IMIS

Seismic surveys are used to map oil deposits under the sea bed, and are a major source of noise in the ocean. Seismic sound pulses are a loud and of low frequency, and can travel for great distances. They are audible for most fish species, and can be heard at distances over 100 km away from the source. At very close range the seismic noise can injure and even kill fish, but behavioral responses, such as avoidance, changed swimming behavior, and reduced feeding has been documented at distances of tens of kilometers. In the SpawnSeis project, we study effects of seismic surveys on the behavior of wild, free ranging, spawning cod using acoustic telemetry in Austevoll, Norway. Cod movements will be studied on two spawning grounds (one to be exposed to seismic surveys and one reference area) during three consecutive spawning seasons. The 2019 spawning season will act as a baseline for both sites. The following years; 2020 and 2021 a seismic survey will be conducted at the exposure site. This will enable us to study changes in behavior, including potential avoidance, in relation to the seismic sound both within and between spawning seasons, as well as to study basic cod behavior.