Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy)
In the summer of 2022, the Po River Delta (Northern Italy), a eutrophication hotspot, was severely affected by high temperatures, exceptional lack of rainfall and saline water intrusion. The effect of saline intrusion on benthic nitrogen dynamics, and in particular the N removal capacity, was invest...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-06-01
|
| Series: | Water |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4441/15/13/2405 |
| _version_ | 1797590796807962624 |
|---|---|
| author | Maria Pia Gervasio Elisa Soana Fabio Vincenzi Monia Magri Giuseppe Castaldelli |
| author_facet | Maria Pia Gervasio Elisa Soana Fabio Vincenzi Monia Magri Giuseppe Castaldelli |
| author_sort | Maria Pia Gervasio |
| collection | DOAJ |
| description | In the summer of 2022, the Po River Delta (Northern Italy), a eutrophication hotspot, was severely affected by high temperatures, exceptional lack of rainfall and saline water intrusion. The effect of saline intrusion on benthic nitrogen dynamics, and in particular the N removal capacity, was investigated during extreme drought conditions. Laboratory incubations of intact sediment cores were used to determine denitrification and DNRA rates at three sites along a salinity gradient in the Po di Goro, an arm of the Po River Delta. Denitrification was found to be the main process responsible for nitrate reduction in freshwater and slightly saline sites, whereas DNRA predominated in the most saline site, highlighting a switch in N cycling between removal and recycling. These results provide evidence that salinity is a key factor in regulating benthic N metabolism in transitional environments. In a climate change scenario, salinity intrusion, resulting from long periods of low river discharge, may become an unrecognized driver of coastal eutrophication by promoting the dissimilatory nitrate reduction to ammonium and N recycling of bioactive nitrogen within the ecosystem, rather than its permanent removal by denitrification. |
| first_indexed | 2024-03-11T01:25:37Z |
| format | Article |
| id | doaj.art-9329b73580cc4bff95e51cb9e958d084 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-11T01:25:37Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-9329b73580cc4bff95e51cb9e958d0842023-11-18T17:47:44ZengMDPI AGWater2073-44412023-06-011513240510.3390/w15132405Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy)Maria Pia Gervasio0Elisa Soana1Fabio Vincenzi2Monia Magri3Giuseppe Castaldelli4DiSAP—Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, ItalyDiSAP—Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, ItalyDiSAP—Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, ItalyDepartment of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 33/A, 43124 Parma, ItalyDiSAP—Department of Environmental and Prevention Sciences, University of Ferrara, Via L. Borsari 46, 44121 Ferrara, ItalyIn the summer of 2022, the Po River Delta (Northern Italy), a eutrophication hotspot, was severely affected by high temperatures, exceptional lack of rainfall and saline water intrusion. The effect of saline intrusion on benthic nitrogen dynamics, and in particular the N removal capacity, was investigated during extreme drought conditions. Laboratory incubations of intact sediment cores were used to determine denitrification and DNRA rates at three sites along a salinity gradient in the Po di Goro, an arm of the Po River Delta. Denitrification was found to be the main process responsible for nitrate reduction in freshwater and slightly saline sites, whereas DNRA predominated in the most saline site, highlighting a switch in N cycling between removal and recycling. These results provide evidence that salinity is a key factor in regulating benthic N metabolism in transitional environments. In a climate change scenario, salinity intrusion, resulting from long periods of low river discharge, may become an unrecognized driver of coastal eutrophication by promoting the dissimilatory nitrate reduction to ammonium and N recycling of bioactive nitrogen within the ecosystem, rather than its permanent removal by denitrification.https://www.mdpi.com/2073-4441/15/13/2405saline intrusionclimate changedenitrificationDNRAeutrophicationPo River Delta |
| spellingShingle | Maria Pia Gervasio Elisa Soana Fabio Vincenzi Monia Magri Giuseppe Castaldelli Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) Water saline intrusion climate change denitrification DNRA eutrophication Po River Delta |
| title | Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) |
| title_full | Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) |
| title_fullStr | Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) |
| title_full_unstemmed | Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) |
| title_short | Drought-Induced Salinity Intrusion Affects Nitrogen Removal in a Deltaic Ecosystem (Po River Delta, Northern Italy) |
| title_sort | drought induced salinity intrusion affects nitrogen removal in a deltaic ecosystem po river delta northern italy |
| topic | saline intrusion climate change denitrification DNRA eutrophication Po River Delta |
| url | https://www.mdpi.com/2073-4441/15/13/2405 |
| work_keys_str_mv | AT mariapiagervasio droughtinducedsalinityintrusionaffectsnitrogenremovalinadeltaicecosystemporiverdeltanorthernitaly AT elisasoana droughtinducedsalinityintrusionaffectsnitrogenremovalinadeltaicecosystemporiverdeltanorthernitaly AT fabiovincenzi droughtinducedsalinityintrusionaffectsnitrogenremovalinadeltaicecosystemporiverdeltanorthernitaly AT moniamagri droughtinducedsalinityintrusionaffectsnitrogenremovalinadeltaicecosystemporiverdeltanorthernitaly AT giuseppecastaldelli droughtinducedsalinityintrusionaffectsnitrogenremovalinadeltaicecosystemporiverdeltanorthernitaly |