Excavations at the Mink Island site, XMK-164., Katmai, Alaska. Source: ADN.com
Some news just puts the fear of Cod into you. For example, there’s an interesting study from earlier this year which suggests that rising sea levels in the Alaskan middle Holocene (in the study: roughly 7,000 to 4,000 years ago) released methyl mercury compounds into the nearshore environment (Open Source paper by Maribeth Murray et al., 2015). These then accumulated in fish, specifically Pacific Cod, Gadus macrocephalus, and presumably also in other species which predate upon these cod, such as humans. It’s an interesting preliminary study, but before you think, “Oh My Gadus, Ancient Alaskans were Mad Hatters running amok with mercury-induced neuropathy”, there are some important details to consider.
Northwest Coast Archaeology 