FishEthoBase:
Short Profiles and FishEthoScore
➜ For full text including Scoring Logic, please click on the PDF download button top right of this window.
The main intent of FishEthoBase is to improve fish welfare by 1) assessing if and to which extent the practices in farming of a fish species satisfy the needs and behaviour patterns observed in the wild, and 2) providing recommendations for improvement to practitioners, based mainly on ethological findings from scientific research.
FishEthoBase is focussing on behaviour
Fish welfare depends on 3 types of factors: physiological, behavioural, and mental factors. In the FishEthoBase short profiles, we focus on 10 core criteria for behaviour. For other factors and criteria, we recommend
Short profile:
A sharp assessment of the welfare state and potential of a species
With the short profiles, we pursue two goals:
FishEthoScore as an indicator for practice and science
The 3 dimensions are assessed and scored separately in each of the 10 criteria and summarised in the FishEthoScore (see page 3, Scoring Logic), indicating the overall extents of Likelihood, Potential and Certainty of a species’ welfare.
For more detailed recommendations please go to our “Recommendations” page (a part of our full profiles) of the species in question, if available. Unfortunately however, for most of the species assessed in a short profile, we are not yet able to provide a full profile as it demands much more work.
The FishEthoScore of the various species may help to decide on which species one should best concentrate research, development, and investments in order to put the industry in a position to positively answer the upcoming fish welfare demands.
➜ Continue reading by clicking on the PDF download button top right of this window.
Short profile rationale | (download as pdf) |
Criteria | Li | Po | Ce | |
---|---|---|---|---|
1 | Home range | |||
2 | Depth range | |||
3 | Migration | |||
4 | Reproduction | |||
5 | Aggregation | |||
6 | Aggression | |||
7 | Substrate | |||
8 | Stress | |||
9 | Malformation | |||
10 | Slaughter | / | / | / |
FishEthoScore | 1 | 2 | 2 |
Li = Likelihood that the individuals of the species experience welfare under minimal farming conditions | ||||||||||||||
Po = Potential overall potential of the individuals of the species to experience welfare under improved farming conditions | ||||||||||||||
Ce = Certainty of our findings in Likelihood and Potential | ||||||||||||||
? | / | |||||||||||||
High | Medium | Low | Unclear | No findings | ||||||||||
FishEthoScore = Sum of criteria scoring "High" (max. 10) |
Morone saxatilis is a very popular species in North America, especially regarding recreational fisheries. Due to the decline of wild stocks, some effort was invested in farming this fish both for re-stocking and commercial purposes. However, there is a lack of knowledge in many aspects of its biology, especially regarding common aquaculture stressors such as handling, aggression, incidence of malformations, and humane slaughter protocols. Most of the information available is old and yet suggest that the welfare state of this species is poor, especially concerning spatial needs and induced spawning practices. Furthermore, this species is currently being hybridised with other Moronids, which raises welfare issues because of the lack of knowledge on the effects of such practices. The welfare of M. saxatilis may be improved if production is focused on freshwater populations, uses appropriate densities, develops solutions towards the use of substrate, and implements humane slaughter procedures.
L |
Likelihood | L |
Potential | M |
Certainty |
LARVAE: WILD: PLANKTONIC, so no home range [1]. FARM: incubation in MacDonald type jars, heath trays [2] or in spawning tanks [3], then transferred to FINGERLINGS ponds of 0.2-0.4 ha [4].
JUVENILES: WILD: 0.1-0.4 km2 [5] [6], <20 km2 [7]. FARM: ponds: 0.4-2.0 ha [4]; raceways: 30 x 3 m or proportionally larger [4]; circular tanks: 10 m diameter [4].
ADULTS: ➝ JUVENILES.
SPAWNERS: WILD: males 30-40 km, females 1-10 km [8]. FARM: circular tanks: 3.7 m diameter [9].
L |
Likelihood | L |
Potential | M |
Certainty |
LARVAE: WILD: 0-7 m [10]. FARM: incubation in MacDonald type jars, heath trays [2], or in spawning tanks [3], then transferred to FINGERLINGS ponds of 1-2 m depth [4].
JUVENILES: WILD: 20-40 m [11]. FARM: ponds: <2.8 m [4].
ADULTS: ➝ JUVENILES.
SPAWNERS: WILD: 1.0-3.5 m [12]. FARM: circular tanks: 1.2 m [9].
H |
Likelihood | H |
Potential | H |
Certainty |
Some populations ANADROMOUS, others landlocked [10].
LARVAE: WILD: perform vertical migrations [10] and downstream movements [13], but some populations remain in fresh water [14]. FARM: reared in brackish water [15] [16]. For details of holding systems ➝ crit. 1 and 2.
JUVENILES: WILD: some populations in fresh water, others in brackish water and others in saltwater [10] [17] [18]. FARM: may be reared in fresh, brackish or saltwater [19] [20] [15] [16]. For details of holding systems ➝ crit. 1 and 2.
ADULTS: ➝ JUVENILES.
SPAWNERS: WILD: spawn in fresh water [8] [5] [6]. FARM: fresh or brackish water [15] [16]. For details of holding systems ➝ crit. 1 and 2.
L |
Likelihood | M |
Potential | H |
Certainty |
WILD: pre-spawning behaviour of both sexes involves staging within the lower and middle parts of estuaries. Males and females move in synchrony from the staging area to the spawning grounds, which they occupy during 1-2 weeks for females and longer for males. Increase in temperature triggers spawning movements [21]. Spawning occurs near the head of tide and at the surface of the water. The spawning act is obvious and can vary from a gentle swirling motion of several fish to an aggressive behaviour that splashes water high into the air. The eggs and milt are broadcast simultaneously by the females and males respectively, and fertilisation occurs in the water column [22].
FARM: in many cases, males and females are kept separately, stripped upon hormonal injections and fertilisation is performed manually [23] [24] [25] [26]. When kept in spawning tanks, ratio is 1 female : 2 males [23]. Spawning can also occur spontaneously in tanks, although relying on GnRH injected males and females [23].
LAB: courtship behaviour (leading, following, aggregating in pack) started 15 h before spawning. Male courted female with side-to-side or face-to-face contact and shimmying. Encircled and pushed against female when she released eggs [27].
L |
Likelihood | M |
Potential | M |
Certainty |
LARVAE: WILD: <600 IND/m3 [28]. FARM: ponds: 125,000-1,500,000 IND/ha in early stages [29] [30], 10,000-250,000 IND/ha in late stages, but densities in the range of 25,000-60,000 IND/ha resulted in more uniform fish and better overall survival [31].
JUVENILES: WILD: form large schools [32], numbers and densities not available. FARM: ponds: 5,600 and 6,600 kg/ha, corresponding to approximately 8,600 IND/ha at harvest [33]; intensive ponds: 7,500 kg/ha [31]; raceways: 43.2 kg/m3 [31].
ADULTS: ➝ JUVENILES.
SPAWNERS: WILD: form spawning aggregations [10]. FARM: no data found yet.
L |
Likelihood | L |
Potential | L |
Certainty |
LARVAE: WILD: no data found yet. FARM: cannibalism in intensive systems [34].
JUVENILES: WILD and FARM: no data found yet.
ADULTS: WILD and FARM: no data found yet.
SPAWNERS: WILD and FARM: no data found yet.
L |
Likelihood | H |
Potential | M |
Certainty |
Eggs and LARVAE: WILD: PELAGIC [10] [21]. FARM: jars, heath trays [2], tanks [3], earthen ponds [4].
JUVENILES: WILD: sandy or gravelly bottoms [10]. FARM: earthen ponds, raceways or tanks [4].
ADULTS: WILD: when inshore, may be found in a variety of environments: sand, gravel, rock [10]. FARM: ➝ JUVENILES.
SPAWNERS: WILD: pelagic spawning (➝ crit. 4). FARM: tanks [9].
L |
Likelihood | L |
Potential | L |
Certainty |
Eggs and LARVAE: no data found yet.
JUVENILES: stressed by handling [35], confinement [36], and temperature changes [37].
ADULTS: ➝ JUVENILES.
SPAWNERS: stressed by high temperatures [38] [39] [40] [41] [42]; less invasive techniques to assess sex and maturation are available [43].
L |
Likelihood | L |
Potential | L |
Certainty |
LARVAE: WILD: high mortalities [44] [45], sensitive to temperature [22]. FARM: high mortalities [46] with survival after 20 days varying between 0.03% and 11% [47]. Swimbladder inflation is a critical event [48] [49].
JUVENILES: WILD: pugheadness, blindness, harelippedness, scoliosis, crossbite, lordosis, and fin deformations [50]. FARM: no data found yet.
ADULTS: WILD: ➝ JUVENILES. FARM: no data found yet.
/ |
Likelihood | / |
Potential | / |
Certainty |
Common slaughter method: no data found yet. High-standard slaughter method: no data found yet.
All age classes: WILD: carnivorous [52] [53]. FARM: fish meal may be completely* replaced by plant-based diets, although requiring feeding stimulants [54] [55] [54], but no data found yet on replacement of fish oil and replacement in FRY and ADULTS.
*partly = <51% – mostly = 51-99% – completely = 100%