Low frequency vibrations are detected by the lateral line system of sense organs that run along the length of the sides of fish, and these respond to nearby movements and to changes in water pressure.
lˈoʊ fɹˈiːkwənsi vˌaɪbɹˈeɪʃənz ɑːɹ dɪtˈɛktᵻd baɪ ðə lˈæɾɚɹəl lˈaɪn sˈɪstəm ʌv sˈɛns ˈɔːɹɡənz ðæt ɹˈʌn ɐlˈɔŋ ðə lˈɛŋθ ʌvðə sˈaɪdz ʌv fˈɪʃ, ænd ðiːz ɹᵻspˈɑːnd tə nˈɪɹbaɪ mˈuːvmənts ænd tə tʃˈeɪndʒᵻz ɪn wˈɔːɾɚ pɹˈɛʃɚ.