Increased noise in the ocean seems to reduce the mating propensity of fish. A new dissertation indicates that sound pollution impedes reproduction of sand gobies and common gobies, which are an important food source for young cod.
Noise in the ocean cannot be seen, nor can we hear it above the surface. Sound travels almost five times faster in the sea than in air, and it carries a much greater distance. “We can record boats that are far out of sight, and the sound is basically unchanged,” says Eva-Lotta Blom, at the Department of Biological and Environmental Sciences, which is examining how the mating of sand and common gobies is affected by sound in the water. “You could compare it to living in Gothenburg and at the same time hearing all the cars driving in Stockholm. That would amount to a great racket, and it would probably not be permitted, because it exceeds the noise level considered to be harmful. However, this does not apply in the ocean, where we don’t have clear rules for noise limits.”