Thursday, April 19, 2012

Field Notes: Week 2 on the Conasauga River

After a week of some cooler weather, TNACI and CFI returned to the Conasauga River for two more days of field work.  We spent the first day catching more Conasauga Logperch and the second day  releasing juveniles at various locations in the Conasauga River. 

On April 12 we worked a 3 mile stretch upstream of the site sampled on April 5.  While the procedures for this week were the same as last week, the conditions were very different.  The water temperature was 50°F when we arrived in the morning; cold enough that some members of the team wore dry suits.  The rest of us wore 7 mm wet suits and everyone wore gloves and hoods to stay as warm as possible.
Dr. Anna George in a dry suit.
Despite the chilly conditions, it was another successful day on the river.  We were able to get nine more fin clips from Percina jenkinsi.  We also caught a few Mobile Logperch (P. kathae) who were also photographed and fin clipped.

Photographing and fin clipping Logperch
In the field it can sometimes be challenging to distinguish between Conasauga Logperch and Mobile Logperch initially.  However, upon closer observation there are some differences in the two species that make them distinguishable from one another.  One of the most distinguishing features is the red or orange color in the first dorsal fin of the Mobile Logperch.  The markings on the two species are different as well.  While both have bars, or “dorsal saddles,” down their body, the markings on the Mobile Logperch are a bit duller.  Conasauga Logperch have more defined stripes, a "teardrop" marking under the eye, and no color on the dorsal fin.  

Conasauga Logperch (Percina jenkinsi)
Mobile Logperch (Percina kathae)

While we were on the hunt for the very special Conasauga Logperch we were fortunate enough to see a few more aquatic animals that call the Conasauga home.

Coosa Darter
Hogsucker with a Lamprey attached

Speckled Darter
On April 13 we returned to release juvenile Conasauga logperch that had been hatched at CFI and reared either at their facilities or at TNACI.  We split up into two groups to cover almost 7 miles of river and release around 200 fish!

Releasing captive-bred fish into the wild is much more complicated than just dumping a bag full of fish into a river.  It takes scientific study and planning. During the previous two trips on the Conasauga, we took GPS coordinates of riffles so that we could designate release sites.  We also had four groups of juveniles (distinguished by the color and placement of their fluorescent elastomer tags).  Individuals from each group were designated to a release site.

Tagged juvenile Conasauga Logperch.
The water in which the fish were transported was a bit warmer than the river water, so the first step prior to release was to get the fish acclimated to the water temperature of their new home.  To begin the acclimation process, we placed the closed bags directly in the river.    

Pat from CFI acclimating fish.
After a little time getting used to the temperature, some water from the Conasauga River was placed directly into the bag to continue the acclimation process.  With our plans in hand and the fish acclimated, we loaded the bags into our boats and set off down the river to release these young fish into their new environment.
One of the release sites.

Evan getting ready to release Conasauga Logperch.
After being released, some individuals did not swim away immediately, giving us one more chance to photograph them before we left. 

We will be back on the Conasaua River soon to release the rest of this year's juveniles.  We will then continue monitoring the population of wild Conasauga Logperch, and we hope to recapture some of these individuals in the future. 

Monday, April 16, 2012

Field Notes: Week 1 on the Conasauga River

One of TNACI’s conservation projects is propagation and augmentation of Conasauga Logperch (Percina jenkinsi).   We, along with Conservation Fisheries, Incorporated (CFI), have been working with this endangered fish for the last couple of years.  One aspect of this project is studying the genetics of the Conasauga Logperch.  We want to make sure that we are maintaining the naturally high genetic diversity of the population when we reintroduce captive bred logperch into the Conasauga River.  In order for CFI to get broodstock to hatch juveniles, and for us to get fin clips for genetic sequencing, each year we work on the river to catch the fish.  They are usually found in riffles and fast moving water, so in the past we have snorkeled at bridges along the river, working in nearby habitat that looks favorable for Conasauga Logperch.  This year, we decided to try something different.  To cover more habitat in less time, we took boats in various shapes and forms down the river, stopping in the riffles to look for fish.  On April 5th, Pat and Crystal from CFI joined us in their canoe, Ashford and Evan took kayaks, while Anna and Dave took paddle boards.

It was a great day to be on the water.  We were in for a treat as the buffalo were running upstream to spawn.  Many of them had scars or lampreys attached.  We saw tens of thousands of these fish!

School of buffalo

Catching logperch can be quite challenging as they're pretty smart.  The best way to catch them is to snorkel until a fish is spotted, then herd it into a small dip net. These fish tend to be found in fast moving water over coarse substrate like cobble and gravel.  This can make the task of catching the logperch challenging. Many times the fish would begin to swim upstream, and they are much faster at it than we are.  
Herding a Conasauga Logperch
However, we were able to catch seven of these imperiled fish.

Crystal from CFI after catching a Conasauga Logperch
Percina jenkinsi
We weren’t keeping any of the fish this trip. Once we caught a Conasauga Logperch we took its photograph and a small piece of the anal fin for genetic testing. It was then released back into the river.

We will be back out there on April 12th and 13th, looking for more of these very special fish and to release juveniles. 

Wednesday, April 4, 2012

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 19th.  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!