Fish Tagging

Quick Links:

• What is a tagged fish? |
• What to do if you catch a tagged fish? |
• How do we tag fish? |
• Why do we tag fish? |
• What have we learned?

What is a tagged fish?

The Coastal Fisheries Division is tagging red drum, spotted seatrout, black drum, tarpon, snook, flounder, and sheepshead along the Texas coast. These fish are tagged with specially marked tags in the abdomen (stomach) area.
A bright yellow tube protrudes from the abdomen with black numbers and letters. Attached to the yellow tubing is a bright red plastic tag on the inside of the fish with identical wording and tag number.

What to do with a tagged fish?

Anglers catching fish should examine their catch for a yellow streamer (sometimes covered with algae) protruding from the fishes stomach area.

• If a fish is under or over the legal limit, the tag number on the streamer can be written down and the fish returned to the water alive.
• If the fish is kept, then the streamer and the red tag can be retained once the fish is cleaned.
• Report:
  • Name of Fisherman:
  • Address:
  • Species: Black drum or Red drum (?)
  • Tag Number: (it will begin with an F or X with 5 digit numbers following)
  • Date Caught Fish:
  • Location of Catch:
  • Total Length:
  • Weight:
• Or, the angler can report the tag to the local coastal fisheries office located in either Port Arthur, Seabrook, Palacios, Port O'Connor, Rockport, Corpus Christi, or Brownsville. The tag number can also be reported using TPWD's toll free number at 1-800-792-1112.

How do we tag fish?

Fish are placed on the measuring board and measured to the nearest millimeter. A uniquely numbered tag is pulled from the tagging board and the number recorded on the data sheet. All tags on the board are numbered in sequence from the lowest to highest number.

The fish is placed on its side and a scalpel is used to make an incision about 1/4 inch long in the abdomen area of the fish . Care is taken to only go through the flesh so no internal organs are touched. This does no harm to the fish and the incision heals in about 2-3 days.
After the tag has been inserted correctly, the fish is released back into the water with the yellow streamer laying against the side of the fish. The yellow streamer has little effect on the swimming ability of the fish.

Why do we tag fish?

These tags help fisheries managers understand more about the fish species and their populations. Texas fish tagging began along the coast in 1950, and has continued uninterrupted since then. Generally about 7% of all tagged fish are recaptured.

Since 1975 about 130,000 tags have been placed in the coastal waters of Texas. Anglers can receive a letter with information on where the fish was tagged, when it was tagged, how much it grew, and how far it moved from the tagging site. The success of the tagging program depends upon information from the angler catching the tagged fish, so it is important that all fish be checked for tags and information reported to the Coastal Fisheries Division.

What have we learned so far?

Most recaptured fishes have been caught in the same bay in which they were tagged. Overall, most fishes don't travel very far with most being captured within 12.5 miles of a release site. But, there have been a few returns from over 100 miles away. Sheepshead, interestingly, have the greatest percentage of movement out of a bay system and also travel greater distances on average than do other fishes. We have documented movement of some fishes from the bays to the Gulf during spawning seasons, cold weather events, and high freshwater inflows into the bays. Most species of fish show no discernable pattern of movement within a bay or the gulf. However, it has been shown that spotted seatrout will sometimes leave an area and one year later return exactly to the place where they were tagged. During the past 25 years we documented 5 tag returns from Mexico and Louisiana waters other than from immediately along the Texas border.

Funding Information:

Information collection, reporting and research are produced with support from the federal Sport Fish Restoration program.