Sea Lampreys are the leeches of the sea; they suck blood from other marine life forms. As a result, they concentrate PFAS, highly toxic flame retardant chemicals of which the US military is probably the largest polluter, that are poisoning other fish, much as fish high on the marine food chain concentrate toxic mercury from the other fish they consume.

The Sea Lamprey attaches to fish with its suction cup mouth, then digs its teeth into the flesh of other fish. Sea Lampreys feed on other fish’s body fluids, similar to how a leech feeds off its host.   Photo – T. Lawrence, Great Lakes Fishery Commission

 Sea Lampreys are loaded with PFAS compared to other species of fish, according to a study that measured the toxins in Maine’s Penobscot River. The Sea Lamprey sucks blood and fluids from other fish. It is a vampire fish, a kind of leech of the sea, so it makes sense that it might contain high levels of PFAS. After all, fish are like PFAS petri dishes that swim along and pick up the carcinogens.

The Sea Lamprey uses its suction cup-like mouth to attach itself to the skin of a fish and digs away tissue with its saw-like teeth. Victims often die from excessive blood loss or infection. After one year of bloodsucking in the sea, the lampreys return to the river to spawn and die.

The Sea Lamprey had a total of 22,970 parts per trillion for 5 compounds examined while the other fish studied had much lower levels.


Species                           Total PFAS (parts per trillion)

Alewife                          3,060
American Shad Roe        4,490
American Shad Filet       4,380
Blueback Herring           5,620
Striped Bass                   7,220
Sea Lamprey                22,970


Source – One health assessment of mercury, persistent organic compounds and PFAS for consumption of restored anadromous fish in the Penobscot River – Daniel Kusnierz, Penobscot Nation; 2022 Atlantic Salmon Ecosystems Forum January 11 & 12, 2022.

The Penobscot River study reported, “Penobscot Indian Nation tribal members fish for sustenance in the Penobscot River and its tributaries in Maine. Recent removal of dams has resulted in the return of anadromous fish species, including Alewife, American Shad, Blueback Herring, Rainbow Smelt, Striped Bass, and Sea Lamprey, into the Tribe’s waters.”

Sure, this study is a tiny snapshot of reality and I’m not pretending to be a scientist. Instead, I’m trying to draw public attention to the fate and transport of PFAS compounds in fish and ambient water. All I hear from state and federal officials is that the fish are OK to eat.

The FDA says, “The US food supply is among the safest in the world, and the available scientific evidence does not support avoiding particular foods because of concerns regarding PFAS exposure.”

Lampreys are born in freshwater and spend most of their lives in freshwater before taking a year-long journey to the sea. When they move back into freshwater at the end of their lives, they cease feeding, and after spawning, they die. Because they spawn in shallow water they’re easy pickings  for eagles, ospreys, hawks, and owls. These species have also been found with high levels of  PFAS, although likely from a host of sources.

I asked a colleague who knows about these things and he suggested that lampreys may have picked up some of the toxins during the 7-15 years they spend as little sand eels looking for things sticking half-way out of the stream substrate, eating any detritus that floats by.  PFAS have yet to be studied in lamprey.

Dear friends,

Thank you for reading this and thank you if you’ve contributed to our water testing campaign. The Women’s League for Peace and Freedom and Military Poisons have raised $3,000 to support testing in the mid-Atlantic region, New England, and Hawaii. The Hawaii testing is ongoing.

We are planning a nine-stop testing tour of bases in the southeast.

The cost of two surface water tests at each location ($79 each) comes to $1,422.  We’ll need to raise $2,000 to cover all expenses. Please help us. Contribute here.

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