Wednesday, February 20, 2013

To the Service With Love: Why One Biological Science Tech Loves Her Job

Kira collecting genetic samples from
Lake Sammamish kokanee salmon
I have a confession. I love playing in the dirt and mud; I love coming home exhausted and dirty from a hard day working in a river; I love going out and collecting information; and I love getting paid to work outside. I currently work as a Biological Science Technician for U.S. Fish and Wildlife Service (USFWS) in Lacey, WA, and I have also worked for the National Park Service (Crater Lake National Park and Biscayne National Park), several state agencies, and the private sector. My job makes me work my mind and body in ways that test my mental and physical endurance, and at the end of the day I always have something to show for it, be it information gathered, a new tracking or monitoring device placed, an invasive species removed and a native replaced, and/or a sore muscle to remind me that I worked hard today!

The field of science has allowed me to travel many places already and it could take me anywhere in the world in the future. At Biscayne, I was privileged to scuba dive on some of the most pristine coral reefs in the U.S., removing invasive lionfish (Pterois volitans and Pterois miles), monitoring algae growth on coral heads, and documenting the population dynamics of the Caribbean Spiny Lobster (Panulirus argus). At Crater Lake, I worked to assess the chemical and biological health of the lake by netting and trapping invasive fish and crayfish, collecting water samples for lab analysis, and installing equipment that will allow scientists to monitor the lake year-round.

Currently my job is to go out into the field and gather information for new and ongoing projects. The best part of my job is that I don’t have one set thing I do. Here is a short list of things I could be asked to do on any given day:

  • Work on the urban stream WRIA-8 project (collecting fish and habitat information)
  • Organize/fix/maintain field equipment
  • Strap on my waders for a river survey
  • Don my dry suit to snorkel for freshwater mussels or for a night fish survey in the lake
  • Collect fish for brood stock at a hatchery
  • Collect genetic samples,
  • Bio-sample and retrieve coded wire tags (CWT’s) from adult fish and enter information into an international database
  • Remove and relocate endangered fish
  • Work in the lab
  • Assist other departments on projects they have going on

In short, my job is to be versatile.

Kira assisting with an elk capture with state
and tribal employees  
I have a great feeling of accomplishment when I consider all the information I have gathered and all the organisms I have helped. You always hear "one person can make a difference" and sometimes that is hard to believe when you think of how big the whole picture is. My job has allowed me to experience that one person CAN make a BIG difference! I see positive changes in the world because of things I have done.

I tell everyone to follow their dreams. I am living my dream.

--Kira Mazzi, Biological Science Technician


Thursday, February 14, 2013

Determining the Age of Sculpin Using the Otolith Burnt Cross-Section Technique

Prickly sculpin
The prickly sculpin (Cottus asper) is a native and little-studied freshwater fish found throughout western Washington. Over the past few weeks, Roger Tabor, Kira Mazzi, Mike Elam, and I have been trying to unlock the information found in a small ear bone (otolith) hiding inside these fishes' heads. The otolith contains a record of a sculpin's growth, much like rings in a tree--the growth of the fish influences both the size and density of the otolith. Through our analysis of these otoliths, we hope to discover if different populations of prickly sculpin are growing faster and living with or without competition from other fish, at different elevations, and consuming different diets. To do this, we removed otoliths from roughly 200 preserved specimens of prickly sculpin and prepared them using a common aging method called the "otolith burnt cross-section technique."

The first step in preparing the otolith is breaking it as closely through the center as possible. I used my fingers to break them in half, but many people use forceps or a hard surface to crack them open. A good break will allow you to view each annulus (yearly growth ring). Next, and most importantly, is the burning procedure. Using lighters, we burned the otolith until we achieved a uniform dark brown. This turns the annuli dark brown and keeps the remainder of the otolith light, giving you distinction between years. Then we added a dab of mineral oil for clarity and had a perfectly prepared otolith to read.

Sculpin otolith

In the photo above, you can see the distinction between the dark brown annuli and the light summer growth. This otolith is from a mature 13-year-old prickly sculpin. As fish mature, they experience a change in growth rate. You can see this by the small separation of annuli in this adult. In juvenile fish, the translucent growth zones are much larger than those later in life (see center of the image).

We have finished all the aging for this study and will now move on to analyzing our data with the environmental and biological information we collected about the fish and their habitats early this year.

--Timothy Grun, Biological Science Technician


Thursday, February 7, 2013

What is an Otolith and Why Do I Care About It?

Fish otolith
An otolith (inner ear bone) can be found in any animal with a vertebra---mammals, birds, amphibians, fish, etc. Otoliths are sensitive to acceleration and gravity; these organ and bone structures tell the brain how the body is moving in relation to the surrounding environment. We are currently looking at kokanee salmon otoliths to evaluate whether hatchery-reared kokanee are helping us recover the native kokanee population in Lake Sammamish. 

Fisheries scientists have figured out that fish otoliths grow much like the rings of a tree trunk. In the summer, when growth is high, the fish lays down a lot of otolith material. In contrast, during the winter when growth is minimal, the fish lays down very little growth material, resulting in the “ring” pattern. Much like a tree, if you count the “rings” you can determine the age of the fish.

Now, bear with me on this one because what I am about to tell you is kind of hard to believe but it's true . . . .

In the hatchery, the temperature of the water the fish are reared in can be controlled. By controlling the water temperature over a short time period (usually a few weeks), a barcode-type pattern is created in the rings of the otolith. This technique is called marking and is permanent. After the fish’s death, the otolith can be extracted, shaved down, put under a microscope and read. By collecting the fish and reading the otoliths, we can tell how old the fish is, what stream its parents came from, whether the fish strayed from its natal stream. That is really, really cool! And all of this from an inner ear bone about 1-4 millimeters in length!

This is what I and other federal, state, and county biologists are doing in the field and in the lab. We are collecting kokanee from Lake Sammamish streams, spawning them, extracting the otolith, collecting biological information on the fish, and then reading the otoliths to see if marking is present. The marking will assist with the research and progression of the Lake Sammamish kokanee supplementation program. This year we saw a larger kokanee run; this is also the first year that the hatchery-reared supplementation fish were old enough to return to spawn. The information we gather from these otoliths will shed new light on the future of kokanee in Lake Sammamish and the human efforts to save this unique population.

--Kira Mazzi, Biological Science Technician


Photo credit:  WDFW Otolith Thermal Marking Lab


Friday, February 1, 2013

Lake Sammamish Kokanee Salmon Observed in 13 Streams

  Map of Lake Sammamish tributaries. Those
  in red are tributaries where kokanee have
  rarely been observed in recent years until
  2012. Those in black are the four main
  spawning tributaries.
This past year’s return of kokanee to Lake Sammamish tributaries saw several thousand spawners in the four main tributaries (Lewis, Ebright, Laughing Jacobs, and Pine Lake Creeks). In addition, kokanee spawners were unexpectedly observed in other tributaries--George Davis and Zaccuse Creeks on the east side; Issaquah, East Fork Issaquah, Tibbetts, Pickering, and Schneider Creeks in the south end; and Vasa and Idylwood Creeks on the west side of Lake Sammamish. For most of these additional creeks, spawning kokanee have been recorded in the past but have not been observed in recent years. In two of the creeks (Pickering and Schneider) kokanee do not appear to have ever been observed before 2012.

Agency staff members from King County, WDFW, and USFWS, as well as private landowners, conducted periodic surveys of these creeks in 2012. In addition to counting the live spawning fish, surveyors also collected kokanee carcasses in order to remove their otoliths (ear bones). The otoliths will be analyzed in the lab to determine if fish originated from Issaquah Creek State Hatchery or were naturally produced. Tissue samples were also taken from some of the fish to determine their genetic make-up.

This past year’s results indicate that Lake Sammamish kokanee are spawning in tributaries on all sides of the lake, underscoring the need to protect and restore as many tributaries as possible in order to sustain this native population.

   Kokanee spawning area in Schneider
   Creek. Prior to 2012, kokanee were
   not known to use this tributary.