Flathead catfish radio tag (2004)study

Discussion in 'IOWA RIVERS TALK' started by onlyriverfish, Apr 17, 2007.

  1. onlyriverfish

    onlyriverfish Member

    Was researching another topic and ran across this:

    Evaluation of seasonal movements of flathead catfish in the Iowa River

    A radio-telemetry study was initiated
    in August 2004 to determine the extent and timing of flathead catfish
    movements in the Iowa River, Iowa. The study was designed to
    complement an ongoing evaluation of flathead catfish populations at 12
    sites on four Iowa rivers. Between August 2004 and June 2006, 51
    flathead catfish were radio-tagged in the Iowa River between the
    Mississippi River and the lowermost dam at Iowa City, Iowa. Fish were
    collected by electrofishing during pre-spawn (June) and post-spawn
    (August) population sampling at three sites. These sites were located 14,
    50, and 62 miles from the Mississippi River. Attempts were made to
    locate fish monthly throughout the year. Preliminary results of our study
    indicate that while some radio-tagged flathead catfish remained near
    their original tagging locations, others made long distance movements
    associated with overwintering and spawning. Although all fish were
    radio-tagged in the Iowa River, five fish were found in a tributary, the
    English River, and seven were located in the Mississippi River. These
    fish were up to 75 miles from their original tagging locations.
    Additional tagging and tracking of flathead catfish will help us to further
    define the extent and timing of their seasonal movements
  2. Ahquabi_Master

    Ahquabi_Master New Member

    WDM Iowa
    Great info, thanks for sharing!

  3. jdstraka

    jdstraka Well-Known Member Supporting Member

    Council Bluffs, Iowa
    That's Some More Good Info James, Reps to You My Friend.J.D.:smile2:
  4. onlyriverfish

    onlyriverfish Member

    The last paragraph is interesting.


    Conservation Department fisheries management biologists followed channel and blue catfish for a year by surgically implanting transmitters in them. The fish were captured, implanted and released in Pony Express Lake near St. Joseph, then followed by biologists with equipment to receive signals from the transmitters. The object was to compare seasonal and daily movements of the two species of catfish.
    Biologists found both species of catfish are most active from sunset to sunrise. This confirms the knowledge of many catfish anglers who restrict their fishing activity to night time hours. Wise anglers also fish near standing and downed timber-biologists found channel catfish near snags 73 percent of the time. During the study, biologists most often found channel catfish in shallower water, information anglers can use to their advantage.
    "Blue cats are open water fish," says the Conservation Department's Steve Fischer. "Although our information showed blue cats were found with structure about 50 percent of the time, these fish were still offshore. The high percentage of flooded timber in Pony Express may have been an influence. Even though these fish are offshore, they swim along the thermocline because no oxygen is available below 10 to 12 feet during the summer."
    The study also showed seasonal differences in the locations of blue cats and channel cats. Channel catfish used most of the lake during spring, tended to use the shallower, southern arms of the lake in summer and used the middle and the southeastern arm of the lake during fall and winter. Blue catfish also were spread across the lake in spring, but used the western arm and mid-impoundment areas during the summer. They moved to deeper areas of the lake during fall.
    Most anglers fish during the summer months and should look for channel catfish in the shallower arms of an impoundment and blue catfish in mid-impoundment areas. Anglers who cast a line in fall might look for channel cats in southern and mid-impoundment waters and blues in deep waters near the dam. Bank anglers will have their best luck catching blue cats in spring, when they will find them inshore more often.
    Some anglers are aware, through experience, that fishing for catfish is often best after heavy rains pour into impoundments. But researchers in the Conservation Department study found only two of the marked fish moved to inflows following a rain; the others remained at the confluence of two large lake arms.
    - jim auckley -