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Angling for Answers to a Thorny Question Thornback Rays The Thornback Ray (Raja clavata) is one of the most common ray species found around the UK and is regularly caught by fishers and recreational anglers. Typically inhabiting continental shelf and upper slope waters from around 10 to 300 m (32 985 ft) and preferring soft substrates such as mud and sand, Thornback Rays can also be found over gravel and rock beds. It is seasonally migratory, spending the winter in deeper water and coming into shallower areas in the late spring and summer to breed. Juveniles are more likely to be found in shallower, coastal waters than adults as these areas are used as nursery grounds. The IUCN Red List classifies the species as Near Threatened and it is believed that some populations around the country have declined significantly. It is therefore important we find out as much about the species as possible if populations are to be preserved at a healthy level. Why We’re Tagging Previous studies of Thornback Rays in the southern North Sea indicate that there are localised subpopulations with limited mixing between them. Information from anglers in North Wales has revealed differences in the morphology of Thornback Rays around the Llŷn Peninsula; it appears that rays in the south are significantly thornier than rays in the north. To further investigate this difference, the Shark Trust and National Museums Liverpool have initiated a tagging programme with local anglers, the primary aim of which is to investigate whether these two morphotypes are from distinct populations with limited mixing between the two stocks. The findings of this study will have implications for the management and conservation of this species in North Wales and the Liverpool Bay area. Reward for recaptures! Anglers: If you catch a tagged Thornback Ray, please record the information listed over the page before carefully releasing the fish as close as possible to the point where it was caught. Contact the Shark Trust with this information to claim the £4 reward. Commercial fishermen: If you catch a tagged Thornback Ray, please record as much information (see over) as possible before processing the fish. Contact the Shark Trust with this information to claim the £4 reward. The reward is provided by National Museums Liverpool as part of the Ray Watch Campaign. A tagged Thornback Ray Record your tag finds here: The Shark Trust: 01752 672020 [email protected] 4 Creykes Court, The Millfields, Plymouth, PL1 3JB This project is a collaboration between the Shark Trust and National Museums Liverpool with funding from Environment Wales. Shark Trust Vs 1. 09/09. Images © Shark Trust/Marc Dando Tagging Guidelines When catch and release fishing, the welfare of the animal is the primary concern. It is important to return the fish to the water as soon as possible after tagging with the minimum of stress. This can be achieved by following a few guidelines. Be prepared - make sure everything you need to tag and release the fish is on hand. Make a note of the tag number before landing the fish. Strike early - avoid gut-hooking the fish and give it a higher chance of survival. Use circle or semi-circle hooks Cannula and tag Keep the ray in the water - when it is necessary to bring the fish onto the boat, make sure to support as much of the body as possible. Position the tag – tagging the wing close to the rear of the body cavity is most effective. Be careful not to penetrate the body cavity – if in doubt, Tag tag further into the wing. Tag at a shallow angle - orientate the tag towards the tail. Ensure it does not penetrate to other side of the wing. Twist and remove – once the barb is fully inserted, turn the cannula while removing it to ensure the tag remains in place. Photograph – if there is time, take a quick photo of the tagged animal Release as soon as possible – carefully return the ray to the water as close as possible to where it was caught. Release injured rays - if a ray is injured in any way, release it as swiftly as possible without tagging. Take care - the skin of the Thornback Ray is highly abrasive and the spines Tagging at the correct angle will easily pierce skin. Handle the ray by the body rather than the tail to avoid injuring the ray. Essential information Additional information 1. 2. 3. Tag number. Location. Date and time. Sex. Contact details of the angler. Length (nose tip to tail tip). Width (wing tip to wing tip). Posterior wing width Weight. Condition (lively or sluggish). Depth of capture and bottom ground. Shark Trust Vs 1. 09/09. Images © Shark Trust/Marc Dando