Meeting Abstract
Over the last few decades, anthropogenic noise has increased underwater ambient sound levels by >30dB in the range that most fishes detect and produce acoustic signals. Although the impacts of increased background noise on fish development have been studied in a variety of species, there is a paucity of information on how noise affects parental care. Mouth brooding is an energetically costly form of parental care in which the brooding fish carries developing larvae in the buccal cavity for the duration of development. In the African cichlid Astatotilapia burtoni, females carry their brood for ~2 weeks during which time she also starves herself. To test the hypothesis that increased background noise impacts maternal care behaviors and brood development, we exposed brooding females to a period of excess noise (~140dB) played through an underwater speaker. Over half of noise-exposed brooding females cannibalized or pre-maturely released their brood, but all silent control females exhibited normal brooding behaviors. Juveniles that were exposed to noise during their brood period had lower growth rates and higher mortality rates than control broods. Further, onset of adult-typical coloration and behaviors was delayed compared to control fish. Because acoustic overstimulation can damage hair-cell based sensory systems, we are currently examining how anthropogenic noise affects development of the lateral line and auditory systems. To our knowledge, this is the first study to examine the impact of excess noise on a mouth brooding fish. As such, these results have important conservation and management implications for protecting against noise-induced effects on maternal care behaviors, development, and ultimately animal survival.
