Plastic tipped dart tags

Hallprint's range of plastic tipped dart tags are designed to provide a diversity of high quality options for researchers embarking on a finfish tagging program.

As with the T-bar anchor tags, dart tags are normally applied in such a way that the barb locks behind about the second or third leading dorsal fin ray. In elasmobranchs the barb is lodged in a cartilagenous section of the fish, usually in the body of the fish adjacent to the dorsal fin in sharks or in the "wings" of rays and skates.

The smallest diameter dart tag, the PDX, is applied with an approx. 2.4 mm outside diameter applicator needle. It is suited to finfish species between about 20 cm and 35 cm. These tags are popular for small fish likely to undergo fast growth rates such as juvenile tuna.

The small dart tag range (PDS, PDL and PDW) is applied with an approx. 3.3 mm outside diameter applicator needle. This range is suited to fish across a wide range of sizes, with the PDS and PDW tag suitable for fish from about 35 cm up to about 55 cm and the increasingly popular "dogleg barb" PDL tag which is suited for fish up to about 80 cm. These tags are very popular with recreational fish tagging programs for a wide variety of species due to the ease of use and lower unit cost of applicators compared to T-bar tags.

Large dart tags (PDA) are applied with an approx. 4.0 mm outside diameter needle and are proven performers with finfish and sharks from about 60 cm including tuna, barramundi, snoek, tarpon and spanish (king) mackerel to name a few.

Hallprint is continually working closely with researchers to further improve the range of options available in terms of dart tag design.

Application methods for plastic tipped dart tags (PD range)

This information is for guidance to the first-time user. Procedures will vary, depending on the species to be tagged, size of tag, fish and field conditions.

Always practice tagging and check correct location of the dart head etc. before engaging in actual tagging operations.

A. Care and storage of tags

Tags should not be subjected to heat much above normal ambient temperatures.

Leave tags in the original packaging until all tags are used. Then keep the packing for considerate disposal on-shore.

Keep the unpacked magazine flat or upright with the barbs uppermost at all times. If not, they will all fall on the deck.

In use, the magazine can usefully be taped to a handy surface or placed in a simple rack.

B. Applicator needles

Fix in a suitable handle or pole of timber/plastic with a wrist strap so that it floats when you drop it in the water.

A screw-chuck type screwdriver handle is useful when using multiple pre-loaded applicators.

C. Care of applicators

The tip only of the applicator should be kept sharp to a V point and preferably spiked on a cork etc. when not in use to prevent damage or injury.

IMPORTANT: When sharpening the applicator take care not to create a cutting edge on the rear of the sliced off part.

After use, wash in clean water and dry. Unless an unavoidable situation of extreme emergency, do not use applicator as a bottle-opener.

D. Loading of applicator

It is a good idea to keep a pre-loaded one, with the tags, your measure, notes and a pen, in a handy place so that the fish does not have to wait too long for you to find them.

Load tag with only the barb exposed at the pointed end.

If the tag does not slide easily out of applicator then it is either choked with debris or bent. This must be rectified otherwise you will probably get a hung-up tag.

Loosely fitting tags can be secured by making a slight bend in the printed marker – do not alter the applicator.

E. Insertion of tags into fish

Minimize trauma and damage to fish. Keep it under control. If it has noticeably suffered by capture do not waste time tagging it. Release gently, or keep if legal and you intend to eat.

Anglers and fisherman should carefully observe the procedures for recording of fish details etc. issued by the tagging programme organisers and ensure that these are reported promptly.

1. Remove a scale with the applicator point just below the base of a dorsal spine, usually the second to fourth depending on the species. Avoid placing the tag deeply into muscle.

2. Hold needle with exposed tag barb in line with fish, with barb facing head. Turn needle so barb is on the fish side.

3. Start inserting the needle at a shallow angle under the scales until you feel it pierce the skin, then raise the needle to an angle of 45 degrees so making clearance for the barb.

4. When barb is below skin, return to a shallow angle and insert until the barb is just beyond the fin spine. A slight “click” can be felt as the barb slides over the bone and locks behind it.

5. Pause for a second then withdraw the needle smoothly. A slight tug will help “set” the tag. Particularly with small tags/small fish do not place any undue strain on either tag or fish after insertion.

6. The fish should then be gently released. Fish showing undue stress, damage or inability to swim should not be released if tagged.

Plastic tipped dart tag applicator needles

Hallprint's plastic tipped dart tag applicators are manufactured from the highest quality industrial stainless steel available. Three differing diameters are available. The smallest diameter applicator is for use on the "extra small" sized dart tags only (type PDX). The next largest diameter applicator is designed for the three "small" diameter dart tags ie the PDS, PDL and PDW. The largest diameter applicator is designed for the large plastic tipped dart tags (PDA) only.

These applicators can either be used alone or attached to a dowell handle. A "chuck" style handle for interchangeable screwdrivers available from most hardware stores is handy for applying pre-loaded applicators on high volume tagging operations.