16AGRITECHCAT5: The neurophysiological and behavioural evaluation of a novel humane electric stunning system for fish
Lead Research Organisation:
University of Bristol
Department Name: Clinical Veterinary Science
Abstract
It has long been recognised that the welfare of fish at slaughter is comparatively poor in relation to the welfare of land animals at slaughter, due in part to technical difficulties associated with developing effective electrical stunning systems for fish that are safe for use in an aquatic environment. Although long neglected, the welfare of fish of slaughter is also receiving significant attention from consumers who are demanding better welfare during the slaughter process. This fact, coupled with the massive expansion of aquaculture to meet the challenges of feeding a rapidly expanding population means that improvements in the welfare of fish at slaughter are urgently required. There are well-defined neurophysiological parameters in mammals and birds that can be used to confirm whether stunning has been effective. However there is little consensus on neurophysiological parameters that indicate an effective stun in fish.
This project will investigate the methodologies currently used by researchers to evaluate effective stunning in other species and determine whether these criteria can be applied to a range of fish species. In addition, if necessary, new techniques will be investigated to further our understanding of stunning effectiveness in farmed fish based on detailed analysis of brain activity. The neurophysiological assessment in the laboratory will be used to identify behavioural signs that can subjectively identify whether fish are stunned or not. Therefore the first part of this proposal will focus on the determination of neurophysiological methodologies that can be used to define an effective stun in fish to reduce excitement, pain or suffering. The methodology developed will be used to assess the effectiveness of commercially used electrical stunning systems to produce a humane stun.
This project will investigate the methodologies currently used by researchers to evaluate effective stunning in other species and determine whether these criteria can be applied to a range of fish species. In addition, if necessary, new techniques will be investigated to further our understanding of stunning effectiveness in farmed fish based on detailed analysis of brain activity. The neurophysiological assessment in the laboratory will be used to identify behavioural signs that can subjectively identify whether fish are stunned or not. Therefore the first part of this proposal will focus on the determination of neurophysiological methodologies that can be used to define an effective stun in fish to reduce excitement, pain or suffering. The methodology developed will be used to assess the effectiveness of commercially used electrical stunning systems to produce a humane stun.
Technical Summary
It has long been recognised that the welfare of fish at slaughter is comparatively poor in relation to the welfare of land animals at slaughter, due in part to technical difficulties associated with developing effective electrical stunning systems for fish that are safe for use in an aquatic environment. Although long neglected, the welfare of fish of slaughter is also receiving significant attention from consumers who are demanding better welfare during the slaughter process. This fact, coupled with the massive expansion of aquaculture to meet the challenges of feeding a rapidly expanding population means that improvements in the welfare of fish at slaughter are urgently required. There are well-defined neurophysiological parameters in mammals and birds that can be used to confirm whether stunning has been effective. However there is little consensus on neurophysiological parameters that indicate an effective stun in fish.
This project will investigate the methodologies currently used by researchers to evaluate effective stunning in other species and determine whether these criteria can be applied to a range of fish species. In addition, if necessary, new techniques will be investigated to further our understanding of stunning effectiveness in farmed fish based on detailed analysis of brain activity. The neurophysiological assessment in the laboratory will be used to identify behavioural signs that can subjectively identify whether fish are stunned or not. Therefore the first part of this proposal will focus on the determination of neurophysiological methodologies that can be used to define an effective stun in fish to reduce excitement, pain or suffering. The methodology developed will be used to assess the effectiveness of commercially used electrical stunning systems to produce a humane stun.
This project will investigate the methodologies currently used by researchers to evaluate effective stunning in other species and determine whether these criteria can be applied to a range of fish species. In addition, if necessary, new techniques will be investigated to further our understanding of stunning effectiveness in farmed fish based on detailed analysis of brain activity. The neurophysiological assessment in the laboratory will be used to identify behavioural signs that can subjectively identify whether fish are stunned or not. Therefore the first part of this proposal will focus on the determination of neurophysiological methodologies that can be used to define an effective stun in fish to reduce excitement, pain or suffering. The methodology developed will be used to assess the effectiveness of commercially used electrical stunning systems to produce a humane stun.
Planned Impact
There are six different key stakeholders that can be clearly identified to benefit from this research as follows:
1) Farmed fish - through improvements in welfare at slaughter.
2) Staff working at fish farms - by providing knowledge that the welfare of their fish at slaughter was assured, as well as economic benefits of a fast throughput system following the introduction of electrical stunning in situ.
3) Consumers - through knowledge that they are eating fish that have been humanely killed.
4) Retailers - by being able to meet consumer demand for better welfare of fish at slaughter
5) Ace Aquatec - through commercialisation and sale of their new stunning system for fish
6) Academics by improved knowledge of neurophysiological parameters that equate to effective stunning in fish that can be used to evaluate new systems in the future
1) In comparison to land based animals the welfare of farmed fish slaughter is recognized to be poor. Many fish farms still place live fish in ice as a means of slaughter without prior stunning, where it can take many hours for fish to be killed. Mechanised percussive machines have been used to kill larger fish such as salmon and sea trout however they do not cater for portion sized fish such as sea bass and bream. Development of a new electrical stunning system that stuns the fish as they exit the holding tanks through a pipe would significantly increase the welfare of millions of fish annually throughout the world.
2) Staff working at fish farms will benefit on an "emotional" level if they are secure in the knowledge that the fish raised on the farm are slaughtered humanely. Furthermore the proposed design by Ace Aquatec is a fast throughput system, increasing the number of fish that can be killed per hour compared to current stun systems and therefore economic revenue generated by the fish farm will increase.
3) Consumers are demanding that fish are humanely slaughtered but current methods to achieve the humane slaughter of fish are limited particularly for salt water species. The development of an electrical stunning system for fish that was supported by robust independent scientific data to show that it produced effective and human stunning with no detriment to meat quality would satisfy consumer demand. Fish could be identified by their label that they had been humanely killed to allow consumers choice in the origin of fish that they bought from suppliers.
4) In order to meet consumer demand supermarkets are already requesting the technology to ensure that fish are fish are stunned humanely before slaughter. Stocking fish that had been humanely killed would bring an economic benefit to supermarkets by increasing the potential market for fish sales if consumers had more confidence in the providence of farmed fish.
5) Ace Aquatec are the only company, currently, with the technical capability to produce an electrical stunning system for farmed fish that can function in situ without having to remove the fish from the water for stunning. The price of such a stunning unit is likely to retail at around £50K with a large number of companies worldwide who are likely to want to purchase such a system. Therefore Ace Aquatec will benefit significantly economically from development of a human stunning system for fish.
6) An important part of this proposal is the development of new neurophysiological techniques to evaluate the effectiveness of stunning in fish. These methodologies will benefit academics working in the field of slaughter research, both in fish and other species.
1) Farmed fish - through improvements in welfare at slaughter.
2) Staff working at fish farms - by providing knowledge that the welfare of their fish at slaughter was assured, as well as economic benefits of a fast throughput system following the introduction of electrical stunning in situ.
3) Consumers - through knowledge that they are eating fish that have been humanely killed.
4) Retailers - by being able to meet consumer demand for better welfare of fish at slaughter
5) Ace Aquatec - through commercialisation and sale of their new stunning system for fish
6) Academics by improved knowledge of neurophysiological parameters that equate to effective stunning in fish that can be used to evaluate new systems in the future
1) In comparison to land based animals the welfare of farmed fish slaughter is recognized to be poor. Many fish farms still place live fish in ice as a means of slaughter without prior stunning, where it can take many hours for fish to be killed. Mechanised percussive machines have been used to kill larger fish such as salmon and sea trout however they do not cater for portion sized fish such as sea bass and bream. Development of a new electrical stunning system that stuns the fish as they exit the holding tanks through a pipe would significantly increase the welfare of millions of fish annually throughout the world.
2) Staff working at fish farms will benefit on an "emotional" level if they are secure in the knowledge that the fish raised on the farm are slaughtered humanely. Furthermore the proposed design by Ace Aquatec is a fast throughput system, increasing the number of fish that can be killed per hour compared to current stun systems and therefore economic revenue generated by the fish farm will increase.
3) Consumers are demanding that fish are humanely slaughtered but current methods to achieve the humane slaughter of fish are limited particularly for salt water species. The development of an electrical stunning system for fish that was supported by robust independent scientific data to show that it produced effective and human stunning with no detriment to meat quality would satisfy consumer demand. Fish could be identified by their label that they had been humanely killed to allow consumers choice in the origin of fish that they bought from suppliers.
4) In order to meet consumer demand supermarkets are already requesting the technology to ensure that fish are fish are stunned humanely before slaughter. Stocking fish that had been humanely killed would bring an economic benefit to supermarkets by increasing the potential market for fish sales if consumers had more confidence in the providence of farmed fish.
5) Ace Aquatec are the only company, currently, with the technical capability to produce an electrical stunning system for farmed fish that can function in situ without having to remove the fish from the water for stunning. The price of such a stunning unit is likely to retail at around £50K with a large number of companies worldwide who are likely to want to purchase such a system. Therefore Ace Aquatec will benefit significantly economically from development of a human stunning system for fish.
6) An important part of this proposal is the development of new neurophysiological techniques to evaluate the effectiveness of stunning in fish. These methodologies will benefit academics working in the field of slaughter research, both in fish and other species.
| Description | On analysis of video data fish that were stunned by application of the electric field displayed generalized seizure-like activity associated with a cessation of normal swimming behaviour immediately afterwards that was prolonged for approximately 20-30 seconds whereas in fish that were not stunned, the period of seizure-like activity was absent and fish continued to swim normally or showed a brief period of excitation following the application of the electric field. Cessation of breathing (absence of opercular movements) was evident in fish that were stunned whereas in fish that were not stunned normal opercular activity continued. The videos were not of sufficient quality to interrogate eye position during or after application of the electric field. Total Power of the EEG increased in the immediate period after application of the electric field in fish that were judged to have been effectively stunned and fish that were judged not to have been stunned with no statistically significant difference in this increase in Total Power between groups. The Total Power decreased to around baseline value in the suppression phase, with no statistically significant difference between groups. Median Frequency increased immediately after application of the electric field and was statistically significantly higher in the group of fish that were stunned. F50 remained around baseline values in the group of fish that were not stunned but was almost triple the baseline values in the group of fish that were stunned, at a median value of 291%. In the suppression phase median frequency also remained higher than baseline values in the stunned fish and was statistically significantly different between groups. Changes in spectral edge frequency 95% followed a similar pattern to median frequency in the fish that were effectively stunned by application of the electric field. It remained around baseline values in the fish that were not effectively stunned, increasing to higher than baseline in the fish that were effectively stunned, with the difference in F95 being statistically significantly different between groups. In the suppression phase F95 was also significantly higher in the fish that were effectively stunned. Recovery time (time taken to resume normal swimming after the stun) was significantly positively correlated with the electric field strength. We have found that there are differences in the brain activity of fish shortly after electrical stunning between fish that are adequately stunned and fish that are inadequately stunned. This will enable us to test new electrical stunning equipment to see whether it adequately stuns fish or not - an important question from a welfare perspective of fish. |
| Exploitation Route | The findings in terms of brain activity can be used to determine the efficacy of electrical stunning equipment for fish. |
| Sectors | Agriculture, Food and Drink,Government, Democracy and Justice |
| Description | Collaboration with Ace Aquatec Ltd |
| Organisation | Ace Aquatec Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | The award was in collaboration with Ace Aquatec Ltd. We worked closely with the industrial partner throughout the project with the direction of the research being driven by the commercial needs of the company. |
| Collaborator Contribution | The industrial partners showed us the industry need for the research and therefore the direction that the research should take throughout the project |
| Impact | We engaged with Ace Aquatec to facilitate their exploitation plan of promoting electric stunning equipment in Norway. We produced a supportive letter to the Animal welfare body in Norway, summarising our current research project on humane electrical stunning and the importance scientific data that can be directly applied to newly built stunning machines. This process is ongoing and Norwegian industry has started adopting Ace Aquatec stunning machines as Norwegian authorities been advised to change their current methodologies (e.g. CO2 stunning) into more humane stunning methods like electric stunning as indicated by European Food Standard Authority (EFSA). |
| Start Year | 2016 |
| Description | Fish veterinary society |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | 3. "Welfare of fish at slaughter" invited speech at Fish Veterinary Society Meeting (FVS), Edinburgh on 29th March 2017 |
| Year(s) Of Engagement Activity | 2017 |
| Description | Winterbotham Darby Day |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | 2. "Welfare of fish at slaughter" at WinterBotham Darby Subject day 23rd March 2017 at university of Bristol |
| Year(s) Of Engagement Activity | 2017 |