Assessing the effectiveness of an electrical stunning and chilling protocol for the slaughter of Atlantic mackerel (Scomber scombrus)

Inducing unconsciousness in fish using electrical stunning prior to slaughter may improve fish welfare and fillet quality if such practises can be disseminated into wild capture fisheries. The objectives of this study were to: 1) evaluate if an established slaughter protocol consisting of dry electrical stunning (using a coupled AC/DC current at ≈ 110 Vrms) followed by chilling could be used to stun the wild captured species Atlantic mackerel (Scomber scombrus) unconscious within 0.5 s; 2) determine if death could be induced without consciousness recovery by longer duration stunning (5 s) combined with chilling in an ice/water slurry for 6 min; and 3) examine the extent of quality defects arising from the applied slaughter protocol. We determined consciousness by examination of behavioural responses in a standardised vitality assessment. Out of a sample of 10 mackerel, 9 were assumed to be rendered unconscious by the 0.5 s stun, as determined by the presence of tonic and/or clonic muscle cramping consistent with a general epileptic insult. Assumed unconsciousness was maintained throughout chilling treatment in all fish (n = 25) following a full stun of 5 s. All fish were assumed to have died as a result of the protocol. There was no evidence of spinal damage or haematoma quality defects post filleting. These results suggest that the examined protocol is effective at slaughtering mackerel in a manner consistent with good welfare and without inducing quality defects, but further research is required to verify the unconscious condition via electroencephalogram (EEG) and before the procedure can be applied in wild capture fisheries.publishedVersio

Electrical stunning and killing of Atlantic salmon

Source at https://nofima.no/publikasjon/2208193/.Atlantic salmon (Salmo salar) at various size 226-1938 g were placed in electric dry stunning either tailor head- first and then exposed to 50 Hz, 240 V AC for 0.5 and thereafter 9.5 s of electricity. This to verify whether the animal is rendered unconscious prior to killing by immersing the animal into cold brine (-14 to -18 °C) or hypoxic water, supersaturated with CO2. In addition, salmon from 2000 to 5000 g were exposed to head stunning only. Behaviour, heart (ECG) and brain (EEG) activity were monitored until animal was classed as dead. Post the treatment, the internal temperature of the animal was measured placing loggers into the neuro and heart cavity. The electric potential across the brain was also measured. A preliminary evaluation of the EEG and ECG registrations in the individual fish showed that loss of consciousness can be induced within 0.5 second and consciousness can be prolonged without recovery when the cold brine or seawater saturated with carbon dioxide is applied as killing method. Our results also suggest that the current can be applied head to tail, which facilitates immediate stunning of Atlantic salmon in a commercial setting. We conclude that electrical stunning in combination with cold brine is effective for humane stunning and killing Atlantic salmon

Electrical stunning and killing of Atlantic salmon

Atlantic salmon (Salmo salar) at various size 226-1938 g were placed in electric dry stunning either tailor head- first and then exposed to 50 Hz, 240 V AC for 0.5 and thereafter 9.5 s of electricity. This to verify whether the animal is rendered unconscious prior to killing by immersing the animal into cold brine (-14 to -18 °C) or hypoxic water, supersaturated with CO2. In addition, salmon from 2000 to 5000 g were exposed to head stunning only. Behaviour, heart (ECG) and brain (EEG) activity were monitored until animal was classed as dead. Post the treatment, the internal temperature of the animal was measured placing loggers into the neuro and heart cavity. The electric potential across the brain was also measured. A preliminary evaluation of the EEG and ECG registrations in the individual fish showed that loss of consciousness can be induced within 0.5 second and consciousness can be prolonged without recovery when the cold brine or seawater saturated with carbon dioxide is applied as killing method. Our results also suggest that the current can be applied head to tail, which facilitates immediate stunning of Atlantic salmon in a commercial setting. We conclude that electrical stunning in combination with cold brine is effective for humane stunning and killing Atlantic salmon.Electrical stunning and killing of Atlantic salmonpublishedVersio

Behavioural effects of seismic dose escalation exposure on captive mackerel (Scomber scombrus)

Petroleum and fisheries are two of the most important industries in Norway, and the goal for management is sustainable coexistence for both. Mackerel is an important pelagic fishery resource, and mackerel can very well detect the seismic sound signals. The aim of this project was to investigate the behavioural responses of mackerel to seismic signals, and to evaluate potential responses in terms of affecting the fishery. Wild captured mackerel in a net pen was exposed to escalating seismic signals from an approaching source vessel, while behaviour was constantly monitored with video and echosounder, as well as the sound pressure level and particle motion level recorded with hydrophone and particle motion sensor, respectively. Fish behavior was analyzed in terms of swimming speed, vertical distribution, schooling and group dynamic. We aimed at conducting a dose escalation to identify the sound level at which a response is initiated. No clear responses were identified in response to the sound exposure. In addition, behavioural responses of farmed salmon and rainbow trout was monitored by video surveillance at three close-by aquaculture farms to avoid any potential harmful effects on the farmed fish. However, no behavioural responses in terms of swimming dynamic, swimming speed and collective behavior were observed from these videos .publishedVersio

Havforskningsinstituttets rådgivning for menneskeskapt støy i havet: seismikk, elektromagnetiske undersøkelser og undersjøiske sprengninger

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A Flexible Autonomous Robotic Observatory Infrastructure for Bentho-Pelagic Monitoring

This paper presents the technological developments and the policy contexts for the project “Autonomous Robotic Sea-Floor Infrastructure for Bentho-Pelagic Monitoring” (ARIM). The development is based on the national experience with robotic component technologies that are combined and merged into a new product for autonomous and integrated ecological deep-sea monitoring. Traditional monitoring is often vessel-based and thus resource demanding. It is economically unviable to fulfill the current policy for ecosystem monitoring with traditional approaches. Thus, this project developed platforms for bentho-pelagic monitoring using an arrangement of crawler and stationary platforms at the Lofoten-Vesterålen (LoVe) observatory network (Norway). Visual and acoustic imaging along with standard oceanographic sensors have been combined to support advanced and continuous spatial-temporal monitoring near cold water coral mounds. Just as important is the automatic processing techniques under development that have been implemented to allow species (or categories of species) quantification (i.e., tracking and classification). At the same time, real-time outboard processed three-dimensional (3D) laser scanning has been implemented to increase mission autonomy capability, delivering quantifiable information on habitat features (i.e., for seascape approaches). The first version of platform autonomy has already been tested under controlled conditions with a tethered crawler exploring the vicinity of a cabled stationary instrumented garage. Our vision is that elimination of the tether in combination with inductive battery recharge trough fuel cell technology will facilitate self-sustained long-term autonomous operations over large areas, serving not only the needs of science, but also sub-sea industries like subsea oil and gas, and mining

Advice from the Institute of Marine Research on anthropogenic noise in the sea

Havforskningsinstituttet gir råd for alle operasjoner til havs som involverer bruk av lydkilder som kan påvirke marine økosystemer. Dette inkluderer vitenskapelige undersøkelser, utbygging og sprenging i sjø, seismiske og elektromagnetiske undersøkelser i forbindelse med petroleumsvirksomhet og utbygging og drift av vindkraftanlegg til havs. Denne rapporten er en sammenstilling av tilgjengelig kunnskap omkring hvordan de overnevnte typer av undersjøisk støy påvirker livet i havet. Videre evalueres denne kunnskapen i lys av hvilke konsekvenser dokumenterte effekter kan gi på økosystemet. Denne rapporten er inndelt med et kapittel for hver av de overnevnte støykildene (seismikk, elektromagnetiske undersøkelser, undersjøiske sprenginger og vindkraft til havs), som igjen er inndelt i delkapitler med 1) kunnskapsgrunnlag, 2) konsekvensvurdering og 3) råd. Rapporten inneholder konkrete råd fra Havforskningsinstituttet for 2022 for de ulike typene av støy.The Institute of Marine Research (IMR) is responsible to provide advice on the impact of anthropogenic sound sources on marine life. This include scientific instigations, underwater explosions, seismic and electromagnetic surveys related to petroleum activity and offshore wind installations. This report intends to summarize available literature on how the above-mentioned sound sources impact marine life. Further, this knowledge is evaluated to show the reader the reasoning behind the advices given. This report give one chapter for each of those sound sources (seismic, underwater explosions, electromagnetic investigations and offshore wind), again separated into subchapters of 1) review of scientific knowledge, 2) evaluation of knowledge and 3) advice. This report includes the advices from IMR for the topics seismic surveys, electromagnetic surveys, underwater explosions and offshore wind valid for 2022.publishedVersio

Advice from the Institute of Marine Research on anthropogenic noise in the sea

Havforskningsinstituttet gir råd for alle operasjoner til havs som involverer bruk av lydkilder som kan påvirke marine økosystemer. Dette inkluderer vitenskapelige undersøkelser, utbygging og sprenging i sjø, seismiske og elektromagnetiske undersøkelser i forbindelse med petroleumsvirksomhet og utbygging og drift av vindkraftanlegg til havs. Denne rapporten er en sammenstilling av tilgjengelig kunnskap omkring hvordan de overnevnte typer av undersjøisk støy påvirker livet i havet. Videre evalueres denne kunnskapen i lys av hvilke konsekvenser dokumenterte effekter kan gi på økosystemet. Denne rapporten er inndelt med et kapittel for hver av de overnevnte støykildene (seismikk, elektromagnetiske undersøkelser, undersjøiske sprenginger og vindkraft til havs), som igjen er inndelt i delkapitler med 1) kunnskapsgrunnlag, 2) konsekvensvurdering og 3) råd. Rapporten inneholder konkrete råd fra Havforskningsinstituttet for 2022 for de ulike typene av støy.The Institute of Marine Research (IMR) is responsible to provide advice on the impact of anthropogenic sound sources on marine life. This include scientific instigations, underwater explosions, seismic and electromagnetic surveys related to petroleum activity and offshore wind installations. This report intends to summarize available literature on how the above-mentioned sound sources impact marine life. Further, this knowledge is evaluated to show the reader the reasoning behind the advices given. This report give one chapter for each of those sound sources (seismic, underwater explosions, electromagnetic investigations and offshore wind), again separated into subchapters of 1) review of scientific knowledge, 2) evaluation of knowledge and 3) advice. This report includes the advices from IMR for the topics seismic surveys, electromagnetic surveys, underwater explosions and offshore wind valid for 2022