Combined scenarios of chemical and ecological quality under water scarcity in Mediterranean rivers

doi:10.1016/j.trac.2011.04.012

TrAC Trends in Analytical Chemistry

Volume 30, Issue 8, September 2011, Pages 1269-1278

https://doi.org/10.1016/j.trac.2011.04.012 Get rights and content

Abstract

Water resources are directly and indirectly affected by anthropogenic activities (e.g., changes in land use) and natural factors (e.g., climate change), that is, global change. The Mediterranean basin is one of the most vulnerable regions of the world to global change, and one of the “hot spots” for forthcoming problems of water availability. The present review provides an overview about the relationship between chemical quality (especially concerning organic microcontaminants) and water scarcity, particularly in the Mediterranean area. We include an overview of environmental contaminants and analytical methodologies and consider the fate and the behavior of organic contaminants, and the effects of pollutants on ecosystems.

Introduction

The preservation of aquatic resources must be seen as a major concern for both ecosystem integrity and human health and well-being. Ensuring environmental sustainability, reducing biodiversity loss and reducing the proportion of people without access to safe drinking water are explicitly cited as part of the fundamental Millennium Development Goals established by the United Nations General Assembly in its Millennium meeting in 2000 [1]. Water resources are directly and indirectly affected by anthropogenic activities (e.g., land-use changes) and natural factors (e.g., climate change), that is, global change. Two of the most evident outcomes of global change are the losses of water quantity and water quality, both essential for ecosystem preservation and water safety for human use (drinking, agriculture and industry) [2].

The most distinctive feature of Mediterranean climate is its seasonality, characterized by summer drought. However, the temporal and spatial variability of rainfall in Mediterranean regions is influenced by surface relief, as high relief areas are commonly associated with higher than mean rainfall values [3]. The topography of the region as well as the intense pulses of rain and marginal growth of vegetation in Mediterranean river systems makes this region vulnerable to processes of land degradation [4]. River flows in Mediterranean regions vary from perennial to ephemeral, these differences occurring within one single basin [5]. The Intergovernmental Panel on Climate Change (IPCC) predicts that the Mediterranean will be particularly sensitive to climate change. IPCC foresees a decrease of annual precipitation and an increase of average temperature, with a higher frequency of extreme events [6], meaning that water resources will be not only less abundant but also less available.

In Mediterranean regions, water abstraction is a relevant part of global change, and it often implies an overpressure on the ecosystems, causing structural drought effects. For the Mediterranean watersheds of the Iberian Peninsula, the use of water accounts for 30–224% of the total available water [7]. Land-use changes also modify the amount of available water in Mediterranean basins. Thus, the significant reduction of the mean annual flow in the last 50 years in Spanish rivers [8] has equal contributions from climate change, rising water consumption, and the historical increase in evaporation due to progressive afforestation of headwaters. Finally, the complex hydrological responses in Mediterranean river systems are compounded by multiple stressors (e.g., dams and other barriers, which prevent biological migration across river networks), the existence of dry sections as a result of water withdrawal, reaches with heavily modified hydraulics, and chemical stressors (e.g., contaminants and nutrients). Intermittent, low flows, which are associated with water scarcity affect the biogeochemical processes, loss of dilution capacity of nutrient loads and fractionation, and also decrease the natural ability of river biota to process sewage waters.

From the European regulatory perspective, the issue addressed in the present review falls within the domain of the application of the Water Framework Directive (WFD, Directive 2000/60/EC) [9]. The WFD, as stated in its title, aims to provide a common action framework to the different member states of the European Union (EU) for the sustainable management of water, its ultimate objective being the achievement of the so-called “good status” of the different water bodies; that milestone must be reached not later than 2015.

For surface waters, this qualification includes the simultaneous fulfillment of the “good ecological and chemical status”. Whereas chemical status is essentially defined by compliance with established environmental quality standards (EQSs) of a list of selected key compounds, the so-called “Priority Substances” (PSs) and Priority Hazardous Substances (PHSs), which have been fixed by daughter Directive 2008/105/EC [10], the ecological status is defined in terms of biological, hydromorphological and physico-chemical indices. Within the last category, besides general physico-chemical conditions (thermal, acidity, salinity, oxygenation and nutrients), all other specific pollutants identified as being discharged into the river basin or sub-basin are included, whether priority substances or any other pollutant considered relevant.

The close relationship between quality (both chemical and ecological) and quantity existing in water systems is therefore fully recognized by the WFD, in not only the aforesaid definitions of ecological quality, but also the conception of monitoring of surface-water status, which explicitly covers “the volume and rate of flow to the extent relevant for ecological and chemical status” (WFD, art. 8). Such an integrative view of the concept of quality of aquatic systems is essential to the WFD and is one of its cornerstones.

The aim of the present review is to provide an overview about the relationship between chemical quality (especially concerning organic microcontaminants) and water scarcity, in particular in the Mediterranean area. We also discuss the consequences for the ecological status of surface waters, and its implications for water use and ecosystem services. We first introduce the analytical techniques necessary to handle the pollutants existing under water scarcity, and later relate the dynamics of pollutants to water-flow characteristics of scarcity. Finally, we tackle the effects of pollutants on ecosystems.

Section snippets

Overview of environmental contaminants

As mentioned above, the WFD defines the chemical status by compliance with established EQSs of a list of selected key compounds: 33 priority substances and 8 other hazardous substances covered by the daughter directives of the Dangerous Substances Directive. This group includes contaminants regulated mainly on the basis of persistence, bioaccumulation and toxicity (PBT) properties, including carcinogenicity, mutagenicity and reproduction (CMR), which have been long recognized as posing risks to

Conclusions

The consequences of global change are already evident in many Mediterranean areas, climate change, water scarcity, land-use changes and socio-economical trends being just some of the most dramatic outcomes. Their potential effects on the aquatic systems are an issue of major concern.

Under this scenario, the concurrence of different stressors [e.g., water pollution and hydrological changes, water scarcity and increased occurrence of extreme events (e.g., floods and droughts)] may pose definite

Acknowledgements

This work was supported by the Spanish Ministry of Science and Innovation through the Consolider-Ingenio 2010 CSD2009-00065 project.

References (68)

M.D. Bejarano et al.
J. Hydrol.
(2010)
P. Falloon et al.
Sci. Total Environ.
(2010)
A. Covaci et al.
J. Chromatogr., A
(2009)
M. Petrovic et al.
J. Chromatogr., A
(2010)
A. Jahnke et al.
J. Chromatogr., A
(2009)
P. Lepom et al.
J. Chromatogr., A
(2009)
M. Farré et al.
Trends Anal. Chem.
(2010)
J. Radjenovic et al.
Trends Anal. Chem.
(2007)
B. Lehner et al.
J. Hydrol.
(2004)
R.J. Batalla et al.
J. Hydrol.
(2004)

D. Vericat et al.

Geomorphology

(2006)

K.E. Murray et al.

Environ. Pollut.

(2010)

I. Waszak et al.

Chemosphere

(2009)

D.A. Devault et al.

Sci. Total Environ.

(2009)

P. Palma et al.

Environ. Int.

(2009)

N.D. Xue et al.

Chemosphere

(2005)

I. Espadaler et al.

Water Res.

(1997)

M. Holmstrup et al.

Sci. Total Environ.

(2010)

A. Serra et al.

Sci. Total Environ.

(2009)

D. Bontje et al.

Water Res.

(2009)

A. Ginebreda et al.

Environ. Int.

(2010)

Millennium Ecosystem Assessment

(2005)

C.J. Vorosmarty et al.

Nature (London)

(2010)

J. Hooke, in: J.S. Rowan, R.W. Duck, A. Werritty (Editors), Sediment Dynamics and the Hydromorphology of Fluvial...

J. Woodward, in: I. Foster, A. Gurnell, B. Webb (Editors), Sediment and Water Quality in River Catchments, John Wiley &...

S. Sabater, K. Tockner, in: S. Sabater, D. Barceló (Editors), Water Scarcity in the Mediterranean: Perspectives Under...

F. Gallart et al.

Water Int.

(2003)

European Council. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a...

European Council. Directive 2008/105/EC of the European Parliament and of the Council of 16 December 2008 on...

H. Piha, V. Dulio, G. Henke (Eds.), EU, 2010. Workshop Report: River Basin-Specific Pollutants - Identification and...

D. Barceló, M. Petrovic (Editors), The Ebro River Basin, The Handbook of Environmental Chemistry, Vol. 13, Springer...

P. Konieczka et al.

Trends Anal. Chem.

(2011)

J.L.M. Vidal et al.

J. Chromatogr., A

(2009)

R.D. Oliveira et al.

Talanta

(2010)

Cited by (100)

Drought impact on pharmaceuticals in surface waters in Europe: Case study for the Rhine and Elbe basins
2024, Science of the Total Environment
Hydrological droughts are expected to increase in frequency and severity in many regions due to climate change. Over the last two decades, several droughts occurred in Europe, including the 2018-drought, which showed major adverse impacts for nature and different sectoral uses (e.g. irrigation, drinking water). While drought impacts on water quantity are well studied, little understanding exists on the impacts on water quality, particularly regarding pharmaceutical concentrations in surface waters. This study investigates the impact of the 2018-drought on concentrations of four selected pharmaceuticals (carbamazepine, sulfamethoxazole, diclofenac and metoprolol) in surface waters in Europe, with a major focus on the Elbe and Rhine rivers. Monitoring data were analysed for the period of 2010–2020 to estimate the spatiotemporal patterns of pharmaceuticals and assess the concentration responses in rivers during the 2018-drought compared to reference years. Our results indicate an overall deterioration in water quality, which can be attributed to the extremely low flow and higher water temperatures (∼ + 1.5 °C and + 2.0 °C in Elbe and Rhine, respectively) during the 2018-drought. Our results show an increase in the concentrations of carbamazepine, sulfamethoxazole, and metoprolol, but reduced concentrations of diclofenac during the 2018-drought. Significant increases in carbamazepine concentrations (+45 %) were observed at 3/6 monitoring stations in the upstream part of the Elbe, which was mainly attributed to less dilution of chemical loads from wastewater treatment plants under drought conditions. However, reduced diclofenac concentrations could be attributed to increased degradation processes under higher water temperatures (R² = 0.60). Moreover, the rainfed-dominated Elbe exhibited more severe water quality deterioration than the snowmelt-dominated Rhine river, as the Elbe's reduction in dilution capacity was larger. Our findings highlight the need to account for the impacts of climate change and associated increases in droughts in water quality management plans, to improve the provision of water of good quality for ecosystems and sectoral needs.
Contaminants of emerging concern fate and fluvial biofilm status as pollution markers in an urban river
2023, Chemosphere
Contaminants of emerging concern (CEC) are still under research given the vast diversity of compounds reaching freshwater ecosystems and adverse effects they might cause. In this study, the environmental fate of 73 CEC, comprising sweeteners, stimulants and several pharmaceutical therapeutic classes, and changes in fluvial biofilm photosynthetic parameters were evaluated in a semi-arid urban river receiving diffuse and point sources of pollution (Suquía river, Argentina). Out of the 37 CEC detected, 30 were quantified in surface water (n.d. – 9826 ng/L), 10 in biofilm (n.d. – 204 ng/g_d.w.) and 9 in the clay fraction of sediments (n.d. – 64 ng/g_d.w.). CEC distribute differently among the 3 matrices: water phase presents the biggest diversity of compounds (14 CEC families), being analgesic/anti-inflammatories the most abundant family. Antibiotics largely predominated in biofilms (7 CEC families), while the stimulant caffeine and some antibiotics where the most abundant in sediments (6 CEC families). Different CEC accumulated in biofilms and sediments upstream and downstream the city, and big shifts of biofilm community occurred downstream WWTP. The shift of biofilm community upstream (F₀ > 0) and downstream the WWTP (F₀ = 0) shows a sensitive response of F₀ to the impact of WWTP. Biofilm photosynthetic parameters responded in less impacted urban sites (sites 1, 2 and 3), where significant correlations were found between ketoprofen and some antibiotics and biofilm parameters. The diversity and amount of CEC found in the urban section of Suquía river alert to the magnitude of point and non-point sources of pollution.
From biomass to fossil fuels: A contemporaneous transition to anthropogenic driven environmental changes recorded in a Central Himalayan Lake
2022, Journal of Hazardous Materials Advances
The timings and extent of anthropogenic impacts in the Indian Himalayas are poorly characterized, ambiguous and difficult to determine. In present study, we investigated the compositional variation, concentration, and temporal trend in the polycyclic aromatic hydrocarbons (PAHs) and fecal biomarker (coprostanol and epi-coprostanol) from the lake sediment core in the central Himalayas to determine the fate of anthropogenic activities in Himalayan ecosystems. The total concentration of PAHs (1422–32077 ng/g) and stanols (0.1–5.53 µg/g) showed an increasing trend, with the greatest values recorded after 2000 CE. In addition, the composition of PAHs changed after the 1970s, reflecting the increase in socio-economic activities in the region and the concurrent environmental change. The PAH diagnostic ratios revealed that pyrogenic sources accounted for the majority of the sedimentary PAHs. Moreover, the high correlation between PAHs and fecal stanols indicated the active role of humans in the catchment. Also, our results indicated that the total organic content (TOC%) of sediments and temperature conditions in the region play a significant role in regulating the deposition/burial of PAHs in lake sediments. In addition, based on the toxic equivalency factor (TEF) of PAHs relative to benzo(a)pyrene (BaP) (BaP_eq) and sediment quality guidelines (SQGs), our findings showed an increase in toxicity with values that exceeded the recommendations for the protection of aquatic life, posing a potential toxicological threat to the lake ecosystem and the health of its human residents. As the first such study from the Indian subcontinent, this research is important/key for deciphering the molecular signals of lacustrine records from the region.
Lagrangian profiles of riverine autotrophy, organic matter transformation, and micropollutants at extreme drought
2022, Science of the Total Environment
Citation Excerpt :
These findings support earlier findings in the Elbe River where no significant variation of Chl a could be found during a period with strongly changing organic and heavy metal pollution (Lehmann and Rode, 2001). Still, in combination with other abiotic stressors such as increased water temperature and decreased oxygen levels, this exposure scenario might have an adverse effect on (other) aquatic organisms (Petrovic et al., 2011). Lagrangian samplings are still rare compared to common point-measurements although they are necessary to reveal and understand riverine dynamics of both chemicals and micro-organisms and to provide databases for the prediction of climate change effects on rivers.
On their way from inland to the ocean, flowing water bodies, their constituents and their biotic communities are exposed to complex transport and transformation processes. However, detailed process knowledge as revealed by Lagrangian measurements adjusted to travel time is rare in large rivers, in particular at hydrological extremes. To fill this gap, we investigated autotrophic processes, heterotrophic carbon utilization, and micropollutant concentrations applying a Lagrangian sampling design in a 600 km section of the River Elbe (Germany) at historically low discharge. Under base flow conditions, we expect the maximum intensity of instream processes and of point source impacts. Phytoplankton biomass and photosynthesis increased from upstream to downstream sites but maximum chlorophyll concentration was lower than at mean discharge. Concentrations of dissolved macronutrients decreased to almost complete phosphate depletion and low nitrate values. The longitudinal increase of bacterial abundance and production was less pronounced than in wetter years and bacterial community composition changed downstream. Molecular analyses revealed a longitudinal increase of many DOM components due to microbial production, whereas saturated lipid-like DOM, unsaturated aromatics and polyphenols, and some CHOS surfactants declined. In decomposition experiments, DOM components with high O/C ratios and high masses decreased whereas those with low O/C ratios, low masses, and high nitrogen content increased at all sites. Radiocarbon age analyses showed that DOC was relatively old (890–1870 years B.P.), whereas the mineralized fraction was much younger suggesting predominant oxidation of algal lysis products and exudates particularly at downstream sites. Micropollutants determining toxicity for algae (terbuthylazine, terbutryn, isoproturon and lenacil), hexachlorocyclohexanes and DDTs showed higher concentrations from the middle towards the downstream part but calculated toxicity was not negatively correlated to phytoplankton. Overall, autotrophic and heterotrophic process rates and micropollutant concentrations increased from up- to downstream reaches, but their magnitudes were not distinctly different to conditions at medium discharges.
Dramatic decline of two freshwater killifishes, main anthropogenic drivers and appropriate conservation actions
2022, Journal for Nature Conservation
Freshwater fish biodiversity loss in the Mediterranean Basin is regarded as among the highest globally, with long-term population data sets required to discern long-term population trends of threatened species, in order to design appropriate conservation interventions. In this study, we assessed the population trends of two threatened freshwater fishes, Valencia letourneuxi and Valencia robertae, employing the most recent and largest compiled database to date (16 populations over 14 years). We applied the innovative methodology of the Living Planet Index (LPI) to assess the average rate of change over time across a set of V. letourneuxi and V. robertae populations in Greece. The LPI application revealed a dramatic decline of both species, with V. letourneuxi declining by 97.7% and V. robertae by 91.0%. Beta regression showed that water pollution, eutrophication and alien Eastern mosquitofish Gambusia holbrooki’ presence were the three best fitting predictors of the decline of V. letourneuxi and V. robertae populations. Based on the above, we outline the conservation measures urgently required to revert the near collapse of the populations of the two species. Conservation actions include the strict protection of the their lowland spring habitats, habitat improvement through changes in water management and agricultural practices, mosquitofish invasion prevention and mosquitofish impact mitigation measures, as well as translocation actions and captive breeding. Lastly, the association patterns of the proposed conservation actions with anthropogenic pressures and their expected outcomes were analysed through an alluvial diagram, providing insights on the scale of pressures mitigated by conservation actions and on their conservation benefits.
Efficiency of the bank filtration technique for diclofenac removal: A review
2022, Environmental Pollution
Bank filtration (BF) has been employed for more than a century for the production of water with a better quality, and it has been showing satisfactory results in diclofenac attenuation. Considered the most administered analgesic in the world, diclofenac has been frequently detected in water bodies. Besides being persistent in the environment, this compound is not completely removed by the conventional water treatments, drinking water treatment plants (DWTPs) and wastewater treatment plant (WWTPs). BF has a high complexity, whose efficiency depends on the characteristics of the observed pollutant and on the environment where the system in installed, which is why this is a topic that has been constantly studied. Nevertheless, studies present the behavior of diclofenac during the BF process. In this context, this research performed the evaluation of the factors and the biogeochemical processes that influence the efficiency of the BF technique in diclofenac removal. The aerobic conditions, higher temperatures, microbial biomass density, hydrogen potential close to neutrality and sediments with heterogeneous fractions are considered the ideal conditions in the aquifer for diclofenac removal. Nonetheless, there is no consensus on which of these factors has the greatest contribution on the mechanism of attenuation during BF. Studies with columns in laboratory and modeling affirm that the highest degradation rates occur in the first centimeters (5–50 cm) of the passage of water through the porous medium, in the environment known as hyporheic zone, where intense biogeochemical activities occur. Research has shown 100% removal efficiency for diclofenac persistent to compounds not removed during the BF process. However, half of the studies had removal efficiency that ranged between 80 and 100%. Therefore, the performance of more in-depth studies on the degradation and mobility of this compound becomes necessary for a better understanding of the conditions and biogeochemical processes which act in its attenuation.

View all citing articles on Scopus

View full text

Combined scenarios of chemical and ecological quality under water scarcity in Mediterranean rivers

Abstract

Introduction

Section snippets

Overview of environmental contaminants

Conclusions

Acknowledgements

J. Hydrol.

Sci. Total Environ.

J. Chromatogr., A

J. Chromatogr., A

J. Chromatogr., A

J. Chromatogr., A

Trends Anal. Chem.

Trends Anal. Chem.

J. Hydrol.

J. Hydrol.

Geomorphology

Environ. Pollut.

Chemosphere

Sci. Total Environ.

Environ. Int.

Chemosphere

Water Res.

Sci. Total Environ.

Sci. Total Environ.

Water Res.

Environ. Int.

Millennium Ecosystem Assessment

Nature (London)

Water Int.

Trends Anal. Chem.

J. Chromatogr., A

Talanta