change due to global warming, resulting from past and ongoing emissions of anthropogenic carbon, is one of the major issues of the 21st century. Kumbier et al [7] investigated the hydrodynamic impacts of sea level rise (SLR) on wave-dominated Australian estuaries with differing geomorphology and found that SLR will affect the hydrodynamics and flooding characteristics of those systems Their geomorphology together with drivers such as spring tides, storm surges, and river inflows constitute the major forcing. They point out that estuarine response to SLR varies between different types of estuaries and that floodplain elevation seems to be the fundamental factor for identifying the most vulnerable systems and estimating how inundation extents and depths may change in response to SLR. The anthropogenic pressure and land-use changes are, as well, very likely to continue impacting those systems, increasing their exposition and vulnerabilities to natural events

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