Past and present mercury flux to a West African crater lake (Lake Bosomtwe/Bosumtwi, Ghana).
Lake sediment cores have been used to reconstruct mercury deposition patterns in many parts of the world; however, no studies to date have used these methods in West Africa, nor are there any published measurements of mercury deposition to this region. We measured mercury in a (210)Pb dated sediment core from a meromictic crater lake in West Africa (Lake Bosomtwe, Ghana). Lake Bosomtwe has a very small catchment area to lake area ratio (1.1) and the sediment mercury profile is expected to reflect past and present atmospheric mercury deposition to the lake. Mercury concentrations in sediments as well as mercury flux to the sediments increased from the mid-1800s to latter half of the 1900s, however there has been a sharp decline in mercury flux to Lake Bosomtwe in recent decades. The recent decline in mercury flux to Lake Bosomtwe's sediments does not appear to be consistent with trends in local, regional or global mercury emissions, and may instead reflect declining global atmospheric mercury concentrations or declining European emissions, highlighting the importance of long-range atmospheric transport of mercury.
Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada N2L 3G1. amanda.poste@gmail.com
Amanda E
AE
Poste
Derek C G
DC
Muir
Megan K
MK
Otu
Roland I
RI
Hall
Robert E
RE
Hecky
D000392:Air Movements; D000397:Air Pollution; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000266:history; D019015:Geologic Sediments / Q000737:chemistry*; D005869:Ghana; D049672:History, 19th Century; D049673:History, 20th Century; D060106:Lakes / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000737:chemistry
D008628:Mercury