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The Soundscape of a Nearshore Reef near an Urban Center. Whitlow W. L. Au, Michael Richlen, Marc Lammers Marine Mammal Research Program Hawaii Institute of Marine Biology University of Hawaii. Kilo Nalu Nearshore Reef Observatory. Kilo Nalu -- “observe the wave”.
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The Soundscape of a Nearshore Reef near an Urban Center Whitlow W. L. Au, Michael Richlen, Marc Lammers Marine Mammal Research Program Hawaii Institute of Marine Biology University of Hawaii
Kilo Nalu Nearshore Reef Observatory Kilo Nalu -- “observe the wave” Acoustic monitor installed – Nov 2008 – 24 kHz sample rate on wet end
Orginally at 22 m depth 690 m off-shore Now closer to shore at 10 m depth Sample rate = 24 kHz = 48 kbytes/s = 4.2 Gbytes/day = 124 Gbytes/mn Modified EAR
Background • The only real time acoustic monitor in tropical waters • (very unique and valuable asset) • Complementary to NMFS/CRED program to collect baseline/time • series data to acoustically monitor the health of coral reefs • Excellent platform to collect acoustic signature of small crafts for • template development • fishing restricted areas • marine protected areas Nature conservancy Homeland security • Data for development of software for automatic detection • humpback whales • fish sounds
Background • Ecological Acoustic Monitor (EAR) modified and deployed at • Kilo Nalu site – up and running 1st week in Nov, 2008 • Sounds being heard Boats, boats, boats and more boats. dinner cruise boats tour-dive boats pleasure crafts tour fishing boats etc snapping shrimps fishes humpback whales rain
EXAMPLE OF RMS SPL IN A DAY: 6 NOVEMBER 6 November 130 Boat 125 120 RMS (db re 1uPa) 115 110 105 Snapping shrimp Snapping shrimp 100 0 1 2 3 4 7 8 9 5 6 12 13 14 16 17 10 15 18 19 20 21 22 23 Hour (HST)
EXAMPLE OF MIXTURE OF SOUNDS IN WINTER SPL 28 February (Mean SPL = 110.4 dB re1uPa) 28 February Boats & Humpback Whales 130 Hump & sshrimp Hump & sshrimp 125 120 115 RMS (dB re1uPa) 110 105 0 1 2 3 4 7 8 9 5 6 12 13 14 16 17 10 15 18 19 20 21 22 23 Hour (HST)
EXAMPLE OF A WEEK RMS SPL: 1-7 NOVEMBER 1-7 November 135 Boat in daylight/ snapping shrimp night 130 125 120 RMS (dB re 1uPa) 115 110 105 100 1 2 3 4 5 6 7 DAY
0 1 2 3 4 5 5 Time (min) EXAMPLE OF A BOAT PASSING BY THE KILO NALU SITE 6 K 5K 4 K 3 K Frequency (Hz) 2 K 1K Sound starts
EXAMPLE OF HUMPBACK WHALE SONG AT THE KILO NALU SITE 3 K 2 K Frequency (Hz) 1K 0 0 1 2 3 4 5 Time (min)
EXAMPLE OF BOAT & HUMPBAC WHALE 3 K 2 K Frequency (Hz) 1K 0 0 1 2 3 4 5 Time (min)
EXAMPLE OF A BOAT SOUND Relative Amplitude Seconds
EXAMPLE FOR HUMPBACK WHALE SIGNALS Relative Amplitude Seconds
CONCLUSIONS • Valuable resource for understanding use of acoustics to monitor • health of coral reef environment & to understand the effects of • anthropogenic noise on organisms 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