GRAND RAPIDS, Mich. (WOOD) — When it comes to sports fishing on the Great Lakes, the Chinook salmon is the king of them all.

The big fish is the top of the food chain in the more than $1 billion boating and tourism industry in Michigan, but state biologists fear the Chinook may be on the verge of a crash.

That was just part of the lesson at Grand Rapids’ fish ladder Friday, as third grade students from Wealthy Elementary School let go of the Chinook fingerlings they have been raising in the classroom since last fall.

For the students, the release marked the end of a months-long school project into the reproductive nature of the Big Lake’s big fish. For the salmon, it’s the start of a years-long swim to open water and back. It can be a hard lesson.

“The survival rates of these fish is about 10 percent. So of the 200 we’re releasing today, only 20 will make it back to the fish ladder,” said science teacher Tom Morris.

The Michigan Department of Natural Resources estimates anglers spend around $2.5 billion in fishing trips, including the cost of food and hotels.

However, biologists say the salmon population on Lake Michigan is down 75 percent from its peak four years ago. It’s feared the loss of the salmon could mean losses to coastal communities.

“We’re not just talking about what’s happening in the water; we’re talking about what’s happening out of the water – hotels, restaurants, sport shops, boat manufacturers. A lot of folks are dependent on the Big Lake to some degree,” said Bob Strek, a member of the Michigan Steelheaders, which is a statewide group dedicated to enhancing sport fishing in the area.

The salmon simply have nothing to eat. A similar crash happened in Lake Huron last decade, blamed in part on invasive species.

“The population of Chinooks are dependent upon the Alewives. The Alewives are dying; they’re not reproducing. Zebra mussels are to blame for that,” Sterk added.

The goal for educators is to unravel the complexity of ecology and natural resources. Their hope is that the next generation can see their role in the environment and how they’re impacting it.

The school programs around the state are run in conjunction with local Steelheader groups and the DNR. They are funded until 2020.