Serving Gogebic, Iron and Ontonagon Counties

Rowe's science class study's fish population

By IAN MINIELLY

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Bessemer - Dave Rowe, science teacher at A.D. Johnston School in Bessemer, is frequently seen outside the walls of the school providing students in his classes with hands on opportunities to use science in life applicable ways.

On Sunday, the Department of Natural Resources and Lake Superior State University lowered three nets into the pond at Bluff Valley Park so Rowe's grade 10 biology students can assess fish population in the pond.

According to Rowe, the fish surveying is a five-year effort to assess the pond and its survivability with an eye to turning it into a fishing pond. Rowe said they have done toxicology tests on fish living in the pond in the past and the fish are healthy and clean.

The problem is the pond is only about 3.5 feet deep and it needs to be somewhere between 15 to 18 feet to provide proper habitat to survive winter and thrive.

Roger Griel, professor at LSSU, said they have netted pumpkinseeds, minnows, bluegills, suckers and brook trout in the pond the last few years. Griel said two years ago they stocked bluegills and last year they added 20 brook trout to the pond and to their surprise, last year they netted brook trout offspring in the pond, which caught them by surprise.

Mark Mylchreest, of the DNR's Crystal Falls office, described the process used to gauge the fish population of the pond. Mylchreest said they focus on the ratio of tagged versus untagged fish captured on the second day of netting to accurately assess population. To do this, on the first day biology students from Rowe's class tag each sucker over 12 inches and each pumpkinseed over 5 inches before throwing them back into the water.

In addition to the tag, the top of the dorsal fin in clipped to mark the fish. The students pulled the three nets on Monday, measuring the size, tagging and returning the fish to the pond. Today, the students will pull the three nets again, repeating the actions of Monday, except the number of tagged fish is compared to the number of fish hauled in overall.

For example, if 100 pumpkinseeds were tagged on Monday and today they net 50 pumpkinseeds with tags and 50 without, this would mean they tagged half the fish in the pond on Monday roughly and there are around 200 pumpkinseeds in the pond. The same process is done with each species to gauge the number of fish, by species, within the confines of the shallow pond.

One of the benefits provided by the tags is when older fish are captured that were tagged in prior years, the students and professionals can gain a snapshot into the fish's life in the pond by how much it has grown and the quality of the habitat for surviving, according to Mylchreest.

The kids are able to take their education in biology and put it to work in the field with professionals who do it for a living.

Mylchreest informed the students before they began documenting the fish that they needed accurate numbers and good penmanship so the results were usable. It would not do anyone any good to spend two days gathering information and then be unable to decipher the results. Rowe said he would inform the Globe by the end of the week what numbers and how healthy the fish looked.