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Mercury Exposure in Lower Trophic Level Organisms in the Mediterranean Sea - GMOS/Fenice Cruise Campaign

The Mediterranean Sea provides food resources to many countries worldwide, including the United States. Numerous marine birds and mammals depend on the Mediterranean food web.

Working in collaboration with Dartmouth College, BRI biologists set out to measure mercury levels in low trophic level zooplankton in the Mediterranean Sea. The goal is to link this data with the abiotic mercury measurements in air/water/sediment collected by the research teams from Italy, France, Sweden, and Slovenia in the Mediterranean Sea (including the Tyrrhenian Sea in 2011, the Straits of Gibraltar, and the Atlantic Ocean in 2012) and to explore mercury exposure in the higher marine organisms such as fish and squid, which are major food sources for many marine birds, fish, and mammals including humans.

BRI Project Coordinator: Oksana Lane

Preliminary Findings

Preliminary Findings

We found elevated levels of mercury in fish captured in 2011 and 2012 in the western basins. In addition, we found high mercury concentrations in the hair of many Italian crew members who live on the ship about six or more months per year and who consume fish on a regular basis. Our work will complement water-atmospheric mercury research carried out by our European colleagues, and will add to the global knowledge of mercury cycling in the marine ecosystem. In addition:

  • Mackerel from the Piombino area have tissue wet weight THg concentrations (over 300 ppb) reaching “effect” levels
  • Mackerel and calamari from the Piombino site have significantly higher muscle THg concentrations than from other sampled sites
  • Euphausiids appear to be a good indicator species and are more appropriate than tiny smelt fish or other small crustaceans. Methylmercury (MeHg) in euphausiids on average is ~81% vs. 57% in small fish. They are an important food species and are likely contributing to the higher MeHg in larger fish at industrial sites.
  • Hair THg concentrations in Urania crew are elevated. It could be attributed to eating tuna and swordfish=pesce spada (Xiphias gladius). Tuna and swordfish are known to have high Hg concentrations (over 1.5 ppm ww) and swordfish was served twice on board Urania during the two-week mission, in both 2011 and 2012.
  • Additional analyses are still pending: additional Hg speciation. Stable C & N for trophic analysis (limited by biomass availability). (Chla could be conducted on frozen filters, but using the CTD fluorometer profiles are likely more informative)
 

Sampling Locations

Sampling locations in the western Mediterranean Sea, from 2011 and 2012.
Sampling locations in the western Mediterranean Sea, from 2011 and 2012.
Presentations

Presentations

Mercury in Biota in the Tyrrhenian Sea—Pilot Study 2011. Oksana Lane, David Evers Biodiversity Research Institute, Maine and Kate Buckman- Dartmouth college, New Hampshire, USA. PowerPoint Presentation

Project Coordinator

Project Coordinator

Oksana Lane
207-839-7600 x106
Biodiversity Research Institute