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Cooperative Extension Service R Glenn Thomas Ph D Associate Professor Fisheries School of Renewable Natural Resources Room 227 RNR Bldg LSU Phone 225 578 0771 Fax 225 578 4227 Baton Rouge LA 70803 gthomas agctr lsu edu Web site www lsuagcenter com Research and Extension Programs Agriculture Economic Community Development Environment Natural Resources Families Nutrition Health 4 H Youth Programs May 1 2007 Volume 31 No 5 Spotted Seatrout Telemetry Project Begins on Calcasieu Lake Researchers from Louisiana State University LSU are teaming up with the Louisiana Department of Wildlife and Fisheries LDWF for a study on the movement patterns of spotted seatrout in Calcasieu Lake The two year study will begin May 2007 and roughly 120 adult spotted seatrout will be outfitted with acoustic transmitters or pingers All fish with acoustic transmitters will be marked with a yellow dart tag below the dorsal fin that states LSU REWARD PLEASE RELEASE Fishermen who catch fish with this tag should release the fish alive and call 1 800 891 3977 to report the tag number and where and when the fish was caught It is vital that these fish be released alive so that researchers can continue to collect movement data The tag number is given at both ends of the tag An example of an LSU tag number is LT166001 Research buoy Fishermen who provide recapture information and release the tagged fish alive will receive a Louisiana Sport Fish Tagging Program hat and T shirt and be entered in an annual drawing for GPS units and cash prizes of up to 500 An array of receivers also will be placed throughout Calcasieu Lake to listen for fish with transmitters Receivers will be placed on channel markers in the Calcasieu Ship Channel and on buoys in the main body of the lake Boaters and fishermen should not tamper with or moor to the buoys The Coastal Conservation Association CCA and LDWF also tag fish in Calcasieu Lake These dart tags are placed in the same location on the fish but have different text on them RESEARCH GOALS A better understanding of movement and seasonal migration patterns of spotted seatrout is critical for effective management of this species The study will address questions such as Do fish leave Calcasieu Lake and move offshore If so do they return and when Where do fish spawn and overwinter Do migration patterns differ by size and sex In addition to exploring seasonal migration patterns this study will examine how fish use different habitat types and change their behavior when their environment changes The degree to which and how spotted seatrout use natural and artificial oyster reefs also will be evaluated Artificial reefs are often assumed to act as beneficial habitat for spotted seatrout but few studies have compared habitat use on natural and artificial reefs to confirm this notion Some questions that will be addressed about behavior include Do fish move to deeper waters or offshore for refuge during storms fronts or when water temperatures peak in the Tagged fish summer How do fish move in response to seasonal changes in temperature and salinity Is there more feeding activity under conditions of increased tidal flow and decreased turbidity Does fish movement closely follow prey distributions such as shrimp And are large old females or sows more solitary than smaller females and males To answer of all of these questions researchers will use acoustic telemetry This involves surgically implanting fish with an acoustic transmitter below the stomach that sends out a sound ping When a fish carrying a transmitter passes within the detection range of a receiver 200 to 300 yards the receiver records the fish identification number and date and time of the detection While this study of movement patterns is focused only on Calcasieu Lake a system renowned for its large trophy trout and also a hot topic because of the recent change to more stringent fishing regulations this particular project is part of a larger state wide study aimed at better understanding stock structure and characteristics seasonal migration and habitat use of spotted seatrout A volunteer recreational angler tagging program CCA LDWF is one part of this larger study Data from this tagging program provides important scientific information collected from recreational anglers on movements and stock characteristics stock size mortality and growth Fishermen wanting to participate in the tagging program should call 1 800 891 3977 or email fishtags wlf louisiana gov for more information Tagged Fish in Calcasieu Lake Researchers Tag Color LSU Yellow Tag Text LSU REWARD PLEASE RELEASE LDWF INFORMATION REWARD LOTTERY or INFORMATION REWARD Green or White CCA Yellow or Red REWARD CONTACT NMFS Tags may foul with algae and need to be scraped to be read Release all fish alive Call 800 891 3977 with tag number date time latitude longitude 800 891 3977 with tag number date location length in centimeters Reward T Shirt hat drawing entry 800 567 2182 2 50 T Shirt or hat Identification of Billfish Species Under Revision New genetic studies of the world s billfishes are demonstrating just how little is known about these fish This work has also found that some previous classifications may have been incorrect with serious implications for stock management Last year two studies were published on the genetics of billfish One looked at the relationships of all the billfish species Collette and others and another investigated the presence of the roundscale spearfish on our side of the Atlantic Shivji and others It was previously believed that billfish can be broken into two families Xiphidae with only one species the swordfish and Istiophoridae including the sailfish genus Istiophorus the genus of large marlins Makaira and the genus Tetrapturus which includes the spearfishes and the white and striped marlins While the swordfish clearly belonged in his own group some researchers thought that the Atlantic and Indo Pacific populations of both sailfishes and blue marlins included separate species that white and striped marlin were actually one species and no one was really sure how many spearfish species existed This uncertainty makes management of these stocks an equally uncertain process The Collette study used mitochondrial and nuclear gene sequencing to demonstrate that even some of the classifications that have been widely accepted are probably incorrect The researchers found that there are likely five genera within the family Istiphoridae and proposed revision


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