September 28, 2001

ORCAWALE 2001:  Weekly Report for 9/20/01 to 9/26/01

 

Barbara Taylor

 

Sometimes you just get lucky.  While evil weather fronts hit both to the north and to the south the Jordan covers trackline so placid I was tempted to whistle up some wind on the bridge to move away the fog.  Fog covering glassy seas is particularly vexing.  Nevertheless, most of our time was spent surveying in fine conditions including one entire day where the sea looked like a giant wrinkled mirror.  Although we saw few marine mammals that day we did see four leatherback turtles, many Xantus’ Murrelets and albacore and sharks galore.  Fortunately many of the albacore were landed and donated to our very able chefs.  This fish is excellent raw, smoked, grilled and stir-fried.  Oh, yes, we found a few juvenile rock fish in their bellies and preserved them for science.

 

We had one banner day of forty-two sightings within sight of Oregon.  Not only did we sight nearly every species expected to be found here but we found, photographed and sampled three blue whales north of their usual haunts.  Small boat operations continue to be impressive (see the biopsy and photo report below) and we are grateful to all the hard workers aboard this ship.  However, despite cooperative seas the bigger surprise is how few whales and dolphins we have found over most of the area.  As in previous surveys of these waters, the importance of coastal waters to marine mammals is striking.  Not dissimilar to humans, a few like the great plains but most prefer to hug the coastlines.

 

                            Trackline Avg

Date   Time    Lat   Long   Miles    Beauf

092001 0903 N41:15.27 W124:36.41  77.8nmi  4.0

       1914 N42:21.61 W124:47.36

092101 0719 N42:50.51 W125:03.69  63.8nmi  2.5

       1912 N43:47.28 W124:20.89

092201 1556 N44:24.83 W125:25.90  10.6nmi  1.0

       1714 N44:24.70 W125:39.40

092301 0750 N44:09.94 W125:45.26  92.2nmi  2.2

       1756 N42:33.77 W126:16.39

092401 0718 N41:58.71 W126:31.63  86.1nmi  4.2

       1746 N41:57.30 W128:11.33

092501 0722 N40:38.27 W127:23.26  94.8nmi  4.0

       1844 N39:55.93 W125:32.33

092601 1050 N39:43.95 W124:07.36  71.5nmi  3.2

       1901 N38:51.28 W124:17.47

 

 Code                        Species     Tot#    

 

   21                    Risso's dolphin    5

   22        Pacific white-sided dolphin    4

   27       northern right whale dolphin    2

   40                    harbor porpoise   12

   44                    Dall's porpoise   30

   46                        sperm whale    1

   49          unidentified beaked whale    1

   69                         gray whale    1

   70               unidentified rorqual    4

   71                        minke whale    2

   74                          fin whale    5

   75                         blue whale    6

   76                     humpback whale    7

   77            unidentified delphinoid    2

   79           unidentified large whale    1

 

                                   TOTAL   83                                   TOTAL   16

 

Biopsy (Juan Carlos Salinas and Erin LaBrecque)

Photo-ID (Todd Chander, Leigh Torres and Laura Morse)

 

Species

#Biopsies

(this week)

Biopsy

Cumulative

Total

#ID Photos

(this week)

Photo

Cumulative

Total

 

 

 

 

 

Physeter macrocephalus

0

8

0

15

Balaenoptera musculus

5

6

6

9

Balaenoptera physalus

0

9

2

15

Megaptera novaeangliae

5

15

11

22

Eschrichtius robustus

1

3

2

7

Delphinus delphis

0

14

0

3

Grampus griseus

1

1

0

0

Lagenorhynchus obliquidens

1

8

0

0

Lissodelphis borealis

0

14

0

0

Phocoenoides dalli

5

8

0

0

Orcinus orca

0

2

0

18

 

 

 

 

 

Total

18

88

21

89

 

Oceanography (Candice Hall)

 

Day                              #CTDs             #XBTs             #Bongos           Notes

 

20 September               0                      4                      1         

21 September               0                      4                      1

22 September               0                      1                      1

23 September               1                      4                      1

24 September               1                      4                      1

25 September               1                      4                      1

26 September               1                      4                      1         

 

Seabirds (Michael Force and Cornelia Oedekoven)

 

The contrast between the neritic and pelagic habitats was again evident this week with transects covering both areas: thousands of birds nearshore compared to meager numbers offshore. The exception offshore was Leach's Storm-Petrel. Hundreds were seen on Monday and Tuesday west of northern California, perhaps dispersing south from coastal nesting areas. We spent the first couple of days out of Eureka along the coast where we saw thousands of Sooty Shearwaters, Common Murres and Cassin's Auklets. We also witnessed a large coastal movement of at least 150 jaegers (about 90% Parasitic) and South Polar Skuas; the next day slightly farther north, less than 10. A rare day of Beaufort 0 or 1 conditions enabled us to get a true idea of how common Xantus'

Murrelets are off Oregon at this time of year. These small inconspicuous birds

spend most of their time on, or beneath, the surface and are extremely difficult to detect in higher seastates. The 30 we saw (and heard!) likely represent a record count for Oregon. Interestingly, all that were identified to subspecies were of the southern form. An adult Red-tailed Tropicbird about 135 NM west of Cape Mendocino was the first for the

cruise and somewhat closer to shore than expected.

 

Acoustics (Shannon Rankin and Julie Oswald)

Leg 3 began with a frenzy of vocal activity.  Multiple groups of Pacific white-sided dolphins and northern right whale dolphins were recorded on our first day out of port.  Day 2 was equally as busy, with Risso’s dolphins joining into the chorus.  High frequency vocalizations were recorded from all three species.  Two sonobuoy recordings provided us with a few potential blue whale vocalizations (Sighting 179 and 232- a biopsied whale!).  There were two acoustic sperm whale detections this week, one of which we were able to get the visual team on as it surfaced behind the ship. Perhaps the most exciting event this week was a brief encounter with the mysterious ‘boing’.   Leg three is off to a great start!

 

Last modified: 12/24/2014