My coauthors (Kelsie Schiavone and Jessica Dutton) and I are pleased to share our just-published paper in the Caribbean Journal of Science, which presents the results of an experiment that tested the effectiveness of ordinary sea salt and table salt in reducing the concentration of mercury in cetacean tissue. While many of us here on the MARMAM list are focused on cetacean conservation, we also acknowledge the existence of traditional whaling operations around the world and are concerned about the impact on human health of consuming food products derived from whaling. This experiment focused on one such operation: the "blackfish" fishery of St. Vincent and the Grenadines, which targets short-finned pilot whales and other small cetaceans. While the impact of this operation on Caribbean cetacean populations is difficult to determine, owing to a lack of population baseline data for the region, recent studies have shown the food products derived from this whaling operation to be heavily contaminated with mercury--in some cases, more so than for the same species sampled in different geographical areas. We collected cetacean muscle tissue samples from St. Vincent and found that, after drying, the samples that we salted had approximately 30% less mercury than unsalted controls, after controlling for the added drying power of the salt. If the method presented in this paper can be implemented at scale, and if several of the complicating social, economic, and environmental issues we discuss can be addressed, this might offer a way to protect human health for whatever amount of time this whaling operation remains active. It may also be applicable to other forms of "seafood" that are known to contain high concentrations of mercury. I would welcome your feedback and any questions you might have to share. 

The paper's abstract is as follows: 

High mercury (Hg) concentrations in seafood present a major global public health concern, especially in regions heavily dependent upon seafood like the Caribbean. Tissues from predatory fishes and other high trophic-level marine organisms such as odontocetes (toothed whales and dolphins) are often elevated in mercury, owing to biomagnification. We investigated whether salting reduces the total mercury (THg) concentration in muscle tissue from odontocetes (“blackfish”) taken for human consumption in St. Vincent and the Grenadines. Muscle from 21 odontocetes was coated in table salt or sea salt and dried for one, three, or seven days, after which the THg concentration in each sample was determined and compared to the THg concentration in the corresponding unsalted control. Every salted sample had a lower THg concentration than the unsalted control (mean decrease = 29.4%). There was no difference in the effectiveness of table salt versus sea salt at reducing the THg concentration. Our results show that, while salting successfully removed Hg, only 11% of samples had a methylmercury (MeHg) concentration below the World Health Organization’s 1.0 μg/g wet weight advisory level, indicating that consuming odontocete muscle still poses a risk to human health—though that risk may be reduced by the application of salt during drying. The method that we present here may also be applicable to tissues from other marine species with lower initial THg concentrations and may be effective at rendering those tissues safer for human consumption.