Habitat for the Coaster Brook Trout

Michigan Technological University has started a crowd-funding website to raise $10,000 needed to help keep Michigan’s endangered population of coaster brook trout in our world. The coaster was once one of Michigan’s most glamorous and sought-after fishes—muscular, brilliantly speckled and easy to catch, the fish swam by the millions along the Lake Superior shore, and as early as the 1800s, people traveled from across the Atlantic to catch them. But today the state’s breeding adult population numbers are possibly as low as 500. The funding opportunity runs through the end of May.
We check in with Dr. Casey Huckins, a top coaster brook trout researcher,  for an update on the coaster’s status. (Read a coaster feature story from our archive).

First, give us a snapshot of what the money will do.

Sure. Well, the short answer is the money will be used to remove sand that is now covering gravel that the fish need for laying eggs. Coasters won’t lay their eggs in sand, and if they do, the embryos will not survive. This is in the Salmon Trout River, near Big Bay, and it’s arguably the last or best documented remaining river on the Michigan mainland where remnant populations of coasters spawn.

Isn’t there gravel bottom all along the river?

The key stretch of spawning gravel is only about 30 meters long. Other stretches might have existed in the past, but they’re not used as extensively by the coasters. Over the past few years, that last stretch of gravel has become smothered with sand.

So, during the Bush administration, the federal government refused to give the coaster endangered species protection. How are the numbers now looking for the coaster brook trout population?

Overall, the numbers are very low. In 2010, we saw 186 adults on the spawning beds. In 2011 we saw only 74. And in 2012 we counted 110. We don’t know the sex ratio, but if you figure 50/50, that is not many females.

That sounds alarming.

Well, yes. And another issue is that we find that coasters have a high site fidelity, that is, they go back to spawn where they have spawned in the past, and if they have to go to another river to find adequate spawning habitat, we don’t know how long it would take for them to find habitat or how long it would take for that to become colonized. It could take a long time, if they even would spawn. And coasters are very keyed to spawning above groundwater inflows, so this is very specialized habitat.

So how do we donate?

Just go to the website, click “Contribute Now” and fill out the form. You can also send a check, and the address is there. superiorideas.org/projects/brook-trout

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