Intern Update: Feeding, Cleaning, and Sampling

Intern update

Well we have been making our summer husbandry interns work hard the last few weeks! May 23^rd we took a road trip down to Warm Springs National Fish Hatchery to pick up 2,000 juvenile sturgeon, which is their primary job this summer. We have research and conservation projects that need field work this summer as well so there is plenty to do.  It takes everyone to keep TNACI going! 

Stephen Floyd is our full-time intern this summer. Stephen comes to us from Virginia where he just graduated from Roanoke College. He has a passion for southeastern fish and is especially intrigued by Southern Appalachian Brook Trout so he is working on an independent study of this species this summer.

Stephen cleaning sturgeon trough.

Jessica holding her first sturgeon

Jessica Hubbuch is graduate student at the University of Tennessee here in Chattanooga and is working with us as a part-time intern this summer. She is currently working on some urban stream surveys with UTC and organizes their museum of biological specimens. She is working hard this summer to help TNACI organize, label and find homes for many cool specimens that we have been saving over the years from the Aquarium. Scientists are always on the lookout for preserved specimens to use as teaching tools believe it or not!

Louise McCallie and Josh Oliver are also working with TNACI this summer. They are both volunteering their time to help us a few days each week. Louise is a 2011 graduate of GPS here in Chattanooga and just finished her freshman year at Lehigh University so we are glad to have her while she is home for the summer. Josh is finishing up his biology degree at Dalton State and is helping us out one day each week to get some fisheries experience.

Whew what a crew! We are lucky to have so much good help this summer. These guys are excited to be here and ready to work hard and learn lots!

Most of the intern work has focused on caring for our lake sturgeon babies so far.  When sturgeon are so little (many of them were 1.5 cm on May 23^rd!), they need to be fed often. The first few weeks we fed four times each day so someone had to be at work at 7am and someone had to stay each evening until 8:30. Now that they are so much bigger (up to 8.5 cm!) we have reduced that to three times per day. Regardless, each time we feed there is cleaning to do. The fish eat for an hour or two with the pumps turned off and the water calm to make it easier for them to “hunt”.  If the food sits on the bottom too long it begins to degrade, which can make the water unhealthy for the small fish, so the tanks are cleaned shortly after the fish eat.  It’s a daily cycle of feeding and cleaning... much like a human baby!

We also have to sort and measure fish so all of the individuals in each tank are approximately the same size.  This minimizes competition for food. Each week we take a series of measurements on a sub-sample of fish to keep up with how fast they are growing so that we can adjust feeding amounts and make other changes as needed. At first, all 2,000 fish were in one trough tank. Currently they have been sorted into 4 tanks and as they continue to grow they will be divided into 6 troughs. This extra space helps the fish to grow but it also increases the amount of work it takes to keep everything clean. Did I mention we clean a lot?

Measuring sturgeon

Our interns also get the chance to go in the field and help with some of our conservation projects.  Last week we went to the Conasauga River to do some surveys for Conasauga Logperch (Percina jenkinsi).  Everyone paddled kayaks down the river and snorkeled in a part of the river that we had not surveyed before.  We were assessing the habitat along this stretch of river and of course, looking for our target species. Unfortunately we didn’t find any Conasauga Logperch, but there was still a lot of aquatic wildlife to be seen so we took pictures of holiday darters, tadpoles, Mobile Logperch, turtles and insects. It was a long day but worth the effort.

Evan and Louise on the Conasauga River

River Cooter

Holiday Darter 

Musk Turtle

Later this summer we will be working at the Colvard Springs restoration site and collecting fish for the Aquarium and ongoing research projects. Stay tuned to hear more about all the work we are doing this summer at TNACI while we have all this great help! 

Start of Sturgeon Season 2012!

Well it’s that time of year again!  On May 23 Kathlina took our team of new interns down to Warm Spring National Fish Hatchery to pick up our baby sturgeon for the year, a little over 2,000 fish!  These are juvenile Lake Sturgeon (Acipenser fulvescens), a very special fish that used to be abundant in the Tennessee River.  However, due to overfishing and habitat degradation they became extirpated from Tennessee in the 1960’s.  With recent water quality improvements, TNACI has been part of a long term program dedicated to returning this fish to Tennessee waters. 

Kathlina and Carlos at Warm Springs National Fish Hatchery

Kathlina and two of our husbandry interns, Jessica and Stephen

These babies are tiny now, approximately 2-3cm (0.8-1.2 inches).  But the fish can grow to be 8 ft long and around 300 pounds!  They are also incredibly long-lived, the oldest on record being 154 years old. Your grandchildren may encounter these baby fish in the future!  Since the start of this project, around 100,000 Lake Sturgeon have been released into the Tennessee River.

The fish that we picked up today will be housed at our husbandry warehouse until they are approximately 6 months old.  In the fall we will release them into the Tennessee or Cumberland River.  Stay tuned over the summer to hear updates on our sturgeon nursery!

Spring Lake Sturgeon Sampling 2012

With 9 boats and about 40 crew people we hit the water hard in search of Lake Sturgeon during the week of March 19^th.  And wow what a week! TNACI sent five people up to assist TWRA, USFWS and UTK with the effort. We, the Tennessee River Lake Sturgeon Working Group, are sampling at various times of the year to learn more about their movement patterns and wild behavior and we were hoping to catch the sturgeon running up stream as the temperatures began to warm. 

Each morning, the Tennessee River Lake Sturgeon Working Group planned where each boat would set trot lines for the day.

We were surprised with an unusually warm spring and even our sampling week provided days in the mid 80’s! The weather made for an incredibly pleasant week on the water, unlike the rain, ice and cold that we experienced in November. But… the fishing was not nearly as successful. Approximately 80 trot lines were set out each day, all baited with carp and buffalo (the fish not the bovine) throughout the upper Tennessee drainage: Ft. Loudon Reservoir, Watts Bar, Melton Hill, Tellico, Chickamauga, Hiwassee, Douglas, Cherokee, etc. By Thursday morning we had managed to catch hundreds of catfish, 2 hellbenders, a few crappie, drum, buffalo and 4 Lake Sturgeon!

GIS Intern Evan Collins with a large Blue Catfish.

Media Intern Jacob Henson and Sustainability Coordinator Ashford Rosenberg pulling in a trot line.

Conservation Intern Sarah Candler with a small Flathead Catfish.

One of these prize catches was actually collected by a team of TWRA staff that was surveying for sauger below Watts Bar Dam. They were pretty surprised to get a Lake Sturgeon as by-catch but of course we were thrilled to take it off their hands. That individual was a 2003 year class fish and measured 41” long so was quite the catch.

Conservation Associate Kathlina Alford with a Lake Sturgeon

Later Thursday evening a team from UTK and TWRA were able to collect four more Lake Sturgeon with dip nets in an air boat! Of course we were glad they could double our sample size but we were all jealous of that experience and hopefully we can recreate that technique next spring. In shallow clear water Lake Sturgeon are easily identified and after dark they are stunned by the lights from a boat so can be scooped up with a dip net. This could prove to be a less labor intensive and less stressful sampling method for this species in the future.

Last November we were able to catch 30, but this spring the numbers were way down with the grand total only being eight. Wild Lake Sturgeon experience their annual spawning run each spring as the water warms up so we are anxious for signs that the released fish in Tennessee will begin spawning in the next few years. 

Each Lake Sturgeon that we catch is scanned for a PIT tag which has a unique identification number. This, along with missing scutes, tells us the age of the fish. If a tag is not found, we inject one under the skin. Weights, measurements and fin tissue for genetic analysis are also taken for each Lake Sturgeon we catch. Through this process we are learning more about how this fish behaves in our warm southern waters and we are able to monitor the success of the reintroduction program for this species.

Measuring a Lake Sturgeon

On a similar note, the Lake Sturgeon in Wisconsin have begun their spawning activity several weeks earlier than expected, so a team from USFWS left this week to go up and collect eggs for the Tennessee River reintroduction program this year. Each year they collect around 90,000 eggs to bring back to Warm Springs National Fish Hatchery where they are hatched and grown for about one month before they are disturbed to the various grow-out facilities, including TNACI. We are anxious to get our 2012 juveniles very soon!