Oceanic mercury concentrations on both sides of the Strait of Gibraltar decreased between 1989 and 2012. (March 2020)

• Record Type: Journal Article
• Authors: Cossa, Daniel; Knoery, Joël; Boye, Marie; Marusczak, Nicolas; Thomas, Bastien; Courau, Philippe; Sprovieri, Francesca
• Is Part Of: Anthropocene. Volume 29(2020)
• Publication Date: 2020-03
• Subjects: AABW Antarctic Bottom Water -- AOU Apparent Oxygen Utilization -- BrCl bromine monochloride -- CFC's chlorofluorocarbons -- CO carbon monoxide -- CRM certified reference material -- FEP fluorinated ethylene propylene -- GEOTRACES an international study of the marine biogeochemical cycles of trace elements and their isotopes (www.geotraces.org) -- Hg mercury -- Hg0 elemental mercury -- HgR reactive or easily reduced mercury -- HgT total mercury -- HgTUNF total mercury in unfiltered samples -- HgTF total mercury in filtered samples -- LDW Lower Deep Water -- LIW Levantine Intermediate Water -- LSW Labrador Sea Water -- MeHg methyl mercury -- MAW Modified Atlantic Water -- MW Mediterranean water -- NEACW North East Atlantic Central Water -- NEADW North East Atlantic Deep Water -- O3 ozone -- OFFTRAC University of Washington three-dimensional offline ocean tracer model -- ORMS-4 certified reference material (River water spiked with inorganic mercury) -- P phosphorus -- Prem remineralized phosphorus -- SnCl2 tin chloride -- SPMW Subpolar Mode Water -- SRP soluble reactive phosphorus -- US-EPA Environmental Protection Agency of the United States of America -- WIW Winter Intermediate Water -- WMDW Western Mediterranean Deep Water; Mercury -- Mediterranean Sea -- Atlantic Ocean -- Gibraltar; Nature -- Effect of human beings on -- Periodicals; Human ecology -- Periodicals; 304.2
• DOI: 10.1016/j.ancene.2019.100230
• Languages: English
• ISSNs: 2213-3054

Abstract

Graphical abstract: Highlights: Hg concentrations in water columns have been determined both sides of the Gibraltar Strait ∼20 years apart (1989–2012). The decrease is around 30 and 50 % in WMDW and NEACW, respectively. Hg concentrations did not change in the deepest waters of the Atlantic Ocean. Abstract: Mercury (Hg) is a toxic metal that threatens the health of aquatic ecosystems and fish consumers. Its natural cycle has been deeply perturbed by Anthropogenic Hg emissions have deeply perturbed its natural cycle, especially since the start of the Industrial Revolution circa 1850 CE. Anthropogenic Hg emissions from North America and Europe have decreased by a factor of two in the last decades following the implementation of strict regulations. The response of North Atlantic Ocean and Mediterranean waters to this decrease remains poorly documented by field observations. A comparison of results obtained between 1989 and 2012 shows a significant decrease of Hg concentrations in waters on both sides of the Strait of Gibraltar. West of Gibraltar, the Hg decrease ranges from ∼35 % in the upper North East Atlantic Deep Water to ∼50 % in the North East Atlantic Central Water. East of Gibraltar, the observed decrease is ∼30 % in the Western Mediterranean Deep Water. No decrease is observed in the deep Atlantic Ocean layer that formed before the industrial era. These results strongly substantiate the effectiveness of global anti-pollution policies on Hg contamination in oceanic waters. A consequent decline of Hg bioaccumulation in Northeastern Atlantic and Western Mediterranean pelagic ecosystems still requires verification.