Monday, November 21, 2011

Lake Sturgeon Sampling

During the week of November 14-18, Kathlina and Sarah (husbandry intern) were privileged to join TWRA, USFWS, UT Knoxville, and TVA in a lake sturgeon sampling effort on the Ft. Loudoun Reservoir/Tennessee River in and near Knoxville. Two commercial fishermen from Alabama also helped with the effort by showing us their techniques. We set trot lines each evening (Monday through Thursday) and pulled them up every morning to see what we caught.
We baited the lines with chunks of common carp, buffalo, gizzard shad, and earthworms. The gizzard shad and earthworms were not popular with the lake sturgeon but seemed to be enjoyed by a whole lot of catfish! (Several hundred catfish were caught as by-catch during this effort.) We didn’t just see catfish, however, as this sampling effort yielded a record 27 lake sturgeon!!! These fish ranged in age from 1-11 years old and were up to 42 inches long! It was a wonderful experience and yielded much needed data about the size and survivability of the lake sturgeon that have been released over the past 11 years. We can tell how old the fish are by how we mark the fish before release.

Each year, a certain scute (bony plates on the side of the body) is removed from each individual. For example, 2003 year class fish are missing the 4th scute on the right side. Many of the sturgeon also have PIT tags, which are imbedded under the skin of the larger fish we release. We can scan fish with a PIT tag to give us a unique identification number. From these tag numbers, we are able to look up exactly when and where the fish was released.

Once all of this information is compiled, a map will be created to illustrate where and how much the fish are moving in the river. Any sturgeon that was not already PIT tagged was given a tag with a unique number in anticipation of future recaptures. What an exciting study to track the progress of this long-term project!

Thanks to everyone who was involved for all of their hard work in the rain and cold! For more pictures visit our Facebook page!!/pages/Tennessee-Aquarium-Conservation-Institute/151884801512568

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