Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium
Mercury (Hg) is a global neurotoxin distributed at trace levels in the earth’s crust. Although Hg input from anthropogenic sources has been reduced in North America and Europe, in some other parts of the world the emission is still high. Considering the longrange transport and long atmospheric half-...
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The University of Bergen
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ftunivbergen:oai:bora.uib.no:1956/20927 2023-05-15T15:27:47+02:00 Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium Azad, Atabak Mahjour 2019-09-18T05:36:18.547Z application/pdf http://hdl.handle.net/1956/20927 eng eng The University of Bergen Paper I: Azad, A.M., Frantzen, S., Bank, M.S., Nilsen, B.M., Duinker, A., Madsen, L., Maage, A., 2019. Effects of geography and species variation on selenium and mercury molar ratios in Northeast Atlantic marine fish communities. Science of the Total Environment 652, 1482-1496. The article is available in the main thesis. The article is also available at: http://hdl.handle.net/1956/20812 . Paper II: Azad, A.M., Frantzen, S., Bank, M.S., Johnsen, I.A., Tessier, E., Amouroux, D., Madsen, L., Maage, A., 2019. Spatial distribution of mercury in seawater, sediment, and seafood from the Hardangerfjord ecosystem, Norway. Science of the Total Environment 667, 622-637. The article is available in the main thesis. The article is also available at: http://hdl.handle.net/1956/20707 . Paper III: Azad, A.M., Frantzen, S., Bank, M.S., Madsen, L., Maage, A. Methylmercury bioaccumulation pathways in tusk (Brosme brosme) from Sognefjord, Norway: insights from C and N isotopes. The article is not available in BORA. container/c8/a4/3a/89/c8a43a89-620d-491e-8db1-60c6ff620bef http://hdl.handle.net/1956/20927 cristin:1728761 In copyright http://rightsstatements.org/page/InC/1.0/ Copyright the Author. All rights reserved Doctoral thesis 2019 ftunivbergen 2023-03-14T17:44:05Z Mercury (Hg) is a global neurotoxin distributed at trace levels in the earth’s crust. Although Hg input from anthropogenic sources has been reduced in North America and Europe, in some other parts of the world the emission is still high. Considering the longrange transport and long atmospheric half-life, Hg and particularly its most toxic form monomethylmercury (MeHg), remains an environmental concern at the global level causing threat to both wildlife and human health. In general, seafood is the main source of MeHg exposure to humans and Hg is the main reason for seafood consumption advisories. Therefore, measuring the Hg levels in seafood species and understanding the processes governing the variation of Hg levels are very important for seafood safety and security. Synthesis, bioaccumulation and biomagnification of MeHg are very critical processes controlling the MeHg levels in the environment and the biota. The main goals of this study were to investigate how Hg levels vary between different fish species as well as between different communities in offshore, fjord and coastal areas of the North East Atlantic Ocean (NEAO). The contribution from different Hg sources and parameters influencing these variations were also investigated. Large variation in Hg levels between fish species form NEAO was found (Paper I). The pelagic species including Atlantic mackerel (Scomber scombrus) and blue whiting (Micromesistius poutassou) with mean value of 0.04 mg kg-1 ww had the lowest Hg concentrations. Blue ling (Molva dypterygia) had the highest Hg levels with a mean of 0.72 mg kg-1 ww. Selenium (Se) varied in a smaller range compared to Hg, with mean concentrations from 0.27 mg kg−1 ww in Atlantic cod (Gadus morhua) to 0.56 mg kg−1 ww in redfish (Sebastes spp.). The Hg level in fish increased from north towards south in most species and this process was independent of Hg pollution in the environment (sediment). It was hypothesized that a gradual increase in water temperature and primary production duration from the north ... Doctoral or Postdoctoral Thesis atlantic cod Gadus morhua Molva dypterygia North East Atlantic University of Bergen: Bergen Open Research Archive (BORA-UiB) |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
Mercury (Hg) is a global neurotoxin distributed at trace levels in the earth’s crust. Although Hg input from anthropogenic sources has been reduced in North America and Europe, in some other parts of the world the emission is still high. Considering the longrange transport and long atmospheric half-life, Hg and particularly its most toxic form monomethylmercury (MeHg), remains an environmental concern at the global level causing threat to both wildlife and human health. In general, seafood is the main source of MeHg exposure to humans and Hg is the main reason for seafood consumption advisories. Therefore, measuring the Hg levels in seafood species and understanding the processes governing the variation of Hg levels are very important for seafood safety and security. Synthesis, bioaccumulation and biomagnification of MeHg are very critical processes controlling the MeHg levels in the environment and the biota. The main goals of this study were to investigate how Hg levels vary between different fish species as well as between different communities in offshore, fjord and coastal areas of the North East Atlantic Ocean (NEAO). The contribution from different Hg sources and parameters influencing these variations were also investigated. Large variation in Hg levels between fish species form NEAO was found (Paper I). The pelagic species including Atlantic mackerel (Scomber scombrus) and blue whiting (Micromesistius poutassou) with mean value of 0.04 mg kg-1 ww had the lowest Hg concentrations. Blue ling (Molva dypterygia) had the highest Hg levels with a mean of 0.72 mg kg-1 ww. Selenium (Se) varied in a smaller range compared to Hg, with mean concentrations from 0.27 mg kg−1 ww in Atlantic cod (Gadus morhua) to 0.56 mg kg−1 ww in redfish (Sebastes spp.). The Hg level in fish increased from north towards south in most species and this process was independent of Hg pollution in the environment (sediment). It was hypothesized that a gradual increase in water temperature and primary production duration from the north ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Azad, Atabak Mahjour |
spellingShingle |
Azad, Atabak Mahjour Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
author_facet |
Azad, Atabak Mahjour |
author_sort |
Azad, Atabak Mahjour |
title |
Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
title_short |
Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
title_full |
Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
title_fullStr |
Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
title_full_unstemmed |
Mercury in fish from the North East Atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
title_sort |
mercury in fish from the north east atlantic: sources, bioaccumulation dynamics and co-occurrence with selenium |
publisher |
The University of Bergen |
publishDate |
2019 |
url |
http://hdl.handle.net/1956/20927 |
genre |
atlantic cod Gadus morhua Molva dypterygia North East Atlantic |
genre_facet |
atlantic cod Gadus morhua Molva dypterygia North East Atlantic |
op_relation |
Paper I: Azad, A.M., Frantzen, S., Bank, M.S., Nilsen, B.M., Duinker, A., Madsen, L., Maage, A., 2019. Effects of geography and species variation on selenium and mercury molar ratios in Northeast Atlantic marine fish communities. Science of the Total Environment 652, 1482-1496. The article is available in the main thesis. The article is also available at: http://hdl.handle.net/1956/20812 . Paper II: Azad, A.M., Frantzen, S., Bank, M.S., Johnsen, I.A., Tessier, E., Amouroux, D., Madsen, L., Maage, A., 2019. Spatial distribution of mercury in seawater, sediment, and seafood from the Hardangerfjord ecosystem, Norway. Science of the Total Environment 667, 622-637. The article is available in the main thesis. The article is also available at: http://hdl.handle.net/1956/20707 . Paper III: Azad, A.M., Frantzen, S., Bank, M.S., Madsen, L., Maage, A. Methylmercury bioaccumulation pathways in tusk (Brosme brosme) from Sognefjord, Norway: insights from C and N isotopes. The article is not available in BORA. container/c8/a4/3a/89/c8a43a89-620d-491e-8db1-60c6ff620bef http://hdl.handle.net/1956/20927 cristin:1728761 |
op_rights |
In copyright http://rightsstatements.org/page/InC/1.0/ Copyright the Author. All rights reserved |
_version_ |
1766358192746397696 |