I got up this morning at 5:00 am to catch fish. Not the normal way,
but with a seine net. A seine is a net you can drag through a small
area of a lake and ensure that you capture every fish in that area. Of
course, you can only use these if you are the DNR and you are doing a
study of the lake. Seines are used to collect young-of-year fish. The
Lake City office of the DNR has seining stations they go back to every
year to seine so they can see how well each new year-class of fish is
doing. I am working on a database application that will allow all the
lake data to be entered and stored in a central server. John Hoxmeier,
the large lake specialist for Lake Pepin invited me along so I could see
how he collected data.
This year, most of the seine sites were under water, so we could
only do three of them. This was lucky for me as I was exhausted after
the first three. Maybe I could have done two more without starting to
cry, but I was ready to go back after three. Each seine station gets
three passes with the net. The net is a couple of hundred feet long and
suspended from two metal poles. At the first station, John said, "get
out and hold the pole on the shore while I sweep the boat around in a
big arc." I was wearing waders so I was very excited to get out of the
boat and stand in the water. I got the pole ready and gave him the
thumbs up. When the boat took off, I waaaaaaahh sploshed into the
water. I thought the net would stretch a little and it wouldn't be hard
to hold onto. I learned after that to dig the pole in and lean back to
hold it.
The best part was pulling the net out to see what we caught.
Generally, we found dozens to hundreds of tiny fish flopping around.
Then we kneeled down in the sand to count them all. 100 emerald shiners
here. 25 gizzard shad there. 10 walleye, a few adult smallmouth bass.
a few young of year white bass. Random shiners and minnows that are
thrown back after they are counted. The "species of concern" are
brought back to the lab to get weighed and identified. When they are
this small, it is hard even for a fish biologist to tell the difference
between walleyes and saugers so you have to cut them open and find a
structure called the pyloric cecum. Saugers have 4 or more of these.
Walleyes only have 3. One of the walleyes had a tiny, tiny shiner in
his belly.
When we were done, we had several paper sheets with long lists of the
species, length and weight of each fish. The only data problem might be
that some types of fish are just counted and measured and then all of
them are weighed together and a bulk weight is stored. Many of the
datasets around here have the bulk weights stored in the same columns as
the individual fish weights and this will not do.
As a bonus they let me take four dead fingerlings home in a baggie for
my children to play with. Tiny dead fish will delight them. Then, when
they are done, the cats can have them.
The boat we used was a Boston Whaler (
http://www.whaler.com/Rec/default.asp ). These are really cool
boats, mostly used on the ocean, but perfect for the waves and wind on
Lake Pepin. I want one. I never in my life have had a desire to own a
boat, but it would be so cool to own one of these.
Lake Pepin is incredibly beautiful because of the bluffs. Bluffs in
front of bluffs in front of bluffs, with points and beaches at the
bottom. Here are some pictures: http://www.umcycling.com/msp12.htm
the following one captures the scenery nicely.
http://www.umcycling.com/lpepinsouthmnw.jpg .
The first haul, all the tiny fish looked the same to me, but after
several hours of sorting and counting and weighing them, they resolved
themselves into very different fish with distinct personalities.
Gizzard shad were species of interest because they are an important
forage species for walleye. They are fat little guys that look like
they were made to be forage food for game species. Lake Pepin is about
the only place in Minnesota where gizzard shad are found.
Emerald shiners are long and sleek and wiggled through the mesh of the
net. They are not species of interest and as such, I didn't really care
where they landed when I threw them back in the water or if they came
apart when I pulled them out of the net. One time a seagull grabbed one
out of the air when I tossed it back.
White bass really are very white and have two back fins, one with
pointy spines. I got the sense that white bass thought they were a lot
more special than they really were.
The walleye/saugers were tiny but really looked to me like they were
bursting with vast potential to grow up into a tasty meal for someone.
5:13:53 PM 
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