High Seas Fisheries Acoustic Surveys NZHSG – decades of experience
Orange Roughy and Alfonsino- breakthroughs with multi- frequency acoustics and optics With the use of new multi-frequency and video technology, we now have substantial evidence to support the dominance of orange roughy in the dead zone that affects vessel based acoustics, and the historical problems with seeing orange roughy with an echosounder on any slope. AOS multi-frequency surveys are the only ones accepted by NZ-Australia Scientific Committees in areas where multi-species occur Orange roughy-Oreo Dories-Sharks Alfonsino-mesopelagic fish-Cardinalfish Jack Mackerel-Anchovy?
What is the multi-frequency AOS 3
AOS in action Volcano-Dork 120 Khz survey
Species Verification (a) Vessel 38 kHz (b) AOS 38 kHz Small gas bladder species (d) AOS 120 kHz minus AOS 38 kHz (c) AOS 120 kHz OR region Seafloor Figure 5. Operation 13, 4 th July 2014. Example of vessel and AOS echograms at 10:34 UTC heading along 330 degrees at The Volcano. (a) 38 kHz vessel mounted echogram, (b) 38 kHz AOS echogram, (c) 120 kHz AOS echogram and (d) logarithmic difference between 120 kHz and 38 kHz AOS signal.
Stereo measurements of fish length and TS for Industry SPRMO surveys Figure 1. Example paired stereo images showing an orange roughy passing under the trawl headline with yellow line indicating stereo measurement of the fish.
And we can look at fish and bottom habitat- VME’s??????
AOS is how you get TS -- Alfonsino data 2014 How good are your mackerel TS measurements?
Multi-frequency and AOS impact on SPRFMO Backscatter estimates- what is really there in the water column which varies diurnally On ridge system ` Adjacent to ridge system
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