Summary of environmental parameters, finless porpoise echolocation click and click train parameters at Seto Inland Sea (St. S) and Mikawa Bay (St. M).

The summary shows environmental parameters (temperature, synthetic flow velocity, and noise level), echolocation click parameters (ASL, peak frequency, center frequency, -3 dB BW, and click duration), and click train parameters (ICI, number of clicks per train, and range from array). ASL was compared using Student’s t-test, while the other parameters were compared using Mann–Whitney U-test to determine significant differences between the sites. 0.01 ≤ p < 0.05 is denoted as > or < and p < 0.01 is denoted as >> or <<; > and >> indicate that the parameter in St. S were larger than that at St. M, while < and << indicate that the parameters in St. M were larger than those in St. S.