Data from: The noise egg: a cheap and simple device to produce low-frequency underwater noise for laboratory and field experiments

Studying the effect of anthropogenic noise on animal behaviour and
physiology is a field of growing scientific and management interest.
Anthropogenic noise is internationally seen as major environmental
concern, but knowledge of the response of animals to noise and its
ecological and evolutionary consequences is disparate. Even though fish
and invertebrates form the majority of aquatic taxa, the effects of noise
on these taxa are largely understudied. Especially the consequences of
noise for short-range communication and behavioural interactions are yet
unknown. While experimental studies on this subject are thus greatly
needed, the expense of the equipment can be a main factor limiting data
generation. Speakers that produce low-frequency sounds under water are
currently either too large or too expensive to allow for sufficient
replication in many research set-ups. Here, we describe a device that can
produce a low-frequency sound, which can be used as an experimental source
of noise both in aquaria and in the field. The device is completely
self-contained and costs around 10 euros per ‘noise egg’. The sound
created consists of frequency bands (harmonics), which has the advantage
that broadband and pulsed sounds, such as sounds produced by vocal fish,
are easily detected in a spectrogram. Because the sound from the egg
attenuates quickly, it can be used in aquaria and in the field to target
certain study species or individuals without affecting a large part of the
surrounding area. We have developed the device to study the effects of
noise on communication and behaviour in small aquatic animals; however, it
could be used for other purposes, such as testing the propagation of
certain frequencies in shallow-water habitats. We hope the described
method will facilitate the generation of experimental data on the effect
of noise on behaviour and communication in aquatic animals in a wide
variety of study systems and study areas.