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Arctic char

Salvelinus alpinus alpinus

Salvelinus alpinus alpinus (Arctic char)
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Distribution
Distribution map: Salvelinus alpinus alpinus (Arctic char)




Information


Author: João L. Saraiva
Version: B | 1.3 (2024-12-31)


Reviewers: Pablo Arechavala-Lopez, Jenny Volstorf
Editor: Billo Heinzpeter Studer

Initial release: 2017-03-03
Version information:
  • Appearance: B
  • Last minor update: 2024-12-31

Cite as: »Saraiva, João L.. 2024. Salvelinus alpinus alpinus (WelfareCheck | farm). In: fair-fish database, ed. fair-fish. World Wide Web electronic publication. Version B | 1.3. https://fair-fish-database.net.«





WelfareScore | farm

Salvelinus alpinus alpinus
LiPoCe
Criteria
Home range
score-li
score-po
score-ce
Depth range
score-li
score-po
score-ce
Migration
score-li
score-po
score-ce
Reproduction
score-li
score-po
score-ce
Aggregation
score-li
score-po
score-ce
Aggression
score-li
score-po
score-ce
Substrate
score-li
score-po
score-ce
Stress
score-li
score-po
score-ce
Malformations
score-li
score-po
score-ce
Slaughter
score-li
score-po
score-ce


Legend

Condensed assessment of the species' likelihood and potential for good fish welfare in aquaculture, based on ethological findings for 10 crucial criteria.

  • Li = Likelihood that the individuals of the species experience good welfare under minimal farming conditions
  • Po = Potential of the individuals of the species to experience good welfare under high-standard farming conditions
  • Ce = Certainty of our findings in Likelihood and Potential

WelfareScore = Sum of criteria scoring "High" (max. 10)

score-legend
High
score-legend
Medium
score-legend
Low
score-legend
Unclear
score-legend
No findings



General remarks

Salvelinus alpinus alpinus is a highly plastic and very resilient freshwater fish. It is thus appealing for farming, but there are several issues in welfare that need improvement as well as many aspects of its biology that remain understudied. Despite its plasticity, spatial needs in farming systems are not met. Stationary morphs should be more suitable for farming. Spawning induction is highly invasive, and the rearing environment should be improved. Proper attention should be given to its feeding needs (it is sually reared on diets formulated for either Oncorhynchus mykiss or Salmo salar), and fish-derived sources should be replaced with sustainable sources. Stress responses to common farming practices are not known, and a humane stunning and slaughter protocol needs to be established.




1  Home range

Many species traverse in a limited horizontal space (even if just for a certain period of time per year); the home range may be described as a species' understanding of its environment (i.e., its cognitive map) for the most important resources it needs access to.

What is the probability of providing the species' whole home range in captivity?

It is low for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a high amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINSWILD: BENTHIC1: restricted to bottom substrate. FARM: hatchery circular tanks: 1.5-3.7 m ∅ x 1.0 m depth, FINGERLINGS circular tanks: 2.0-4.6 m x 1.0 m depth 2

FRYALEVINS.

JUVENILES: WILD: usually 2-7 km 3, up to 25 km, max 940 km 45. High intra-specific variation and plasticity 65. FARM: grow-out circular tanks: 127 m3 (9 m ∅ x 2 m height) to 156 m3 (9.1 m ∅ x 2.4 m height) 2.

ADULTSJUVENILES.

SPAWNERSWILD: usually 2-7 km 3, up to 25 km, max 940 km 45. High intra-specific variation and plasticity 65.  FARM: no data found yet




2  Depth range

Given the availability of resources (food, shelter) or the need to avoid predators, species spend their time within a certain depth range.

What is the probability of providing the species' whole depth range in captivity?

It is low for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

Eggs: WILD: littoral zone at 0-0.5 m depth 1. FARM: hatchery circular tanks: 1.0 m depth 2.

ALEVINS and FRY: Eggs.

FRY: Eggs.

JUVENILES: WILD: usually 0-20 m, but some morphs prefer 70-72 m 1. FARM: grow-out systems: 2-2.4 m depth 2.

ADULTS: JUVENILES.

SPAWNERS: WILD: spawn from 0-50 m 7. FARM: no data found yet




3  Migration

Some species undergo seasonal changes of environments for different purposes (feeding, spawning, etc.), and to move there, they migrate for more or less extensive distances.

What is the probability of providing farming conditions that are compatible with the migrating or habitat-changing behaviour of the species?

It is unclear for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINS: WILD: stationary in cold rivers and lakes 89710. FARM: circular tanks 2. For details on rearing systems F1 and F2.

FRY: ALEVINS

JUVENILES: WILD: some morphs are ANADROMOUS11, others are stationary in fresh water 12. ANADROMOUS morphs migrate yearly to littoral zones in spring 8910. FARM: grow-out tanks 2. For details on rearing systems F1 and F2.

ADULTS: JUVENILES.

SPAWNERS: WILD: some stationary 12, some ANADROMOUS11. Spawn in fresh water 1. FARM: no data found yet.




4  Reproduction

A species reproduces at a certain age, season, and sex ratio and possibly involving courtship rituals.

What is the probability of the species reproducing naturally in captivity without manipulation of these circumstances?

It is low for minimal and high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

WILD: spawning in summer and autumn 101. Form spawning aggregations with male-biased sex ratio 101. Female builds nest, male courts female 1. FARM: temperature manipulation to induce ovulation 2; ripe females are stripped of eggs, milt is collected from males, both under anaesthesia 2.




5  Aggregation

Species differ in the way they co-exist with conspecifics or other species from being solitary to aggregating unstructured, casually roaming in shoals or closely coordinating in schools of varying densities.

What is the probability of providing farming conditions that are compatible with the aggregation behaviour of the species?

It is high for minimal and high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINS: WILD: 4.7 IND/m21. FARM: densities of up to 70 IND/L do not seem to affect growth or mortality 13. Highly plastic species 5.

FRY: ALEVINS.

JUVENILES: WILD: schooling 1415. FARM: density of 2.2 IND/L increases growth, whereas 0.3 IND/L hinders growth and increase mortality 16. Form schools and tolerate high densities of at least 120 kg/m3 2. Highly plastic species 5.

ADULTS: JUVENILES.

SPAWNERS: WILD: spawning aggregations of unknown size 101. FARM: lower density than on-growing tanks 17.




6  Aggression

There is a range of adverse reactions in species, spanning from being relatively indifferent towards others to defending valuable resources (e.g., food, territory, mates) to actively attacking opponents.

What is the probability of the species being non-aggressive and non-territorial in captivity?

It is low for minimal and high-standard farming conditions. Our conclusion is based on a high amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINS: WILD: cannibalistic 5. FARM: cannibalistic 18. LAB: cannibalistic 19.

FRY: ALEVINS.

JUVENILES: WILD: aggressive and territorial 6. FARM: high densities in farms of 300 IND/tank reduce aggression 20. LAB: aggressive and territorial 21, establish dominance hierarchies in groups of 3 21.

ADULTS: JUVENILES.

SPAWNERS: WILD: males aggressively guard females 1. FARM: no data found yet.




7  Substrate

Depending on where in the water column the species lives, it differs in interacting with or relying on various substrates for feeding or covering purposes (e.g., plants, rocks and stones, sand and mud, turbidity).

What is the probability of providing the species' substrate and shelter needs in captivity?

It is low for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

Eggs: WILD: BENTHIC1. FARM: hatched in shallow throughs or concrete tanks 17.

ALEVINSWILD: immediately seek shelter in the substrate upon hatching 2FARM: ponds usually have stones, pebbles, and gravel as substrate 17.

JUVENILES: WILD: usually BENTHIC, but can shift to PELAGIC (independent of bottom substrate) depending on feed abundance 22FARM: ALEVINS.

ADULTS: JUVENILES.

SPAWNERSWILD: spawn in substrate 1FARM: maturation ponds usually have stones, pebbles, and gravel as substrate 17.




8  Stress

Farming involves subjecting the species to diverse procedures (e.g., handling, air exposure, short-term confinement, short-term crowding, transport), sudden parameter changes or repeated disturbances (e.g., husbandry, size-grading).

What is the probability of the species not being stressed?

It is unclear for minimal and high-standard farming conditions. Our conclusion is based on a low amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINS: no data found yet.

FRY: no data found yet.

JUVENILES: stressed by handling, but habituated to repeated handling 23. Further research needed on other common stressors.

ADULTS: JUVENILES

SPAWNERS: no data found yet.




9  Malformations

Deformities that – in contrast to diseases – are commonly irreversible may indicate sub-optimal rearing conditions (e.g., mechanical stress during hatching and rearing, environmental factors unless mentioned in crit. 3, aquatic pollutants, nutritional deficiencies) or a general incompatibility of the species with being farmed.

What is the probability of the species being malformed rarely?

It is unclear for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a low amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

ALEVINS: frequency of malformations <2% 242526. Overall malformation rate lower than other species such as Rainbow trout >10% 27, Atlantic salmon >17% 28292930 , Pikeperch >10% 31323334, Sea bass ca 30% 35363738.

FRY: ALEVINS.

JUVENILES: no data found yet.

ADULTS: no data found yet.




10  Slaughter

The cornerstone for a humane treatment is that slaughter a) immediately follows stunning (i.e., while the individual is unconscious), b) happens according to a clear and reproducible set of instructions verified under farming conditions, and c) avoids pain, suffering, and distress.

What is the probability of the species being slaughtered according to a humane slaughter protocol?

It is low for minimal farming conditions. It is medium for high-standard farming conditions. Our conclusion is based on a medium amount of evidence.

Likelihoodscore-li
Potentialscore-po
Certaintyscore-ce

Minimal slaughter method: for the related Oncorhynchus kisutch, anaesthesia with high CO2 or iced water 39, then bled by cutting gill arches and immersing in iced water 3940. High-standard slaughter method: indications that electrical stunning after 30 s DC 9.6 V/cm at 1,000 Hz is most effective 41. Further research needed to confirm for farming conditions.




Side note: Domestication

Teletchea and Fontaine introduced 5 domestication levels illustrating how far species are from having their life cycle closed in captivity without wild input, how long they have been reared in captivity, and whether breeding programmes are in place.

What is the species’ domestication level?

DOMESTICATION LEVEL 542, fully domesticated. Selective breeding programme since 1982 2.




Side note: Forage fish in the feed

450-1,000 milliard wild-caught fishes end up being processed into fish meal and fish oil each year which contributes to overfishing and represents enormous suffering. There is a broad range of feeding types within species reared in captivity.

To what degree may fish meal and fish oil based on forage fish be replaced by non-forage fishery components (e.g., poultry blood meal) or sustainable sources (e.g., soybean cake)?

All age classes: WILD: carnivorous 1434445. FARM: for JUVENILES, fish oil may be completely* replaced by plant material 4647.

*partly = <51% – mostly = 51-99% – completely = 100%




Side note: Commercial relevance

How much is this species farmed annually?

6,232 t in 2022 48.




Glossary


ADULTS = mature individuals
ALEVINS = larvae until the end of yolk sac absorption
ANADROMOUS = migrating from the sea into fresh water to spawn
BENTHIC = living at the bottom of a body of water, able to rest on the floor
DOMESTICATION LEVEL 5 = selective breeding programmes are used focusing on specific goals 42
FARM = setting in farming environment or under conditions simulating farming environment in terms of size of facility or number of individuals
FINGERLINGS = early juveniles with fully developed scales and working fins, the size of a human finger
FRY = larvae from external feeding on
IND = individuals
JUVENILES = fully developed but immature individuals
LAB = setting in laboratory environment
PELAGIC = living independent of bottom and shore of a body of water
SPAWNERS = adults during the spawning season; in farms: adults that are kept as broodstock
WILD = setting in the wild



Bibliography


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