October 5, 2001

ORCAWALE 2001:  Weekly Report for 9/27/01 to 10/03/01

Barbara Taylor

This was whale challenge week:  how late can a whale appear before us and still allow us to launch, photograph and biopsy.  Almost every night this week we had a whale sighting within a half hour of sunset and almost every night we met the challenge.  Most of these evenings we took the small boat in with lights flooding the fantail of the ship.  These successes were a credit to all through seamless launching, boat maneuvering, communications from visual observers and acousticians to get the small boat positioned for its limited daylight opportunities, sampling both photographic and biopsy, and to the officers willing to let operations continue into the darkness.

The advantage of ending the day with a whale sighting is that we have the potential of staying near the animals even after dark if they are vocalizing.  Just such an event occurred with two blue whales sighted minutes before sunset.  Although there were two whales, we got biopsies of both and decided to drop a sonobuoy beside them.  The reason to record blue whales is that it remains unknown whether both sexes vocalize.  Knowing who makes the deep groans of the blue whale is of more than academic interest.  The U.S. Navy wants to use information on the distribution of whales to plan Navy exercises to minimize impact.  Navy microphones at the bottom of the sea (in undisclosed locations) have the potential of revealing whale distributions and movements throughout the year.  But what if only males vocalize?  What if females go to different places than males?  Hence the reason we want to know who makes the sounds and whether males and females go to different areas.

Our evening challenge whales proved to be very vocal.  The acoustician’s room was crowded with people lining up to listen to the incredible deep moans of the blue whale.  If both our biopsies reveal the whales to be male then we have another data point showing that only males vocalize.  If we had instead a mixed double then we have some great recordings, and if we had only females we’ll have the first recordings of known vocalizing females.

We were looking forward to more active days in the Channel Islands, which are usually rich with marine mammals.  Unfortunately we spent much of our time foiled by fog.  In the hours of good visibility we encountered the expected high densities of marine mammals including very large schools of common dolphins.

                                 Trackline Avg
Date   Time    Lat      Long      Miles    Beauf

092701 0716 N38:15.71 W124:34.39  92.7nmi  3.5
            1825 N38:39.84 W126:31.12
092801 0804 N38:14.07 W127:45.46  71.6nmi  3.8
            1912 N36:49.00 W128:16.97
092901 0730 N35:56.68 W127:47.92  88.1nmi  4.7
            1903 N35:31.34 W125:55.02
093001 0708 N35:05.29 W123:57.34  82.8nmi  4.3
            1826 N34:38.57 W122:03.31
100101 0741 N34:37.11 W121:51.84  24.4nmi  3.2
            1817 N34:14.56 W120:13.51
100201 1144 N33:53.71 W118:37.44  28.3nmi  3.9
            1822 N34:08.54 W119:24.44
100301 0654 N33:28.67 W117:50.41  82.6nmi  2.6
            1821 N31:48.24 W118:28.56


 Code                        Species                 Tot#    
   05      common dolphin (unclassified)    3
   13                             striped dolphin    1
   17           shortbeak common dolphin   26
   18                       bottlenose dolphin    1
   21                            Risso's dolphin    5
   44                            Dall's porpoise    2
   46                               sperm whale    3
   74                                    fin whale    2
   75                                 blue whale    2
   77               unidentified delphinoid    3
   79              unidentified large whale    1

                                              TOTAL   49

Biopsy (Juan Carlos Salinas and Erin LaBrecque)
Photo-ID (Todd Chander, Leigh Torres and Laura Morse)

                                                                          Biopsy                                      Photo
Species                                       #Biopsies               Cumulative       #ID-Photos            Cumulative
                                               (this week)                Total                   (this week)   Total
Physeter macrocephalus                    1                      9                       1                      16
Balaenoptera musculus                      4                      10                    3                      12
Balaenoptera physalus                       0                      9                      0                      15
Megaptera novaeangliae                    0                      15                    0                      22
Delphinus delphis                            27                      41                    8                      11
Grampus griseus                                0                      1                      1                        1
Lagenorhyncus obliquidens                 0                      8                      0                        0
Lissodelphis borealis                         0                      14                    0                         0
Phocoenoides dalli                           0                      8                      0                          0
Orcinus orca                                    0                      2                      0           .            18
Eschrictius robustus                          0                      3                      0                       7
Stenella coeruleoalba                        0                      0                      1                         1
Tursiops truncatus                            3                      3                      0                        0

             Total                                    35                   123                        14                103

Oceanography (Candice Hall)

Day                              #CTDs              #XBTs                #Bongos           Notes
27 September               1                      4                      1         
28 September               1                      4                      1
29 September               1                      4                      1
30 September               0                      4                      1            weather
1 October                     1                      3                      1
2 October                     1                      3                      1
3 October                     1                      4                      1         

Seabirds (Michael Force and Cornelia Oedekoven)

We spent the first few days of this week in offshore waters counting the ever familiar Leach’s Storm-Petrels, Red Phalaropes and Black-footed Albatross. However, interrupting the monotony was the occasional Long-tailed and Parasitic Jaeger and 3 special sightings–a Red-tailed Tropicbird, a Cookilaria-type Petrel and a Magnolia Warbler. Of interest was also a sighting of an Ashy Storm-petrel in offshore waters. The farther south on our trackline the easier gulls become to identify. We are now out of the contact zone between Western and Glaucous-winged Gulls putting those pesky hybrids behind us. Things changed immensely Tuesday evening attempting to make our way through the Santa Barbara Channel, where many dolphin sightings interrupted our progress. The birders were almost cross-eyed due to large, multi-species flocks that were associated with some of the Delphinus-schools. These flocks included Brown Pelicans, Sooty, Black-vented and Pink-footed Shearwaters, jaegers, California, Western and Heerman’s Gulls. As a final thought, what brings together 4500 storm-petrels crowded onto a small patch of ocean? An impressive sight in Gulf of Santa Catalina.

Acoustics (Shannon Rankin and Julie Oswald)

Imagine an acoustics lab full of headphone laden groupies oohing and ahhhing while staring intently at thick black lines cascading down a fuzzy screen.  Is it an acoustic dream of obtaining popularity? Believe it or not, it did happen, and I have photos to prove it.  Our highlight of this week was a four hour recording of blue whales (two animals with photos and biopsies).  We have also been busy with several sperm whale detections, common dolphins, Risso's dolphins, and mixed schools containing common and striped dolphins as well as Risso's and bottlenosed dolphins.  This, along with a few trips in J1 with the directional hydrophone on sperm whales and an evil sickness that stole our Julie for several days, has kept the acoustics team busy busy busy...

Last modified: 12/24/2014