| We left the
sperm whales we had worked so successfully with on Tuesday to
seek new areas with whales. We traveled southwestward and then
south approximately along the 96W longitude line to 26 7.68'N.
No whales were heard or, once visuals were on effort, seen on
this transit.
We then turned east to survey into deep
water. This took us across the region with anticyclonic
circulation. XBT data showed the depth of the 15C isotherm was
deepening from about 200 to 261 meters as we transited into the
interior of the anticyclone. Currents were northward on this
transect.
The 38 kHz fishery echo sounder was
deployed (see photo) from about 16:45 to 19:15 local time to
obtain acoustic backscatter data in the interior of the
anticyclone. The RHIBs were deployed from late morning to late
afternoon to extend the area of listening and observing, but no
whales were heard or seen by any of the searching teams. This is
not unexpected for a region of anticyclonic circulation. A group
of 15-20 rough-toothed dolphins went bowriding for a time in the
afternoon.
We are surveying eastward approximately
along the 2000-meter isobath, and we have just had a faint
detection of a sperm whale to try to find.
Ann |
Alyson Azzara and Bill Green deploy the 38 kHz fishery echo
sounder on 22 June 2005. The echo sounder is attached to a pole
which is lowered into the water and locked in the vertical
position when the instrument is deployed.
|
