How to Tag Dolphinfish

The value, integrity, and credibility of this research program depend on the recording of accurate field data.  The quality of the information that you provide will decide the value of the recovery of your tagged fish.

Click here to download the document below that details everything you need to know to properly tag and release healthy dolphinfish.


Loading Scientific Tags into the Applicator

Implanting the Tag

Place the tag in the back musculature from 1/4 to ½ the fish’s body length behind its head. The applicator should be inserted at a 45o angle toward the head of the fish with the plastic tag bard facing down toward the fish and its trailing tip pointing toward the fish’s tail. Insert the applicator point deep enough to allow the barb to pass between the spines that radiate off the top of the backbone at the midline of the back. This permits the barb to lock around one of the spines ensuring that the tag will not be shed. Take not to hit the fish’s spine, which will cause paralysis. Typically ¾ to 1 ½ inches of the tag head should be buried in the fish. As a final step give a light tug on the tag to make sure that it is securely implanted.

Tagging Large Dolphinfish

Many anglers who are currently tagging their small dolphin for this research program would occasionally like to be able to tag big dolphin safely. Fishermen who regularly fish offshore occasionally encounter days when their fish box is not large enough for all of the big dolphin they’re catching, or they are tired of cleaning fish and do not want to bring any fish to the dock. At these times participating taggers would like to have a little longer tag applicator to tag the fish in the water. Any angler who has fished offshore for any length of time has learned that a 36-inch dolphin can slap the fool out of you when trying to handle it.

There is a simple solution that allows you to instantly convert a handheld applicator into one for use on fish beside the boat and then return to using it as a handheld. It only requires a piece of PVC pipe, a plastic end cap, one bolt, a short length of duct tape and just a dab of silicone. An additional plus is that it will not rust or corrode in saltwater.

Materials Needed

    • Power drill with 1/8th bit (not shown)
    • 1 – small tube of silicone caulk (A)
    • 1 – 3 to 4ft ¾ in. PVC schedule 40 pipe (B)
    • 1 – plastic end cap to fit ¾ in. pipe (not shown)
    • 1 – standard dolphin tag applicator (C )
    • 1 – 3 in. length duct tape (D)
    • 1 – 1/8th in. diameter X 1 ¼ in. stainless steel bolts with nut (E)
    • 1 – 7 in. long wire or piece of plastic 1/16th in. diameter. (F)Construction is simple and quick. Step 1. Drill a 1/8th in. hole through the center of the pipe 4 ½ inches from one end. Insert the bolt and secure it with the nut. A dab of silicone caulk on the bolt threads will keep the nut from backing loose in the future. Place a small amount of silicone on the inside wall of the end cap for an adhesive and slip it onto the other end of the pipe.Step 2. Apply a moderate coating of silicone to the wire or plastic rod leaving 1 in. clean to hold it by. Slowly insert the wire into the applicator needle where the tag goes. Spin the wire inside the needle to ensure that you get a thin coating on the inside of the needle. This coating will provide a little friction to the tag to keep it from falling out when the applicator is pointed downward during tagging. Caution, too much silicone in the needle will prevent the tag from being fully inserted into the needle.   Step 3. Wrap a single layer of duct tape around the top of the wooden handle opposite from the needle. The tape should provide enough additional friction to hold the applicator up inside the pipe while tagging the fish. If the applicator is still loose in the pipe with one layer of tape, add a second layer of tape.Step 4. Slide the applicator into the pipe until it rests firmly against the bolt. The needle should extend 2 ½ in. beyond the pipe. You now have an in-water tagging stick.Tagging fish in the water.To properly tag dolphin in the water beside the boat requires patience and the philosophy that if the fish gets off before being tagged, it is no big deal. As soon as the fish comes to the boat, you should determine where the fish is hooked. If it is hooked in an eye, the gills or stomach, it should not be tagged. The absolute worst thing is to jab wildly at a thrashing fish.  This commonly results in a tag placement that is fatal to the fish. The boat should continue idling ahead to force the fish to swim beside the boat with its head toward the bow. The person doing the tagging should position himself along the gunwale between the person holding the leader and the stern. This provides the most open access to the fish. Wait for the fish to calm down to where it swims on its side in a stable position. Quickly position the applicator so that the needle is pointing to the place where you want to implant the tag holding the needle point about 2 to 3 inches above the fish. When the fish is not moving, use a short, quick jab to implant the tag. The tag should be inserted in the dorsal (back) muscle mid-way between the spine and the base of the dorsal fin from ¼ to ½ the fish’s body length back behind the head.
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