Evaluation of Fisheries Sonar for Whale Detection in Relation to Seismic Survey Operations

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SpawnSeis MV exposure experiment - Survey Report — IMR Survey number 2022812

In the project SpawnSeis MV, we aimed to study how a novel seismic source, a marine vibrator, affects behaviour and acoustic communication of wild, free ranging, spawning cod. Cod behaviour was studied by using acoustic telemetry to track movement of individual cod in Austevoll, Norway. During the cod spawning season in 2020 and 2021, a 5-day exposure survey with seismic airguns was used to examine cod movement in response to such sound exposure. In the spawning season of 2022, an exposure survey with a marine vibrator was conducted to evaluate differences between how cod respond to these two types of seismic testing (airguns and marine vibrator). The current cruise report describes the exposure survey with the marine vibrator.SpawnSeis MV exposure experiment - Survey Report — IMR Survey number 2022812publishedVersio

Forskerutvalg om sjøpattedyr 2020 - Tilrådning om forskning og forvaltning

Forskerutvalg om sjøpattedyr som ble opprettet i 2009, består av femten forskere fra syv forskningsinstituttet i Norge. Utvalget møttes 22.-23. oktober i Tromsø for å utarbeide anbefalinger om forvaltning, vern og forskning på sjøpattedyr i 2021.publishedVersio

Lack of behavioural responses of humpback whales (Megaptera novaeangliae) indicate limited effectiveness of sonar mitigation

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Spawning Atlantic cod (Gadus morhua L.) exposed to noise from seismic airguns do not abandon their spawning site

Seismic airgun surveys may disturb and displace fish at large ranges. If such displacement causes fish to abandon spawning grounds, reproductive success could be impacted. To investigate whether airgun sound causes cod (Gadus morhua L.) to leave their spawning grounds, acoustic telemetry arrays were deployed on two cod spawning grounds: a test and a reference site. From 2019 to 2021, 136 mature cod from the test site and 45 from the reference site were tagged with acoustic transmitters. Intermittent seismic shooting of two 40 in.3 airguns for 1 week during the spawning periods of 2020–2021 resulted in fluctuating sound exposure levels (SEL) at the test site, comparable to a full-scale industrial survey 5–>40 km away. Residency and survival of tagged cod were analysed with capture–mark–recapture models fitted to the detection and recapture data. Departure rate of the mature cod varied between spawning seasons but was similar between the test and reference sites. Neither survival nor departure significantly differed between seismic exposure and baseline periods. The results indicated that exposure to airguns at received SEL of up to ∼145 dB re 1 μPa2 s, comparable to a seismic survey occurring several kilometres away, did not displace tagged cod from spawning grounds.publishedVersio

Sperm whales reduce foraging effort during exposure to 1-2 kH z sonar and killer whale sounds

We would like to thank 3S partners and funders especially for enabling this research (NL Ministry of Defence, NOR Ministry of Defence, US Office of Naval Research, and World Wildlife Fund, Norway). PLT was supported by the Scottish Funding Council (grant HR09011) through the Marine Alliance for Science and Technology for Scotland.The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kH z, source level 214 dB re 1 μPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records). Time spent in foraging states and the probability of prey capture attempts were reduced during these two types of exposures with little change in overall locomotion activity, suggesting an effect on energy intake with no immediate compensation. Whales switched to the active non-foraging state over received sound pressure levels of 131-165 dB re 1 μPa during LFAS exposure. In contrast, no changes in foraging behavior were detected in response to experimental negative controls (no-sonar ship approach or noise control playback) or to experimental medium-frequency active sonar exposures (MFAS; 6-7 kH z, source level 199 re 1 μPa m, received sound pressure level [SPL] = 73-158 dB re 1 μPa). Similarly, there was no reduction in foraging effort for three whales exposed to incidental, unidentified 4.7-5.1 kH z sonar signals received at lower levels (SPL = 89-133 dB re 1 μPa). These results demonstrate that similar to predation risk, exposure to sonar can affect functional behaviors, and indicate that increased perception of risk with higher source level or lower frequency may modulate how sperm whales respond to anthropogenic sound.Publisher PDFPeer reviewe

Behavioural responses of wild, spawning Atlantic cod (Gadus morhua L.) to seismic airgun exposure

Seismic airgun surveys to map petroleum deposits in the seabed may impact behaviour of marine animals over large distances. Understanding whether fish spawning behaviour is affected by this anthropogenic noise source is important because reproductive success may be impacted. The fine-scale behavioural responses of Atlantic cod to airgun exposure over an extended period were investigated using an acoustic telemetry positioning system on a spawning ground in Norway. During 2019 to 2021, 135 spawning cod were equipped with telemetry sensor tags and were exposed to airgun shooting during the spawning periods of 2020 and 2021, with varying received sound levels comparable to a full-scale survey at distances of 5 to >40 km. Cod demonstrated only weak responses to the disturbance from repeated 3-h treatment periods over 5-d, swimming on average slightly deeper during seismic exposure compared to silent control periods. This response varied between individuals. Longer-term effects of seismic exposure on swimming depth were not detected. No changes in swimming acceleration, displacement, or area use occurred. These results suggest that relatively distant seismic surveys do not substantially alter cod behaviour during the spawning period at received sound exposure levels varying between 115 and 145 dB re 1 µPa2s over a 5-d period.publishedVersio

First indications that northern bottlenose whales are sensitive to behavioural disturbance from anthropogenic noise

-Although northern bottlenose whales were the most heavily hunted beaked whale, we have little information about this species in its remote habitat of the North Atlantic Ocean. Underwater anthropogenic noise and disruption of their natural habitat may be major threats, given the sensitivity of other beaked whales to such noise disturbance. We attached dataloggers to 13 northern bottlenose whales and compared their natural sounds and movements to those of one individual exposed to escalating levels of 1–2 kHz upsweep naval sonar signals. At a received sound pressure level (SPL) of 98 dB re 1 μPa, the whale turned to approach the sound source, but at a received SPL of 107 dB re 1 μPa, the whale began moving in an unusually straight course and then made a near 180° turn away from the source, and performed the longest and deepest dive (94 min, 2339 m) recorded for this species. Animal movement parameters differed significantly from baseline for more than 7 h until the tag fell off 33–36 km away. No clicks were emitted during the response period, indicating cessation of normal echolocation-based foraging. A sharp decline in both acoustic and visual detections of conspecifics after exposure suggests other whales in the area responded similarly. Though more data are needed, our results indicate high sensitivity of this species to acoustic disturbance, with consequent risk from marine industrialization and naval activity

Effekter av menneskeskapt støy på havmiljø. Rapport til Miljødirektoratet om kunnskapsstatus.

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Flerspråkig undervisning av nyanlända elever – transspråkande i en språkintroduktionskontext

Föreliggande studie undersöker transspråkande i undervisningen av flerspråkiga nyanlända elever på en gymnasieskolas Språkintroduktionsprogram med hjälp av följande frågor: Hur uppmuntras och används transspråkande av lärarna i undervisningen? På vilka sätt beskriver modersmålslärarna att flerspråkiga nyanlända elevers möjligheter till lärande påverkas av en undervisningspraktik som tillåter och uppmuntrar transspråkande? Forskning har visat att stöttning på modersmålet är en viktig faktor för nyanlända elevers skolframgång, samt har en positiv inverkan för andraspråkets utveckling. Modersmålslärarna blir därför betydelsefulla i undervisning som riktar sig till flerspråkiga nyanlända elever. På skolan där studien är genomförd har rektor organiserat undervisning i ämnet samhällskunskap så att fyra modersmålslärare och en ämneslärare, med svenska som modersmål, arbetar tillsammans i klassrummet och på så vis skapat förutsättningar för en flerspråkig undervisning. Det empiriska materialet består av fältanteckningar, som producerats genom deltagande observationer av undervisningen i praktiken, och av transkriberat material från enskilda kvalitativa intervjuer med modersmålslärarna. Resultatet visar att lärarna använder flera språk och multimodala resurser som stöttning i kommunikationsprocesserna och uppmuntrar och tillåter eleverna att använda sina olika språkliga resurser för att stötta varandra i planerade samarbetsinriktade aktiviteter. Modersmålslärarna beskriver att en flerspråkig undervisning kan påverka flerspråkiga nyanlända elevers lärande positivt eftersom eleverna blir mer delaktiga, intresserade av och motiverade till skolarbetet. Men, det framkommer även uppfattningar om att en transspråkande undervisning innebär utmaningar, såsom att samarbeta kring och att planera en sådan undervisning så att alla elever ges likvärdiga förutsättningar för kunskapsmässig och personlig utveckling, vilket uppfattas kunna påverka nyanlända elevers möjligheter att utveckla sina språk- och ämneskunskaper