For Friday, July 18, 2025

1 – Where do sea lamprey go?

The invasive, parasitic fish travel through the deepest parts of rivers, according to Michigan State University researchers.

Their findings could help refine strategies for controlling lamprey — not just with dams and pesticides, but with smarter trap placement.

Using acoustic telemetry — with sound-emitting tags surgically implanted into lamprey — scientists tracked 56 individuals in the White River near Whitehall.

Of those, 46% preferred the river’s deepest quarter.

That’s useful to verify, since the river’s edge is a prime spot for installing traps and other devices.

Lamprey resemble eels and kill Great Lakes fish by sucking their blood and bodily fluids.

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2 – Mercury is still building up in Lake Huron’s food web, according to a new study in the Journal of Great Lakes Research.

It mostly gets there through air pollution, falling from the sky after being released by coal-burning and industrial sources.

Researchers found high levels of toxic methylmercury in zooplankton and lake trout, which can harm wildlife and people who eat the fish.

Two big reasons it’s sticking around: invasive mussels have changed how nutrients move through the lake, and fish are eating different prey, which affects how mercury travels up the food chain.

Mercury exposure is linked to brain and nervous system damage, especially in children and pregnant women.

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3 – Shipping on the Great Lakes keeps food, fuel, and raw materials moving — and a recent Capitol Hill briefing says it needs more support.

Ice delays have cost the region $2 billion and 10,000 jobs in the past decade, but there’s just one heavy icebreaker for 4,500 miles of shoreline.

Officials say better infrastructure and more funding could help ports handle cargo more efficiently and keep shelves stocked during winter.

The President’s budget proposes $1 billion for port improvements, combining new and existing funding — the biggest investment ever in the program.

Speakers urged Congress to invest in locks, ports, and icebreaking to protect jobs and keep the region’s $6 trillion economy moving.

– Mr. Great Lakes is heard at 6:45 and 8:45 Friday mornings on Delta College Public Radio 90.1 FM WUCX in University Center, Michigan, near Bay City (listen live). Follow @jeffkart on Twitter #MrGreatLakes