SpawnSeis: Effects of seismic sound on spawning behaviour and reproductive sucsess of cod (completed)

• Opdal, Anders Martin Frugård; Alix, Maud; Kjesbu, Olav Sigurd; Jørgensen, Christian; Langangen, Øystein Ole Gahr & Karlsen, Ørjan [Show all 11 contributors for this article] (2026). Despite temperature effects on gonad development, timing of spawning is remarkably flexible in Atlantic cod. ICES Journal of Marine Science. ISSN 1054-3139. 83(2), p. 1–12. doi: 10.1093/icesjms/fsag020. Full text in Research Archive Show summary

  At high latitudes, early life stage survival of fish is often associated with how spawning time relates to the timing of the spring bloom. With ocean warming, basic physiological rates of ectotherms, like fish, will speed up—including gonadal development rates, which dictate spawning time. Since warmer water is thought to influence the spring bloom timing differently than that of fish spawning time, the two may fall out of synchrony in the future. The precise mechanisms between temperature and gonadal development and spawning time have, however, been difficult to disentangle. Here, we take advantage of a series of independent laboratory experiments measuring individual oocyte development up to or near spawning for 153 Atlantic cod (Gadus morhua) kept between 3 and 12°C. From these data we derive a predictive, mechanistic equation for daily oocyte growth rate as a function of temperature and oocyte developmental status (diameter). The vitellogenic oocyte growth follows an accelerating pattern, and the model predicts that spawning can advance by up to 7 days per 1°C increase. Within-treatment variation is, however, of comparable magnitude to between-treatment temperature effects. The model was also tested in the field by back-calculating oocyte development of 82 fish (2018–2021) sampled at two locations along the Norwegian coast, using daily ambient temperatures from telemetry tags during vitellogenesis as model input. We find that Atlantic cod are able to initiate vitellogenesis over a period of several months in late summer and autumn, as well as regulate the oocyte development rate across a wide range of temperatures—both leading to significant phenotypic plasticity in spawning phenology.

• Vereide, Emilie Hernes; Mihaljevic, Marina; Browman, Howard; Fields, David M.; Agersted, Mette Dalgaard & Titelman, Josefin [Show all 7 contributors for this article] (2023). Effects of airgun discharges used in seismic surveys on development and mortality in nauplii of the copepod Acartia tonsa. Environmental Pollution. ISSN 1566-0745. 327. doi: 10.1016/j.envpol.2023.121469. Full text in Research Archive Show summary

  Seismic surveys are conducted worldwide to explore for oil and gas deposits and to map subsea formations. The airguns used in these surveys emit low-frequency sound waves. Studies on zooplankton responses to airguns report a range of effects, from none to substantial mortality. A field experiment was conducted to assess mortality and naupliar body length of the calanoid copepod Acartia tonsa when exposed to the discharge of two 40-inch airguns. Nauplii were placed in plastic bags and attached to a line at a depth of 6 m. For each treatment, three bags of nauplii were exposed to one of three treatments for 2.5 h: Airgun array discharge, a boat control, or a silent control. After exposure, nauplii were kept in filtered seawater in the laboratory without food. Immediate mortality in the nauplii was approximately 14% compared to less than 4% in the silent and boat control. Similarly, there was higher mortality in the airgun exposed nauplii up to six days after exposure compared to the control treatments. Nearly all of the airgun exposed nauplii were dead after four days, while >50% of the nauplii in the control treatments were alive at six days post-exposure. There was an interaction between treatment and time on naupliar body length, indicating lower growth in the nauplii exposed to the airgun discharge (growth rates after 4 days: 1.7, 5.4, and 6.1 μm d−1 in the airgun exposed, silent control, and boat control, respectively). These experiments indicate that the output of two small airguns affected mortality and growth of the naupliar stages of Acartia tonsa in close vicinity to the array.

• Seri, Sai Geetha; Schinault, Matthew Edward; Penna, Seth Michael; Zhu, Chenyang; Sivle, Lise Doksæter & Jong, Karen de [Show all 8 contributors for this article] (2023). Characterizing coastal cod vocalization using a towed hydrophone array. ICES Journal of Marine Science. ISSN 1054-3139. 80(6), p. 1727–1745. doi: 10.1093/icesjms/fsad104. Full text in Research Archive Show summary

  To better understand spawning vocalizations of Norwegian coastal cod (Gadus morhua), a prototype eight-element coherent hydrophone array was deployed in stationary vertical and towed horizontal modes to monitor cod sounds during an experiment in spring 2019. Depth distribution of cod aggregations was monitored concurrently with an ultrasonic echosounder. Cod vocalizations recorded on the hydrophone array are analysed to provide time–frequency characteristics, and source level distribution after correcting for one-way transmission losses from cod locations to the hydrophone array. The recorded cod vocalization frequencies range from ∼20 to 600 Hz with a peak power frequency of ∼60 Hz, average duration of 300 ms, and mean source level of 163.5 ± 7.9 dB re 1 μPa at 1 m. Spatial dependence of received cod vocalization rates is estimated using hydrophone array measurements as the array is towed horizontally from deeper surrounding waters to shallow water inlet areas of the experimental site. The bathymetric-dependent probability of detection regions for cod vocalizations are quantified and are found to be significantly reduced in shallow-water areas of the inlet. We show that the towable hydrophone array deployed from a moving vessel is invaluable because it can survey cod vocalization activity at multiple locations, providing continuous spatial coverage that is complementary to fixed sensor systems that provide continuous temporal coverage at a given location.

• Sivle, Lise Doksæter; Jong, Karen de; Vereide, Emilie Hernes; Forland, Tonje Nesse; Wehde, Henning & Dalen, John (2021). Effects of sound from seismic surveys on fish reproduction, the management case from Norway. Journal of Marine Science and Engineering (JMSE). 9. doi: 10.3390/jmse9040436. Full text in Research Archive Show summary

  Anthropogenic noise has been recognized as a source of concern since the beginning of the 1940s and is receiving increasingly more attention. While international focus has been on the effects of noise on marine mammals, Norway has managed seismic surveys based on the potential impact on fish stocks and fisheries since the late 1980s. Norway is, therefore, one of very few countries that took fish into account at this early stage. Until 1996, spawning grounds and spawning migration, as well as areas with drifting eggs and larvae were recommended as closed for seismic surveys. Later results showed that the effects of seismic surveys on early fish development stages were negligible at the population level, resulting in the opening of areas with drifting eggs and larvae for seismic surveys. Spawning grounds, as well as concentrated migration towards these, are still closed to seismic surveys, but the refinement of areas and periods have improved over the years. Since 2018, marine mammals have been included in the advice to management. The Norwegian case provides a clear example of evidence-based management. Here, we examine how scientific advancements informed the development of Norwegian management and how management questions were incorporated into new research projects in Norway.

• Jong, Karen de; Forland, Tonje Nesse; Amorim, Maria Clara P.; Rieucau, Guillaume; Slabbekoorn, Hans & Sivle, Lise Doksæter (2020). Predicting the effects of anthropogenic noise on fish reproduction. Reviews in Fish Biology and Fisheries. ISSN 0960-3166. 30(2), p. 245–268. doi: 10.1007/s11160-020-09598-9. Full text in Research Archive Show summary

  Aquatic animals use and produce sound for critical life functions, including reproduction. Anthropogenic noise is recognized as a global source of environmental pollution and adequate conservation and management strategies are urgently needed. It becomes therefore critical to identify the reproductive traits that render a species vulnerable to acoustic disturbances, and the types of anthropogenic noise that are most likely to impact reproduction. Here, we provide predictions about noise impact on fish reproduction following a two-step approach: first, we grouped documented effects of noise into three mechanistic categories: stress, masking and hearing-loss, and test which type of noise (continuous vs intermittent and regular vs irregular) was most likely to produce a significant response in each category with either a meta-analysis or a quantitative review, depending on data availability. Second, we reviewed existing literature to predict which reproductive traits would render fish most sensitive to stress, masking and hearing-loss. In step one, we concluded that continuous sounds with irregular amplitude and/or frequency-content (e.g. heavy ship traffic) were most likely to cause stress, and continuous sounds were also most likely to induce masking and hearing-loss. From step two we concluded that the vulnerability of a species to noise-induced stress will mainly depend on: (1) its potential to reallocate reproduction to more quiet times or locations, and (2) its vulnerability to masking and hearing-loss mainly on the function of sound communication in its reproductive behaviour. We discuss in which stages of reproduction fish are most likely to be vulnerable to anthropogenic noise based on these findings.

View all works in NVA

• Jong, Karen de (2019). Testar seismikk på gytetorsk. [Journal]. Marsteinen. Full text in Research Archive
• Jong, Karen de (2019). Her ror forskerne frem og tilbake i fjorden mens de utsetter torsk for seismikk. [Internet]. Tekfisk. Full text in Research Archive
• Jong, Karen de (2019). Fiskelyd og reproduksjon og menneskeskapt støy. Full text in Research Archive
• Nyqvist, Daniel; Sivle, Lise Doksæter; Karlsen, Ørjan; Olsen, Esben Moland; Jong, Karen de & Forland, Tonje Nesse [Show all 7 contributors for this article] (2019). Behaviour of spawning cod in relation to marine seismic surveys. Full text in Research Archive
• Nyqvist, Daniel; Sivle, Lise Doksæter; Karlsen, Ørjan; Olsen, Esben Moland; Jong, Karen de & Forland, Tonje Nesse [Show all 7 contributors for this article] (2019). Do seismic surveys affect the behavior of spawning cod? Full text in Research Archive
• Nyqvist, Daniel; Forland, Tonje Nesse; Sivle, Lise Doksæter; Durif, Caroline; Johnsen, Magnar Gullikstad & Jong, Karen de (2019). Electric and magnetic senses in marine animals , and potential effects of electromagnetic surveys. Full text in Research Archive
• Jong, Karen de; Forland, Tonje Nesse; Amorim, M. Clara P.; Rieucau, Guillaume; Slabbekoorn, Hans & Sivle, Lise Doksæter (2019). How could we predict effects of noise on fish reproduction. Full text in Research Archive
• Jong, Karen de; Forland, Tonje Nesse; Amorim, M. Clara P.; Rieucau, Guillaume; Slabbekoorn, Hans & Sivle, Lise Doksæter (2019). Integrating existing knowledge to predict effects of anthropogenic noise on fish reproduction. Full text in Research Archive
• Sivle, Lise Doksæter; Jong, Karen de; Nyqvist, Daniel & Bjelland, Reidun Marie (2019). Informasjonsmøte - Telemetri og torsk på Austevoll. Full text in Research Archive
• Nyqvist, Daniel & Sivle, Lise Doksæter (2018). Skal testa seismikk i Austevoll. [Journal]. Marsteinen. Full text in Research Archive
• Jong, Karen de; Forland, Tonje Nesse; Nyqvist, Daniel & Sivle, Lise Doksæter (2018). Konsekvenser av seismikk. Full text in Research Archive
• Jong, Karen de; Forland, Tonje Nesse; Nyqvist, Daniel & Sivle, Lise Doksæter (2018). The SpawnSeis-project. Testing the impact of seismic sound on spawning cod. Full text in Research Archive

View all works in NVA