Award: OCE-1333976

The purpose of this project was to measure the concentrations of methyl mercury, a neurotoxin, within fog. Additionally, we sought to both qualitatively and quantitatively determine the source of this compound and estimate its flux into terrestrial ecosystems as a result of the collection of fog water along the coast. Methyl mercury is a compound that is generated when dimethyl mercury breaks down. Dimethyl mercury is formed from microbiological activity in the ocean water column, at depths of around 1000 feet. Elemental mercury, the source of all of these compounds and primarily anthropogenic in origin, is derived from both mining activity and from coal-fired power plants. When mercury accumulates in the ocean, bacteria that normally reduce sulfur consume the elemental mercury and produce these toxic methylated compounds. Colleagues at Moss Landing Marine Lab had two cruises per year over the course of two years during which time they collected data on dimethyl mercury in the water column at a number of sampling locations. With a ship-based active fog collector, they also collected over-water fog samples that they analyzed for monomethyl mercury. This was done in conjunction with six active fog collectors and numerous passive fog collectors deployed at various coastal and near-coastal areas from Marina, CA to Arcata, CA. Results indicate enhanced areas of dimethyl mercury in areas associated with upwelling, high concentrations of monomethyl mercury in the ocean microlayer, surprisingly low concentrations of monomethyl mercury in fog water collected over the ocean, much higher levels of monomethyl mercury in fog water collected in coastal locations, and lower levels of monomethyl mercury apparent at greater distances inland from the coast. Higher mercury levels were also seen in samples taken from coastal top predators, such as wolf spiders and mountain lion whiskers, with much lower values measured on their more-inland counterparts. This is consistent with the hypothesis that there could be a cycling of mercury compounds from ocean ecosystems to terrestrial ecosystems with coastal fog as a possible vector. Additionally, to better quantify the extent of the input of mercury from fog, an extensive passive collector network has been established across the state, with funding from this NSF grant, as well as with additional incentive funds from CSU Monterey Bay and support from NBD Nanotechnologies, a startup interested in increasing the effectiveness of fog collection materials. All told, over 40 passive fog water collectors were built and deployed from central to northern California as a result of this activity, generating significant research on fog variability and fog collection materials as well as enormous public interest and awareness. Additionally, numerous public as well as scientific talks have been given on fog collection as a direct result of the funding received. These include invited talks at CSU Fullerton on the relationship between current fog water collection efforts and Frank Herbert?s classic science fiction novel, Dune, to a presentation at the Pacific Grove Natural History Museum on Central California Fog Collection Efforts. Last Modified: 09/26/2016 Submitted by: Daniel M Fernandez