Frequency of different types of trajectory by diel phase.

<p>To calculate the frequency of occurrence of each trajectory type, all of the trajectories recorded in each diel phase were first classified by type and then divided by the total recording time for each diel phase.</p

Descriptive statistics of the different trajectory types.

<p>The duration of each type of trajectory (in min) is given as the mean ± standard error (SE) with minimum (Min) and maximum (Max) values.</p

Diel pattern of echolocation encounters.

<p>The data were combined and averaged across the entire acoustic monitoring period.</p

Frequency of boat traffic (including upriver boats, downriver boats and the combination of upriver and downriver boats) by diel phase and time of day.

<p>The data were pooled and averaged over the entire boat monitoring period. The horizontal bar at the top indicates the diel phase, and the bar at the bottom denotes the time of day (hour GMT +8).</p

Correlation among dolphin acoustic, fish density and boat traffic.

<p>*Represents significance at p<0.05; n represents not significant with p>0.05.</p

Types of trajectory.

<p>The positive and negative time differences indicate that the sound came from upstream or downstream, respectively. A value of zero denotes that the sound came from a point equidistant from the two ultrasonic hydrophones of the A-tag (the passing point). A = upstream stay, B = downstream stay, C = straight up, D = straight down, E = milling and up, F = milling and down.</p

Descriptive statistics of porpoise acoustic detection (including minutes of clicks and number of click trains and buzzes) and echolocation encounters (including number, group size and duration) for each day.

<p>The duration of echolocation encounters is given as the mean ± standard error (SE) and range.</p

Diel pattern of the frequency of click trains (A) and buzzes (B) per 10 min.

<p>The data were combined and averaged across the entire acoustic monitoring period. Error bars (mean ± SE) with different lowercase letters refer to post hoc Duncan’s multiple-comparison tests that yielded significant results (<i>p</i><0.05).</p

Map of the static acoustic monitoring area.

<p>The MSA port consisted of an anchored cruise vessel (27 m long and 5 m wide) and a rectangular wharf boat (39 m long and 9 m wide) connected to a waterway administration port of the same size. Three miniature stereo pulse event data loggers were deployed at two sites on the cruise vessel (sites A and B) and at one site on the wharf boat at the MSA port (site C). The possible cruise boat anchor sites represent possible sites for fish data monitoring. The inset map in the upper left corner shows the position of the study area in the middle region of the Yangtze drainage basin.</p

The daily occurrence of porpoise click trains (A) and buzzes (B) by diel phase and time of day.

<p>The data were grouped into 10(hour GMT +8).</p