Key-words: Pleuronectes platessa, Plaice, DSTs, Floy-T-bar
Institute: Marine Research Institute, Iceland (MRI)
Contact (author): Jon Solmundsson
E-mail of contact: firstname.lastname@example.org
Name of experiment: Migration pattern of plaice (Pleuronectes platessa) West of Iceland
Financial source: MRI
Annual cost (ECUs): IKR 1.500.000
Experiment ends: 2001
Purpose of study:
Species (Latin): Pleuronectes platessa
Common name: Plaice
Life stage: sub-adults, adults
Min size: 29 cm
Max size: 58 cm
Average size: 38 cm
Type of (primary) tag: Floy
Type of secondary tag (double tagging): DST
(Floy, Carlin, Torpeto, Stud, Microtag, Finclip, Dye,PIT, DST, Transmitting, etc.)
Site of attachment of (primary) tag: Body surface - right dorsal side
Site of attachment secondary tag (in double tagging): Body surface - right dorsal side
Method of attachment of (primary) tag: Tag gun
Method of attachment secondary tag (in double tagging): Tag gun, wire/thread
(Tag gun, syringe, surgical implant, plunger, wire/thread, etc.)
Tag release to environment: High seas, Shelf seas, Coastal seas
Tag rel location: Iceland-west, northwest
Number of tags released (mean/year, primary tag): 1800
General tag recovery rate (%/year): 25-45% after 1 year, 30-50% after 1.5 year.
Reward type: Money
Value of reward: Floy T-bar: IKR 1.000, DST: IKR 4.000
Reward currency: IKR
Short method description: A total of 8 tagging experiments at 6 locations west and northwest of Iceland. Plaice were tagged in the period between April 1997 and September 1998. A total of 4 experiments were carried out in 1997 including tagging of 2000 plaice with Floy T-Bar Anchor tags, and 4 experiments in 1998 including tagging of 1600 plaice with Floy tags and 160 plaice with both Floy tags and DST tags.
The plaice were captured by a seine net and kept in 500 L deck tanks with running seawater until tagging, 10 minutes to 2 hours later. The total length of tagged plaice was measured and the sex and maturity noted when possible. Concurrent to the tagging, measurements of length, weight, age, sex and maturity of plaice were made. All recoveries are through commercial fisheries. About 70% of recoveries include both tags and tagged fish.
The data storage tags (DST 300) were manufactured in 1998 by Star Oddi, Iceland. They are cylindrical, 13 mm in diameter, 46 mm in length, weight 1 g in water, have a memory of 8.100 measurements and were programmed to measure both depth (pressure) and temperature at specified time intervals for 6-12 months.
Tags were attached to the right dorsal side anterior to the widest part of the plaice. Two third of the DSTs were attached by inserting stainless silver wire (0.5 mm diameter) through temporarily inserted hollow needles. A silicon mat and the DST were then slipped over the wire. The wire ends were twisted together above the DST, leaving a slack of approximately 5 mm left in the wire to allow growth. Oval plastic plates were used to minimize erosion by the wire at the other side. One third of the DSTs were attached by shooting nylon double T-Bar Anchor attachments through loops at both ends on the DSTs, the tags reaching under the bones for a firm grip. A silicon mat was also fitted under those DSTs in order to protect the plaice.