Assessment of effects of fish farm effluents on freshwater systems

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1 Is freshwater aquaculture in cages a future way of farming Arctic charr? Lars-Ove Eriksson Department of Wildlife, Fish, and Environmental studies Swedish University of Agricultural Sciences SE Umeå, Sweden Iceland

2 Is freshwater aquaculture in cages a future way of farming Arctic charr? No! Freshwaters should be maintained at their natural state-no nutritional load! Arctic charr don t grow well in cages and utilizes food badly since they are slow feeders! Yes, conditionally! Some freshwaters have become culturally oligotropicated and unproductive! Adopted feeding techniques can be developed!

3 Assessment of effects of fish farm effluents on freshwater systems Inflow Water Nutrients Nutrients from feed removal by produced fish Outflow

4 Nutrition loads from fish farms Today = 5-6 kg P per ton produced fish kg N - - P is the production limiting nutrient in freshwater = is the important nutrient causing eutropication effects

5 Feed effiency (kilogram of feed per kilogram of wet weight gain) at 11 different farms From Alanärä 1990a

6 Culturally ll degraded d d waters Many large Scandinavian rivers have been developed d for hydroelectric power production Large lakes are used as seasonal reservoirs Water level variation 6-30m Gets with time depleted of nutrients (C,P,N)

7 What is with dams in regulated rivers? The regulation will initially lead to an increased nutritional state of the water with respect to carbon(c), phosporus(p) and nitrogen(n) However, the effect will dimnish i within years and the regulated lake will become increasingly i nutritionally depleted d Within15-25 years, the nutrient levels will reach levels considerably lower than was the case before the regulation

9 Change of Phosporous levels following impundment regulation (free from Stockner et al 2000) P (mg/l) Oligotrophic Ultraoligotrophic pre reg reg 5 y reg 10 yreg 15 y reg 20 y East West North Time

10 The use of regulated rivers as sites for charr farming Impounded lakes of regulated rivers are often (will become) depleted d of nutrients t Production o of natural a fish populations o are below pre-regulation regulation levels Habitats for spawning are often depleted Positive ecosystem and socioeconomic effects by farm activities that add N,P, and carbon?

11 Charr farms in regulated rivers- restoring ecosystems The space of nutrient enrichment to balance pre-regulation regulation levels l in the 5 biggest Swedish rivers corresponds to an annual production of tons Limited risk for genetic interactions with natural charr populations Suitable techniques are available

Estimated theoretical farm fish production to restore pre-regulatory regulatory nutrition conditions in Malgomaj lake.three different calibrations of the Vollenweider-model (A.

13 Estimated theoretical farm fish production to restore pre-regulatory regulatory nutrition conditions in Malgomaj lake.three different calibrations of the Vollenweider-model (A.Alanärä) Calibration OECD (1982) Complete database OECD (1982) Nordisk kalibrering Johansson & Nordvarg (2002) Theoretically possible production to reach pre- regulation levels 2200 tonnes 2700 tonnes 5000 tonnes Malgomaj:Surface 101km2 Average depth 40,3 m Volume m3 Discharge m3/yr Pre-regulation regulation P-levels 6.9 mg/l 45y post-regulation P-levels (2006) 3 mg/l Alanärä 2007

14 What will happen with the natural production of fish in Malgomaj? Present production( P= 3 μg / l): 1.4 kg per ha/year A production of 2000 tons annually of Arctic charr in net-pens will increase the P-level to around 6 μg / l As a result, the production of wild fish will increase to about 7.2 kg per ha/year The state and natural fish production of the impounded lake has been restored to pre- regulation levels

15 Charr farming Restoring impounded lakes Robin Hood-principle; Recirculation of nutrients from the Baltic Sea to nutritionally t depleted eted lakes in regulated rivers Cleansing + Fish feed production Removal of nutrients (N, P) by fisheries (7500 tonnes N, 1000 tonnes P)

16 Effects of the selective breeding program

17 Effects of selective breeeding on growth of Actic charr Weight (g) Age (years)

18 So, what do we have A species (Arctic charr), uniquely suited to be produced d only in the freshwaters of the Northern periphery Developed, domesticated strains (Swe, Isl) Very good biological knowledge Promising new developments in biotechnology

19 Ready to go!

20 Thank you!

22 Thank You for Your Attention! Department for Wildlife, Fish, and Environmental studies

23 The use of regulated rivers as sites for charr farming Lakes of regulated rivers are often depleted d of nutrients t Production o of natural a fish populations o are below pre-regulation regulation levels Habitats for spawning are often depleted Positive ecosystem and socioeconomic effects by farm activities

24 Farming sites in regulated rivers Suitable impoundments are normally situated in the upper parts of the rivers Large water-bodies and discharges means huge capacity Damming has caused oligotrophication and are sincs for nutrients Nutrient contribution from i.e. farming of charr might contribute to restore nutritional levels and improve natural production of fish

25 Farming sites in regulated rivers Suitable impoundments are normally situated in the upper parts of the rivers-good temperature regimes Large water-bodies and discharges means huge capacity Damming has caused oligotrophication and are sincs for nutrients Nutrient contribution from i.e. farming of charr might contribute to restore nutritional levels, improve autoctonous as well as alloctonous production, and improve natural production of fish

26 The use of regulated rivers as sites for charr farming Impounded lakes of regulated rivers are often (will become) depleted d of nutrients t Production o of natural a fish populations o are below pre-regulation regulation levels Habitats for spawning are often depleted Positive ecosystem and socioeconomic effects by farm activities that add N,P, and carbon?

27 Farming of Arctic charr in Sweden: what needs to be done next? Improved access to selected offspring for farmers Research to improve egg quality Improved methods for selective breeding Assessment and Evaluation of further waterbodies with respect to suitability and ecological effects of farming (i.e. genetic effects of escapees on natural populations) Market development

28 Present state of charr farming in Sweden 2008 = around 800 tonnes delivered 2009 = around 1500 tonnes anticipated (mainly) New farming licenses allowed to farm 5000 tonnes/year Further licence applications anticipated Support to the Arctic charr selective breeding programme by the Swedish government

29 Arctic Superior The Arctic charr breding program Starting in 1982 by population comparisons (growth, maturation aso) Selective breeding program starting in 1985

30 Family selection Eggkept separately by family Suitable parents are stripped Until tilthe fish can be Freeze branded Families are further kept separately in the hatchery After Nilsson

31 Change of Phosporous levels following impundment regulation (free from Stockner et al 2000) P (mg/l) pre reg reg 5 y reg 10 yreg 15 y reg 20 y East West North Time

Conference in Iceland 2006 (Egilstadir) How to make charr farming take off? Offensive promotion of the possibillities

Triple helix in aquaculture industry in northern Sweden Leif Sollén SOLLÉN UTVECKLING AB SE-901 47 Umeå, Sweden Conference in Iceland 2006 (Egilstadir) How to make charr farming take off? Offensive promotion