Wednesday, March 28, 2012

Time to take a few fish?

I recieved this from a friend regarding the Driftless of Wisconsin, and sounds like we can help

Gill Lice in the Driftless

All Concerned,

I wanted to bring this up as I'm sure a lot of the folks on here enjoy fishing for trout in SW Wisconsin. Unfortunately, Gill Lice is becoming more prevalent in the driftless area and is taking its toll on the brook trout as it directly affects the respiration, oxygen and carbon dioxide process. Below is a response from Susan Marcquenski, a Fish Health Specialist, to a gentlemen’s email that lives in SW Wisconsin.

I am the Department's fish health specialist and Mike Staggs asked me to respond to your e-mail regarding gill lice affecting brook trout in Wisconsin streams.

You are right, gill lice (a parasitic copepod called Salmincola edwarsii) can cause significant physical trauma to the gill filaments, causing deformities which affect respiration and the efficient uptake of oxygen and the release of carbon dioxide, ammonia and other metabolites. Fish that are heavily infected cannot obtain sufficient oxygen when they are exercised, such as when they are caught by angling.
Gill lice have a direct life cycle- when the egg sacs release nauplii, they immediately molt and become the first copepodid (larval) stage and they have about 24 hours in which to find a new host and anchor onto the gills and continue their development. After several molts, the copepods reach maturity and remain permanently anchored in the gill tissue. This is a significant stress especially when more than one parasite is attached to a gill arch.
In streams with dense brook trout populations, the success rate for the larvae to attach to gills increases due to the greater chance of contacting a fish within the 24 hour "post hatch" period. Streams with faster water flow (velocity) can make it harder for the larvae to successfully attach. So fish density and water velocity are two factors that affect the prevalence and intensity of infection by Salmincola edwardsii in a stream. A third factor that may play a greater role in the future is temperature trends. Gill lice are invertebrates and therefore their development is proportional to the water temperature of the stream. If water temperatures increase, the parasites will develop to maturity faster and will then be able to reproduce one or more extra "generations" each year. Because the copepods remain on the fish, the affect of more generations of parasites is cumulative and we may see far higher numbers of gill lice on individual fish in the future.
So rather than not fish the streams where gill lice are present, I would encourage people to fish and take fish home (reduce the density of the fish) as long as the fishing regulations allow this. Anything that can be done to keep water moving (faster velocity) may also help reduce the probability of larvae to successfully attach to fish.
It would take a special study to do this, but it would be interesting to compare the prevalence (percent of fish infected) and the intensity of infection (number of gill lice per fish) of gill lice in brook trout streams that have high densities with those that have low densities; those with faster velocity vs those with slower; and slightly warmer vs colder streams.
Thank you for taking the time to share your concern with us, and please let me know if you have any questions.
Susan V. Marcquenski
Fish Health Specialist
WI Department of Natural Resources
Box 7921
101 S. Webster St.
Madison WI 53707


  1. I think I want to Find Out More about these fishes. Sound like they are going to cause a lot of disturbance to the natives. Is it safe to say that we can harvest these species daily? I think I am going to be up to the challenge.

  2. This is the second game to take place outside of the Mushroom Kingdom and also
    the first game chronologically that the Mario Bros.
    (2004): Bringing politics back in: examining the link between globalization and democratization; journal of International Political Economy 11(2), pp.
    The Iranian system gives supreme powers to a council of Islamic
    elders called 'vali-e-faqih'.

    Feel free to surf to my weblog :: clash of clans hack no survey 2013

  3. These two titans are an inspiration to anyone who has a dream and intends
    to overcome whatever challenges present themselves
    along the way. Morgan brought mischievous charm and heart to the Wizard.
    com, they believe Dorothy represents Theodore Roosevelt because Dor-o-thy are the
    reverse of the syllables The-o-dore.

    My blog wizard101 cheats

  4. Journaling allows people reconnect with their Inner Wizard
    to clarify their thoughts and feelings, and gain self-awareness.

    ' A list will appear, and then double click the library you want to access, and then double-click the file or folder you want to access. com to learn all you need to know about the 'Wizard of Oz' hanging.

    My web-site ... wizard101 cheats :: ::

  5. You may be called to be a healer with herbs, you may be called to making food using more
    regional ingredients. You just need to log on to the router (like you just
    did) and copy it down again. You can find yourself fighting
    dragons to save the Wizards Castle or you can fly
    around on your broomstick to capture spell books that have
    run away.

    My site; Wizard101 Cheat Tool Generator Crown 2012