90-day Monitoring Report - National Marine Fisheries Service - NOAA

UME04085
R.V Marcus G. Langseth
L-DEO/NMFS
05 January 2012
Visual Observation Locations
3:12
49:29
354:14
Figure 6. Total visual effort from observation locations on board the R/V Langseth.
4.3. ACOUSTIC MONITORING SURVEY SUMMARY
16
Tower
Bridge
BR/TO
The hydrophone cable was deployed for the first time on 13 September 2011 after the vessel
had completed deployment of the seismic equipment. Acoustic monitoring began immediately
at 00:50 UTC and continued throughout the project with PSOs monitoring the hydrophones
aurally and monitoring the Pamguard detection software visually both day and night. Acoustic
monitoring for the project ended at 04:31 UTC on 05 October 2011 when acquisition of the final
survey line was completed and the hydrophone cable was retrieved in preparation for the
retrieval of the seismic equipment.
Over the course of the project, PSOs conducted 526 hours and 20 minutes of acoustic
monitoring, all but 46 minutes occurred while the acoustic source was active (Table 5). There
was one period on of acoustic monitoring downtime (6 hours and 15 minutes) on October 2011,
when the PAM system could not be utilized because the hydrophone cable was not deployed
due to rough seas.
Table 5. Total passive acoustic monitoring (PAM) effort.
Passive Acoustic Monitoring Effort Duration (hh:mm)
Total monitoring while acoustic source active
Total monitoring while acoustic source silent
Total acoustic monitoring
4.4. SIMULTANEOUS VISUAL AND ACOUSTIC MONITORING SUMMARY
525:34
00:46
526:20
While visual observations began on 8 September 2011 acoustic observations began on 13
September 2011, due to the hydrophone cable needing to be deployed after the airgun arrays to
avoid entanglement. Of the total observation effort performed by PSOs during this survey,
visual monitoring accounted for 44% (406 hours 55 minutes) while acoustic monitoring
accounted for 56% (526 hours 20 minutes). As displayed in Figure 7 there were 294 hours 38