The Soundscape of a Nearshore Reef near an Urban Center Whitlow W. L. Au, Michael Richlen, Marc Lammers Marine Mammal Research Program Hawaii Institute.

The Soundscape of a Nearshore Reef near an Urban Center

Whitlow W. L. Au, Michael Richlen, Marc LammersMarine Mammal Research ProgramHawaii Institute of Marine Biology University of Hawaii

Kilo Nalu Nearshore Reef Observatory

Acoustic monitor installed – Nov 2008 – 24 kHz sample rate on wet end

Kilo Nalu -- “observe the wave”

Orginally at 22 m depth690 m off-shore

Sample rate = 24 kHz = 48 kbytes/s = 4.2 Gbytes/day = 124 Gbytes/mn

Modified EAR

Now closer to shore at 10 m depth

Background

1. The only real time acoustic monitor in tropical waters(very unique and valuable asset)

2. Complementary to NMFS/CRED program to collect baseline/time series data to acoustically monitor the health of coral reefs

3. Excellent platform to collect acoustic signature of small crafts fortemplate development

fishing restricted areasmarine protected areas

Nature conservancyHomeland security

4. Data for development of software for automatic detectionhumpback whalesfish sounds

Background

1. Ecological Acoustic Monitor (EAR) modified and deployed at

Kilo Nalu site – up and running 1st week in Nov, 2008

2. Sounds being heard

Boats, boats, boats and more boats.dinner cruise boatstour-dive boatspleasure craftstour fishing boatsetc

snapping shrimpsfisheshumpback whalesrain

6 November

100

105

110

115

120

125

130

0 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 22 23

Hour (HST)

RM

S (

db

re

1uP

a)

Boat

Snapping shrimp Snapping shrimp

EXAMPLE OF RMS SPL IN A DAY: 6 NOVEMBER

SPL 28 February (Mean SPL = 110.4 dB re1uPa)

105

110

115

120

125

130

RM

S (

dB

re1

uP

a)

0 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 18 19 20 21 22 23

Hour (HST)

28 February

Boats & Humpback Whales Hump & sshrimpHump & sshrimp

EXAMPLE OF MIXTURE OF SOUNDS IN WINTER

1-7 November

100

105

110

115

120

125

130

135

RM

S (

dB

re

1uP

a)

1 2 3 4 5 6 7

DAY

EXAMPLE OF A WEEK RMS SPL: 1-7 NOVEMBER

Boat in daylight/ snapping shrimp night

3 K

2 K

1K

0 1 2 3 4

Time (min)

55

Fre

qu

ency

(H

z)4 K

5K

6 K

EXAMPLE OF A BOAT PASSING BY THE KILO NALU SITE

Soundstarts

EXAMPLE OF HUMPBACK WHALE SONG AT THE KILO NALU SITE

3 K

2 K

1K

00 1 2 3 4 5

Time (min)

Fre

qu

ency

(H

z)

3 K

2 K

1K

0

Fre

qu

ency

(H

z)

0 1 2 3 4 5

Time (min)

EXAMPLE OF BOAT & HUMPBAC WHALE

EXAMPLE OF A BOAT SOUND

Seconds

Rel

ativ

e A

mp

litu

de

EXAMPLE FOR HUMPBACK WHALE SIGNALS

Seconds

Rel

ativ

e A

mp

litu

de

CONCLUSIONS

2. Need to develop smart processing as close to wet end as possible to minimize data management issues

3. Need to develop parallel scheme rather than present serial scheme

4. Better results can be achieved by understanding and using the characteristics of different biological sounds

1. Valuable resource for understanding use of acoustics to monitorhealth of coral reef environment & to understand the effects ofanthropogenic noise on organisms