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Journals 2007/2008

Heather Judkins
Seminole High School, Seminole, FL

"Equatorial Pacific Dolphin Abundance Study - R/V McArthur II"
November 3 - 29, 2007
Journal Index:
November 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10
               12 - 13 - 14 - 15 - 16 - 17
               19 - 20 - 21 - 23 - 24 - 25
               26 - 27 - 29 - 30

Additional Resources

November 23, 2007
We Found the Blues

The last few days have been slightly different in how we have been moving along the transect line. As I have mentioned in past entries, there is a passing and then a closing mode day for observations of the marine mammals. Due to excellent weather conditions, we have not needed the two "weather" days that are built into the schedule for this leg of the cruise. The decision was made to repeat one of the transect lines for three additional days in the closing mode to see what differences may or may not occur on a small-scale daily basis.

So, Wednesday morning through this evening were the closing mode days for the repeating transect line. The past three days produced five or less sitings each day. Needless to say, there was plenty of watching the empty horizon! Some Brown and Re-footed Boobies kept us entertained as they were fighting for space on the jackstaff. We also learned that they have great aim with their excrement and we had to "duck and cover" often to avoid the onslaught of guano. Today, however, brought with it the "last day" luck for us because we saw many mammals along the line!

Last night ended with a calf/cow pair of Blue Whales! They were very close and the calf was estimated to be approximately 8m long and the mother was approximately 28m long. They are traveling south to the Costa Rica dome where they spend the winter. It was a great way to end the day!

This morning started the same way it ended, with the same cow/calf pair! It was 15 hours later and the same pair were still on our transect line! We got close enough for photo identification purposes. There were many great shots taken by Adam, Sophie, and Juan Carlos. The scientists didn't attempt any biopsies because it was the cow/calf pair.

As the day progressed, the sitings continued! We saw Rough-toothed dolphins, Striped dolphins, and as the moon was rising and the sun setting, 2 more Blue Whales! These looked to be two adults cruising south as the others we have along the leg. They were at the bow right in front of us for quite some time. We stayed with them until the sun set. I couldn't have asked for a better way to end the observer operations... Absolutely stunning.

Marine Science Questions:

1. How long do Blue calves stay with their mothers before they go it alone in the big oceans of the world?

2. Why do the Blue Whales migrate south at this time? What is their goal and how long do they remain in the warm, tropical waters?