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 7, 2007
Oceanography in Action

Today started with me being trained to deploy the XBT (expendable bathythermograph) which is responsible for creating a profile of the water column from the surface to 760 meters. Why 760 m? It is because the thermocline occurs well above this depth in our area. I was also training to conduct the chlorophyll count which involves collecting a water sample at the surface and filtering the chlorophyll out for density. These tests are conducted four times throughout the day and create an overall picture of the water in the study area.

Also this morning, we had biopsy training. This involved learning the equipment that would be used in the workboat (zodiac) if and when dolphins or whales are close enough to biopsy. There are two types of crossbows that can be used, the "wildcat" crossbow which is used for smaller dolphins, and the "compound" crossbow which is used if the animal is further off or larger. There are two types of darts that fit into the crossbow which are used depending on the size of the mammal, orange or yellow. I will not be using this piece of equipment due to lack of skill and experience! It is an extremely quick process which needs someone who can effectively do it the first time...

Why collect a skin/blubber sample from these animals? There are many genetic studies that are being conducted with the biopsies after the DNA has been coded. Dolphin stock structure, depletion of a group (like the False Killer Whales) and whale counts worldwide are all studies that are benefited from these biopsies. The biopsies can be collected from the bow of the McArthur II if the animal is bow riding or from the workboat.

The McArthur II makes it own water so we are slightly more restricted in water use than on land. There are 35 people onboard for this leg of the trip and we are divided into different laundry days. Today, for example is a "C" day so my laundry is clean! More details to follow on how the freshwater is created on board. Stay tuned!

As for my mammal, reptile, and bird observations, I saw another Olive Ridley Turtle floating along with a Red-footed Booby standing on top of it! Also, while the sun was setting we saw a whale which we couldn't identify because darkness was falling quickly. We did learn that it stayed under the water for approximately 20 minutes before coming to the surface to breathe. It came up 3 times before the light disappeared. Maybe tomorrow!

Marine Science Questions:

1. What are three ways oxygen gets put into the oceans?

2. What is the average temperature of deep sea?