8th international charr symposium c&r

Arctic Charr fishery management Catch and release in Eyjafjarðará, Iceland

Erlendur Steinar Friðriksson

Elli Steinar

Based on Magister Scientiarum degree thesis in Natural Resource Sciences

2008-2014By Erlendur Steinar Friðriksson

SupervisorsPhD Kristinn Pétur MagnússonGuðmundur Kristján Óskarsson

School of Business and Science, Faculty of Natural Resource Sciences

University of Akureyri

8TH INTERNATIONAL CHARR SYMPOSIUM14 -18 JUNE 2015

TROMSØ, NORWAY

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Bleikja (Salvelinus alpinus)

15.6.2015ElliSteinar@gmail.com

• Arctic Charr stocks declining• Increasing fishing effort• Fishing numbers going down• Collapse in Eyjafjarðará

(Guðni, 2014a; Statistics Norway, 2014)

Why and what to do?

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• Find out why the stocks af charr are declining• Remove fishing mortality out of the equation

• The goal of catch and release (C&R) as fishery management method is to reduce mortality due to fishing by releasing cought fish, alive back to the water

• The method has been applied for many years with a decent performance in a variety of sport fish species, including salmon and trout

• 2008 - Fishing management changed to C&R – tributaries closed for fishing

• Little documentation, however, was found for C&R beeing used for the charr fishery management

• So there was also a need for research on the effects of C&R

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Recreational fishing - 30% of world total catch

Catch & release - 30% of total angling

„Can catch & release (C&R) be considered as a feasible fishery management policy of charr in Eyjafjarðará?„

Use the method af tag and recapture

Catch= landed + releasedCommercial v.s. Recreational - Different approach

Explore:• Mortality• Recapture– By river, angling method, angler, fish size, time of season

• Data also used to estimate:– Migration, growth, mortality and stocksize

• Flyfishing only

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The area..

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30-40% of all searun Charr in Iceland ?

(Jørgensen & Johnsen, 2013)

• 1504 tagged 184 cought in net

• Charr 1194 / 830• Salmon 64 / 1• Trout 230 / 87• (Total / Eyjafjarðará)

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The riverEyjafjarðará

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Unstable systemLarge catchment areaRunoff, glacier and springfedCold, 0-12°CNot fertile <25 S/cmAverage run sep-apr 25 m3/sFloods, mai-juli 100 m3/sMelting snow from heavy snow areaPassable for fish 60 kmTributaries passable for fish 24 km, some very good for spawning and nursing grounds

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Anchor tag, Floy tag or T-bar anchor tags. Each tag has an ID-number, => each tagged fish has an ID Directorate of Fisheries allocates themAll icelandic fish-tags: IS-xxxxxx

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• Short term mortality (48h - cage expirement)? 0%• Recapture? 9,1%• Difference in recapture by;

– Angling method? Not confirmed– Angler? Not confirmed– Fish length? Not confirmed– Time of year? Not confirmed

• All recaptures in same river as tagged or at sea• 83 recaptured charr in Eyjafjarðará;

37, 29, 13, 4 in year 0,1,2,3 respectively• Average growth: 4 cm/year

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Results

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„Can catch & release (C&R) be considered as a feasible fishery management policy of charr in Eyjafjarðará?„

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YES

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Living proof..

Charr ID: IS-93006

Tagged april 2008 – 41 cm

Recaptured 2011 – 65 cm

ReRecaptured 2014 – 71 cm

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Disscussion and further research

• 9,1% recapture?– Supports C&R fishery management – Higher survival? - Study further with radiotagges– Recalculate catch („correct“ the numbers)

• Short term mortality 0%– Supports C&R fishery management

• Difference in recapture by:– Angling method, angler, fish length, time of year

• Fishing rate and stock size?– Further tagging and installation af a fish counter

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Thank you

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Results - Eyjafjarðará

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P=0,137