Module 17
Welfare of fish
魚的動物福利
Scope of lecture講授範圍
This module will enable you to
此模組能夠讓你
• Understand the basics of 瞭解基本概念
– fish biology 魚的生活規律
– fish husbandry 養魚業
• Assess the welfare
of fish 評估魚類福利
• Identify the main
welfare concerns in
fish that we eat
辨識食用魚的福利關注議題
Fish biology魚生物學
• Bony fish (Teleosts) 有骨魚類
– One of the five main groups of vertebrates
五大有脊椎動物群組之一
– > 30,000 species 逾三萬種
– Bony skeleton, swim bladder 多骨骼、有魚鰾
– Many subgroups 小型群組多
• Cartilaginous fish 軟骨魚類
– Sharks etc. 如鯊魚等
Example: Salmonids舉例:鮭魚
• Atlantic salmon Salmo salar 大西洋鮭魚
Example: Cichlids舉例:慈鯛魚
• Tilapia Tilapia rendalii 慈鯛魚
Fish Biology魚生物學
• Poikilothermic 變溫動物
• Many have narrow temperature range
多數品種的溫差較狹窄
– Some can tolerate a wider range 有的可接受較大溫差
Fish Biology魚生物學
• Respiration 呼吸作用
– Gills: covered by opercula 魚鰓：由鰓蓋保護
– Oxygen carried by haemoglobin 帶血紅素的
氧氣
– Carp can breathe air orally 鯉魚可張嘴呼吸
Fish Biology魚生物學
Fish Biology魚生物學
• Importance of water quality 水質的重要
– Influence of light levels 光度的影響
– Methaemoglobinaemia 正鐵血紅蛋白血症
Fish Biology魚生物學
• Wild fish have many stressors 野魚壓力多
Fish Biology魚生物學
• Stress response 對壓力的反應
– Physiological: similar to mammals
生理反應：與哺乳動物類似
– Behavioural: many different responses
possible, depending on stressor
行為反應：種類有很多，視乎壓力源而定
– Individual variation—partly genetic
個別反應：部分屬遺傳
Fish Biology魚生物學
• Reproduction 生殖方式
– Energetically costly 能量消耗大
– Differs between species 動物種類不同
• Feeding 飼料
– Carnivores (e.g salmonids) vs. herbivores
(e.g. carp) 肉食類 (如鮭魚) 對 草食類 (如鯉魚)
– Appetite varies with temp., reproduction etc
食慾會因應溫度和生殖方式等因素而異
Fish Biology魚生物學
• Memory, cognition, learning 記憶、認知與學習
– Fish can learn and remember 魚能夠學習和
記憶
Fish Biology魚生物學
• Pain perception 對疼痛的感覺
– Nociceptors exist 有傷害感受器
– Injection of acetic acid into the lips of trout
=> rubbed lips, rocked their bodies, and did
not eat 把醋酸注射至鱒魚唇  用嘴唇摩擦、全身
搖擺、不欲進食
– Morphine blocked avoidance of electric
shock 嗎啡會令魚對觸電變得麻木
– Without morphine, fish responded to
electric shock 沒有接受嗎啡注射的魚
會對觸電起反應
Fish Biology魚生物學
• The balance of probability is that adult
fish can suffer 以平均概率計算，成年魚類會受苦
• Lack of neocortex does not mean fish
cannot suffer 缺乏新大腦皮層不代表魚不能受苦
– Neural processing is more important
神經處理過程更為重要
• More research needed 需要更多研究
Fish Husbandry魚養殖經營
• Fisheries 漁場
– Any body of water containing fish有魚的水域
– Commercial vs. sports 商業對體育
• Fish farms 養魚場
– Facilities where
fish bred & reared
養殖魚類設施
– Selected for fast
growth
基因選擇對魚的成長
Fish Husbandry魚養殖經營
• Facts and figures 事實與統計數字
– 38 million humans worldwide catch fish for
a living 全球有3,800萬人以捕魚為生
– 10 million people work in aquaculture
1,000萬人從事水產養殖業
– Fish farms provide ~40% of all fish
consumed 養殖魚約佔全球魚類消耗量的40%
– In 2002, the total world trade of fish
products was greater than rice, tea and
coffee combined
在2002年，全球漁獲總交易量超過稻米、
茶葉和咖啡交易量之總和
Fish husbandry魚養殖經營
• Stocking density 養殖密度
– Weight of fish per unit volume of water?
以每個水量單位計算魚的體重？
– Weight per unit flow of water? 以每個水流量單位
計算魚的體重？
Fish husbandry魚養殖經營
• Stocking density 養殖密度
– Physical effects 體質影響
– Behavioural effects 行為影響
Fish husbandry魚養殖經營
• Feeding 餵飼系統
– Piscivorous (e.g. salmon, halibut)
以吃魚為生 (如鮭魚、比目魚)
– Herbivorous (e.g. carp) 以吃草為生 (如鯉魚)
Fish husbandry魚養殖經營
• Feeding 餵飼系統
– Aggression vs. competition 侵略對競爭
– To reduce fighting 減少打鬥
• Deliver food according to appetite
按照個別魚兒的食慾提供足夠食物
• Distribute food widely 均勻散播食物
• Use of cameras 利用照相機
• Keep older, larger fish with juveniles?
把年紀較長的大魚與幼魚養在一起？
• Keep fish of the same size together?
把體積相同的魚養在一起？
Fish husbandry魚養殖經營
• Reproductive management 養殖管理
– Varies with species e.g. salmon vs.
tilapia 因應魚的種類而異 (如鮭魚對吳郭魚)
Fish husbandry魚養殖經營
• Reproductive management (Atlantic
salmon) 生殖管理 (大西洋鮭魚)
– Triploidy 三套染色體
– All-female stock
全部繁殖雌魚後代
• Artificial lighting
人工照明
Fish husbandry魚養殖經營
• Catching and handling
捕捉和處理過程
– When moving from pond
to pond 由一個魚池移到另一個
– For slaughter 用於宰魚
– For vaccination and
reproduction assistance
用於支援接種和生殖
– For grading--to monitor
size and weight
用於分級，以監察魚的大小和重量
– Stressful; max. time out of
water = 15 secs
壓力非常大；魚離開水面最多15秒
Fish harvest捕獲
Slaughter methods屠宰方法
• Slaughter methods 宰魚方法
– Slow loss of sensibility 讓魚慢慢失去知覺
– Immediate loss of sensibility 讓魚即時失去知覺
Slaughter methods屠宰方法
• Slow loss of sensibility 讓魚慢慢失去知覺的方法
– Asphyxiation –air, ice 窒息法 (空氣，冰塊)
– Exsanguination 摘除魚鰓法
– CO2 narcosis 二氧化碳麻醉法
– Evisceration of live fish 活體除臟術
– Decapitation (eels) 砍頭法 (用於鰻魚)
– Anaesthesia 麻醉法
– Salt or ammonia (eels) 鹽浴或氨浴 (用於鰻魚)
– Electrical immobilisation 電擊靜止法
Slaughter methods屠宰方法
• Immediate loss of sensibility
讓魚即時失去知覺的方法
– Percussive stunning 擊昏法
– Spiking 刺穿法
– Shooting 槍射法
– Electrical stunning 電昏法
Slaughter methods屠宰方法
• Percussive stunning 擊昏法
Slaughter methods屠宰方法
• Slaughter methods, from best welfare to
worst 屠宰法(由動物福利最好至最差排列)
1. Electrical stunning; anaesthetics 電昏、麻醉
2. Percussive stunning, spiking, shooting
擊昏、刺穿、槍擊
3. Carbon dioxide; asphyxiation in air or ice
二氧化碳麻醉、以空氣或冰塊窒息
4. Decapitation; evisceration; electroimmobilisation; salt or ammonia bath
砍頭、除臟、電擊靜止、鹽浴或氨浴
(Office Internationale des Epizooties 2006)
Slaughter methods屠宰方法
•
Assess effectiveness of stunning using
評估擊昏法成效的方法
– Swimming 泳姿
– Righting reflex when fish inverted 魚倒立時眼睛會校正
反射動作
–
Attempt to escape when handled 人拿著魚的時候，魚
會嘗試逃跑
–
–
•
Opercular movement 鰓蓋跳動
“Eye roll” 眼睛滾動
Concern re starvation before slaughter
屠宰前先讓魚禁食的關注議題
– Should not exceed 72 hours
不應該超過72小時
Assessing welfare in fish
評估魚的動物福利
•
Water 池水
– Flow rate 流量
– Quality 水質
Assessing welfare in fish
評估魚的動物福利
•
Environmental measures 環境測量指標
– Bird activity 雀鳥活動
Assessing welfare in fish
評估魚的動物福利
• Animal-based 動物為
本
– Colour 顏色
– Ventilation rate
透氣率
– Behaviour 行為
– Food intake 攝取量
– Body condition
身體狀況
– Growth rate 生長率
– Mortality rate 死亡率
–
–
–
–
Morphology 魚的結構
Injury 傷勢
Disease 疾病
Reproductive
performance 生育水平
– Stocking density
養殖密度
(Huntingford et al 2006)
Assessing welfare in fish:
Input-output system
評估魚的動物福利:投入與產出系統
• Input – assessment 投入系統評估指標
– Measurements of housing 魚舍面積
– Provision of food and water 食物和食水供應
– Qualification of stockperson 場主資格
– Medicine records 醫療紀錄
• Output – assessment 產出系統評估指標
– Assessment of live animal 對現存動物的評估
– Assessment of dead animal (abattoir, post-mortem
examinations)
對已逝動物的評估 ( 屠宰法、死後驗屍法 )
Assessing welfare in fish
評估魚的動物福利
• Other measures 其它指標
– “Smart Tag”—ventilation rate
「智慧標籤」記憶體：魚的透氣率
(Aas-Hansen & Damsgard, In: Damsgard et al
2006)
– Integrated index—cortisol, glucose, body
condition 綜合指數：皮質醇、葡萄糖、身體狀況
(Turnbull et al 2005)
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Five Freedoms 「五項自由」
• Need for research 研究需要
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Freedom from hunger, thirst and malnutrition
免受飢渴和營養不良的自由
– Starvation before transport or slaughter 運送或屠宰前禁食
– Feed reduction / starvation to keep fish off the market until
prices rise 低買高賣法：在價格回升前減少或停止餵魚
– High protein requirement of carnivores
肉食動物對高蛋白質的需求
– Aggression 侵略行為
– Malnutrition in juveniles 幼魚營養不良
– Osmolarity of water 水的滲透壓
– Welfare of wild fish used to feed farmed fish?
把野生魚類的福利套用在養殖魚類身上？
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Freedom from pain, injury and disease
免於痛苦與傷病的自由
–
–
–
–
Handling 處理過程
Injuries 傷勢
Diseases 疾病
Vaccination lesions
接種疫苗的傷害
– Morphological
abnormalities 結構異常
– Overcrowding 過度擁擠
– Algal blooms and jellyfish海藻和水母的繁殖
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Freedom from exposure and extremes
of temperature
免受動物侵襲和極端溫差的自由
– Lack of shelter--vulnerable
to predators
缺乏保護：易受獵食者侵襲
– Importance of water
quality 水質的重要
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Freedom from fear and distress 免於恐懼和痛苦的自由
– Vulnerable to predators 易受獵食者侵襲
– Handling 處理過程
– Transport 運輸過程
– Overcrowding 過度擁擠
– Slaughter 屠宰過程
– Escapees 漏網之魚
Farmed fish: welfare concerns
養殖魚類:福利的關注議題
• Freedom to perform normal behaviour
展現正常行為的自由
– No environmental complexity and no
environmental control
環境單純、環境控制缺乏
– Assisted reproduction 助產
– Individual variation 個體行為變化
Summary摘要
• Diversity of fish biology
魚類的生活習慣多姿多彩
• Many sources of distress and
suffering in fish husbandry, but
better approaches are available
魚的壓力和痛苦來源很多，但有更好的解決方法
• Good stockmanship essential
良好的魚場管理水平是十分重要的
Bibliography參考書目
• Chandroo KP, Duncan IJH , Moccia RD. Can fish suffer?:
perspectives on sentience, pain, fear and stress. Appl Anim
Behav Sci 2004; 86: 225-250.
• Conte FS. Stress and the welfare of cultured fish. Applied
Animal Behaviour Science 2004; 86: 205-223
• Damsgard B, Juell JE, Braastad BO. Welfare in farmed fish.
Fiskeriforskning Report 5/ January 2006. Available from:
http:www.fiskforsk.norut.no/fiskeriforskning/publikasjoner/
rapporter/welfare_in_farmed_fish
• Farm Animal Welfare Council. Report on the welfare of farmed
fish. 1996 .Available from:
http://www.fawc.org.uk/reports/fish/fishrtoc.htm
• Huntingford FA, Adams C, Braithwaite VA, Kadri S, Pottinger
TG, Sandoe P, Turnbull JF. Current issues in fish welfare.
Journal of Fish Biology 2006; 68: 332-372
•
Huntingford FA, Adams C. Behavioural syndromes in farmed
fish: implications for production and welfare. Behaviour 2005;
142:1207-1221
Bibliography參考書目
•
•
•
•
•
•
Kestin SC, van de Vis JW, Robb DHF. Protocol for assessing brain
function in fish and the effectiveness of methods used to stun and kill
them. Veterinary Record 2002; 150: 302-307.
Lymbery P. In Too Deep-The Welfare of Intensively Farmed Fish.
Compassion in World Farming Trust, Petersfield, Hampshire, UK. 2002
Office internationale des epizooties. Report of the Meeting of the Aquatic
Animal Health Standards Commission, March 13-17 2006, OIE, Paris.
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Robb DHF, Kestin SC. Methods used to kill fish: field observations and
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Bibliography參考書目
• Stevenson P. Closed Waters: The Welfare of Farmed Atlantic
Salmon, Rainbow Trout, Atlantic Cod & Atlantic Halibut.
(Compassion in World Farming / World Society for the Protection
of Animals.) Compassion in World Farming Trust , Godalming,
Surrey, UK. 2007. Available online at:
http://www.wspafarmwelfare.org/resources/WSPA%20CIWF%20F
ish%20Farming%20Report%202007.pdf
• Wolffrom T. Farmed fish and welfare. European Commission
Directorate General for Fisheries 2004. Available from:
http://ec.europa.eu/comm/fisheries/doc_et_publ/liste_publi/farmedf
ish_en.pdf. Pages 19-20
• Yue S, Moccia RD, Duncan IJH. Investigating fear in domestic
rainbow trout Onchorynchus mykiss using an avoidance learning
task. Appl An Behav Sci 2004; 87: 343-354.