scholarly journals Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy)

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1591 ◽  
Author(s):  
Michela Mazzoni ◽  
Claudia Ferrario ◽  
Roberta Bettinetti ◽  
Roberta Piscia ◽  
Davide Cicala ◽  
...  
Keyword(s):  
Fish Community ◽  
Northern Italy ◽  
Emerging Pollutants ◽  
Trophic Levels ◽  
Perfluoroalkyl Acids ◽  
Trophic Chain ◽  
Magnification Factors ◽  
Subalpine Lake ◽  
Wet Weight ◽  
Cold Lake

The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived. Zooplankton and thirteen species of fish were collected and analyzed, and the results showed the elevated level of biota contamination from both legacy and emerging pollutants, even if direct discharges were avoided. Concentrations in biota, expressed as sums of compounds, ranged from 0.4 to 60 µg kg−1 wet weight (ww) for PFASs, from 16 to 1.3 104 µg kg−1 lipid content (lw) for DDTs, from 17 to 1.5 104 µg kg−1 lw for PCBs and from 20.0 to 501 µg kg−1 ww for mercury (Hg). TMFs of this deep, cold lake, with a prevalent pelagic trophic chain, were high and clearly indicated fish biomagnification, except for PFAS. The biomagnification capability of PFAS in a fish-only food web was discussed by using the biomagnification of Hg as a benchmark for assessing their bioaccumulation potential.

scholarly journals Mercury Bioaccumulation in Benthic Invertebrates: From Riverine Sediments to Higher Trophic Levels

Toxics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 197
Author(s):  
Laura Marziali ◽  
Claudio Roscioli ◽  
Lucia Valsecchi
Keyword(s):  
Benthic Invertebrates ◽  
Sediment Accumulation ◽  
Dry Weight ◽  
Quality Standard ◽  
Trophic Levels ◽  
Accumulation Factor ◽  
Trophic Chain ◽  
Top Predators ◽  
Riverine Sediments ◽  
Wet Weight

Riverine sediments are important sites of mercury methylation and benthic invertebrates may be indicators of Hg exposure to higher organisms. From 2014 to 2018, sediments and invertebrates were collected along a mercury gradient in the Toce River (Northern Italy) and analyzed for THg and MeHg. Concentrations in invertebrates, separated according to taxon and to Functional Feeding Group, ranged from 20 to 253 µg kg−1 dry weight (d.w.) for THg, increasing from grazers (Leuctra, Baetis, Serratella) to predators (Perla). MeHg ranged from 3 to 88 µg kg−1 d.w. in biota, representing 6–53% of THg, while in sediments it was mostly below LOD (0.7 µg kg−1), accounting for ≤3.8% of THg. The Biota-Sediment Accumulation Factor (BSAF, ranging 0.2–4.6) showed an inverse relation to exposure concentrations (THg in sediments, ranging 0.014–0.403 µg kg−1 d.w.) and to organic carbon. THg in invertebrates (up to 73 µg kg−1 wet weight), i.e., at the basal levels of the aquatic trophic chain, exceeded the European Environmental Quality Standard for biota (20 µg kg−1 w.w.), posing potential risks for top predators. Concentrations in adult insects were close to those in aquatic stages, proving active mercury transfer even to terrestrial food chains.

scholarly journals Monitoring priority substances in biota under the Water Framework Directive: How effective is a tiered approach based on caged invertebrates? A proof of concept study targeting PFOS in French rivers.

2020 ◽  
Author(s):  
Marc Babut ◽  
Benoit J.D. Fe ◽  
Patrick Jame ◽  
Azziz Assoumani ◽  
François Lestremau ◽  
...  
Keyword(s):  
Water Framework Directive ◽  
Fish Muscle ◽  
Trophic Levels ◽  
Priority Substances ◽  
Proof Of Concept ◽  
Tiered Approach ◽  
European Water ◽  
Magnification Factors ◽  
Wet Weight ◽  
Second Tier

Abstract Background : This study aims to describe and test a tiered approach for assessing compliance to Environmental Quality standards (EQSs) for priority substances in biota in line with the European Water Framework Directive. This approach is based on caged gammarids and trophic magnification factors (TMFs) at the first tier, with fish analysed at the second tier at sites predicted to exceed the EQS at the first tier. A dataset was implemented by monitoring perfluorooctane sulfonate (PFOS) in caged gammarids exposed at 15 sites in French rivers, and in fish muscle and rest-of- body from the same sites. Isotopic ratios (d 13 C and d 15 N) were also measured in gammarids and fish. Two scenarios were developed to compare measured PFOS concentrations in fish against predicted concentrations based on measures in caged gammarids and TMFs. Scenario (1) compared measured PFOS concentrations in fish fillets with predicted PFOS concentrations based on measured concentrations in caged gammarids and d 15 N. Scenario (2) tested whether or not EQS exceedance was correctly predicted based on measured concentrations in caged gammarids and trophic levels (TLs) from wild fish and gammarid populations. Results : d 13 C and d 15 N variations showed that caged gammarids used local food resources during exposure in the field. PFOS concentrations in gammarids were fairly variable through time at each site. In fish, concentrations ranged from <1 ng g -1 to 250 ng g -1 (wet weight). After adjustment to the TL at which the EQS is set, 12 sites were above the EQS for PFOS. In scenario (1), predicted concentrations were almost correct at 7 sites out of 15. Most incorrect predictions were overestimations that were slightly improved by applying a lower (neutral) TMF. In scenario (2) we tested several variants for parameters involved in the predictions. The most efficient combination yielded two wrong predictions out of 15. This result was obtained with a higher (more conservative) TMF value, mean concentrations in gammarids from several field exposures during a year, and a TL for gammarids at the median of the distribution in French rivers. Conclusion : The proposed tiered approach was thus efficient. However, the number of sites was relatively limited, and the dataset was biased towards EQS exceedance. The tiered approach warrants further validation.

scholarly journals Monitoring priority substances in biota under the Water Framework Directive: How effective is a tiered approach based on caged invertebrates? A proof of concept study targeting PFOS in French rivers.

2020 ◽  
Author(s):  
Marc Babut ◽  
Benoit J.D. Fe ◽  
Patrick Jame ◽  
Azziz Assoumani ◽  
François Lestremau ◽  
...  
Keyword(s):  
Water Framework Directive ◽  
Fish Muscle ◽  
Trophic Levels ◽  
Priority Substances ◽  
Proof Of Concept ◽  
Tiered Approach ◽  
European Water ◽  
Magnification Factors ◽  
Wet Weight ◽  
Second Tier

Abstract Background: This study aims to describe and test a tiered approach for assessing compliance to Environmental Quality standards (EQSs) for priority substances in biota in line with the European Water Framework Directive. This approach is based on caged gammarids and trophic magnification factors (TMFs) at the first tier, with fish analysed at the second tier at sites exceeding the EQS. A dataset was implemented by monitoring perfluorooctane (PFOS) in caged gammarids exposed at 15 sites in French rivers, and in fish muscle and rest-of- body from the same sites. Isotopic ratios (δ13C and δ15N) were also measured in gammarids and fish. Two scenarios were developed to compare measured PFOS concentrations in fish against predicted concentrations based on measures in caged gammarids and TMFs. Scenario (1) compared measured PFOS concentrations in fish fillets with predicted PFOS concentrations based on measured concentrations in caged gammarids and δ15N. Scenario (2) tested whether or not EQS exceedance was correctly predicted based on measured concentrations in caged gammarids and trophic levels (TLs) from wild fish and gammarid populations.Results: δ13C and δ15N variations showed that caged gammarids used local food resources during exposure in the field. PFOS concentrations in gammarids were fairly variable through time at each site. In fish, concentrations ranged from non-quantifiable to 250 ng g− 1 (wet weight). After adjustment to the TL at which the EQS is set, 12 sites were above the EQS for PFOS. In scenario (1), predicted concentrations were almost correct at 7 sites out of 15. Most incorrect predictions were overestimations that were slightly improved by applying a lower TMF. In scenario (2) we tested several variants for parameters involved in the predictions. The most efficient combination yielded two wrong predictions out of 15. This result was obtained with a higher TMF value, mean concentrations in gammarids from several field exposures, and a TL for gammarids at the median of the distribution in French rivers.Conclusion: The proposed tiered approach was thus efficient. However, the number of sites was relatively limited, and the dataset was biased towards EQS exceedance. The tiered approach warrants further validation.

scholarly journals Monitoring priority substances in biota under the Water Framework Directive: how effective is a tiered approach based on caged invertebrates? A proof-of-concept study targeting PFOS in French rivers

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Marc Babut ◽  
Benoit J. D. Ferrari ◽  
Patrick Jame ◽  
Azziz Assoumani ◽  
François Lestremau ◽  
...  
Keyword(s):  
Water Framework Directive ◽  
Fish Muscle ◽  
Trophic Levels ◽  
Priority Substances ◽  
Proof Of Concept ◽  
Tiered Approach ◽  
European Water ◽  
Magnification Factors ◽  
Wet Weight ◽  
Second Tier

Abstract Background This study aims to describe and test a tiered approach for assessing compliance to Environmental Quality standards (EQSs) for priority substances in biota in line with the European Water Framework Directive. This approach is based on caged gammarids and trophic magnification factors (TMFs) at the first tier, with fish analyzed at the second tier at sites predicted to exceed the EQS at the first tier. A dataset was implemented by monitoring perfluorooctane sulfonate (PFOS) in caged gammarids exposed at 15 sites in French rivers, and in fish muscle and rest-of-body from the same sites. Isotopic ratios (δ13C and δ15 N) were also measured in gammarids and fish. Two scenarios were developed to compare measured PFOS concentrations in fish against predicted concentrations based on measures in caged gammarids and TMFs. Scenario (1) compared measured PFOS concentrations in fish fillets with predicted PFOS concentrations based on measured concentrations in caged gammarids and δ15 N. Scenario (2) tested whether or not EQS exceedance was correctly predicted based on measured concentrations in caged gammarids and trophic levels (TLs) from wild fish and gammarid populations. Results δ13C and δ15 N variations showed that caged gammarids used local food resources during exposure in the field. PFOS concentrations in gammarids were fairly variable through time at each site. In fish, concentrations ranged from < 1 to 250 ng g−1 (wet weight). After adjustment to the TL at which the EQS is set, 12 sites were above the EQS for PFOS. In scenario (1), predicted concentrations were almost correct at 7 sites out of 15. Most incorrect predictions were overestimations that were slightly improved by applying a lower (neutral) TMF. In scenario (2) we tested several variants for parameters involved in the predictions. The most efficient combination yielded two wrong predictions out of 15. This result was obtained with a higher (more conservative) TMF value, mean concentrations in gammarids from several field exposures during a year, and a TL for gammarids at the median of the distribution in French rivers. Conclusion The proposed tiered approach was thus efficient. However, the number of sites was relatively limited, and the dataset was biased towards EQS exceedance. The tiered approach warrants further validation.

Modeling the hydrodynamics of a wetland under strong anthropic pressures (Torbiere del Sebino, Italy)

2021 ◽  
Author(s):  
Stella Volpini ◽  
Marco Pilotti ◽  
Giulia Valerio ◽  
Steven C. Chapra
Keyword(s):  
Water Quality ◽  
Specific Conductivity ◽  
Quantitative Information ◽  
Northern Italy ◽  
The South ◽  
The North ◽  
Subalpine Lake ◽  
Ecological Importance ◽  
Set Up ◽  
And Shifts

&lt;p&gt;The Natural Reserve &amp;#8220;Torbiere del Sebino&amp;#8221; is situated on the southern bank of Lake Iseo and is one the most meaningful wet zone for extension and ecological importance of northern Italy, belonging to the Natura2000 network.&lt;/p&gt;&lt;p&gt;Torbiere occupies an area of 3.60 km&lt;sup&gt;2&lt;/sup&gt; within a 14 km&lt;sup&gt;2&lt;/sup&gt; watershed where almost 12000 inhabitants live and where agricultural activities, mostly vineyards, cover almost 40% of the area; this leads to a significant anthropic pressure that over the last 50 years has compromised the system and changed the equilibria between species, enhancing eutrophication.&lt;/p&gt;&lt;p&gt;Despite the ecological relevance of the area, one of the most important in northern Italy, very little quantitative information is available regarding its current state and evolution in terms of water quality and hydrodynamics.&amp;#160; Given the critical environmental condition of the habitat, it is necessary to address the consequences of human impact on the trophic state of Torbiere.&lt;/p&gt;&lt;p&gt;Torbiere consists of a system of shallow lakes or ponds (average depth 1.5 m) whose main affluent is a creek (called R&amp;#236;) entering from the South. A secondary occasional affluent enters the system from the East and consists of a combined sewer overflow (CSO). Finally, the main effluent is an artificial channel located in the North connecting Torbiere directly with the subalpine Lake Iseo. Although originally subdivided into a set of many interconnected ponds, the separation levees have been demolished over the last decades to enhance internal circulation, under the assumption that this would decrease the residence time and improve the water quality. However, no rational argument was used to support this decision that led to a system where similar characteristics (Secchi&amp;#8217;s depth, turbidity, specific conductivity) are found all over the study area and where the expansion of invasive species was easier; now there is some evidence that a separate set of ponds would be better manageable to contrast the eutrophication process. To understand this process, a 3D hydrodynamic model has been set up using Delft-3D, an open source, finite difference package.&amp;#160;&lt;/p&gt;&lt;p&gt;Given the great extension of the system, the inner circulation of the water is not driven by the momentum of the affluents, instead the wind plays a major role. This forcing term presents a daily pattern: it blows from the North in the mornings and shifts to the opposite direction in the late afternoon. The water mainly flows from the South to the North. However, preliminary results by Delft 3D showed that the circulation is made complex by the wind. The model shows that opposite directions of horizontal flow velocities are found at the surface and at the bottom of the water column, showing that only the upper layers follow the direction of the wind.&lt;/p&gt;&lt;p&gt;By comparing the actual and previous conditions of separation of the ponds, the model aims to give an answer to whether the choice of demolishing the banks was positive or negative for the water quality of Torbiere. Once the role of the banks will be clarified, the effects of their possible restoration will be addressed.&lt;/p&gt;

scholarly journals Towards End-2-End modelling in a consistent NPZD-F modelling framework (ECOSMOE2E_vs1.0): Application to the North Sea and Baltic Sea

2018 ◽  
Author(s):  
Ute Daewel ◽  
Corinna Schrum ◽  
Jed Macdonald
Keyword(s):  
Baltic Sea ◽  
North Sea ◽  
Food Chain ◽  
Current System ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Production Model ◽  
Fish Mortality ◽  
Fish Biomass ◽  
Trophic Chain

Abstract. Coupled physical-biological models usually resolve only parts of the trophic food chain and hence, run the risk of neglecting relevant ecosystem processes. Additionally, this imposes a closure term problem at the respective “ends” of the considered trophic levels. Here we propose a consistent NPZD-Fish modelling approach (ECOSMO E2E) to address the above-mentioned problem in lower trophic ecosystem modelling, and to understand how the implementation of higher trophic levels in a NPZD model affects the simulated response of the combined North Sea and Baltic Sea ecosystem. On the basis of the coupled ecosystem model ECOSMO II we implemented one functional group that represents fish and one group representing macrobenthos in the 3d model formulation. Both groups are linked to the lower trophic levels and to each other via predator-prey relationships. The model allows investigating bottom-up impacts on primary and secondary production and cumulative fish biomass dynamics, but also top-down mechanisms on the lower trophic level production. Model results for a ten-year long simulation period (1980–1989) were analysed and discussed with respect to the observed pattern. To address the relevance of the newly implemented trophic levels for the simulated model response, we compare the performance of the ECOSMO E2E to a respective truncated NPZD model (ECOSMO II), which simulated the same time period. Additionally, we performed scenario tests to analyse the new role of the zooplankton mortality closure term in the truncated NPZD and the fish mortality term in the end-to-end model, which summarizes pressure imposed on the system by fisheries and mortality imposed by apex predators. We found that the model-simulated macrobenthos and fish spatial and seasonal pattern agree well with current system understanding. Considering a dynamic fish component in the ecosystem model resulted in slightly improved model performance with respect to representation of spatial and temporal variations in nutrients, changes in modelled plankton seasonality and nutrient profiles. Model sensitivity scenarios showed that changes in the zooplankton mortality parameter are transferred up and down the trophic chain with little attenuation of the signal, while major changes in fish mortality and in fish biomass cascade down the food chain.

Trophic Levels

Ecology ◽  
2012 ◽  
Author(s):  
Lee A. Dyer
Keyword(s):  
Trophic Level ◽  
Evolutionary Biology ◽  
Trophic Levels ◽  
Trophic Chain ◽  
The Third ◽  
Third Trophic Level ◽  
Primary Consumers ◽  
Trophic Chains ◽  
Secondary Consumers ◽  
Applied Fields

Trophic levels are determined by feeding relationships, with basal levels consisting of primary producers or detritus and upper levels based on consumption of these basal levels. Organisms on the second trophic level are referred to as primary consumers, which are in turn consumed by secondary consumers, and so on up a theoretical trophic chain. Primary consumers consist of herbivores and detritivores, while the third trophic level and those above include predators and parasites. Energy and matter move up trophic chains, and some compounds, including various toxins, may bioaccumulate at upper trophic levels. The concept of trophic level has generated a sizeable literature yielding useful ecological models, such as trophic cascades, and debates about top-down versus bottom-up regulation of herbivores. This article focuses on the contributions of the trophic-level concept to ecological theory, evolutionary biology, and the applied fields of agricultural and global change biology.

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