01844nas a2200193 4500008004100000022001400041245011000055210006900165260001600234300001600250490000800266520121600274100002101490700001801511700001801529700002501547700002701572856005101599 2018 eng d a0001-496600aMonitoring noise levels and delphinid presence through autonomous acoustic in Rio de Janeiro coastal area0 aMonitoring noise levels and delphinid presence through autonomou cJan-09-2018 a1885 - 18850 v1443 a

In order to investigate the soundscape in a Rio de Janeiro coast site, passive acoustic monitoring was conducted during two non-consecutive weeks in the summer of 2015/2016 by deploying one SM2M + device. The equipment recorded at a 66% duty cycle with sample rate of 96 kHz and 36 dB gain. Third octave levels (TOLs) were calculated for all recordings through PAMGuide software. To search for delphinid presence, a band limited energy detector was employed using Raven 1.5 in a 512 Hann window, 50% overlap. TOLs varied across frequencies and day hours. Light hours were noisier than dark hours in 25 frequency bands (MW, p<0.01), with highest mean level being measured at 794 Hz at 06am (105.4 ± 5.4 dB re 1μPa), and lowest mean level measured at 39.8 kHz at 01am (80.3 ± 3.7 dB re 1μPa). A total of 281 delphinid sound emissions were detected in nine occasions, seven during week 1 and two during week 2. Seven detection events occurred during dark hours. Although more than one species of delphinid is known to occur in Rio de Janeiro coast, these results indicate a frequent nocturnal use of the area, which was only possible to observe through autonomous monitoring.

1 aBittencourt, Lis1 aSousa, André1 aBisi, Tatiana1 aLailson-Brito, José1 aAzevedo, Alexandre, d. uhttp://asa.scitation.org/doi/10.1121/1.506826402032nas a2200205 4500008004100000022001400041245016300055210006900218260001600287300001600303490000800319520131500327100002101642700002101663700002101684700001801705700002501723700002701748856005101775 2018 eng d a0001-496600aCharacteristics of Guiana dolphins ( Sotalia guianensis) burst-pulse sounds emitted during different surface activity rates in Rio de Janeiro’s coast0 aCharacteristics of Guiana dolphins iSotalia guianensisi burstpul cJan-09-2018 a1978 - 19780 v1443 a

Burst-pulses are still the least studied signals in delphinid acoustic repertoire. In this study, acoustic data were gathered in two Rio de Janeiro coastal bays where groups of Guiana dolphins can be found regularly. The acoustic equipment consisted of a C54XRS hydrophone (-155.8 dBV, 0.006 Hz a 203 kHz) and a Fostex digital recorder (192 kHz sampling rate). During each recording, the surface activity rate of the group was classified as being high or low. Burst-pulses were analyzed using SoundRuler software. Fifty signals were randomly selected and the values for duration (low = 143.9 ± 145.4; high = 82.2 ± 74.8), interpulse interval (low = 2.81 ± 1.92; high = 1.34 ± 1.35), number of pulses (low = 52.6 ± 55.7; high = 71.6 ± 64.5), peak frequency (low = 37.4 ± 2.5; high = 38.5 ± 3.2), and minimum frequency (low = 15.4 ± 6.5; high = 6.7 ± 5.3) were measured. Additionally, a Mann-Whitney U test compared all acoustic parameters of burst-pulses emitted during both surface activity rates. Significant differences between activity rates were found for interpulse interval (p<0.01) and minimum frequency (p<0.01). This scenario could indicate that some burst-pulse parameters are related to group arousal and behavior.

1 aBarbosa, Mariana1 aBittencourt, Lis1 aAndrade, Luciana1 aBisi, Tatiana1 aLailson-Brito, José1 aAzevedo, Alexandre, d. uhttp://asa.scitation.org/doi/10.1121/1.5068636